Frequency Of Immune Cells Research Articles

A spatially resolved timeline of the human maternal-fetal interface.

Beginning in the first trimester, fetally derived extravillous trophoblasts (EVTs) invade the uterus and remodel its spiral arteries, transforming them into large, dilated blood vessels. Several mechanisms have been proposed to explain how EVTs coordinate with the maternal decidua to promote a tissue microenvironment conducive to spiral artery remodelling (SAR)1-3. However, it remains a matter of debate regarding which immune and stromal cells participate in these interactions and how this evolves with respect to gestational age. Here we used a multiomics approach, combining the strengths of spatial proteomics and transcriptomics, to construct a spatiotemporal atlas of the human maternal-fetal interface in the first half of pregnancy. We used multiplexed ion beam imaging by time-of-flight and a 37-plex antibody panel to analyse around 500,000 cells and 588 arteries within intact decidua from 66 individuals between 6 and 20 weeks of gestation, integrating this dataset with co-registered transcriptomics profiles. Gestational age substantially influenced the frequency of maternal immune and stromal cells, with tolerogenic subsets expressing CD206, CD163, TIM-3, galectin-9 and IDO-1 becoming increasingly enriched and colocalized at later time points. By contrast, SAR progression preferentially correlated with EVT invasion and was transcriptionally defined by 78 gene ontology pathways exhibiting distinct monotonic and biphasic trends. Last, we developed an integrated model of SAR whereby invasion is accompanied by the upregulation of pro-angiogenic, immunoregulatory EVT programmes that promote interactions with the vascular endothelium while avoiding the activation of maternal immune cells.

Deconvolution of whole blood transcriptomics identifies changes in immune cell composition in patients with systemic lupus erythematosus (SLE) treated with mycophenolate mofetil

BackgroundSystemic lupus erythematosus (SLE) is a clinically and biologically heterogeneous autoimmune disease. We explored whether the deconvolution of whole blood transcriptomic data could identify differences in predicted immune cell frequency between active SLE patients, and whether these differences are associated with clinical features and/or medication use.MethodsPatients with active SLE (BILAG-2004 Index) enrolled in the BILAG-Biologics Registry (BILAG-BR), prior to change in therapy, were studied as part of the MASTERPLANS Stratified Medicine consortium. Whole blood RNA-sequencing (RNA-seq) was conducted at enrolment into the registry. Data were deconvoluted using CIBERSORTx. Predicted immune cell frequencies were compared between active and inactive disease in the nine BILAG-2004 domains and according to immunosuppressant use (current and past).ResultsPredicted cell frequency varied between 109 patients. Patients currently, or previously, exposed to mycophenolate mofetil (MMF) had fewer inactivated macrophages (0.435% vs 1.391%, p = 0.001), naïve CD4 T cells (0.961% vs 2.251%, p = 0.002), and regulatory T cells (1.858% vs 3.574%, p = 0.007), as well as a higher proportion of memory activated CD4 T cells (1.826% vs 1.113%, p = 0.015), compared to patients never exposed to MMF. These differences remained statistically significant after adjusting for age, gender, ethnicity, disease duration, renal disease, and corticosteroid use. There were 2607 differentially expressed genes (DEGs) in patients exposed to MMF with over-representation of pathways relating to eosinophil function and erythrocyte development and function. Within CD4 + T cells, there were fewer predicted DEGs related to MMF exposure. No significant differences were observed for the other conventional immunosuppressants nor between patients according disease activity in any of the nine organ domains.ConclusionMMF has a significant and persisting effect on the whole blood transcriptomic signature in patients with SLE. This highlights the need to adequately adjust for background medication use in future studies using whole blood transcriptomics.

Immune cell profiling of vaginal blood from patients with early pregnancy bleeding.

Vaginal bleeding during early pregnancy is estimated to occur in 20% of all pregnancies and it is often difficult to predict who will ultimately miscarry. The role of immune cells in early pregnancy loss is poorly understood. In this prospective cohort study, 28 pregnant women presenting with first-trimester vaginal bleeding donated vaginal blood, peripheral venous blood, and saliva during their initial emergency room visit, and at a follow-up. The composition, frequency, and phenotype of immune cells in the vaginal blood were determined using flow cytometry. The proteome of serum and saliva was analyzed with OLINK proximity extension assay and correlated to vaginal immune cell phenotype and outcome of pregnancy. The course and outcome of pregnancies were followed and recorded. Vaginal blood contained all main immune cell lineages including B cells, NK cells, T cells, and monocytes/macrophages. Notably, vaginal blood immune cells expressed tissue residency markers including CD49a. Women who subsequently miscarried had a higher frequency of vaginal blood CD49a+ NK cells compared to those who did not miscarry, and this correlated with serum levels of granzyme A and H, as well as CSF1, CAIX, and TWEAK. Women in the miscarriage group also had a higher frequency of peripheral blood T cells expressing CD49a. Our study provides novel insight into human reproductive immunology in relation to miscarriage. Tissue-resident NK cells in vaginal blood alone or in combination with serological biomarkers hold potential as prognostic factors in the prediction of pregnancy outcome in women with early pregnancy bleedings.

#4983 THE UNEXPECTABLE BALANCE OF PROINFLAMMATORY CELLS IN PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims Chronic kidney disease (CKD) is a complex and heterogeneous disease and is increasingly becoming a global public health concern. It is is characterized by a persistent inflammation state which appear to be caused by cytokines, grown factors and hormones. Peritoneal dialysis (PD) accounts for 9% of all kidney replacement therapy (KRT) and over time, some changes are expected to occur in the peritoneal membrane mainly due to exposure to PD solutions, infectious processes and non-infectious complications. This inflammatory process is poorly understood and needs further clarification, but Th17 cells and Th1 cells seem to be involved. Therefore, we aimed to quantify the frequency of peripheral immune cells and the concentration of IL-17A in peripheral blood (PB) and peritoneal effluent (PE) and compare to a healthy control group. Method In a cross-sectional study of 26 PD patients and 10 healthy, age and sex-matched controls we evaluated PB and PE frequencies of T lymphocytes, T CD4, T CD8 and Th1 cells by flow cytometry as well as IL-17 concentrations using enzyme-linked immunosorbent assay. Comparisons were performed between PD patients and controls and between the different groups of PD patients according to PD modality, number of exchanges, dialysate tonicity, extraneal use, infusion and daily total volumes, type of peritoneal transport and volume indexes. Statistical analyses were performed using the SPSS statistics version 26. Results Table 1 summarizes the main characteristics of PD patients and controls. Overall, in comparison with the control group, the frequency of Th1 cells in PB of PD patients was significantly lower (P = 0.001). On the other hand, frequency of Th1 cells substantially expanded in the PE, as compared to the PB (P = 0.001). PD patients also presented lower Th17 cells frequencies (P = 0.061) and those prescribed Extraneal had the lowest frequencies of Th17 (P = 0.030). IL-17A concentration was significantly higher in PE vs PB of PD patients (P = 0.012). Finally, the frequency of total lymphocytes in high PD transporters was significantly higher in comparison with high-average transporters (P = 0.021). Conclusion In our cohort, PE presented high concentrations of proinflammatory cells and cytokines. Th1 cells rather than Th17 cells were increased, pointing to a predominant cytolytic activity but IL-17 was also increased. Treatment with Extraneal associated with a lower frequency of these cells, somehow counterbalancing the inflammatory millieu associated with high glucose concentrations.

A Comparison of Lymphoid and Myeloid Cells Derived from Human Hematopoietic Stem Cells Xenografted into NOD-Derived Mouse Strains.

Humanized mice are an invaluable tool for investigating human diseases such as cancer, infectious diseases, and graft-versus-host disease (GvHD). However, it is crucial to understand the strengths and limitations of humanized mice and select the most appropriate model. In this study, we describe the development of the human lymphoid and myeloid lineages using a flow cytometric analysis in four humanized mouse models derived from NOD mice xenotransplanted with CD34+ fetal cord blood from a single donor. Our results showed that all murine strains sustained human immune cells within a proinflammatory environment induced by GvHD. However, the Hu-SGM3 model consistently generated higher numbers of human T cells, monocytes, dendritic cells, mast cells, and megakaryocytes, and a low number of circulating platelets showing an activated profile when compared with the other murine strains. The hu-NOG-EXL model had a similar cell development profile but a higher number of circulating platelets with an inactivated state, and the hu-NSG and hu-NCG developed low frequencies of immune cells compared with the other models. Interestingly, only the hu-SGM3 and hu-EXL models developed mast cells. In conclusion, our findings highlight the importance of selecting the appropriate humanized mouse model for specific research questions, considering the strengths and limitations of each model and the immune cell populations of interest.

Infusion of GMSCs relieves autoimmune arthritis by suppressing the externalization of neutrophil extracellular traps via PGE2-PKA-ERK axis

IntroductionRheumatoid arthritis (RA) is a systemic autoimmune disease with limited treatment success, characterized by chronic inflammation and progressive cartilage and bone destruction. Accumulating evidence has shown that neutrophil extracellular traps (NETs) released by activated neutrophils are important for initiating and perpetuating synovial inflammation and thereby could be a promising therapeutic target for RA. K/B × N serum transfer-induced arthritis (STIA) is a rapidly developed joint inflammatory model that somehow mimics the inflammatory response in patients with RA. Human gingival-derived mesenchymal stem cells (GMSCs) have been previously shown to possess immunosuppressive effects in arthritis and humanized animal models. However, it is unknown whether GMSCs can manage neutrophils in autoimmune arthritis. ObjectivesTo evaluate whether infusion of GMSCs can alleviate RA by regulating neutrophils and NETs formation. If this is so, we will explore the underlying mechanism(s) in an animal model of inflammatory arthritis. MethodsThe effects of GMSCs on RA were assessed by comparing the symptoms of the K/B × N serum transfer-induced arthritis (STIA) model administered either with GMSCs or with control cells. Phenotypes examined included clinical scores, rear ankle thickness, paw swelling, inflammation, synovial cell proliferation, and immune cell frequency. The regulation of GMSCs on NETs was examined through immunofluorescence and immunoblotting in GMSCs-infused STIA mice and in an in vitro co-culture system of neutrophils with GMSCs. The molecular mechanism(s) by which GMSCs regulate NETs was explored both in vitro and in vivo by silencing experiments. ResultsWe found in this study that adoptive transfer of GMSCs into STIA mice significantly ameliorated experimental arthritis and reduced neutrophil infiltration and NET formation. In vitro studies also showed that GMSCs inhibited the generation of NETs in neutrophils. Subsequent investigations revealed that GMSCs secreted prostaglandin E2 (PGE2) to activate protein kinase A (PKA), which ultimately inhibited the downstream extracellular signal-regulated kinase (ERK) pathway that is essential for NET formation. ConclusionOur results demonstrate that infusion of GMSCs can ameliorate inflammatory arthritis mainly by suppressing NET formation via the PGE2-PKA-ERK signaling pathway. These findings further support the notion that the manipulation of GMSCs is a promising stem cell-based therapy for patients with RA and other autoimmune and inflammatory diseases.

Prolonged inflammation in patients hospitalized for coronavirus disease 2019 (COVID-19) resolves 2 years after infection.

Long-term complications from coronavirus disease 2019 (COVID-19) are concerning, as survivors can develop subclinical multiorgan dysfunction. It is unknown if such complications are due to prolonged inflammation, and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) vaccination may reduce sequela. We conducted a prospective longitudinal study on hospitalized patients over 24 months. Clinical symptoms were collected by self-reporting during follow-up, along with blood samples for quantification of inflammatory markers and immune cell frequencies. All patients were given one dose of mRNA vaccine at 12-16 months. Their immune profiles at 12 and 24 months were compared. Approximately 37% and 39% of our patients reported post-COVID-19 symptoms at 12 and 24 months, respectively. The proportion of symptomatic patients with more than one symptom decreased from 69% at 12 months to 56% at 24 months. Longitudinal cytokine profiling revealed a cluster of individuals with persistently high inflammatory cytokine levels 12 months after infection. Patients with prolonged inflammation showed elevated terminally differentiated memory T cells in their blood; 54% had symptoms at 12 months. The majority of inflammatory markers and dysregulated immune cells in vaccinated patients recovered to a healthy baseline at 24 months, even though symptoms persisted. Post-COVID-19 symptoms can linger for 2years after the initial infection and are associated with prolonged inflammation. Prolonged inflammation in hospitalized patients resolves after 2years. We define a set of analytes associated with persistent inflammation and presence of symptoms, which could be useful biomarkers for identifying and monitoring high-risk survivors.

Single-cell RNA sequencing reveals heterogeneous immune landscape of tumor infiltrated immune cell population in B cell deficiency against glioblastoma

Abstract The distinct immune landscape of glioblastoma (GBM) from other cancer is an obstacle to GBM treatment. To overcome the limited efficacy of GBM therapy, identifying the interaction between the tumor and infiltrated immune cells is needed. The function of B cells against tumors is recently focused on to understand tumor microenvironments. However, there are still few studies on the function of B cells in glioblastoma. Here, we identify tumor infiltrated immune cell population in B cell deficient mouse GBM by landscape analysis against glioblastoma. Using single-cell transcriptome analysis, we find that the frequency of tumor infiltrated immune cells including T cells and monocyte/macrophage is changed by the absence of B cells in mouse GBM. The frequency of effector CD8 and CD4 T cells decreases in B cell deficient mice. Also, expression of the cytotoxic signature protein is downregulated in tumor infiltrated T cells which are known to play an important role in tumor cell killing. In the case of tumor infiltrated macrophage and microglia, expression of M2 signature increased in B cell deficient GBM which can lead immunosuppressive tumor microenvironment. This study reveals changes in the immune cell landscape according to the presence or absence of B cells and shows how B cells contribute to antitumor immunity through immune interaction.

Dendritic cell expansion and activation enhances the adaptive immune response against TNBC brain metastases

Abstract Despite initial control by chemotherapy, Triple Negative Breast Cancer (TNBC) quickly acquires resistance and metastasizes to distal organs, including the brain. Median survival following diagnosis of TNBC brain metastases is a meager 7.3 months—indicative of a substantial unmet clinical need, with only a small subpopulation responding to checkpoint immunotherapy. As suboptimal antigen presentation can contribute to the weak T lymphocyte response to intracranial tumors, we hypothesized that enhancing dendritic cell (DC) presence in tumors may support intracranial T cell responses to tumors. Using a murine model of intracranial metastasis, we assessed immune cell frequency and function and in vivocytokine staining for flow cytometry to test whether Flt3L can be used to promote DC presence within tumors, and whether the addition of polyIC further enhances subsequent T cell responses. Flt3L treatment effectively increases the number of DC within the brains and meninges of mice, however these newly expanded populations exhibit lower proportions of the costimulatory molecule CD86 than the untreated control group, indicative of an immature phenotype. 24 hours after polyIC treatment, a higher percentage of DCs in brain tumors express CD86 but do not produce IL-12. Despite the lack of intratumoral IL-12, the combination of Flt3L and polyIC treatments led to a higher presence of T cells within tumors and their production of IFN-γ in the TME than either treatment alone. In conclusion, simply increasing the presence of DC within intracranial tumors is insufficient to promote T cell immunity; rather, deliberate activation of de novo DC is required for this full effect. Supported by grants from NIH (2T32CA009109-46 and 1R21CA226607-01A1) and the Schiff Foundation

Changes in HCMV immune cell frequency and phenotype are associated with chronic lung allograft dysfunction.

Human cytomegalovirus (HCMV) infection is common and often severe in lung transplant recipients (LTRs), and it is a risk factor associated with chronic lung allograft dysfunction (CLAD). The complex interplay between HCMV and allograft rejection is still unclear. Currently, no treatment is available to reverse CLAD after diagnosis, and the identification of reliable biomarkers that can predict the early development of CLAD is needed. This study investigated the HCMV immunity in LTRs who will develop CLAD. This study quantified and phenotyped conventional (HLA-A2pp65) and HLA-E-restricted (HLA-EUL40) anti-HCMV CD8+ T (CD8 T) cell responses induced by infection in LTRs developing CLAD or maintaining a stable allograft. The homeostasis of immune subsets (B, CD4T, CD8 T, NK, and γδT cells) post-primary infection associated with CLAD was also investigated. At M18 post-transplantation, HLA-EUL40 CD8 T responses were less frequently found in HCMV+ LTRs (21.7%) developing CLAD (CLAD) than in LTRs (55%) keeping a functional graft (STABLE). In contrast, HLA-A2pp65 CD8 T was equally detected in 45% of STABLE and 47.8% of CLAD LTRs. The frequency of HLA-EUL40 and HLA-A2pp65 CD8 T among blood CD8 T cells shows lower median values in CLAD LTRs. Immunophenotype reveals an altered expression profile for HLA-EUL40 CD8 T in CLAD patients with a decreased expression for CD56 and the acquisition of PD-1. In STABLE LTRs, HCMV primary infection causes a decrease in B cells and inflation of CD8 T, CD57+/NKG2C+ NK, and δ2-γδT cells. In CLAD LTRs, the regulation of B, total CD8 T, and δ2+γδT cells is maintained, but total NK, CD57+/NKG2C+ NK, and δ2-γδT subsets are markedly reduced, while CD57 is overexpressed across T lymphocytes. CLAD is associated with significant changes in anti-HCMV immune cell responses. Our findings propose that the presence of dysfunctional HCMV-specific HLA-E-restricted CD8 T cells together with post-infection changes in the immune cell distribution affecting NK and γδT cells defines an early immune signature for CLAD in HCMV+ LTRs. Such a signature may be of interest for the monitoring of LTRs and may allow an early stratification of LTRs at risk of CLAD.

Irradiation plus myeloid-derived suppressor cell-targeted therapy for overcoming treatment resistance in immunologically cold urothelial carcinoma

BackgroundRadiotherapy (RT) has recently been highlighted as a partner of immune checkpoint inhibitors. The advantages of RT include activation of lymphocytes while it potentially recruits immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs). This study aimed to investigate the mechanism of overcoming treatment resistance in immunologically cold tumours by combining RT and MDSC-targeted therapy.MethodsThe abscopal effects of irradiation were evaluated using MB49 and cisplatin-resistant MB49R mouse bladder cancer cells, with a focus on the frequency of immune cells and programmed cell death-ligand 1 (PD-L1) expression in a xenograft model.ResultsMB49R was immunologically cold compared to parental MB49 as indicated by the fewer CD8+ T cells and lower PD-L1 expression. Polymorphonuclear MDSCs increased in both MB49 and MB49R abscopal tumours, whereas the infiltration of CD8+ T cells increased only in MB49 but not in MB49R tumours. Interestingly, PD-L1 expression was not elevated in abscopal tumours. Finally, blocking MDSC in combination with RT remarkably reduced the growth of both MB49 and MB49R abscopal tumours regardless of the changes in the frequency of infiltrating CD8+ T cells.ConclusionsThe combination of RT and MDSC-targeted therapy could overcome treatment resistance in immunologically cold tumours.

Abstract 5079: Intratumoral CD40 agonist enhances the antitumor effect of anti-PD1 immunotherapy by activation of antigen-presenting cells and selective expansion of effector CD8+ T cells

Abstract Agonistic CD40 antibodies have shown promise when used in combination with checkpoint inhibitors in clinical trials for the treatment of malignancies. However, the mechanisms driving antitumor immune responses in patients are not well understood. The aim of this study was to use a preclinical melanoma model to evaluate the impact of intratumoral anti-CD40 administration on treatment efficacy and the tumor immune landscape in the context of systemic anti-PD1 therapy. Mice bearing 8-day established B16 melanoma tumors were injected with CD40 agonist intratumorally, either alone or in combination with anti-PD1 Ab, every 3 days for a total 4 doses. All mice treated with the combination therapy exhibited tumor growth arrest while progressive tumor growth was observed in control mice and mice treated with anti-PD1 alone. At day 15, tumor weights were 7- and 3-fold reduced in mice treated with the combination therapy as compared to control IgG or PD1 monotherapy, respectively. CyTOF analysis showed a 4-fold increase in the frequency of tumor-infiltrating immune cells in mice treated with either CD40 agonist alone or the combination therapy. Interestingly, CD40 agonistic Ab selectively expanded CD8+ T cells and the combination therapy exhibited a more pronounced effect compared to treatment with anti-PD1 Ab alone. Moreover, CD39+ CD8 T cells, representing tumor antigen-specific cytotoxic T cells, were 14- and 3-fold higher in tumors from mice treated with the combination therapy as compared to control or PD1-treated mice, respectively. This effect correlated with increases in the frequency of antigen-presenting cells, including cDC1 (6-fold) and B cells expressing CD40 (3-fold) in response to the combination therapy. In addition, the combination therapy significantly decreased myeloid cell population resulting in an 8-fold reduction in the ratio of myeloid cells to T cells. Amongst myeloid cells, the density of the monocytic population was diminished, with a selective 10-fold reduction of CD206+ M2-macrophages in tumors from mice treated with both Abs. Our findings provide evidence that combining systemic anti-PD1 therapy with intratumoral CD40 agonist enhanced antitumor immune responses by selectively expanding tumor antigen-specific effector CD8+ T cells, which was associated with increased infiltration of antigen-presenting cells and attenuation of immunosuppressive myeloid cells. Citation Format: Barbara Pazdrak, Heather M. Sonnemann, Salah-Eddine Bentebibel, Barbara M. Nassif, Greg Lizee, Adi Diab. Intratumoral CD40 agonist enhances the antitumor effect of anti-PD1 immunotherapy by activation of antigen-presenting cells and selective expansion of effector CD8+ T cells. [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 5079.

Abstract 4648: How inherited mutations affect single cells within the tumor microenvironment in breast tumors stratified by receptor status

Abstract The tumor microenvironment (TME) plays important roles in tumor progression, therapy response and patient survival. In this comprehensive study, we performed a detailed multiomic single cell analysis of breast cancers with inherited mutations in different genes (BRCA1, BRCA2, PALB2, ATM, CHEK2), and wild type mutation negative (WT) patients, stratified by hormone receptor status, to understand the relationship between inherited mutation and immunogenicity. Using spatial tissue multiplexing (PhenoCycler), single cell RNAseq (10X Genomics) and bulk RNAseq, we evaluated cellular markers within the TME associated with DNA damage as well as phenotypes with tumor suppressive (M1, CD8 T cells, NK cells) or tumor promotive (M2, Treg, CAF) properties. We developed a 43-plex antibody panel and characterized eight tissue microarrays containing 443 patient samples from mutation carriers (BRCA1: n=142, BRCA2: n=118, CHEK2: n=2, TP53: n=3, PALB2: n=7) and WT tumors (n=171). We addressed how the TME differs in mutation carriers versus WT tumors stratified by receptor status. To further investigate immune cell function (cytolytic function, exhaustion, immune checkpoint) as well as pathways involved in immune suppression and/or promotion, we performed scRNA sequencing using isolated single cells from fresh collected BC samples (WT ER: n=3, BRCA2 ER: n=1, CHEK2 ER: n=1, VUS ER: n=1) and bulk RNA (BRCA1: n=17, BRCA2: n=9). To determine immune cell (IC) frequency, we analyzed CD45+ cells detectable in each cohort and their co-expression of markers to determine specific phenotypes. Our data suggest that within BRCA mutation-associated BC, there are two groups: 1) with increased tumor infiltrating lymphocytes (TILs) including CD8+ cytotoxic T cells with high cytolytic function; and 2) with decreased TILs and cytolytic function. The frequency of CD8+ T cells is significantly decreased in breast cancers with BRCA2 mutations compared to BRCA1. Characterizing ER+ CHEK2 BC reveals T cell exhaustion compared to WT ER+ BC. Furthermore, preliminary scRNA results reveal increased fibroblast markers in ER+ CHEK2 and ER+ WT compared to ER+ BRCA2 tumors. Interestingly, cancer associated fibroblast (CAFs) markers (ACTA2, COL1A1, FAP, PDGFRA, PDGFRB, PDPN, THY1) as well as TAMs (CCL2, CD163, CD206, CD68, IL10, LOX, PLOD2, SIGLEC1) are increased in ER+ CHEK2 tumors compared to ER+ WT. These data could provide insights into how the TME associated with ER+ CHEK2 mutations might be driven by CAFs and TAMs with a frequency much higher than in ER+ WT. The detection of immune suppressive (Treg, M2) and immune promotive (M1) phenotypes differs in BRCA1 compared to BRCA2 mutated and WT TNBC. Our findings could decipher the role of DNA repair gene mutations and their effect on cells within the TME that might influence the design of treatment options in patients with inherited mutations based on their receptor status. Citation Format: Dana Pueschl, Derek A. Oldridge, Jonathan Belman, William Chandler, Anupma Nayak, Bradley Wubbenhorst, John Pluta, Michael Feldman, E. John Wherry, Heather Thorne, Georgia Chenevix-Trench, Kathleen Cuningham Foundation Consortium for Resea kConFab, Susan M. Domchek, Katherine L. Nathanson. How inherited mutations affect single cells within the tumor microenvironment in breast tumors stratified by receptor status. [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 4648.

S-allylmercaptocysteine promotes anti-tumor immunity by suppressing PD-L1 expression

SAMC (S-allylmercaptocysteine) possesses significant anti-tumor effects and is proven to inhibit inflammation in chronic obstructive pulmonary disease. The potential to regulate the immune system of SAMC inspired us to detect whether SAMC can promote anti-tumor immunity. Here we found that SAMC inhibits tumor development and progression by boosting CD8+ T cell and NK cell infiltration and decreasing the frequency of immune suppressing Treg cells in tumor tissue and enhancing the systemic immune function. Mechanistically, we found that SAMC suppresses PD-L1 expression at transcriptional level to increase the activation of anti-tumor cytotoxic T cells. Finally, we proved that SAMC inhibits PD-L1 transcription by suppressing the phosphorylation activation of STAT3. In conclusion, our findings reveal that SAMC is a potent immunity regulator and a potential agent for immune checkpoint inhibition in tumor therapy.

Combinatory analysis of immune cell subsets and tumor-specific genetic variants predict clinical response to PD-1 blockade in patients with non-small cell lung cancer.

Immunotherapy by blocking programmed death protein-1 (PD-1) or programmed death protein-ligand1 (PD-L1) with antibodies (PD-1 blockade) has revolutionized treatment options for patients with non-small cell lung cancer (NSCLC). However, the benefit of immunotherapy is limited to a subset of patients. This study aimed to investigate the value of combining immune and genetic variables analyzed within 3-4 weeks after the start of PD-1 blockade therapy to predict long-term clinical response. Blood collected from patients with NSCLC were analyzed for changes in the frequency and concentration of immune cells using a clinical flow cytometry assay. Next-generation sequencing (NGS) was performed on DNA extracted from archival tumor biopsies of the same patients. Patients were categorized as clinical responders or non-responders based on the 9 months' assessment after the start of therapy. We report a significant increase in the post-treatment frequency of activated effector memory CD4+ and CD8+ T-cells compared with pre-treatment levels in the blood. Baseline frequencies of B cells but not NK cells, T cells, or regulatory T cells were associated with the clinical response to PD-1 blockade. NGS of tumor tissues identified pathogenic or likely pathogenic mutations in tumor protein P53, Kirsten rat sarcoma virus, Kelch-like ECH-associated protein 1, neurogenic locus notch homolog protein 1, and serine/threonine kinase 11, primarily in the responder group. Finally, multivariate analysis of combined immune and genetic factors but neither alone, could discriminate between responders and non-responders. Combined analyses of select immune cell subsets and genetic mutations could predict early clinical responses to immunotherapy in patients with NSCLC and after validation, can guide clinical precision medicine efforts.

The immunomodulatory effect of intradermal allogeneic PBMC therapy in patients with recurrent spontaneous abortion

BackgroundThere has been limited study on the impact of PBMC therapy in RSA patients with immunological disorders such as Th17 and Treg cell dysregulation, as well as their associated factors. This study aimed to assess the efficacy of PBMC therapy in modulating immune cell frequency, cytokine production, transcription factors, and miRNAs implicated in the regulation of their function, as well as their potential superiority to routine treatments. MethodsFifty RSA women who had received PBMCs and 50 matched-paired control RSA women who had received the routine treatments were recruited and followed for three months. The frequencies of Th17, Treg, NK, and B cells were assessed using flow cytometry. Thereafter, the gene expression level of the transcription factors and related miRNAs of Treg cell and Th17 cell was quantified using RT-PCR. Then ELISA was employed to assess the cytokine production of Th17 and Treg cells. Finally, the live birth rate and miscarriage rate were evaluated as clinical outcomes in this study. ResultsFlow cytometry analysis revealed that PBMC therapy significantly reduces the frequencies of Th17 and NK cells while enhancing the frequency of Treg cells. RT-PCR analysis confirmed that PBMC therapy significantly downregulates RORγt and upregulates FoxP3. Likewise, RT-PCR analysis showed that PBMC therapy reduces the expression of miR-25, miR-155, and miR-326 while increasing the expression of miR-10a. ELISA results demonstrated that PBMC therapy considerably decreases the concentration of inflammatory cytokines IL-1β, IL-17, and TNF-α and enhances the concentration of anti-inflammatory cytokines IL-10 and TGF-β. Following PBMC therapy live birth rate raised while miscarriage rate reduced. ConclusionOur findings suggested that, in contrast to routine treatments, PBMC therapy can significantly modulate the maternal immune system by enhancing the Treg/Th17 paradigm and regulating the expression of Treg and Th17 cell-associated cytokines, transcription factors, and miRNAs. This treatment also can increase the live birth rate in RSA patients.

Susceptibility identification for seasonal influenza A/H3N2 based on baseline blood transcriptome.

Influenza susceptibility difference is a widely existing trait that has great practical significance for the accurate prevention and control of influenza. Here, we focused on the human susceptibility to the seasonal influenza A/H3N2 of healthy adults at baseline level. Whole blood expression data for influenza A/H3N2 susceptibility from GEO were collected firstly (30 symptomatic and 19 asymptomatic). Then to explore the differences at baseline, a suite of systems biology approaches - the differential expression analysis, co-expression network analysis, and immune cell frequencies analysis were utilized. We found the baseline condition, especially immune condition between symptomatic and asymptomatic, was different. Co-expression module that is positively related to asymptomatic is also related to immune cell type of naïve B cell. Function enrichment analysis showed significantly correlation with "B cell receptor signaling pathway", "immune response-activating cell surface receptor signaling pathway" and so on. Also, modules that are positively related to symptomatic are also correlated to immune cell type of neutrophils, with function enrichment analysis showing significantly correlations with "response to bacterium", "inflammatory response", "cAMP-dependent protein kinase complex" and so on. Responses of symptomatic and asymptomatic hosts after virus exposure show differences on resisting the virus, with more effective frontline defense for asymptomatic hosts. A prediction model was also built based on only baseline transcription information to differentiate symptomatic and asymptomatic population with accuracy of 0.79. The results not only improve our understanding of the immune system and influenza susceptibility, but also provide a new direction for precise and targeted prevention and therapy of influenza.

Rab44 Deficiency Induces Impaired Immune Responses to Nickel Allergy.

Rab44 was recently identified as an atypical Rab GTPase that possesses EF-hand and coiled-coil domains at the N-terminus, and a Rab-GTPase domain at the C-terminus. Rab44 is highly expressed in immune-related cells such as mast cells, macrophages, osteoclasts, and granulocyte-lineage cells in the bone marrow. Therefore, it is speculated that Rab44 is involved in the inflammation and differentiation of immune cells. However, little is known about the role of Rab44 in inflammation. In this study, we showed that Rab44 was upregulated during the early phase of differentiation of M1- and M2-type macrophages. Rab44-deficient mice exhibited impaired tumor necrosis factor alpha and interleukin-10 production after lipopolysaccharide (LPS) stimulation. The number of granulocytes in Rab44-deficient mice was lower, but the lymphocyte count in Rab44-deficient mice was significantly higher than that in wild-type mice after LPS stimulation. Moreover, Rab44-deficient macrophages showed impaired nickel-induced toxicity, and Rab44-deficient mice showed impaired nickel-induced hypersensitivity. Upon nickel hypersensitivity induction, Rab44-deficient mice showed different frequencies of immune cells in the blood and ears. Thus, it is likely that Rab44 is implicated in immune cell differentiation and inflammation, and Rab44 deficiency induces impaired immune responses to nickel allergies.

Circulating cytokine and chemokine patterns associated with cytomegalovirus reactivation after stem cell transplantation.

Human cytomegalovirus (HCMV) reactivation is the leading viral complication after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Understanding of circulating cytokine/chemokine patterns which accompany HCMV reactivation and correlate with HCMV DNAemia magnitude is limited. We aimed to characterise plasma cytokine/chemokine profiles in 36 allo-HSCT patients (21 with HCMV reactivation and 15 without HCMV reactivation) at four time-points in the first 100-day post-transplant. The concentrations of 31 cytokines/chemokines in plasma samples were analysed using a multiplex bead-based immunoassay. Cytokine/chemokine concentrations were compared in patients with high-level HCMV DNAemia, low-level HCMV DNAemia or no HCMV reactivation, and correlated with immune cell frequencies measured using mass cytometry. Increased plasma levels of T helper 1-type cytokines/chemokines (TNF, IL-18, IP-10, MIG) were detected in patients with HCMV reactivation at the peak of HCMV DNAemia, relative to non-reactivators. Stem cell factor (SCF) levels were significantly higher before the detection of HCMV reactivation in patients who went on to develop high-level HCMV DNAemia (810-52 740 copies/mL) vs. low-level HCMV DNAemia (< 250 copies/mL). High-level HCMV reactivators, but not low-level reactivators, developed an elevated inflammatory cytokine/chemokine profile (MIP-1α, MIP-1β, TNF, LT-α, IL-13, IL-9, SCF, HGF) at the peak of reactivation. Plasma cytokine concentrations displayed unique correlations with circulating immune cell frequencies in patients with HCMV reactivation. This study identifies distinct circulating cytokine/chemokine signatures associated with the magnitude of HCMV DNAemia and the progression of HCMV reactivation after allo-HSCT, providing important insight into immune recovery patterns associated with HCMV reactivation and viral control.

Dendritic Cell-Triggered Immune Activation Goes along with Provision of (Leukemia-Specific) Integrin Beta 7-Expressing Immune Cells and Improved Antileukemic Processes

Integrin beta 7 (β7), a subunit of the integrin receptor, is expressed on the surface of immune cells and mediates cell-cell adhesions and interactions, e.g., antitumor or autoimmune reactions. Here, we analyzed, whether the stimulation of immune cells by dendritic cells (of leukemic derivation in AML patients or of monocyte derivation in healthy donors) leads to increased/leukemia-specific β7 expression in immune cells after T-cell-enriched mixed lymphocyte culture-finally leading to improved antileukemic cytotoxicity. Healthy, as well as AML and MDS patients' whole blood (WB) was treated with Kit-M (granulocyte-macrophage colony-stimulating factor (GM-CSF) + prostaglandin E1 (PGE1)) or Kit-I (GM-CSF + Picibanil) in order to generate DCs (DCleu or monocyte-derived DC), which were then used as stimulator cells in MLC. To quantify antigen/leukemia-specific/antileukemic functionality, a degranulation assay (DEG), an intracellular cytokine assay (INTCYT) and a cytotoxicity fluorolysis assay (CTX) were used. (Leukemia-specific) cell subtypes were quantified via flow cytometry. The Kit treatment of WB (compared to the control) resulted in the generation of DC/DCleu, which induced increased activation of innate and adaptive cells after MLC. Kit-pretreated WB (vs. the control) led to significantly increased frequencies of β7-expressing T-cells, degranulating and intracellular cytokine-producing β7-expressing immune cells and, in patients' samples, increased blast lysis. Positive correlations were found between the Kit-M-mediated improvement of blast lysis (vs. the control) and frequencies of β7-expressing T-cells. Our findings indicate that DC-based immune therapies might be able to specifically activate the immune system against blasts going along with increased frequencies of (leukemia-specific) β7-expressing immune cells. Furthermore, β7 might qualify as a predictor for the efficiency and the success of AML and/or MDS therapies.