High Expression Of Immune-related Genes Research Articles

New insights into transcriptional and metabolic differences between pregnant males and embryos in seahorses

Seahorses exhibit a unique reproduction mode of male pregnancy. Successful gestation plays a crucial role in the seahorse reproduction process and the aquaculture industry. However, the substantial paternal-embryo differences in seahorses remain largely unexplored. In the present study, transcriptomic and metabolic differences between pregnant males and embryos during gestation were explored to investigate the roles of key genes and metabolites in pregnant males and embryos in seahorses. Higher levels of essential amino acids and polyunsaturated fatty acids in embryos compared to fathers may indicate their vital role in embryonic development. The high expression of immune-related genes (CCLs and CCRs) and downregulation of antioxidants in fathers may provide immune protection and reduce the immunological rejection of embryos during gestation. The transcript-metabolite correlation network during pregnancy further indicated the role of key genes and metabolites during embryonic eye (N-acetyl-L-histidine, PAX6, and FZT4) and tail (WNT5 and WNT8) development. The findings of the present study not only provide valuable data on differences between pregnant males and embryos in seahorse, but also lay foundation for future research on seahorse aquaculture.

Exploring the molecular landscape of cancer of unknown primary: A comparative analysis with other metastatic cancers.

Cancer of unknown primary (CUP) tumors are biologically very heterogeneous, which complicates stratification of patients for treatment. Consequently, these patients face limited treatment options and a poor prognosis. With this study, we aim to expand on the current knowledge of CUP biology by analyzing two cohorts: a well-characterized cohort of 44 CUP patients, and 213 metastatic patients with known primary. These cohorts were treated at the same institution and characterized by identical molecular assessments. Through comparative analysis of genomic and transcriptomic data, we found that CUP tumors were characterized by high expression of immune-related genes and pathways compared to other metastatic tumors. Moreover, CUP tumors uniformly demonstrated high levels of tumor-infiltrating leukocytes and circulating Tcells, indicating a strong immune response. Finally, the genetic landscape of CUP tumors resembled that of other metastatic cancers and demonstrated mutations in established cancer genes. In conclusion, CUP tumors possess a distinct immunophenotype that distinguishes them from other metastatic cancers. These results may suggest an immune response in CUP that facilitates metastatic tumor growth while limiting growth of the primary tumor.

Abstract PO3-14-07: Characterizing Immune Infiltration in Metastatic Hormone Receptor-Positive/HER2-Negative Breast Cancer: A Comprehensive Translational Analysis from four SOLTI Clinical Trials

Abstract Background: Hormone Receptor-positive (HR+)/HER2-negative (HER2-) metastatic breast cancer (BC) is a highly heterogenous disease. Non-luminal subtypes within HR+/HER2- BC have been linked to poor survival in the metastatic setting. However, these subtypes might exhibit higher expression of immune-related genes, tumor-infiltrating lymphocytes (TILs), and APOBEC signatures. This study aimed to investigate the presence of tertiary lymphoid structures (TLS), TILs and immune gene expression (GE) across PAM50 intrinsic subtypes (IS) in metastatic samples from patients (pts) with HR+/HER2- BC. Methods: We included pts with HR+/HER2- metastatic BC who participated in the molecular prescreening of the SOLTI-1904-ACROPOLI (NCT04802876), SOLTI-1502-ARIANNA (NCT04142060), SOLTI-1718-NEREA (NCT04460430) and SOLTI-1716-TATEN (NCT04251169) studies, providing metastatic samples for analysis. The proportion of TILs was centrally evaluated by a single pathologist using standard criteria. GE analysis was performed on the same FFPE tumor block using a panel of 72 genes, including 10 immune genes and the PAM50 IS. In a subset of patients, we conducted additional GE analysis using a panel of 192 genes, including the 14-gene B-cell/IgG (IGG) signature, while also retrospectively assessing the presence of TLS. Descriptive statistics, significance analysis of microarrays (using False Discovery Rate [FDR]) and logistic regressions were used to investigate the association between TLS, TILs, immune GE and PAM50 IS. Results: A total of 401 pts were included. Distribution across IS was: 53.4% Luminal B (n=197), 27.1% Luminal A (n=100), 16% HER2-enriched (n=59), 2.7% basal-like (n=10) and 0.8% normal-like (n=3). TILs were evaluated in 375 samples (93.5%). Median (m) TILs proportion was 2% (IQR: 1-4, range 0-80). Non-luminal subtypes exhibited a higher enrichment of TILs compared to luminal subtypes (m=3% vs m=1%, p=0.002). Moreover, significant differences of TILs were also seen according to the site of metastasis (M1): m=6.5% in lymph nodes vs m=4.5% in lung M1 vs m=1% in liver M1 (p< 0.001). Immune GE was significantly higher in samples with a high proportion of TILs ( >10%), although the correlation between TILs and immune genes was moderate (e.g, coefficient=0.44, p< 0.001, between CD8A and TILs). TLS were evaluated in 147 samples and detected in 16 pts (10.9%). Compared to TLS-negative tumors, TILs were significantly higher in TLS-positive (TLS+) tumors (m=1.5% vs m=10%, p< 0.001). In addition, the presence of TLS was significantly higher in non-luminal subtypes compared to luminal subtypes (18% (11/61) vs 5.8% (5/86), p=0.019). TLS+ tumors had a significant enrichment of genes related to activated B-cells (CD19, CD79A), plasma cells (CD27), immunoglobulins (IGKC, IGLV), and T-cells (CD8A, PDCD1). Notably, the IGG signature as a continuous variable demonstrated a significant association with TLS presence, independently of the PAM50 IS and TILs (p=0.033, ROC AUC=0.817). Finally, higher expression of some immune genes was observed in non-luminal subtypes vs luminal subtypes (e.g., CD19 (p=0.016) and CD274/PDL1 (p< 0.001)). Conclusions: Our translational analysis reveals that non-luminal subtypes within metastatic HR+/HER2- BC exhibit a higher enrichment of TILs, immune GE, and presence of TLS. Importantly, we identified the IGG signature as a robust immune GE pattern that is strongly associated with TLS across PAM50 IS, independent of TILs. These findings highlight the potential significance of the IGG signature as a novel biomarker for precisely measuring TLS and selecting pts who might be more likely to derive benefit from immunotherapy. Citation Format: Elia Seguí, Esther Sanfeliu, Fara Brasó-Maristany, Blanca González-Farré, Fernando Salvador, Laura Angelats, Lorea Villanueva, Alejandra Espinosa, Patricia Galván, Esther Fernández, Xavier Gonzalez-Farré, Santiago Escrivá-de-Romaní, Núria Chic, Eva Ciruelos, Cristina Saura, Luis Manso, Mafalda Oliveira, Josep Tabernero, Aleix Prat, Tomás Pascual. Characterizing Immune Infiltration in Metastatic Hormone Receptor-Positive/HER2-Negative Breast Cancer: A Comprehensive Translational Analysis from four SOLTI Clinical Trials [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-14-07.

Expression of immuno-transcriptome response in red hybrid tilapia (Oreochromis sp.) hindgut following vaccination with feed-based bivalent vaccine.

Streptococcosis and aeromoniasis are the main obstacles to sustainable tilapia production. Vaccination offered an effective method to control microbial infections. Previously, a feed-based bivalent vaccine (FBBV) containing killed whole organisms of Streptococcus agalactiae and Aeromonas hydrophila mixed with 10% palm oil was successfully developed, which provided good protection against streptococcosis and aeromoniasis in Oreochromis sp. However, the mechanisms of immunities in vaccinated fish still need clarification. Here, the hindgut transcriptome of vaccinated and control fish was determined, as the gut displays higher affinity towards antigen uptake and nutrient absorption. The efficacy of FBBV to improve fish immunity was evaluated according to the expression of immune-related genes in the vaccinated fish hindgut throughout the 8-week experimental period using RT-qPCR. The vaccinated fish hindgut at week 6 was further subjected to transcriptomic analysis due to the high expression of immune-related genes and contained killed whole organisms. Results demonstrated the expression of immune-related genes was in correlation with the presence of killed whole organisms in the vaccinated fish hindgut. Transcriptomic analysis has allowed the prediction of robust immune-related pathways, including innate and adaptive immunological responses in vaccinated fish hindgut than control fish. Pathways related to the regulation of lipid metabolism and modulation of the immune system were also significantly enriched (p ≤ .05). Overall, results offer a fundamental study on understanding the immunological response in Oreochromis sp. following vaccination with the FBBV pellet and support further application to prevent bacterial diseases in aquaculture.

Season affects the estrogen system and the immune response of common carp.

The physiology of ectothermic animals, including fish, is strictly regulated by season-related external factors such as temperature or photoperiod. The immune response and the production of hormones, such as estrogens, are therefore also subject to seasonal changes.This study in common carp aimed to determine how the season affects the estrogen system and the immune response, including the antibacterial response during Aeromonas salmonicida infection. We compared the immune reaction in spring and autumn in the head kidney and liver and found that carp have higher levels of blood 17β-estradiol in autumn, while in the liver of these fish there is a higher constitutive expression of genes encoding vitellogenin, estrogen receptors and Cyp19 aromatase than in spring. Fish sampled in autumn also exhibited higher expression of immune-related genes in the liver. In contrast, in the head kidney from fish sampled in the autumn, the expression of genes encoding estrogen receptors and aromatase was lower than in spring, and a similar profile of expression was also measured in the head kidney for inos, arginases and il-10. In turn, during bacterial infection, we observed higher upregulation of the expression of inos, il-12p35, ifnγ-2, arginase 2 and il-10 in the liver of carp sampled in spring. In the liver of carp infected in spring a higher upregulation of the expression of the genes encoding CRPs was observed compared to fish infected during autumn. The opposite trend occurred in the head kidney, where the upregulation of the expression of the genes involved in the immune response was higher in fish infected in autumn than in those infected in spring. During the infection, also season-dependent changes occurred in the estrogen system.In conclusion, we demonstrated that season differentially affects the estrogenic and immune activity of the head kidney and liver. These results reinforce our previous findings that the endocrine and immune systems cooperate in maintaining homeostasis and fighting infection.

Effects of Lactobacillus plantarum Ep-M17 on growth, immunity and intestinal microbiota of Penaeus vannamei under Microcystin-LR stress

Microcystins (MCs) are biologically active cyclic heptapeptide compounds released by cyanobacteria in water bodies, and MC-LR is one of the most widespread and toxic isoforms. It frequently poses a serious threat to Penaeus vannamei aquaculture. Our previous study revealed that the supplementation of Lactobacillus plantarum Ep-M17 has a probiotic effect on P. vannamei health and whether Ep-M17 can alleviate the stressful effects of MC-LR on shrimp remains unclear. Therefore, in the present work, shrimp were fed MC-LR alone or combined with Ep-M17 for six weeks, and then evaluated the effects on histology, enzyme activity, gene expression, and intestinal flora. The results showed that MC-LR stress lead to slow growth and reduced survival rates in shrimp. However, feeding Ep-M17 significantly increased both the growth rate and survival rate. Meanwhile, MC-LR stress caused severe tissue damage in the hepatopancreas and intestines of shrimp, but Ep-M17 significantly reduced the toxic effects and protected the integrity of these tissues. Additionally, Ep-M17 significantly enhanced the activities of antioxidant enzymes and digestive enzymes, and induced higher expression of immune-related genes, thereby promoting the digestive and immune responses in shrimp. Furthermore, MC-LR stress disrupted the intestinal flora in shrimp intestines, while the use of Ep-M17 significantly increased the abundance of immune- and metabolism-related bacteria and inhibited the growth of pathogenic bacteria to maintain intestinal flora balance and intestinal health. In conclusion, our results indicate that Ep-M17 can reduce the toxic effect of MC-LR on shrimp and has a positive function in the prevention and control of shrimp diseases caused by MC-LR.

Predictive biomarkers of benefit to axitinib plus avelumab in patients with recurrent/metastatic adenoid cystic carcinoma (R/M ACC).

6096 Background: ACC is a heterogeneous malignancy with no standard treatment for patients (pts) with R/M disease. Two distinct ACC subtypes have been identified proteogenomically, which contribute to ACC’s biological variability. ACC-I is enriched with NOTCH activating mutations and MYC overexpression and has a poor prognosis (median survival [mOS] = 3.4 years). ACC-II has upregulation of TP63 and presents with an indolent disease course (mOS = 23.2 years). In a phase II trial of axitinib (VEGFR inhibitor) plus avelumab (PD-L1 inhibitor) in R/M ACC, clinical benefit was heterogenous. We hypothesized that ACC subtype and gene expression profile are associated with benefit to axitinib plus avelumab. Methods: Cohort of 28 R/M ACC pts with radiological or clinical progression within 6 months (mos) of enrollment in the axitinib plus avelumab trial (NCT03990571). Target transcriptome profile including 19,616 probes was generated using HTG Transcriptome Panel [HTP]. Gene expression was used to identify ACC subtypes (ACC-I vs. ACC-II). Confirmed overall response rate (ORR), disease control rate (DCR), and progression-free survival (PFS) per RECIST v1.1 was assessed for each ACC subtype. An analysis of genes associated with benefit vs. no benefit from axitinib plus avelumab was conducted for the overall population and per ACC subtype. Benefit was defined as disease control (partial response [PR] or stable disease [SD]) and PFS longer than the median PFS. PFS > 6 mos was not used to define benefit due to the significant differences in PFS between ACC subtypes. Results: Out of 28 pts, 14 (50%) were classified as ACC-I and 14 (50%) were ACC-II. For ACC-I, ORR was 14.3% (2/14; 95%CI: 1.8-42.8%), DCR was 35.7% (2 PR + 3 SD; 95%CI: 12.8-64.9%) and median PFS was 1.86 mos (95%CI: 1.81-8.61 mos). For ACC-II, ORR was 21.4% (3/14; 95%CI: 4.7-50.8%), DCR was 100% (3 PR + 11 SD; 95%CI: 76.8-100%) and median PFS was 10.5 mos (95%CI: 7.40-NA). PFS was significantly longer for ACC-II vs. ACC-I (HR 0.19 [95%CI: 0.08 – 0.49], p = 0.0002). Through the previously defined benefit vs. no benefit cutoff, ACC-I had a 42.9% (6/14) and ACC-II had a 50.0% (7/14) benefit rate. Benefit in all ACC pts, ACC-I and ACC-II was associated with high expression of immune-related genes, especially B and T-lymphocyte function. Angiogenesis-related genes were not significantly upregulated in the benefit group as previously reported in renal cell carcinoma pts treated with the same combination. Conclusions: Clinical outcomes to axitinib plus avelumab were distinct between ACC-I and ACC-II subtypes, with ACC-II pts demonstrating an improved DCR and significantly longer PFS. Gene expression analysis revealed high expression of immune function-related genes in patients who benefited from axitinib plus avelumab in both ACC subtypes, indicating possible biomarkers predictive of benefit from the combination in ACC. Clinical trial information: NCT03990571 .

124O Patritumab deruxtecan (HER3-DXd) in hormonal receptor-positive/HER2-negative (HR+/HER2-) and triple-negative breast cancer (TNBC): Results of part B of SOLTI TOT-HER3 window of opportunity trial

We previously reported the biologic and clinical activity of HER3-DXd in Part A of SOLTI TOT-HER3 in patients (pts) with HR+/HER2- early breast cancer (BC) after a single dose of 6.4 mg/kg (Prat A. et al, ESMO BREAST 2022). Here, we present the main efficacy and safety results of TOT-HER3 Part B. In Part B of this window of opportunity trial, 2 cohorts of pts with treatment-naïve HER2- primary operable BC, ≥1 cm by US or MRI were recruited. Pts received a single dose of HER3-DXd 5.6 mg/kg. Primary objective was the variation in tumor cellularity and tumor-infiltrating lymphocytes (CelTIL) score between pre- and post-treatment tumors. Associations of baseline clinical and biological features with CelTIL changes and overall response rate (ORR) by US were explored. Thirty-seven pts with HER2- BC were recruited (HR+ n=20; TNBC n=17). Mean age was 53 (30-81); 20 (54%) were pre-menopausal; mean tumor size was 21 mm (range 10-81 mm); and median Ki67 was 30% (12-95%). In response to treatment with HER3-DXd CelTIL score increased and decreased in 21 (57%) and 16 (43%) pts, respectively. Overall, a statistically significant change in CelTIL was observed between paired samples overall (p=0.046) and in TNBC (p=0.016), but not in HR+ (p=0.793). ORR by US in all patients was 32% (35% in TNBC and 30% in HR+). The absolute change in CelTIL was associated with ORR (AUC=0.693; p=0.049). Baseline ERBB3 levels were not associated with CelTIL change or ORR. HER3-DXd induced high expression of immune-related genes (e.g., PD1, CD8 and CD19), and suppressed proliferation-related genes. Thirty-one (84%) patients reported AEs at any grade. Most common AEs were nausea, fatigue, alopecia, diarrhea, constipation and vomiting. Grade 3 treatment-related nausea occurred in 1 patient. No ILD events were reported. A single dose of HER3-DXd was associated with clinical response and significant biological changes in HER2- tumors, irrespective of baseline ERBB3 levels. The safety profile was consistent with that previously reported. Additional correlative analysis will be presented on site.

Abstract 664: Characterization of double-negative B cells within the NPC microenvironment

Abstract Introduction: IgD-CD27- double-negative (DN) B cells are involved in various autoimmune and infectious diseases. A DN B cell population was identified within the tumor microenvironment (TME) of nasopharyngeal carcinoma (NPC), a malignancy highly associated with Epstein-Barr Virus (EBV) infection. The DN B cell population was associated with poor clinical outcomes. However, the mechanisms associating DN B cells with poor NPC prognosis are unknown. This study aims to characterize NPC-infiltrating DN B cells and elucidate their interactions with the NPC TME. Methods: We analyzed the single-cell RNA-seq (scRNA-seq) data from four NPC cohorts. Fifty-nine samples from 43 NPC patients and 6 healthy subjects, consisting of 10 NPC-patient derived peripheral blood samples, 43 NPC tissue samples, and 6 normal tissue samples; and a total of 463,913 cells were included in this study. Results: NPC-infiltrating B cells were divided into 14 unique subclusters, with NPC tumor samples being enriched in DN B cells compared to normal tissue samples (P = 0.07) and NPC-patient-derived blood samples (P < 0.01). The majority of NPC-infiltrating DN B cells do not express marker genes associated with previously described DN B subtypes, such as CR2 and CXCR5 for DN1, ITGAX and TBX21 for DN2, TBX21 for DN3 and IGHE for DN4 B cells. However, we observed a small proportion of NPC-infiltrating DN B cells expressing DN1-associated marker genes. Some of the genes differentially expressed by the DN B cells, such as HNRNPH1 and DDX17, are involved in mRNA processing. Network functional enrichment analysis identified biological pathways involved in mRNA processing, viral genome replication regulation, and viral responses to be enriched in DN B cells. This suggests the DN B cells may have altered mRNA processing, while the presence of EBV in the NPC TME might affect those DN B cells. We next conducted trajectory analysis to investigate the cellular development in relation to mRNA processing from the NPC-infiltrating DN B cells. They were identified as an intermediary B cell development state, suggesting the DN B cell population may represent a B cell developmental block within the NPC TME. Finally, we compared the gene expression profiles of NPC cancer cells from NPC-high and NPC-low tumors and revealed an association between DN B cell content and NPC tumors with high expression of immune-related genes, such as Human Leukocyte Antigen (HLA) genes and interferon-induced genes. Conclusion: We characterized the NPC-infiltrating DN B cells and revealed their potential alterations in mRNA-splicing and differentiation. Further research is needed to study the interactions between DN B cells with NPC tumors with high immune-related gene expression, as well as the potential effects of EBV on the DN B cells. Acknowledgments: This study is supported by the Theme-based Research Scheme (TBRS) (T12-703/22-R). Citation Format: Michael King Chung, Ngar Woon Kam, Wei Dai. Characterization of double-negative B cells within the NPC microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 664.

Immune response and protective efficacy of mannosylated polyethylenimine (PEI) as an antigen delivery vector, administered with a Streptococcus agalactiae DNA vaccine in Nile tilapia (Oreochromis niloticus)

This study examined the effectiveness of a DNA vaccine for S. agalactiae that was delivered by mannose-based polyethyleneimine (Man-PEI). The results showed that Man-PEI/pcDNA-Sip stimulated a higher serum antibody titer compared to control or other vaccine groups (p < 0.05). Additionally, it induced higher expression of immune-related genes, and increased activities of superoxide dismutase (SOD), acid phosphatase (ACP) and alkaline phosphatase (AKP). Furthermore, the Man-PEI/pcDNA-Sip group showed an improved relative percent survival (RPS) of 85.71%. These results demonstrate the potential value of Man-PEI as a vaccine delivery vehicle, and suggest that it can be effective in boosting the immune protective rate induced by pcDNA-Sip vaccines.

Abstract P3-06-02: TATEN TRIAL (SOLTI-1716) Targeting non-Luminal disease by PAM50 with pembrolizumab + paclitaxel in Hormone Receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer (MBC): interim analysis

Abstract Background Within HR+/HER2- disease, patients with non-luminal subtypes of breast cancer (HER2-enriched [HER2-E] and Basal-like) have poorer prognosis than those with luminal subtypes, may be more sensitive to chemotherapy, and have higher expression of immune-related genes and tumor infiltrating lymphocytes (TILs). Here, we report the interim efficacy and safety data of the TATEN trial (NCT04251169), the first study designed to evaluate pembrolizumab and paclitaxel in HR+/HER2-negative, PAM50 non-luminal, metastatic breast cancer (MBC). Methods TATEN is a single-arm, multicenter phase II study evaluating pembrolizumab in combination with paclitaxel in patients with HR+/HER2-, PAM50 non-luminal, MBC. Key inclusion criteria include progression to prior CDK4/6 inhibitors, presence of measurable disease by RECIST V1.1, no prior chemotherapy for MBC, and ECOG 0-1. Patients receive pembrolizumab at 200 mg every 3 weeks (on D1 of each 21-day cycle, beginning at cycle 1) in combination with weekly paclitaxel at 80 mg/m2, beginning at cycle 2. The primary endpoint is to evaluate overall response rate (ORR), defined as the rate of complete (CR) and partial response (PR) according to RECIST V1.1. Secondary endpoints include clinical benefit rate (CBR; CR + PR + stable disease &amp;gt;24 weeks), progression free survival, overall survival, safety, and predictive biomarkers. Tumor samples collected during advanced/metastatic disease are mandatory to assess PAM50 and other translational endpoints. This study had a planned interim analysis after 15 patients were evaluable for ORR based on a Simon’s two stage design with 80% power and a type I error rate of 0.05. Stage I of the trial would be considered successful if at least 6 patients achieved a PR and/or CR. In that case, the trial would recruit up to 46 evaluable patients for a target ORR ≥ 41. Here we report results from the patients who received at least one dose of combination treatment and had a first, post-baseline, tumor assessment according to RECIST v1.1 (evaluable population). Results From July 2020 to December 2021, 119 patients were screened, and 25 PAM50 non-luminal tumors were identified (21%). From these, 17 (68%) patients were recruited, and 15 were evaluable for primary endpoint. Two patients discontinued the trial before the first dose of pembrolizumab and paclitaxel, because of clinical progressive disease (PD). Baseline patient characteristics were as follows: median age 53 years (range: 40-77), ECOG 0 52.9%, de novo MBC at diagnosis 29.4%, and visceral disease 64.7% (including 53.3% with liver metastasis). Ten patients had received paclitaxel treatment in the adjuvant setting. Regarding PAM50 intrinsic subtype, two patients had basal-like and 13 HER2-E tumors. At the time of data cut-off (May 17,2022), 8 patients (53.3%) had stopped their treatment because of PD and 2 (13.3%) due to toxicity. Five patients (33.3%) were still on treatment. The ORR was 53.3 % (8 of 15, 95% CI 26.6-78.7), meeting the pre-specified ORR for the first stage of the trial. The CBR was 86.6% (13 of 15, 95%CI 59.5-98.34), and median PFS was 7.5 months (95% CI: 5.6 – 10.2). Overall, all patients experienced treatment-related adverse events (TRAEs) of any grade, while 53.3% of patients experienced grade 3 TRAEs. No grade 4 or 5 TRAEs were reported in the evaluable population. Correlative analysis including gene expression analysis and centralized TILs scoring and PD-L1 IHC will be presented. Conclusions The first stage of TATEN combining pembrolizumab with paclitaxel after progression to CDK4/6 inhibitors in patients with HR+/HER2-negative, PAM50 non-luminal MBC met its pre-specified endpoint. Completion of the stage II part of the trial with the inclusion of up to 46 patients is warranted to assess the activity of this combination in this group of patients. Correlative studies to find predictive biomarkers of response to this regimen are ongoing and will be presented at the meeting. This study was funded by MSD. Citation Format: Aleix Prat, Tomás Pascual, Montserrat Muñoz, Cristina Hernando, Silvia Vazquez, Salvador Blanch, Manuel Alva, Mafalda Oliveira, Esther Sanfeliu, Lorea Villanueva, Fara Brasó-Maristany, Nuria Chic, Eva Ciruelos. TATEN TRIAL (SOLTI-1716) Targeting non-Luminal disease by PAM50 with pembrolizumab + paclitaxel in Hormone Receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer (MBC): interim analysis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-06-02.

Abstract OT2-08-02: SOLTI-1907 ATREZZO: Targeting hormonal receptor negative (HR-) or PAM50 non-luminal disease with atezolizumab in combination with trastuzumab and vinorelbine in HER2-positive metastatic breast cancer (MBC)

Abstract Background Today, there is no clear therapeutic algorithm for patients with metastatic HER2-positive (HER2+) breast cancer (BC) who have progressed to trastuzumab, pertuzumab, tyrosine kinase inhibitors and antibody-drug conjugates (ADC). Among the emerging strategies, the use of immune checkpoint inhibitors in combination therapy is showing promising clinical benefit in the advanced setting of HER2+ BC by overcoming immune resistance and enhancing antitumor cellular immunity. The intrinsic subtypes Basal-like and HER2-enriched (i.e PAM50 non-luminal tumors) represent approximately the 60% of HER2+ BC and are associated with higher expression of immune-related genes, tumor-infiltrating lymphocytes (TILs) presence and high tumor mutational burden (TMB), compared to luminal subtypes. Additionally, immune infiltration and TMB in HER2+ BC are associated with chemo/antiHER2 responsiveness and with potential benefit from anti-PD-1/PD-L1 inhibitors. We hypothesize that combining atezolizumab with trastuzumab and vinorelbine may improve outcomes in HR- or PAM50 non-luminal/HR-positive (HR+) disease within HER2+ MBC. Methods ATREZZO is an open-label, single-arm, Simon 2-stage, multicenter phase II study. The trial will include 55 pre- or post-menopausal female or male patients with unresectable locally advanced or metastatic HR- or PAM50 non-luminal/HR+ HER2+ BC and progressed to trastuzumab-based chemotherapy and anti-HER2 ADC. Prior pertuzumab is allowed, but not required. Treatment consists of atezolizumab IV 1200 mg every 3 weeks combined with trastuzumab and vinorelbine. Patients with stable, progressing, or untreated brain metastasis not requiring immediate local therapy are eligible. The primary objective is to evaluate the Overall Response Rate (ORR) according to RECIST v 1.1 and secondary endpoints include ORR in patients with PD-L1 positive breast cancer, clinical benefit rate, overall survival and progression-free survival. The final recruited population will contain no more than 60 % of patients with PD-L1 negative tumors. Tumor assessments will be performed every 9 weeks. Incidence, duration and severity of adverse events, and further correlative molecular analyses will be also evaluated. An interim analysis will be conducted when 19 patients are evaluable for ORR and if the number of responses is ≥ 3, 36 additional patients will be included. As of July 15th, 2022, 48 patients were screened and 15 were included in sixteen Spanish sites. This study was funded by Roche Farma SA. Trial identification: NCT04759248 Citation Format: Eva Ciruelos, Antonia Perelló, Santiago González-Santiago, Ana López, Francisco Javier Salvador Bofill, Cinta Albacar, Juan Miguel Cejalvo, Santiago Escrivá-de-Romani, Isabel Blancas, Sonia Pernas, Olga Martínez-Sáez, Josefina Cruz, Jose Ponce, Sonia Servitja, Maria-Eva Perez-Lopez, Juan A Guerra, Esther Sanfeliu, Cesar A Rodríguez, Guillermo Villacampa, Lorea Villanueva, Pablo Tolosa, Tomás Pascual, Aleix Prat. SOLTI-1907 ATREZZO: Targeting hormonal receptor negative (HR-) or PAM50 non-luminal disease with atezolizumab in combination with trastuzumab and vinorelbine in HER2-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-08-02.

A Novel Molecular Analysis Approach in Colorectal Cancer Suggests New Treatment Opportunities.

Colorectal cancer (CRC) is a molecular and clinically heterogeneous disease. In 2015, the Colorectal Cancer Subtyping Consortium classified CRC into four consensus molecular subtypes (CMS), but these CMS have had little impact on clinical practice. The purpose of this study is to deepen the molecular characterization of CRC. A novel approach, based on probabilistic graphical models (PGM) and sparse k-means-consensus cluster layer analyses, was applied in order to functionally characterize CRC tumors. First, PGM was used to functionally characterize CRC, and then sparse k-means-consensus cluster was used to explore layers of biological information and establish classifications. To this aim, gene expression and clinical data of 805 CRC samples from three databases were analyzed. Three different layers based on biological features were identified: adhesion, immune, and molecular. The adhesion layer divided patients into high and low adhesion groups, with prognostic value. The immune layer divided patients into immune-high and immune-low groups, according to the expression of immune-related genes. The molecular layer established four molecular groups related to stem cells, metabolism, the Wnt signaling pathway, and extracellular functions. Immune-high patients, with higher expression of immune-related genes and genes involved in the viral mimicry response, may benefit from immunotherapy and viral mimicry-related therapies. Additionally, several possible therapeutic targets have been identified in each molecular group. Therefore, this improved CRC classification could be useful in searching for new therapeutic targets and specific therapeutic strategies in CRC disease.

Molecular differences between younger versus older ER-positive and HER2-negative breast cancers

The RxPONDER and TAILORx trials demonstrated benefit from adjuvant chemotherapy in patients age ≤ 50 with node-positive breast cancer and Recurrence Score (RS) 0–26, and in node-negative disease with RS 16–25, respectively, but no benefit in older women with the same clinical features. We analyzed transcriptomic and genomic data of ER+/HER2− breast cancers with in silico RS < 26 from TCGA (n = 530), two microarray cohorts (A: n = 865; B: n = 609), the METABRIC (n = 867), and the SCAN-B (n = 1636) datasets. There was no difference in proliferation-related gene expression between age groups. Older patients had higher mutation burden and more frequent ESR1 copy number gain, but lower frequency of GATA3 mutations. Younger patients had higher rate of ESR1 copy number loss. In all datasets, younger patients had significantly lower mRNA expression of ESR1 and ER-associated genes, and higher expression of immune-related genes. The ER- and immune-related gene signatures showed negative correlation and defined three subpopulations in younger women: immune-high/ER-low, immune-intermediate/ER-intermediate, and immune-low/ER-intermediate. We hypothesize that in immune-high cancers, the cytotoxic effect of chemotherapy may drive the benefit, whereas in immune-low/ER-intermediate cancers chemotherapy induced ovarian suppression may play important role.

Immune Response of the Monocytic Cell Line THP-1 Against Six Aeromonas spp.

Aeromonas are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic identification shows that 95.4% of the strains associated with clinical cases correspond to the species Aeromonas caviae (37.26%), Aeromonas dhakensis (23.49%), Aeromonas veronii (21.54%), and Aeromonas hydrophila (13.07%). However, few studies have investigated the human immune response against some Aeromonas spp. such as A. hydrophila, Aeromonas salmonicida, and A. veronii. The present study aimed to increase the knowledge about the innate human immune response against six Aeromonas species, using, for the first time, an in vitro infection model with the monocytic human cell line THP-1, and to evaluate the intracellular survival, the cell damage, and the expression of 11 immune-related genes (TLR4, TNF-α, CCL2, CCL20, JUN, RELA, BAX, TP53, CASP3, NLRP3, and IL-1β). Transcriptional analysis showed an upregulated expression of a variety of the monocytic immune-related genes, with a variable response depending upon the Aeromonas species. The species that produced the highest cell damage, independently of the strain origin, coincidentally induced a higher expression of immune-related genes and corresponded to the more prevalent clinical species A. dhakensis, A. veronii, and A. caviae. Additionally, monocytic cells showed an overexpression of the apoptotic and pyroptotic genes involved in cell death after A. dhakensis, A. caviae, and Aeromonas media infection. However, the apoptosis route seemed to be the only way of producing cell damage and death in the case of the species Aeromonas piscicola and Aeromonas jandaei, while A. veronii apparently only used the pyroptosis route.

Mutation burden-orthogonal tumor genomic subtypes delineate responses to immune checkpoint therapy

BackgroundIn cancer therapy, higher-resolution tumor-agnostic biomarkers that predict response to immune checkpoint inhibitor (ICI) therapy are needed. Mutation signatures reflect underlying oncogenic processes that can affect tumor immunogenicity, and thus...

Transcriptome-Based Dissection of Intracranial Aneurysms Unveils an "Immuno-Thermal" Microenvironment and Defines a Pathological Feature-Derived Gene Signature for Risk Estimation.

Immune inflammation plays an essential role in the formation and rupture of intracranial aneurysm (IA). However, the current limited knowledge of alterations in the immune microenvironment of IA has hampered the mastery of pathological mechanisms and technological advances, such as molecular diagnostic and coated stent-based molecular therapy. In this study, seven IA datasets were enrolled from the GEO database to decode the immune microenvironment and relevant biometric alterations. The ssGSEA algorithm was employed for immune infiltration assessment. IAs displayed abundant immune cell infiltration, activated immune-related pathways, and high expression of immune-related genes. Several immunosuppression cells and genes were also coordinately upregulated in IAs. Five immune-related hub genes, including CXCL10, IL6, IL10, STAT1, and VEGFA, were identified from the protein-protein interaction network and further detected at the protein level. CeRNA networks and latent drugs targeting the hub genes were predicted for targeted therapy reference. Two gene modules recognized via WCGNA were functionally associated with contractile smooth muscle loss and extracellular matrix metabolism, respectively. In blood datasets, a pathological feature-derived gene signature (PFDGS) for IA diagnosis and rupture risk prediction was established using machine learning. Patients with high PFDGS scores may possess adverse biological alterations and present with a high risk of morbidity or IA rupture, requiring more vigilance or prompt intervention. Overall, we systematically unveiled an “immuno-thermal” microenvironment characterized by co-enhanced immune activation and immunosuppression in IA, which provides a novel insight into molecular pathology. The PFDGS is a promising signature for optimizing risk surveillance and clinical decision-making in IA patients.

Abstract OT1-17-01: Solti-1716. Targeting with pembrolizumab + paclitaxel non-luminal by PAM50 hormone receptor-positive/HER2-negative advanced/metastatic breast cancer patients who have progressed on or after CDK4/6 inhibitor treatment (TATEN trial)

Abstract Background.Patients with metastatic hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer (BC) are usually treated with CDK4/6 inhibitors combined with endocrine therapy (ET) as first line treatment. The addition of CDK4/6 inhibitors to endocrine therapy has demonstrated improved progression free survival (PFS), overall response rate (ORR) and, more recently, overall survival (OS). However, there is a 20% of patients who do not benefit from these drugs and those who respond eventually progress to the treatment, for whom no standard treatment exists. The information provided by the intrinsic subtypes (PAM50) highlight the potential value of BC molecular classification as a prognosis and predictive marker. Within HR+/HER2- disease, patients with non-luminal subtypes (HER2-enriched and Basal-like) present poorer prognosis than those with luminal subtypes, may be more sensitive to chemotherapy, and have higher expression of immune-related genes and tumor infiltrating lymphocytes (TILs). Recently, immunotherapy has been approved for treating metastatic triple negative (TN) BC and several trials evaluating the action of immune checkpoint inhibitors are ongoing both in TN and in HR+/HER2- BC. TATEN study aims to evaluate the combination of pembrolizumab and chemotherapy in metastatic HR+/HER2-negative, PAM50 non-luminal BC.Study design. TATEN is an open-label, single arm, multicenter phase II study evaluating pembrolizumab in combination with paclitaxel in patients with locally advanced or metastatic PAM50 non-luminal HR+/HER2- BC who had recurrence or progression after therapy with a CDK4/6 inhibitor plus endocrine therapy. Tumor samples collected during advanced/metastatic disease are mandatory. No prior chemotherapy for inoperable locally advanced or metastatic BC is permitted. Eligible patients will receive pembrolizumab 200 mg every 3 weeks (on day 1 of each 21-day cycle, beginning in Cycle 1) in combination with paclitaxel 80 mg/m2 administered at days 1, 8, 15 of each 21-day cycle beginning at cycle 2. The primary endpoint of the study is to evaluate ORR according to RECIST V1.1. The study will use a Simon’s 2-stage design and will include up to 46 evaluable patients. If 6 or more responses are observed in up to 15 patients in the first stage, the trial will continue to the second stage and 31 additional patients may be evaluated for a total of 46 evaluable patients. The null hypothesis will be rejected if 19 or more responses are observed. Tumor assessments will be performed every 9 weeks. Secondary endpoints include clinical benefit rate (CBR), PFS, duration of response (DoR), time to response (TtR), OS, as well as the correlation of clinical benefit (ORR, PFS) with PD1 mRNA expression and early dynamic changes in ctDNA after 1 cycle of pembrolizumab (collection of blood samples at Cycle 1 Day 1, Cycle 2 Day 1 and end of treatment are mandatory). Safety and tolerability of the combination will also be assessed. Exploratory objectives include to determine ORR, PFS, DoR and TtR based on iRECIST and to identify predictive biomarkers of response to pembrolizumab plus paclitaxel. As of July 2021, 10 patients have been enrolled in 7 sites in Spain. Clinical trial identification: NCT04251169. Acknowledgements:This study is financially supported by MSD Citation Format: Eva Ciruelos, Montserrat Muñoz, Mafalda Oliveira, Nuria Chic, Cristina Hernando, Juan Antonio Viruzuela, Silvia Vázquez, Salvador Blanch, Laia Paré, Fernando Salvador, Patricia Villagrasa, Tomás Pascual, Aleix Prat. Solti-1716. Targeting with pembrolizumab + paclitaxel non-luminal by PAM50 hormone receptor-positive/HER2-negative advanced/metastatic breast cancer patients who have progressed on or after CDK4/6 inhibitor treatment (TATEN trial) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-17-01.

Abstract PD13-04: Activity of patritumab deruxtecan, a HER3-directed antibody drug conjugate, in early breast cancer according to ERBB3 expression: Interim analysis results of a window-of-opportunity study (SOLTI-1805 TOT-HER3)

Abstract Introduction Patritumab deruxtecan (U3-1402; HER3-DXd) is a HER3-directed antibody drug conjugate with demonstrated clinically meaningful antitumor activity and acceptable safety profile in heavily pre-treated metastatic breast cancer (BC) with high or low HER3 expression levels (Masuda et al. Cancer Res. 2019; Krop et al. SABCS 2020). Here, we report the interim efficacy and safety data of the TOT-HER3 trial (NCT04610528), the first window-of-opportunity study designed to assess whether a single dose of HER3-DXd may increase immune infiltration during short-term preoperative treatment in early BC. Methods This is a prospective, phase 0, multicenter, single arm trial planned to enroll 80 patients with treatment naïve hormone receptor positive, HER2 negative primary operable BC ≥1 cm by ultrasound. Patients are allocated to one of 4 cohorts based on centrally assessed levels of ERBB3 mRNA by the nCounter platform in a pre-treatment biopsy and receive HER3-DXd administered as a single dose of 6.4 mg/kg. Post-treatment biopsy at C1D21 is obtained to explore primary and correlative endpoints. The primary objective is to evaluate the median change in the CelTIL score (-0.8*tumor cellularity% + 1.3*tumor-infiltrating lymphocytes%) (Nuciforo et al. Ann Oncol. 2018) in paired pre- and post-treatment samples in the overall cohort. Change in CelTIL score and the expression of 67 genes across ERBB3 cohorts and PAM50 subtypes is also explored. Adverse events (AEs) are graded according to CTCAE v 5.0. Results As of April 21 2021, 30 patients (all women) received the study treatment and were evaluable for the primary endpoint. Mean age was 52 years (range 35-77 years); 19 patients were pre- and 11 were post-menopausal. Median tumor size was 20 mm (range 10-60 mm); cN0 70%; mean Ki67 35% (range 10-90%); grade 1-2 67%. According to ERBB3 expression, 6 (20%), 13 (43%), 5 (17%) and 6 (20%) patients were categorized as high, medium, low and ultra-low, respectively. CelTIL score increased, was stable and decreased in 17 (57%), 3 (10%) and 10 (33%) patients, respectively. Overall, a statistically significant increase in CelTIL was observed between paired samples (p=0.028). At C1D21, a total of 12 (44%) patients experienced a response (7 complete and 5 partial response) by clinical palpation. CelTIL significantly changed in responders (p=0.006) but not in patients with stable disease (p=0.61). Baseline ERBB3 levels did not correlate with CelTIL change or clinical response. Moreover, PAM50 subtype distribution was as follows: Luminal A 15 (50%), Luminal B 13 (43%), HER2-Enriched 1 (3.5%), Basal-like 1 (3.5%). CelTIL score did not change significantly between Luminal A and Luminal B tumors. Five (38.5%) Luminal B tumors switched to Luminal A at C1D21. Interestingly, baseline high PAM50 risk-of-recurrence was associated with higher CelTIL score at C1D21 (p=0.002). Patritumab deruxtecan induced high expression of immune-related genes including PD1, CD8a and CD19 and Luminal A signature and suppressed proliferation-related genes. Overall, 29 (97%) patients reported at least one AE and 98% of AEs were grade 1 or 2. The most common AEs were nausea, asthenia, abdominal pain, alopecia, vomiting, diarrhea, neutropenia, increased liver enzymes. A grade 3 treatment-related reversible AST increase occurred in 1 patient. Conclusion In this interim trial analysis, a single dose of patritumab deruxtecan was associated with clinical response and important biological changes irrespective of baseline ERBB3 expression. The safety profile was consistent with that previously reported for the drug. Citation Format: Aleix Prat, Juan M. Cejalvo, Laia Pare, Olga Martínez-Sáez, Mireia Margelí Vila, Claudette Falato, Josefina Cruz, Miriam Arumí de Dios, Maria J Vidal, Juan Antonio Guerra, Ana Maria Luna Barrera, Pablo Tolosa, Francisco Javier Salvador-Bofill, Sonia Pernas, Blanca Gonzáles-Farré, Esther Sanfeliu, Eva Ciruelos, Violeta Serra, Martin Espinosa-Bravo, Yann Izarzugaza, Stephen Esker, Pang-Dian Fan, Guillermo Villacampa, Juan M Ferrero-Cafiero, Tomás Pascual, Mafalda Oliveira. Activity of patritumab deruxtecan, a HER3-directed antibody drug conjugate, in early breast cancer according to ERBB3 expression: Interim analysis results of a window-of-opportunity study (SOLTI-1805 TOT-HER3) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD13-04.

Evaluation of immune effect of Streptococcus suis biofilm-associated protein PDH

As a zoonotic pathogen, Streptococcus suis(S. suis) takes pigs as the main host and is mainly colonizes in the upper respiratory tract and tonsil of pigs, causing septicemia, endocarditis and meningitis in pigs. Pyruvate dehydrogenase (PDH) is an enzyme that catalyzes the conversion of pyruvate to acetyl-CoA. As an immunogenic membrane-associated protein in S. suis, it has been found to be closely related to the formation of biofilm. In this study, the recombinant PDH (rPDH) of S. suis ZY05719 (serotype 2) was expressed and purified in E. coli by His affinity chromatography. Western blotting analysis showed that there was a strong specific reaction between PDH protein and PDH antiserum. Mice were immunized with recombinant PDH and inactivated bacteria, and the relative survival rates were 70 % and 60 %, respectively. In addition, mice immunized with PDH caused high levels of antibodies and high expression of immune-related genes in the spleen, which significantly protected the liver, brain and spleen from pathological damage. In addition, PDH antiserum could significantly inhibit the growth of S. suis and the formation of S. suis biofilm in vitro. These results further suggest that PDH is a promising candidate for S. suis biofilm-related subunit vaccine.