CD4 Th Cells Research Articles

Coronavirus disease 2019-related myocardial injury is associated with immune dysregulation in symptomatic patients with cardiac magnetic resonance imaging abnormalities.

While acute cardiovascular complications of coronavirus disease 2019 (COVID-19) are well described, less is known about longer-term cardiac sequelae. For many individuals with cardiac signs or symptoms arising after COVID-19 infection, the aetiology remains unclear. We examined immune profiles associated with magnetic resonance imaging (MRI) abnormalities in patients with unexplained cardiac injury after COVID-19. Twenty-one participants {mean age 47 [standard deviation (SD) 13] years, 71% female} with long COVID-19 (n = 17), raised troponin (n = 2), or unexplained new-onset heart failure (n = 2), who did not have pre-existing heart conditions or recent steroid/immunosuppression treatment, were enrolled a mean 346 (SD 191) days after COVID-19 infection in a prospective observational study. Cardiac MRI and blood sampling for deep immunophenotyping using mass cytometry by time of flight and measurement of proteomic inflammatory markers were performed. Nine of the 21 (43%) participants had MRI abnormalities (MRI(+)), including non-ischaemic patterns of late gadolinium enhancement and/or visually overt myocardial oedema in 8 people. One patient had mildly impaired biventricular function without fibrosis or oedema, and two had severe left ventricular (LV) impairment. MRI(+) individuals had higher blood CCL3, CCL7, FGF-23, and CD4 Th2 cells, and lower CD8 T effector memory (TEM) cells, than MRI(-). Cluster analysis revealed lower expression of inhibitory receptors PD1 and TIM3 in CD8 TEM cells from MRI(+) patients than MRI(-) patients, and functional studies of CD8 T αβ cells showed higher proportions of cytotoxic granzyme B+(GZB+)-secreting cells upon stimulation. CD8 TEM cells and CCL7 were the strongest predictors of MRI abnormalities in a least absolute shrinkage and selection operator regression model (composite area under the curve 0.96, 95% confidence interval 0.88-1.0). CCL7 was correlated with diffuse myocardial fibrosis/oedema detected by quantitative T1 mapping (r = 0.47, P = 0.04). COVID-19-related cardiac injury in symptomatic patients with non-ischaemic myocarditis-like MRI abnormalities is associated with immune dysregulation, including decreased peripheral CD8 TEM cells and increased CCL7, persisting long after the initial infection.

A pathological joint–liver axis mediated by matrikine-activated CD4+ T cells

The knee joint has long been considered a closed system. The pathological effects of joint diseases on distant organs have not been investigated. Herein, our clinical data showed that post-traumatic joint damage, combined with joint bleeding (hemarthrosis), exhibits a worse liver function compared with healthy control. With mouse model, hemarthrosis induces both cartilage degeneration and remote liver damage. Next, we found that hemarthrosis induces the upregulation in ratio and differentiation towards Th17 cells of CD4+ T cells in peripheral blood and spleen. Deletion of CD4+ T cells reverses hemarthrosis-induced liver damage. Degeneration of cartilage matrix induced by hemarthrosis upregulates serological type II collagen (COL II), which activates CD4+ T cells. Systemic application of a COL II antibody blocks the activation. Furthermore, bulk RNAseq and single-cell qPCR analysis revealed that the cartilage Akt pathway is inhibited by blood treatment. Intra-articular application of Akt activator blocks the cartilage degeneration and thus protects against the liver impairment in mouse and pig models. Taken together, our study revealed a pathological joint–liver axis mediated by matrikine-activated CD4+ T cells, which refreshes the organ-crosstalk axis and provides a new treatment target for hemarthrosis-related disease.Intra-articular bleeding induces cartilage degradation through down-reulation of cartilage Akt pathway. During this process, the soluble COL II released from the damaged cartilage can activate peripheral CD4+ T cells, differention into Th17 cells and secretion of IL-17, which consequently induces liver impairment. Intra-articular application of sc79 (inhibitor of Akt pathway) can prevent the cartilage damage as well as its peripheral influences.

Natural antibodies drive type 2 immunity in response to damage-associated molecular patterns.

Allergic airway disease (AAD) is an example of type 2 inflammation that leads to chronic airway eosinophilia controlled by CD4 Th2 cells. Inflammation is reinforced by mast cells and basophils armed with allergen-specific IgE made by allergen-specific B2 B cells of the adaptive immune system. Little is known about how AAD is affected by innate B1 cells, which produce natural antibodies (NAbs) that facilitate apoptotic cell clearance and detect damage- and pathogen-associated molecular patterns (DAMPS and PAMPS). We used transgenic mice lacking either B cells or NAbs in distinct mouse models of AAD that require either DAMPS or PAMPS as the initial trigger for type 2 immunity. In a DAMP-induced allergic model, driven by alum and uric acid, mouse strains lacking B cells (CD19DTA), NAbs (IgHEL MD4), or all secreted antibodies (sIgm-/-Aid-/-) displayed a significant reduction in both eosinophilia and Th2 priming compared with WT or Aid-/- mice lacking only germinal center-dependent high-affinity class-switched antibodies. Replenishing B cell-deficient mice with either unimmunized B1 B cells or NAbs during sensitization restored eosinophilia, suggesting that NAbs are required for licensing antigen-presenting cells to prime type 2 immunity. Conversely, PAMP-dependent type 2 priming to house dust mite or Aspergillus was not dependent on NAbs. This study reveals an underappreciated role of B1 B cell-generated NAbs in selectively driving DAMP-induced type 2 immunity.

Abstract B038: CD4Th1 cytokine interferon gamma regulates genome profiles and inhibits tumorigenesis of disseminated cancer cells in breast cancer

Abstract Detection and persistence of disseminated cancer cells (DCCs) in the bone marrow (BM) of breast cancer (BC) patients has been identified as a primary source for late recurrence and distant metastasis in multiple organs and the central nervous system. Selective targeting and eradication of DCCs in BM can be of a significant advantage to prevent future recurrence and enhance disease-free survival in BC patients. Unfortunately, no such targeted therapy presently exists. Instead, intense chemotherapy in the adjuvant or neoadjuvant setting are given with the ultimate goal to prevent DCC-driven metastasis in these patients. Clinical studies have confirmed that DCCs have not been effectively eradicated by conventional chemotherapies. DCCs express unique gene signatures that differ from circulating tumor cells (CTC) in BC, but only limited knowledge is available for the genome profiles of DCCs compared to primary and metastatic lesions in BC patients. Here we investigated the detailed gene expression profiles of DCCs compared to primary and metastatic lesions from a murine spontaneous metastasis model and BC patients. Using a two-step immunomagnetic enrichment assay, we were able to successfully isolate highly enriched EpCAM+ DCCs from both the BM aspirates of HER2+ early BC patients and BALB-HER2/neu transgenic (BALB-neuT) spontaneous metastasis mice. RNA sequencing revealed that DCCs from HER2+ BC patients and BALB-neuT mice displayed remarkably similar genomic expression profiles, but both had substantially different profiles when comparing to primary and metastatic lesions. We identified highly enriched signatures in DCCs associated with cancer stemness, epithelial to mesenchymal transition (EMT), cell cycle, cell adhesion, progesterone signaling and cholesterol biosynthesis. Notably, these DCCs showed loss of MHC class I, MHC class II, and CD1d expression leading to a defect in antigen presentation machinery and their subsequent escape from CD4 T, CD8 T, B and NKT-cell mediated clearance. Interestingly, we observed for the first time that anti-tumor CD4Th1 cells, through interferon gamma (IFN-γ) production, upregulated CD1d, MHC class I and II expressions in DCCs leading to high infiltration of CD4Th1, NKT and B cells into the BM to selectively target and eliminate DCC burden. IFN-γ remarkably downregulated stemness, EMT, self-renewing potential and their genome signatures and induced apoptosis and irreversible senescence in DCCs of HER2+ BC patients. Notably, these IFN-γ treated patient DCCs lost their ability to grow into tumors in an immunodeficient NSG mouse model. Collectively, these results provide a detailed genome profile of DCCs from HER2+ BC patients and a novel role for anti-tumor CD4Th1 response in inhibiting DCC-driven tumorigenesis and metastasis. Citation Format: Ganesan Ramamoorthi, Marie Catherine Lee, Krithika Kodumudi, Colin Snyder, Namrata Gautam, Saurabh K. Garg, Shari Pilon-Thomas, Brian Czerniecki. CD4Th1 cytokine interferon gamma regulates genome profiles and inhibits tumorigenesis of disseminated cancer cells in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B038.

Examining the spatial distribution of tumor-infiltrating immune cells in patients with stage I to IIIA LUAD.

This study aimed to examine the spatial distribution of immune cells by application of Gcross function in 170 patients with stage I to IIIA lung adenocarcinoma (LUAD) and explore its prognostic value. A total of 170 stage I to IIIA LUAD patients who underwent radical surgery were enrolled. Paraffinized tumor sections were collected for 2 panels of multicolor immunofluorescence staining (panel 1: CD4, CD8, FOXP3, CD69, CD39, CD73, and DAPI; panel 2: CD68, CD163, CD20, CD11c, PDL1, IDO, and DAPI). The immune cells were categorized as CD8+, CD4+ T helper cell (CD4Th), regulatory T cell, macrophage type 1 (M1), M2, dendritic cell (DC), and B cell. The immune cell numbers were enumerated, and the immune cell proximity score was calculated employing the Gcross function. The correlation between immune cell variables and disease-free survival (DFS) was explored through univariate Cox regression analyses. Factors with P < 0.05 were subjected to multivariate analyses. According to univariate Cox regression analyses, total PDL1+ and PDL1+ DC counts were negative factors (P = 0.003 and 0.031, respectively). CD4Th and IDO-DC counts were positive factors (P = 0.022 and 0.024, respectively). The proximity score (M1 to M2) was a positive factor for DFS (P = 0.032), and the proximity score (PDL1 + DC to M1) was a negative factor (P = 0.009) according to univariate Cox analyses. In multivariate analyses, stage (IIIA vs I + II) (hazard ratio [HR]: 1.77 [95% confidence interval (CI): 1.18-2.64], P = 0.006) and proximity score (PDL1 + DC to M1) (HR: 1.60 [95% CI: 1.07-2.37], P = 0.021) were independent negative factors and CD4Th counts (HR: 0.60 [95% CI: 0.40-0.90], P = 0.013) was an independent positive factor. Our study indicated that a higher level of tumor-infiltrating CD4Th cells predicted longer DFS, and a closer proximity of PDL1+ DCs to M1 cells was associated with dismal DFS in stage I to IIIA LUAD patients.

CD8 T cells are dispensable for experimental autoimmune prostatitis induction and chronic pelvic pain development.

Chronic Pelvic Pain Syndrome or Chronic Prostatitis (CPPS/CP) is the most prevalent urologic affliction among young adult men. It is a challenging condition to treat, which significantly decreases patient quality of life, mostly because of its still uncertain aetiology. In that regard, an autoimmune origin is a prominent supported theory. Indeed, studies in patients and in rodent models of Experimental Autoimmune Prostatitis (EAP) have provided compelling evidence suggesting a key role of CD4 Th1 cells in disease pathogenesis. However, the implication of other prominent effectors of the immune system, such as CD8 T cells, has yet to be studied. We herein analyzed the induction of prostatitis and the development of chronic pelvic pain in EAP using CD8 T cell-deficient animals. We found similarly elevated PA-specific immune responses, with high frequencies of specific IFNg+CD4+ and IL17+CD4+ T cells in prostate draining lymph nodes from PA-immunized either CD8 KO or wild type animals with respect to controls. Moreover, these peripheral immune responses were paralleled by the development of significant chronic pelvic pain, and accompanied by prostate histological lesions, characterized by hemorrhage, epithelial cell desquamation, marked periglandular leukocyte infiltration, and increased collagen deposition in both, PA-immunized CD8 KO and wild type animals. As expected, control animals did not develop prostate histological lesions. Our results indicate that CD8 T cells do not play a major role in EAP pathogenesis and chronic pelvic pain development. Moreover, our results corroborate the previous notion that a CD4 Th1 associated immune response drives the induction of prostate tissue inflammation and the development of chronic pelvic pain.

SLAMF3 promotes Th17 differentiation and is reversed by iguratimod through JAK1/STAT3 pathway in primary Sjögren's syndrome

ObjectiveThe signaling lymphocytic activation molecule family of receptors (SLAMF) is involved in the activation of T cells and plays important roles in the pathogenesis of autoimmune diseases. The purpose of this study is to observe the expression of SLAMF3 on CD4 + T cells and its effect on the differentiation of T helper 17 (Th17) in primary Sjögren's syndrome (pSS). Furthermore, we found iguratimod (IGU) could effectively reverse the aberrant Th17 differentiation through JAK1/STAT3 signaling. MethodsPeripheral blood mononuclear cells from 40 pSS and 40 healthy control subjects were enrolled for analysis of expression of SLAMF3 on CD4 + T and Th17 cells by flow cytometry. Serum IL-17 and SLAMF3 were detected by ELISA assay. Labial biopsies from 20 pSS patients and 20 non-pSS controls were performed immunohistochemical for staining expression of CD4, IL-17, and SLAMF3. Under the priming conditions with anti-CD3/CD28 or CD3/SLAMF3 antibodies on CD4 + T cells extracted from pSS and controls, the proportion of Th17 cells in CD4 + T cells and the amount of soluble IL-17A were assessed by flow cytometry and ELISA. Furthermore, RNA sequencing was performed for the transcriptomics study. Additionally, RNA level of RORγt and IL-17A and the protein level of RORγt, p-JAK1 and p-STAT3, were detected by real-time PCR and western blot. ResultsThe expression levels of SLAMF3 on CD4 + T and Th17 cells in the peripheral blood and salivary glands in pSS patients were significantly elevated than that in control groups. The serum IL-17A and SLAMF3 in pSS patients were much higher compared with the control group. Although co-stimulation of CD3/SLAMF3 could promote CD4 + T cells differentiate into Th17 cells both in pSS and controls, the CD4 + T cells from pSS have a more sensitive response in Th17 differentiation with the SLAMF3 stimulation. Transcriptomics results showed the CD3/SLAMF3 stimulation caused the activation of Th17 signaling and JAK1/STAT3 pathway. Quantitative PCR and western blotting confirmed the IGU (iguratimod), which is a safe clinical drug in treatment of autoimmune diseases, effectively reversed the increased Th17 proportion, the expression levels of RORγt, pJAK1, and pSTAT3 caused by CD3/SLAMF3 stimulation. ConclusionSLAMF3 upregulates Th17 cell differentiation of CD4 + T cells and IL-17A secretion through enriching RORγt and activating the transcriptomics participating in the pathogenesis of primary Sjögren's syndrome. IGU could inhibit the process through this therapeutic target in pSS.

Multimodality imaging and immunophenotyping of COVID-19 related myocardial injury (the MIIC-MI Study)

Abstract Background Cardiac injury is a well-recognised complication of acute COVID-19 infection, with varied aetiologies ranging from myocarditis to endothelial dysfunction, micro-embolic phenomena, and acute coronary syndromes. While persistent cardiac symptoms in patients with post-acute COVID-19 syndrome are also common, the underlying mechanisms remain unclear. A better understanding of immune-mediated drivers of chronic cardiac injury after COVID-19 infection is urgently needed to inform the management of patients with, or at risk of, long-term sequelae. Purpose To examine immune mechanisms associated with clinically detectable imaging abnormalities across a spectrum of patients with unexplained cardiac injury and/or symptoms after COVID-19 infection. Methods Participants with a history of COVID-19 infection and suspected cardiac involvement based on: a) troponin I elevation (&amp;gt;99th percentile upper reference limit), b) new-onset heart failure not attributable to another cause, or c) persistence of unexplained cardiac symptoms, were enrolled at a single centre in the United Kingdom between October 2020 and February 2022. Individuals with prior myocardial infarction or heart failure and those treated with immunosuppression within the past four weeks, were excluded. Cardiac magnetic resonance imaging (MRI) was performed on a 1.5T scanner following a standard clinical protocol. In parallel to cardiac imaging, peripheral blood samples were analysed for immunophenotyping using cytometry by time of flight (Fluidigm, 32 marker panel) and proteomic analysis (Olink, Target 96 Inflammation panel). Results Twenty-one patients (mean age 47 (SD 13) years, 71% female) were enrolled who had unexplained cardiac symptoms (n=17), raised troponin I (n=2), or new-onset heart failure (n=2). In total, 9/21 (43%) patients had MRI abnormalities, including a non-ischaemic pattern of late gadolinium enhancement (Figure 1a; arrow) and/or visually overt myocardial oedema on T2-weighted imaging (Figure 1b; arrow) in 8 patients, and one with impaired ventricular function in the absence of fibrosis. Patients with MRI abnormalities had higher CCL3, CCL7 (MCP-3), FGF21, and CD4 Th2 cells, and lower CD8 T effector memory cells (Figure 2, volcano plot), compared to those without. CCL7 (MCP-3) levels were correlated with native T1 mapping (r=0.45, p&amp;lt;0.05) and these along with CD8 T effector memory cell counts were the strongest predictors of MRI abnormalities in a LASSO regression model incorporating all clinical, cell phenotyping and proteomic data (composite AUC 0.96, CI 0.88-1). Conclusion Here we show for the first time that COVID-19 related cardiac injury in patients with MRI abnormalities is associated with increased CCL7 (MCP-3), a chemokine known to be important in viral myocarditis1, as well as decreased CD8 T effector memory cells. These findings provide novel insights into the immune-mediated mechanisms underlying non-ischemic cardiac complications of COVID-19.Fig. 1.Post-COVID imaging abnormalitiesFig. 2.Immunophenotyping and proteomics

ALCAM on human oligodendrocytes mediates CD4 T cell adhesion.

Multiple sclerosis is a chronic neuroinflammatory disorder characterized by demyelination, oligodendrocyte damage/loss and neuroaxonal injury in the context of immune cell infiltration in the CNS. No neuroprotective therapy is available to promote the survival of oligodendrocytes and protect their myelin processes in immune-mediated demyelinating diseases. Pro-inflammatory CD4 Th17 cells can interact with oligodendrocytes in multiple sclerosis and its animal model, causing injury to myelinating processes and cell death through direct contact. However, the molecular mechanisms underlying the close contact and subsequent detrimental interaction of Th17 cells with oligodendrocytes remain unclear. In this study we used single cell RNA sequencing, flow cytometry and immunofluorescence studies on CNS tissue from multiple sclerosis subjects, its animal model and controls to characterize the expression of cell adhesion molecules by mature oligodendrocytes. We found that a significant proportion of human and murine mature oligodendrocytes express melanoma cell adhesion molecule (MCAM) and activated leukocyte cell adhesion molecule (ALCAM) in multiple sclerosis, in experimental autoimmune encephalomyelitis and in controls, although their regulation differs between human and mouse. We observed that exposure to pro-inflammatory cytokines or to human activated T cells are associated with a marked downregulation of the expression of MCAM but not of ALCAM at the surface of human primary oligodendrocytes. Furthermore, we used in vitro live imaging, immunofluorescence and flow cytometry to determine the contribution of these molecules to Th17-polarized cell adhesion and cytotoxicity towards human oligodendrocytes. Silencing and blocking ALCAM but not MCAM limited prolonged interactions between human primary oligodendrocytes and Th17-polarized cells, resulting in decreased adhesion of Th17-polarized cells to oligodendrocytes and conferring significant protection of oligodendrocytic processes. In conclusion, we showed that human oligodendrocytes express MCAM and ALCAM, which are differently modulated by inflammation and T cell contact. We found that ALCAM is a ligand for Th17-polarized cells, contributing to their capacity to adhere and induce damage to human oligodendrocytes, and therefore could represent a relevant target for neuroprotection in multiple sclerosis.

CXCR3 antagonist NBI-74330 mitigates joint inflammation in Collagen-Induced arthritis model in DBA/1J mice.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by uncontrolled synovial proliferation, pannus formation, cartilage injury, and bone destruction. We used the CXCR3-specific antagonist NBI-74330 to block T-cell-mediated signaling in a DBA/1J mouse model of collagen-induced arthritis (CIA). After CIA induction, DBA/1J mice were treated with NBI-74330 (100mg/kg) daily from day 21 until day 34 and evaluated for arthritic score and histopathological changes. Furthermore, using flow cytometry, we investigated the effects of NBI-74330 on Th1 (IFN-γ, TNF-α, T-bet, STAT4, Notch-3, and RANKL), Th17 (IL-21, IL-17A, STAT3, and RORγt), and Th22 (IL-22) cells in splenic CD4+ and CXCR3+T-cells. We also used RT-PCR to assess the effect of mRNA levels of IFN-γ, TNF-α, T-bet, RANKL, IL-17A, RORγt, and IL-22 in knee tissues. The IFN-γ, TNF-α, and IL-17A serum protein levels were measured using ELISA. Compared to vehicle-treated CIA mice, the severity of arthritic scores and histological severity of inflammation decreased significantly in NBI-74330-treated CIA mice. Moreover, compared to vehicle-treated CIA mice, the percentages of CD4+IFN-γ+, CD4+TNF-α+, CD4+T-bet+, CD4+STAT4+, CD4+Notch-3+, CXCR3+IFN-γ+, CXCR3+TNF-α+, CXCR3+T-bet+, CXCR3+STAT4+, CXCR3+Notch-3+, CD4+RANKL+, CD4+IL-21+, CD4+IL-17A+, CD4+STAT3+, CD4+RORγt+, and CD4+IL-22+ cells decreased in NBI-74330-treated CIA mice. Furthermore, NBI-74330-treatment downregulated IFN-γ, TNF-α, T-bet, RANKL, STAT3, IL-17A, RORγt, and IL-22 mRNA levels. Serum IFN-γ, TNF-α, and IL-17A levels were significantly lower in NBI-74330-treated CIA mice than in vehicle-treated CIA mice. This study demonstrates the antiarthritic effects of NBI-74330 in CIA mice. Therefore, these data suggest that NBI-74330 could be considered a potential RA treatment.

Abstract 4056: Intratumoral delivery of autologous tumor antigen specific CD4 Th1 cells combined with dendritic cells eradicates HER2 mammary carcinoma

Abstract Human epidermal growth factor receptor 2 (HER2) overexpression accounts for 30% of invasive breast cancer (BC) and is critically associated with aggressive disease, recurrence and metastasis. Adoptive cell therapy approaches using cytotoxic CD8 T cells and natural killer cells have been shown to trigger anti-tumor immunity in BC. However, the immunosuppressive tumor microenvironment (TME) can inhibit response to these therapies and diminish the presence and function of tumor-infiltrating lymphocytes. Recently, we have shown a critical role for anti-tumor CD4 Th1 cells in dendritic cells (DC) intratumoral (i.t.) delivery in combination with anti-HER2 therapy. This combination therapy enhanced systemic and local anti-tumor immunity and eradicated tumors in HER2 positive BC with a requirement for CD4 Th1 cells. Here we investigated the efficacy of i.t. delivery of both autologous anti-tumor CD4 Th1 cells and tumor antigen pulsed type 1 polarized dendritic cells (HER2-DC1) in a HER2 mammary carcinoma model. CD4 T cells were isolated from BALB/c mice that had completely regressed (pCR) from orthotopic TUBO tumors following HER2-DC1 i.t. or combination therapy with anti-HER2 antibody. CD4 Th1 cells were then expanded by co-culturing with HER2-DC1 in the presence of interleukin (IL)-2 and IL-7 cytokines. BALB/c mice bearing orthotopic TUBO tumors were treated weekly for six weeks with anti-tumor CD4 Th1 cells i.t., non-specific CD4 Th1 cells i.t., HER2-DC1 i.t. or combination therapy. The i.t. delivery of anti-tumor CD4 Th1 cells combined with HER2-DC1 induced a strong anti-tumor response with survival benefit and complete tumor eradication in 50% of treated mice. Importantly, the i.t. delivery of anti-tumor CD4 Th1 cells were critical for providing priming signals to HER2-DC1 within the TME via CD40/CD40L engagement (licensing). This was supported by a strong anti-tumor response and complete tumor regression in 60% of orthotopic TUBO tumor bearing mice treated with CD40/CD40L licensed HER2-DC1 i.t. therapy compared to un-licensed HER2-DC1 i.t. therapy. Additionally, enhanced survival and functionality of human and mouse HER2-DC1 was observed following activation of CD40/CD40L signaling using anti-CD40 agonistic antibody in vitro. Collectively, these results suggest a new promising therapeutic strategy using DC1-anti-tumor CD4 Th1 adoptive cell therapy intratumoral delivery to induce DC1 priming and create robust anti-tumor immunity within the TME in BC. Citation Format: Ganesan Ramamoorthi, Amy Aldrich, Colin Snyder, Brian Czerniecki. Intratumoral delivery of autologous tumor antigen specific CD4 Th1 cells combined with dendritic cells eradicates HER2 mammary carcinoma. [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 4056.

Effect of Med1 on T cell development and CD4+ T cell differentiation in immune response.

The differentiation of CD4+ T cells is regulated by a complex and fine signaling pathway composed of many molecules during immune response, and the molecular mechanism for regulating T-bet expression is unclear. Mediator complex subunit 1 (Med1) can combine with a variety of co-factors to regulate gene transcription, promote cell proliferation and survival, and affect invariant natural killer T cell (iNKT) development. This study aims to investigate the effect of Med1 on T cell development and CD4+ T cell differentiation in immune response. Mice with T cell-specific knockout of Med1 gene (Med1F/FCD4cre+, KO) were constructed and verified. The percentage and number of CD4+ and CD8+ T cells in thymus, spleen, and lymph nodes of KO mice and control (Con) mice (Med1F/FCD4cre-) were detected by flow cytometry. After 8 days of infection with lymphocytic choriomeningitis virus (LCMV), the percentage and number of CD4+ T cells or antigen-specific (GP66+) CD4+ T cells, the percentage and number of Th1 cells (Ly6c+PSGL1+) in CD4+ T cells or antigen-specific CD4+ T cells were examined in the spleen of mice. Moreover, the fluorescence intensity of T-bet in CD4+ T cells or antigen-specific CD4+ T cells was analyzed. Compared with the Con group, the percentage and number of CD4+ T cells and CD8+ T cells in the thymus, CD4+ T cells in the spleen and lymph nodes of the KO group showed no significant differences (all P>0.05), but the percentage and number of CD8+ T cells in the spleen and lymph nodes of the KO group were diminished significantly (all P<0.05). After 8 days of infection with LCMV, there was no significant difference in the percentage and number of CD4+ T cells or antigen-specific CD4+ T cells in the spleen between the KO group and the Con group (all P>0.05), while in comparison with the Con group, the percentage and number of Th1 cells in CD4+ T cells or antigen-specific CD4+ T cells, and the expression of T-bet in CD4+ T cells or antigen-specific CD4+ T cells were significantly reduced in the spleen of the KO group (all P<0.05). Specific knockout of Med1 in T cells does not affect the development of CD4+ and CD8+ T cells in the thymus, but does affect the maintenance of peripheral CD8+ T cells. In the immune response, Med1 gene deletion affects the expression of transcription factor T-bet, which in turn to reduce Th1 cell differentiation.

Single-cell RNA sequencing reveals distinct T cell populations in immune-related adverse events of checkpoint inhibitors

PD-1 is an inhibitory receptor in Tcells, and antibodies that block its interaction with ligands augment anti-tumor immune responses. The clinical potential of these agents is limited by the fact that half of all patients develop immune-related adverse events (irAEs). To generate insights into the cellular changes that occur during anti-PD-1 treatment, we performed single-cell RNA sequencing of circulating Tcells collected from patients with cancer. Using the K-nearest-neighbor-based network graph-drawing layout, we show the involvement of distinctive genes and subpopulations of Tcells. We identify that at baseline, patients with arthritis have fewer CD8 TCM cells, patients with pneumonitis have more CD4 TH2 cells, and patients with thyroiditis have more CD4 TH17 cells when compared with patients who do not develop irAEs. These data support the hypothesis that different populations of Tcells are associated with different irAEs and that characterization of these cells' pre-treatment has the potential to serve as a toxicity-specific predictive biomarker.

Serum brain‐derived neurotrophic factor in coronary heart disease: Correlation with the T helper (Th)1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events

Brain-derived neurotrophic factor (BDNF) exerts protective roles against dyslipidemia, atherosclerosis, and inflammation in cardiovascular diseases; meanwhile, it retards CD4+ T cell differentiation into T helper (Th)1 and Th17 cells. Hence, this study aimed to investigate the linkage of serum BDNF with Th1/Th2 ratio, Th17/regulatory T (Treg) ratio, and major adverse cardiovascular events (MACE) risk in the coronary heart disease (CHD) patients. This prospective study detected serum BDNF in 210 CHD patients, 50 disease controls (DCs), and 50 healthy controls (HCs) using an enzyme-linked immunosorbent assay. For CHD patients only, the proportion of Th1, Th2, Th17, and Treg cells in blood CD4+ T cells was calculated by flow cytometry. The BDNF varied among CHD patients, DC, and HC (p < 0.001). Specifically, BDNF was declined in CHD patients compared with DCs (p < 0.001) and HCs (p < 0.001). In CHD patients, BDNF was negatively related to Th1 cells (p=0.031), Th1/Th2 ratio (p=0.026), Th17 cells (p=0.001), and Th17/Treg ratio (p=0.002). Concerning the prognosis, BDNF was reduced in patients with MACE occurrence compared to patients without MACE occurrence (p=0.006). Furthermore, BDNF showed a trend (lacked statistical significance) to relate to longer MACE-free survival (p=0.059). Besides, BDNF was related to the absence of obesity (p=0.019), decreased total cholesterol (p=0.043), low-density lipoprotein cholesterol (p=0.019), C-reactive protein (p=0.012), and Gensini score (p=0.005). Serum BDNF negatively correlates with Th1/Th2 ratio, Th17/Treg ratio, and estimates lower MACE risk in CHD patients.

IL-10 regulates Th17 response to inhibit hepatobiliary injury caused by Clonorchis sinensis infection in C57BL/6J mice.

Clonorchiasis caused by Clonorchis sinensis is a mainly foodborne parasitic disease. It can lead to hepatobiliary duct inflammation, fibrosis, obstructive jaundice, liver cirrhosis, and even cholangiocarcinoma. Interleukin (IL)-10 is an immune-regulatory cytokine which plays an immunosuppressive role during infection. Our previous study found that IL-10 was increased in mice with C. sinensis infection. However, the role and mechanism of IL-10 playing in hepatobiliary injury induced by C. sinensis infection remain unknown. Herein, Il10+/+ mice and Il10+/- C57BL/6J mice were infected with C. sinensis. It was found that IL-10 deficiency aggravated biliary hyperplasia and exacerbated periductal fibrosis induced by C. sinensis infection. Moreover, IL-10 deficiency increased CD4+T cells and CD8+T cells but not macrophages in the liver of mice with infection. There were no apparent differences in Th1 and Treg cells between Il10+/+ and Il10+/- mice infected with C. sinensis. However, the proportion of Th17 cells in CD4+T cells in Il10+/- infected mice was significantly higher than that in Il10+/+ infected mice. IL-10 deficiency also enhanced the increase of Th17 cells induced by ESPs stimulation in vitro. Taken together, our results suggest that IL-10 plays a protective role in hepatobiliary injury in C57BL/6J mice induced by C. sinensis infection via inhibiting Th17 cells, which could deepen our understanding of the immunopathology of clonorchiasis.

Migrating Type 2 Dendritic Cells Prime Mucosal Th17 Cells Specific to Small Intestinal Commensal Bacteria.

Dendritic cells (DCs) are professional APCs equipped with MHC-restricted Ags, costimulations, and cytokines that effectively prime and differentiate naive T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of Ag uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign Ags and inflammatory cues, DCs are predominantly activated and migratory. In the small intestine, CD4 Th17 cells are abundant and have been shown to be regulated by DCs and macrophages. Using a mouse commensal bacteria experimental model, we identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of type 2 DCs (DC2s) from the small intestine to the mesenteric lymph nodes (MLNs) is essential for the activation of naive CD4 T cells. The migratory DC2 population in the MLNs is almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of costimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Thus, early Th17 cell differentiation is initiated by a small subset of migratory DC2s in the gut-draining lymph nodes.

Migratory type 2 dendritic cells mediate mucosal Th17 response to gut commensal bacteria

Abstract Dendritic cells (DCs) are professional antigen-presenting cells equipped with MHC-restricted antigens, co-stimulations, and cytokines that effectively prime and differentiate naïve T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of antigen uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign antigens and inflammatory cues, DCs are predominantly activated and migratory. The gut commensal bacteria contribute to immune health by educating the immune system at this unique location interfacing with the outside environment. In the small intestine, CD4 Th17 cells are abundant and play a critical role in mucosal defense against bacterial and fungal infections. We identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of DC2s from the small intestine to the mesenteric lymph nodes is essential for the activation of naïve CD4 T cells. The migratory DC2 population in the MLN are almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of co-stimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Our study indicates that the mucosal Th17 cell response is regulated by a restricted subset of migratory DC2s in the gut draining lymph nodes. Supported by NIAID U01AI125859

Detoxification II Prescription Suppresses the Th-17/IL-17 Inflammatory Axis to Improve the Liver Function of ACLF-Rats via Inactivating the P38MAPK Pathway.

Hepatitis is a metabolic system disease which is a serious challenge to the medical and healthcare system of the world. This study attempted to investigate the therapeutic effect and illustrate the regulation pharmacological mechanism of Detoxification II Prescription on ACLF. In this study, the rats were injected with D-galactosamine to establish ACLF-rat models, and the levels of cholinesterase (CHE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBiL) were measured with the related kits to reflect the liver functions of the rats. The levels of IL-17, IL-6, and IFN-γ in the serums of the rats were detected by qRT-PCR, and the percentages of Th-17 cells in CD4+ cells of the rats were measured by flow cytometry assay. In the results, the increased ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4+ and decreased ALB and CHE were found in the serums of the ACLF-rats, while Detoxification II Prescription could partly reverse those indexes of the ACLF-rats. Moreover, it was also found that Detoxification II Prescription could inhibit the expression of P38MAPK, and P38MAPK downregulation obviously improved the liver function indexes of the ACLF-rats including the levels of ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4+ cells. In conclusion, this study suggested that Detoxification II Prescription could suppress the Th-17/IL-17 inflammatory axis to improve the liver function of ACLF-rats via inhibiting the activity of the P38MAPK pathway.

Adverse Outcomes in Acute Myeloid Leukemia Are Associated with Tumor Cell-Mediated Immunosuppression

Background: A normal karyotype is the most common cytogenetic finding in acute myeloid leukemia cells (“NK-AML”) and has highly variable and difficult to predict outcomes at presentation. Refinements introduced with the ELN 2017 Criteria (presence or absence of mutations in NPM1, FLT3-ITD, and/or biallelic CEBPA mutations) have improved–but not completely solved–up-front risk classification. NK-AML patients with very long first remissions after chemotherapy only are rare, and their genetic and epigenetic characteristics have not yet been definitively evaluated, but could potentially provide clues regarding determinants that affect chemotherapy responses.Results: Using exome sequencing, RNA-sequencing, and functional studies, we performed an in-depth characterization of 28 de novo adult NK-AML patients with >5 year, Long First Remissions (LFR) after chemotherapy only (7+3 with HiDAC consolidation). As comparators, we studied a well-matched group of 31 NK-AML patients who relapsed within 2 years (Standard First Remissions, SFR). None of the patients in either group received an allogeneic transplant in first remission. Bulk RNA sequencing and targeted investigation of cell type proportions and pathways expected to be relevant for chemotherapy sensitivity (i.e. cell cycle, DNA repair, or AraC responsiveness) revealed no significant differences between LFR and SFR AML samples. However, single cell RNA sequencing (sc-RNAseq) analyses of genetically-defined AML cells from 8 LFR and 7 SFR cases showed that SFR AML cells expressed significantly higher levels of stem cell markers, and of several immunomodulatory genes (MHC class II, CD200, MRC1). Combined sc-RNAseq and flow cytometry analyses of the AML bone marrow samples from LFR patients revealed well-preserved CD4 and CD8 populations that responded robustly to TCR-mediated activation, achieved through CD3/28 bead stimulation. In contrast, SFR AML marrows had reduced numbers of immune cells (particularly of CD4 Th1 cells) and their residual T cells expressed an exhaustion signature. TCR-mediated T cell activation was blocked in the SFR samples by the presence of the AML cells in the bone marrow samples: removing the AML cells released this blockade. Evaluation of T cell immune checkpoints and their putative ligands revealed LAG3 to be a leading candidate for immune suppression, because of its high expression in SFR T cells, and because the genes encoding its major ligands (MHC Class II) were highly expressed in SFR AML cells. Indeed, blocking the inhibitory receptor LAG-3 was able to reverse the AML cell-mediated T cell suppression of most SFR cases. To validate and extend these findings, we performed the T cell activation assay in an independent cohort of 50 AML cases representing all ELN risk groups. The ability of marrow derived CD4+ T cells to activate correlated strongly with ELN groups. Importantly, for the ELN intermediate patients, the immune activation assay stratified these patients in 2 groups with very different relapse free survival (RFS): the T cell “activators” had an RFS of 1200 days, while the “non-activators” had RFS of 146 days (Mantel-Cox Log-rank = 0.02). A multivariate analysis of covariates at diagnosis, including sex, age, ELN risk category, WBC count, bone marrow blast count at presentation, and mutation status (for DNMT3A, NPM1, FLT3, NRAS, WT1, TET2, CEBPA, PTPN11, IDH1, IDH2, RUNX1, RAD21, SMC1A, and SRSF2) identified none that were predictive of CD4 T cell activation status at presentation.Conclusions: These data strongly suggest that most AML cases have an immunosuppressive phenotype at presentation, mediated by inhibitory T cell receptors (e.g. LAG3) via ligands that are expressed by AML cells (e.g. MHC Class II proteins). The absence of this immunosuppressive phenotype was strongly correlated with favorable clinical outcomes with standard chemotherapy. The ability of CD4 T cells to be activated via the TCR in the presence of AML cells at presentation (which indirectly measures AML cell-mediated immunosuppression) is a novel biomarker for risk assessment that is currently not captured by any other well-recognized covariate (especially for ELN intermediate risk cases), and should be further evaluated for its predictive potential in prospective clinical trials. DisclosuresEisfeld: Karyopharm (spouse): Current Employment. Retting: BioLineRx Ltd.: Research Funding. Uy: GlaxoSmithKline: Consultancy; Agios: Consultancy; Novartis: Consultancy; Genentech: Consultancy; AbbVie: Consultancy; Macrogenics: Research Funding; Astellas: Honoraria, Speakers Bureau; Jazz: Consultancy. Spencer: Wugen, Inc.: Consultancy, Other: Stock options.

Regulation of T Cells in Cancer by Nitric Oxide.

The T cell-mediated immune response is primarily involved in the fight against infectious diseases and cancer and its underlying mechanisms are complex. The anti-tumor T cell response is regulated by various T cell subsets and other cells and tissues in the tumor microenvironment (TME). Various mechanisms are involved in the regulation of these various effector cells. One mechanism is the iNOS/.NO that has been reported to be intimately involved in the regulation and differentiation of the various cells that regulate the anti-tumor CD8 T cells. Both endogenous and exogenous .NO are implicated in this regulation. Importantly, the exposure of T cells to .NO had different effects on the immune response, depending on the .NO concentration and time of exposure. For instance, iNOS in T cells regulates activation-induced cell death and inhibits Treg induction. Effector CD8 T cells exposed to .NO result in the upregulation of death receptors and enhance their anti-tumor cytotoxic activity. .NO-Tregs suppress CD4 Th17 cells and their differentiation. Myeloid-derived suppressor cells (MDSCs) expressing iNOS inhibit T cell functions via .NO and inhibit anti-tumor CD8 T cells. Therefore, both .NO donors and .NO inhibitors are potential therapeutics tailored to specific target cells that regulate the T cell effector anti-tumor response.