Cell Receptor Research Articles

Abstract C011: The impact of reproductive factors on breast tumor and normal-adjacent tissue immune profile from menarche to menopause

Abstract Background: Reproductive factors and sex hormones are tightly linked to systemic immunity. However, no studies have examined whether reproductive factors and exogenous hormone use modulate the immune microenvironment of breast tissue. Methods: We prospectively evaluated the associations of reproductive factors (age at menarche, parity, age at first birth, age at menopause, and menopausal status) and exogenous hormone use (oral contraceptives, and menopausal hormone therapy (MHT)) with breast tumor and normal-adjacent tissue immune cell markers among 935 breast cancer cases in the Nurses’ Health Studies. We deconvoluted immune cell abundance using CIBERSORTx and derived gene expression signatures of markers for immune checkpoint (PD1, PDL1, and CTLA4), co-regulatory signal and antigen presentation (MHC class I/ II and T cell receptor) and mammary cytokine signaling (IFN gamma, IL2, IL4, IL12, IL13, TGF beta). Linear regression was used with adjustment for potential confounders. Results: Majority of participants had estrogen receptor (ER)-positive breast cancer (81%) and were post-menopausal at diagnosis (72%). Compared to tumors from pre-menopausal women, tumors from post-menopausal women had higher signature scores for tumor pro-inflammatory cytokine signaling (IFN gamma, IL2, IL4, IL12, IL13, TGF beta) and antigen presentation (FDR≤0.05). Several of the inflammatory cytokine signatures showed modest inverse relations with signatures of immune checkpoint markers (ρ=-0.3 to -0.4). Women who reported current use of estrogen only MHT had higher expression of CTLA4 in ER-positive breast tumors. For normal-adjacent tissues of ER-positive tumors, parity was associated with higher CD8+ T cell abundance, higher PDL1 expression and lower cytokine signaling in normal-adjacent tissues at p≤0.05; while breastfeeding was associated with lower abundance of CD8+ T cell and higher expression of cytokine signaling in normal-adjacent tissues of ER-negative tumors (p≤0.05). None of the associations in normal-adjacent tissues met FDR significance. The associations between other reproductive factors and immune cell profiles were in general weak. Conclusions: Our study suggests pre-diagnostic reproductive factors may influence breast tumor immune profiles. Future studies are needed to validate these results. Citation Format: Cheng Peng, Yuxi Liu, Yujing Heng, Clara Bodelon, Daniel Stover, Wendy Y. Chen, Michelle D. Holmes, A. Heather Eliassen, Peter Kraft, Rulla M. Tamimi. The impact of reproductive factors on breast tumor and normal-adjacent tissue immune profile from menarche to menopause [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C011.

Abstract B018: Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer

Abstract Colorectal cancer (CRC) ranks second in mortality and advanced CRCs are resistant to current immunotherapies and prone to metastasis, which necessitates research into enhancing innate and adaptive anti-cancer immune responses. Chronic inflammation mediated by cytokines like IL6 and notably, IL17 activates the oncogenic pathways in cancer cells, promoting sporadic and inflammatory CRC. What is unknown, is the ability of cytokines to control tumor microenvironment (TME) via cell type specific mechanisms to increase cancer progression, metastasis and/or therapy resistance. Increased levels of IL17A in CRC portends poor prognosis indicating its potential involvement into metastasis. However, the role of IL17 signaling in TME in the process of CRC progression and metastasis remains enigmatic. We utilized different models of CRC progression and metastasis, as well as variety of genetic mice models and therapeutic interventions. First, using a model of colitis-associated cancer we found that “late” IL17A neutralization decreases tumor burden, possibly acting through regulation of ferroptosis, NK cells mediated cytotoxicity, as well as myeloid cells and chemokine network essential for the control of immunosuppressive TME. Next, models of CRC metastasis, including those based on MC38 cells and APTAK cancerous organoids, showed that IL17A neutralization reduces metastasis growth. Also, FACS analysis revealed that IL17A promotes the recruitment of tumor- associated macrophages and other key myeloid subsets into the metastatic liver environment. Further research, using mice with conditional knockout of IL17RC receptor in myeloid cells (Il17rc f/f -LysMCre) or hepatocytes (Il17rc f/f -AlbCre) also showed significance of IL17 signaling activation in CRC metastasis through two distinct mechanisms. Employing different techniques, from FACS, immunohistochemistry, to RNAseq and scRNAseq data analysis, we observed that local hepatic activation of IL17RC signaling recruits neutrophils and reduces infiltration of cytotoxic CD8+T and NK cells to the metastatic niche supporting tumor growth, while myeloid IL17RC signaling reshapes TME, including macrophages and neutrophils, enhancing CRC metastasis. Our research indicates that IL17 signaling plays a multifaceted pathogenic role in CRC progression by operating in at least several cell types, providing new insights into the basic biology of CRC metastasis and potentially illuminating the design and improvement of CRC treatment strategies. Citation Format: Katarzyna Chojnacka, Katrina Mae Reyes, Hana Tomizawa, Sergei Grivennikov. Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B018.

Defective kinase activity of IKKα leads to combined immunodeficiency and disruption of immune tolerance in humans.

IKKα is a multifunctional serine/threonine kinase that controls various biological processes, either dependent on or independent of its kinase activity. However, the importance of the kinase function of IKKα in human physiology remains unknown since no biallelic variants disrupting its kinase activity have been reported. In this study, we present a homozygous germline missense variant in the kinase domain of IKKα, which is present in three children from two Turkish families. This variant, referred to as IKKαG167R, is in the activation segment of the kinase domain and affects the conserved (DF/LG) motif responsible for coordinating magnesium atoms for ATP binding. As a result, IKKαG167R abolishes the kinase activity of IKKα, leading to impaired activation of the non-canonical NF-κB pathway. Patients carrying IKKαG167R exhibit a range of immune system abnormalities, including the absence of secondary lymphoid organs, hypogammaglobulinemia and limited diversity of T and B cell receptors with evidence of autoreactivity. Overall, our findings indicate that, unlike a nonsense IKKα variant that results in early embryonic lethality in humans, the deficiency of IKKα's kinase activity is compatible with human life. However, it significantly disrupts the homeostasis of the immune system, underscoring the essential and non-redundant kinase function of IKKα in humans.

B cell adapter for PI 3-kinase (BCAP) coordinates antigen internalization and trafficking through the B cell receptor.

B cell adapter for PI 3-kinase (BCAP) is an adaptor molecule associated with signaling through multiple immune receptors, including the B cell receptor (BCR). However, B cell-intrinsic role of BCAP in antibody responses is unclear. We investigated the role of BCAP in B cell response to viral particles and found a previously unidentified mechanism by which BCAP regulates antigen-specific responses. B cell-specific deletion of BCAP in mice leads to decreases in antigen-specific responses through defects in BCR-antigen endocytosis. BCAP is necessary to orchestrate actin reorganization around the antigen for efficient endocytosis through BCR and intracellular processing of antigens. Therefore, loss of BCAP from B cells leads to defects in antigen endocytosis, hampering the propagation of antigen-derived signals and decreasing the ability of B cells to present antigens to T cells. Thus, our study clarifies how BCAP regulates B cell responses to complex antigens and elucidates that antigen positioning inside B cells determines different B cell activation outcomes.

Defective germinal center selection results in persistence of self-reactive B cells from the primary to the secondary repertoire in Primary Antiphospholipid Syndrome.

Primary antiphospholipid syndrome (PAPS) is a life-threatening clotting disorder mediated by pathogenic autoantibodies. Here we dissect the origin of self-reactive B cells in human PAPS using peripheral blood and bone marrow of patients with triple-positive PAPS via combined single-cell RNA sequencing, B cell receptors (BCR) repertoire profiling, CITEseq analysis and single cell immortalization. We find that antiphospholipid (aPL)-specific B cells are present in the naive compartment, polyreactive, and derived from the natural repertoire. Furthermore, B cells with aPL specificities are not eliminated in patients with PAPS, persist until the memory and long-lived plasma cell stages, likely after defective germinal center selection, while becoming less polyreactive. Lastly, compared with the non-PAPS cells, PAPS B cells exhibit distinct IFN and APRIL signature as well as dysregulated mTORC1 and MYC pathways. Our findings may thus elucidate the survival mechanisms of these autoreactive B cells and suggest potential therapeutic targets for the treatment of PAPS.

Mitophagy drives maldifferentiation of tissue-resident memory T cells in patients with rheumatoid arthritis

Objective To investigate the function of mitophagy in instructing T-cell differentiation of patients with rheumatoid arthritis (RA). Method The mRNA and protein levels of optic atrophy protein-1 were detected in T cells from 94 RA patients and 37 age- and sex-matched healthy individuals by quantitative polymerase chain reaction and Western blotting. The impact of mitophagy on the differentiation of T cells was determined by flow cytometry. The therapeutic effect of targeting mitophagy was explored in humanized RA chimeras. Results Our study showed that T cells exerted high levels of mitophagy in RA patients. Since multiple T-cell subtypes play crucial roles in RA, we determined that mitophagy had a significant impact on the differentiation of tissue-resident memory T (Trm) cells, but not Th1 or Th17 cells. Importantly, we demonstrated that inhibiting mitophagy significantly reduced the number of Trm cells and downregulated inflammatory responses, as evidenced by diminished levels of T cell receptor β, interferon-γ, and interleukin-17A, in the humanized RA chimeras. Conclusions Mitophagy is elevated in RA T cells, leading to maldifferentiation of Trm cells in RA patients. Since these findings were obtained from clinical patients, mitophagy may be a potential therapeutic target for RA treatment.

The potential of lactoferrin as antiviral and immune-modulating agent in viral infectious diseases

Emerging infectious diseases are caused by unpredictable viruses with the dangerous potential to trigger global pandemics. These viruses typically initiate infection by utilizing the anionic structures of host cell surface receptors to gain entry. Lactoferrin (Lf) is a multifunctional glycoprotein with multiple properties such as antiviral, anti-inflammatory and antioxidant activities. Due to its cationic structure, Lf naturally interacts with certain host cell receptors, such as heparan sulfate proteoglycans, as well as viral particles and other receptors that are targeted by viruses. Therefore, Lf may interfere with virus-host cell interactions by acting as a receptor competitor for viruses. Herein we summarize studies in which this competition was investigated with SARS-CoV-2, Zika, Dengue, Hepatitis and Influenza viruses in vitro. These studies have demonstrated not only Lf’s competitive properties, but also its potential intracellular impact on host cells, such as enhancing cell survival and reducing infection efficiency by inhibiting certain viral enzymes. In addition, the immunomodulatory effect of Lf is highlighted, as it can influence the activity of specific immune cells and regulate cytokine release, thereby enhancing the host’s response to viral infections. Collectively, these properties promote the potential of Lf as a promising candidate for research in viral infectious diseases.

Technical challenges of intracellular flow cytometry-based assays as a functional complement to diagnosis of signaling defects of inborn errors of immunity: PI3K pathway as a case of study

BackgroundThe use of next-generation sequencing in inborn errors of immunity (IEI) has considerably increased the identification of novel gene variants, many of which are identified in patients without the described clinical phenotype or with variants of uncertain pathogenic significance in previously described genes. Properly designed functional and cellular assays, many necessarily accomplished by research-based laboratories, reveal the pathogenic consequences of the gene variants and contribute to diagnosis. Activated PI3Kδ syndrome (APDS) is a rare disease that can be divided into APDS1, caused by gain of function (GOF) mutations in PIK3CD gene, and APDS2, with loss of function (LOF) variants in the PIK3R1 gene. Both entities present hyperactivation of the PI3K pathway, which can be analyzed through Akt and S6 phosphorylation status.MethodsOur objective was to perform an accurate, robust, and reproducible functional assay to analyze the phosphorylation status of proteins in the PI3K-Akt-S6 pathway by flow cytometry, to contribute to diagnosis, to monitor treatments, and to establish intra-assay standardization.ResultsWe illustrate the robustness and reproducibility of our experimental procedure in patients with APDS who had high Akt and/or S6 phosphorylation levels at baseline, and after anti-IgM stimulation in B cells. We show the relevance of an appropriate cohort of samples from healthy donors, processed within the same conditions as the suspected samples, in particular the time frame for sample processing once blood is collected.DiscussionWe highlight the importance of B cell stimulation through B cell receptor signaling, which is highly recommended, especially for samples that would be processed more than 24 hours after blood extraction. Also, having a defined experimental procedure is important, including the cytometer setup, which allows cytometer reproducibility for a period of time, enabling the comparison of a sample at different times.

Single cell RNA-sequencing of feline peripheral immune cells with V(D)J repertoire and cross species analysis of T lymphocytes

IntroductionThe domestic cat (Felis catus) is a valued companion animal and a model for virally induced cancers and immunodeficiencies. However, species-specific limitations such as a scarcity of immune cell markers constrain our ability to resolve immune cell subsets at sufficient detail. The goal of this study was to characterize circulating feline T cells and other leukocytes based on their transcriptomic landscape and T-cell receptor repertoire using single cell RNA-sequencing.MethodsPeripheral blood from 4 healthy cats was enriched for T cells by flow cytometry cell sorting using a mouse anti-feline CD5 monoclonal antibody. Libraries for whole transcriptome, αβ T cell receptor transcripts and γδ T cell receptor transcripts were constructed using the 10x Genomics Chromium Next GEM Single Cell 5’ reagent kit and the Chromium Single Cell V(D)J Enrichment Kit with custom reverse primers for the feline orthologs.ResultsUnsupervised clustering of whole transcriptome data revealed 7 major cell populations - T cells, neutrophils, monocytic cells, B cells, plasmacytoid dendritic cells, mast cells and platelets. Sub cluster analysis of T cells resolved naive (CD4+ and CD8+), CD4+ effector T cells, CD8+ cytotoxic T cells and γδ T cells. Cross species analysis revealed a high conservation of T cell subsets along an effector gradient with equitable representation of veterinary species (horse, dog, pig) and humans with the cat. Our V(D)J repertoire analysis identified a subset of CD8+ cytotoxic T cells with skewed TRA and TRB gene usage, conserved TRA and TRB junctional motifs, restricted TRA/TRB pairing and reduced diversity in TRG junctional length. We also identified a public γδ T cell subset with invariant TRD and TRG chains and a CD4+ TEM-like phenotype. Among monocytic cells, we resolved three clusters of classical monocytes with polarization into pro- and anti-inflammatory phenotypes in addition to a cluster of conventional dendritic cells. Lastly, our neutrophil sub clustering revealed a larger mature neutrophil cluster and a smaller exhausted/activated cluster.DiscussionOur study is the first to characterize subsets of circulating T cells utilizing an integrative approach of single cell RNA-sequencing, V(D)J repertoire analysis and cross species analysis. In addition, we characterize the transcriptome of several myeloid cell subsets and demonstrate immune cell relatedness across different species.

Staphylococcal superantigens evoke temporary and reversible T cell anergy, but fail to block the development of a bacterium specific cellular immune response.

Superantigens (sAgs) are bacterial virulence factors that induce a state of immune hyperactivation by forming a bridge between certain subsets of T cell receptor (TCR) β chains on T lymphocytes, and class II major histocompatibility complex (MHC-II) molecules; this cross-linking leads to indiscriminate T cell activation, cytokine storm and toxic shock. Here we show that sAg exposure drives the preferential expansion of naive and central memory T cell subsets, but not effector or resident memory T cells, which instead, hyper release pro-inflammatory cytokines. A targeted therapeutic approach to minimise cytokine release by effector memory T cells attenuated sAg-induced cytokine release. Irrespective of antigen experience, sAg activation does not render mature T cells permanently dysfunctional, and full restoration of effector function is observed following a transient and reversible anergy. Moreover, we show that in the face of sAg induced immune hyperactivation, an intact bacterium-specific CD4+ T cell response can be mounted.

Extracellular ATP Release Triggered by 131I-Trastuzumab Mitigates Radiation-Induced Reduction in Cell Viability through the P2Y6 Receptor in SKOV3 Cells.

Intracellular ATP is released outside cells by various stimuli and is involved in cytoprotection by activating purinergic receptors. However, it remains unclear whether targeted radionuclide therapy induces extracellular ATP release. Here, we prepared 131I-labeled trastuzumab (131I-trastuzumab) and examined extracellular ATP release and its roles in 131I-trastuzumab's growth inhibitory effects. 131I-trastuzumab was prepared by labeling with the chloramine-T method. The binding of 131I-trastuzumab to cells was investigated using the human epidermal growth factor receptor 2 (HER2)-positive cells (SKOV3) and the HER2-negative cell (MCF7). Extracellular ATP was determined by measuring chemiluminescence using a luciferin-luciferase reagent. The growth inhibitory effects of 131I-trastuzumab were investigated by colony formation assay. 131I-trastuzumab bound exclusively to SKOV3 cells. Treatment with 131I-trastuzumab at 4 MBq/mL and higher concentrations significantly increased extracellular ATP levels, whereas non-radioactive trastuzumab didn't. This suggested that ATP release was specifically induced by radiation derived from 131I. The growth inhibitory effects of 131I-trastuzumab were significantly enhanced by pretreatment with apyrase (ecto-ATPase) or MRS2578 (a P2Y6-selective antagonist), whereas they were significantly reduced by treatment with a P2Y6-selective agonist. In conclusion, 131I-trastuzumab induced extracellular ATP release, and the released ATP was shown to be involved in mitigating radiation-induced reduction in cell viability through P2Y6 receptor.

The Immunologic Downsides Associated with the Powerful Translation of Current COVID-19 Vaccine mRNA Can Be Overcome by Mucosal Vaccines

The action of mRNA-based vaccines requires the expression of the antigen in cells targeted by lipid nanoparticle–mRNA complexes. When the vaccine antigen is not fully retained by the producer cells, its local and systemic diffusion can have consequences depending on both the levels of antigen expression and its biological activity. A peculiarity of mRNA-based COVID-19 vaccines is the extraordinarily high amounts of the Spike antigen expressed by the target cells. In addition, vaccine Spike can be shed and bind to ACE-2 cell receptors, thereby inducing responses of pathogenetic significance including the release of soluble factors which, in turn, can dysregulate key immunologic processes. Moreover, the circulatory immune responses triggered by the vaccine Spike is quite powerful, and can lead to effective anti-Spike antibody cross-binding, as well as to the emergence of both auto- and anti-idiotype antibodies. In this paper, the immunologic downsides of the strong efficiency of the translation of the mRNA associated with COVID-19 vaccines are discussed together with the arguments supporting the idea that most of them can be avoided with the advent of next-generation, mucosal COVID-19 vaccines.

Cell Division Cycle 42 Improves Renal Functions, Fibrosis, Th1/Th17 Infiltration and Inflammation to Some Degree in Diabetic Nephropathy.

Our two previous studies observed that cell division cycle 42 (CDC42) was lower and correlated with improved renal function and inflammation in diabetic nephropathy (DN) patients, and CDC42 inhibited renal tubular epithelial cell fibrosis and inflammation under high glucose condition. Sequentially, this current study aimed to investigate the effect of CDC42 on improving renal function, fibrosis, and inflammation in DN mice, and its interaction with T cell receptor (TCR) related pathways. Mice were treated by streptozotocin to construct early-stage DN model, then transfected with CDC42 overexpression adenovirus, followed by simultaneous treatment of LY294002 (PI3K/AKT inhibitor) and CI-1040 (ERK inhibitor), respectively. CDC42 reduced blood glucose, creatinine, and 24h urine protein in DN mice, but only showed a tendency to decrease blood urea nitrogen without statistical significance. Hematoxylin&eosin staining revealed that CDC42 descended the glomerular volume, basement membrane thickness, and inflammatory cell infiltration in kidney. Meanwhile, CDC42 lowered fibronectin, TGF-β1, and Collagen I expressions in kidney, but not decreased α-SMA significantly. Besides, CDC42 decreased T-helper (Th) 1 and Th17 cells in kidney, and reduced serum IFN-γ, IL-1β, IL-17A, and TNF-α but not IL-6. Regarding TCR-related pathways, CDC42 activated AKT and ERK pathways but not JNK pathway. However, the treatment of LY294002 and CI-1040 had limited effect on attenuating CDC42's functions on renal function and fibrotic markers. CDC42 improves renal functions, fibrosis, Th1/Th17 infiltration and inflammation to some degree in DN mice, these functions may be independent to AKT and ERK pathways.

MS O03 - HPB Vitamin D deficiency and Survival in Pancreatic Ductal Adenocarcinoma Patients Who Received Adjuvant Chemotherapy

Abstract Background It is proposed that vitamin D contributes to reducing inflammation and tumour size by binding to vitamin D receptors (VDR) of pancreatic cancer cells, which activates response pathway thus enhancing delivery of intracellular chemotherapy. As vitamin D is a fat-soluble vitamin, individuals with pancreatic ductal adenocarcinoma (PDAC) are at risk of being vitamin D deficient due to the high prevalence of pancreatic exocrine insufficiency (PEI). We investigated the relationship between vitamin D deficiency and survival outcomes of patients with PDAC. Method Patients who had resected PDAC at Queen Elizabeth Hospital Birmingham between 2014-2020 were reviewed. Patients who died within 90 days of the operation were excluded. Patient demographics, pre-operative vitamin D levels, adjuvant chemotherapy (AC) details and survival outcomes were collected. Vitamin D deficiency was defined as the serum 25-hydroxyvitamin D (25(OH)D) level of less than 25 nmol/L. Results 202 patients were identified, of whom 63 (31%) were vitamin D deficient. Among 151 patients who received AC, 48 (32%) were vitamin D deficient. Patient demographics were comparable between the AC and non-AC groups, except age, which was higher in the non-AC group (p<0.01)(Table 1). OS and DFS were significantly reduced in patients with vitamin D deficiency compared to those with sufficient vitamin D levels (p< 0.05). This trend was also observed in the AC subgroup. However, no significant differences in OS and DFS were found between vitamin D deficient and sufficient patients in the non-AC subgroup (Table 2). Conclusion Vitamin D deficiency is associated with lower OS and DFS, particularly in patients receiving adjuvant chemotherapy (AC). The greater survival outcomes observed in the AC group suggests that vitamin D enhances chemotherapy efficacy. Further studies are required to explore the cellular interactions between vitamin D and PDAC.

AI Promoted Virtual Screening, Structure-Based Hit Optimization, and Synthesis of Novel COVID-19 S-RBD Domain Inhibitors.

Coronavirus disease 2019 (COVID-19) is caused by a new, highly pathogenic severe-acute-respiratory syndrome coronavirus 2 (SARS-CoV-2) that infects human cells through its transmembrane spike (S) glycoprotein. The receptor-binding domain (RBD) of the S protein interacts with the angiotensin-converting enzyme II (ACE2) receptor of the host cells. Therefore, pharmacological targeting of this interaction might prevent infection or spread of the virus. Here, we performed a virtual screening to identify small molecules that block S-ACE2 interaction. Large compound libraries were filtered for drug-like properties, promiscuity and protein-protein interaction-targeting ability based on their ADME-Tox descriptors and also to exclude pan-assay interfering compounds. A properly designed AI-based virtual screening pipeline was applied to the remaining compounds, comprising approximately 10% of the starting data sets, searching for molecules that could bind to the RBD of the S protein. All molecules were sorted according to their screening score, grouped based on their structure and postfiltered for possible interaction patterns with the ACE2 receptor, yielding 31 hits. These hit molecules were further tested for their inhibitory effect on Spike RBD/ACE2 (19-615) interaction. Six compounds inhibited the S-ACE2 interaction in a dose-dependent manner while two of them also prevented infection of human cells from a pseudotyped virus whose entry is mediated by the S protein of SARS-CoV-2. Of the two compounds, the benzimidazole derivative CKP-22 protected Vero E6 cells from infection with SARS-CoV-2, as well. Subsequent, hit-to-lead optimization of CKP-22 was effected through the synthesis of 29 new derivatives of which compound CKP-25 suppressed the Spike RBD/ACE2 (19-615) interaction, reduced the cytopathic effect of SARS-CoV-2 in Vero E6 cells (IC50 = 3.5 μM) and reduced the viral load in cell culture supernatants. Early in vitro ADME-Tox studies showed that CKP-25 does not possess biodegradation or liver metabolism issues, while isozyme-specific CYP450 experiments revealed that CKP-25 was a weak inhibitor of the CYP450 system. Moreover, CKP-25 does not elicit mutagenic effect on Escherichia coli WP2 uvrA strain. Thus, CKP-25 is considered a lead compound against COVID-19 infection.

Abstract A008: Adaptive immune receptor repertoire characterization highlights the importance of interplay between B and T cells in disease progression

Abstract Understanding the adaptive immune system is integral to disease progression studies, development of diagnostic biomarkers, identification of therapeutic targets, and discerning varied treatment responses. Despite growing interest in profiling B and T cells in cancer research, the interaction between these cells and also the crucial roles of γδ T cells often go overlooked. In this research project, we explored the role of crucial yet frequently ignored γδ T cells in cancer research, using immune repertoire data from bladder cancer patients. We also studied the synergy between B and T cells in the immune repertoires of COVID-19 patients.Roche has developed immunoPETE (immune repertoire Primer Extension Target Enrichment), a DNA- based target enrichment assay to capture adaptive immune repertoire data*. immunoPETE efficiently identifies the heavy chains of B cells, alongside αβ and γδ T cells in one reaction, facilitating normalized clone counts across the adaptive immune system. To explore the significance of γδ T cells, we profiled the immune repertoires of 24 Non-Muscle Invasive Bladder Cancer patients treated with Bacillus Calmette-Guerin (BCG). Additionally, we evaluated the interplay between B and T cells in 117 peripheral blood immune repertoire from healthy and COVID-19 afflicted individuals, ranging from mild to severe cases.Immune repertoire data analysis indicates that underrepresentation of T cell receptor delta locus (TRD) is associated with higher risk of bladder cancer recurrence or progress. Urine pellet DNA was available for a subset of the patients in this study. Comparing immune repertoires from PBMC and urine revealed that urine repertoires represent the tumor repertoire more accurately than PBMC. Analysis of the immune repertoires from the COVID-19 patients linked disease severity with immune repertoire measures across all three cell types, highlighting the importance of multiple lymphocyte classes in disease progression. Using immunoPETE technology, which is capable of capturing the heavy chain of multiple immune cell types simultaneously in a single reaction, we have demonstrated that both B cell and T cell compartments provide distinct and valuable information in cancer and infectious diseases, each responding uniquely to the disease. Additionally, we emphasized the significance of γδ T cells in predicting cancer prognosis. Note: immunoPETE is for Research Use Only. Not for use in diagnostic procedures. Citation Format: Hossein Asgharian, Hamid Mirebrahim, Dilduz Telman, Hahn Zhao, Ulrich Schlecht, Sylvie McNamara, Rajiv Dua, Jan Berka, Patrick Bogard, Dinesh Kumar. Adaptive immune receptor repertoire characterization highlights the importance of interplay between B and T cells in disease progression [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A008.

FoxO1 signaling in B cell malignancies and its therapeutic targeting.

FoxO transcription factors (FoxO1, FoxO3a, FoxO4, FoxO6) are a highly evolutionary conserved subfamily of the 'forkhead' box proteins. They have traditionally been considered tumor suppressors, but FoxO1 also exhibits oncogenic properties. The complex nature of FoxO1 is illustrated by its various roles in B cell development and differentiation, immunoglobulin gene rearrangement and cell-surface B cell receptor (BCR) structure, DNA damage control, cell cycle regulation, and germinal center reaction. FoxO1 is tightly regulated at a transcriptional (STAT3, HEB, EBF, FoxOs) and post-transcriptional level (Akt, AMPK, CDK2, GSK3, IKKs, JNK, MAPK/Erk, SGK1, miRNA). In B cell malignancies, recurrent FoxO1 activating mutations (S22/T24) and aberrant nuclear export and activity have been described, underscoring the potential of its therapeutic inhibition. Here, we review FoxO1's roles across B cell and myeloid malignancies, namely acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), mantle cell lymphoma (MCL), Burkitt lymphoma (BL), Hodgkin lymphoma (HL), and multiple myeloma (MM). We also discuss preclinical evidence for FoxO1 targeting by currently available inhibitors (AS1708727, AS1842856, cpd10).

In utero human cytomegalovirus infection expands NK-like FcγRIII+ CD8+ T cells that mediate Fc antibody functions.

Human cytomegalovirus (HCMV) profoundly impacts host T and natural killer (NK) cells across the lifespan, yet how this common congenital infection modulates developing fetal immune cell compartments remains underexplored. Using cord blood from neonates with and without congenital HCMV (cCMV) infection, we identify an expansion of Fcγ receptor III (FcγRIII)-expressing CD8+ T cells following HCMV exposure in utero. Most FcγRIII+ CD8+ T cells express the canonical αβ T cell receptor (TCR) but a proportion express non-canonical γδ TCR. FcγRIII+ CD8+ T cells are highly differentiated and have increased expression of NK cell markers and cytolytic molecules. Transcriptional analysis reveals FcγRIII+ CD8+ T cells upregulate T-bet and downregulate BCL11B, known transcription factors that govern T/NK cell fate. We show that FcγRIII+ CD8+ T cells mediate antibody-dependent IFNγ production and degranulation against IgG-opsonized target cells, similar to NK cell antibody-dependent cellular cytotoxicity (ADCC). FcγRIII+ CD8+ T cell Fc effector functions were further enhanced by interleukin-15 (IL-15), as has been observed in neonatal NK cells. Our study reveals that FcγRIII+ CD8+ T cells elicited in utero by HCMV infection can execute Fc-mediated effector functions bridging cellular and humoral immunity and may be a promising target for antibody-based therapeutics and vaccination in early life.

Abstract 4136727: The role of immune mechanism in Immune Checkpoint Inhibitor-Associated Myocarditis: seeking key genes

Background: Immune checkpoint inhibitors (ICIs) are extensively employed in cancer treatment; however, the development of ICI-associated myocarditis (ICI-MC) introduces a severe and potentially fatal complication with elusive pathophysiological mechanisms. This study aimed to pinpoint pivotal immune-related genes in ICI-MC and unveil potential therapeutic targets using bioinformatics. Methods: Utilizing the GSE180045 dataset (comprising three groups: Group A - ICI patients without immune adverse events, Group B - ICI patients with non-myocarditis immune adverse events, Group C - ICI patients with myocarditis), we scrutinized differentially expressed genes (DEGs) between ICI-MC samples (Group C) and non-myocarditis controls (Group A&B). These DEGs were cross-referenced with 1796 immune-related genes (IRGs) from the immPort database to derive IR-DEGs. We conducted functional enrichment analyses (GO, KEGG, GSEA), constructed a PPI network, and identified hub genes. Validation was performed using the GSE4172 dataset, and optimal feature genes (OFGs) were identified from the overlap of hub genes and validation DEGs. Predictions of target miRNAs were made, and a ceRNA network was constructed. Target drugs for hub genes were forecasted using the cMAP database. Results: We pinpointed 58 DEGs between ICI-MC and controls, leading to the identification of 32 IR-DEGs after intersecting with 1796 IRGs. Functional analyses revealed enrichment in cell lysis, CD8+ T cell receptor, natural killer cell-mediated cytotoxicity, and RAGE signaling. Up-regulated hub genes (IL7R, PRF1, GNLY, CD3G, NKG7, GZMH, GZMB, KLRB1, KLRK1, CD247) were highlighted. In the validation dataset, 407 DEGs were uncovered, resulting in the identification of 3 OFGs (KLRB1, NKG7, GZMH). Predicted target miRNAs, lincRNAs, and circRNAs formed a comprehensive ceRNA network. The top 10 drugs with elevated connectivity scores included acetohydroxamic-acid, suggesting caution in ICI treatment. Conclusion: NKG7, GZMH, and KLRB1 emerged as pivotal immune-related genes in ICI-MC. Biological enrichments encompassed cell lysis, CD8+ T cell receptor pathway, natural killer cell-mediated cytotoxicity, RAGE signaling, and proinflammatory pathways. The ceRNA network shed light on critical molecules, emphasizing the need to avoid drugs like acetohydroxamic-acid in ICI treatment.

Abstract 4120749: GPR39 Orchestrates the Myogenic Response in Coronary Autoregulation

Background: Coronary autoregulation is the ability of a normal heart to maintain constant coronary blood flow (CBF) over a wide range of coronary driving pressures (CDPs) provided cardiac work remains constant. It is based on the myogenic response, the molecular mechanism of which is unknown. We recently described the presence of a G-protein coupled receptor (GPR39) in the vascular smooth muscle cells (VSMCs) of coronary arterioles in the mouse heart. We showed that endogenous eicosanoids, the vasoconstrictor 15-hydroxyeicosatetraenoic acid (15-HETE) and the vasodilator 14,15-epoxyeicosatrienoic acid (14,15 EET). act through this receptor to maintain coronary vascular tone. Hypothesis: We, therefore, hypothesized that GPR39 is the molecular switch responsible for the coronary myogenic response and autoregulation. Methods: We studied 6 anesthetized dogs at baseline and after administration of VC-108, a specific, potent GPR39 antagonist. Both during baseline and drug administration multiple coronary stenoses were created on the left anterior descending coronary artery (LAD). At each stage, heart rate, mean aortic pressure, distal LAD pressure, and right atrial pressure (RAP) were measured, as was CBF. Stenosis severity was defined by the CDP (LAD pressure minus RAP). Results: Mean basal coronary hyperemic response was 3.0 in all anesthetized animals indicating normal vasomotor function. Systemic hemodynamics did not differ between baseline and drug stages. Figure 1 is an example from a single dog where, at baseline, CBF remained constant over a CDP of 40-90 mm Hg indicating intact autoregulation. As expected, CBF declined when CDP fell below the autoregulatory range. After VC-108 administration CBF correlated linearly with CDP, indicating abolishment of the myogenic response. Baseline CDP vs. CBF data from all 6 animals within the autoregulatory range is depicted in Figure 2. No relation is noted between the two indicating intact autoregulation. In contrast, CDP vs. CBF relation is linear in all animals after VC108 is administered over the entire range of CDP’s measured, indicating abolishment of autoregulation (Figure 3). Conclusions: Our results indicate that GPR39 is a potential molecular switch for the regulation of the myogenic response underlying coronary autoregulation. Pharmacological blockage of GPR39 abolishes the myogenic tone. These novel findings set the stage for development of novel pharmacological agents for treatment of coronary artery disease.