Phenotype Of CD4 Research Articles

The effect of early life cytomegalovirus infection on the immune profile of children

Cytomegalovirus (CMV) infection has a life-long impact on the immune system, particularly on memory T cells. However, the effect of early life CMV infection on the phenotype and functionality of T cells in infants and especially longitudinal changes occurring during childhood have not been explored in detail.The phenotype and functionality of peripheral blood CD8+ and CD4+ T cells from children infected with CMV in early life (< 6 months of age) was analyzed using high-dimensional flow cytometry. Samples from CMV IgG-seropositive (CMV+) children were collected at 6 months and 6 years of age and compared to samples from CMV-seronegative (CMV-) children.Early life CMV infection caused multiple alterations within T cells. These include downregulation of CD28 expression and upregulation of CD57 expression within both CD27+ early and CD27- late effector memory CD8+ and CD4+ T-cells at 6 months of age. Of these changes, only alterations within the highly differentiated late effector memory compartment persisted at the age of 6 years.Early life CMV-infection has a distinct impact on developing CD8+ and CD4+ memory T cell compartments. It appears to induce both temporary as well as longer-lasting alterations, which may affect the functionality of the immune system throughout life.

Mapping the complexity and diversity of tertiary lymphoid structures in primary and peritoneal metastatic gastric cancer

BackgroundTertiary lymphoid structures (TLSs) are thought to stimulate antitumor immunity and positively impact prognosis and response to immune checkpoint blockade. In gastric cancers (GCs), however, TLSs are predominantly found in...

Exosomes derived from cancer cells relieve inflammatory bowel disease in mice

Exosome therapy has garnered significant attention due to its natural delivery capabilities, low toxicity, high biocompatibility, and potential for personalised treatment through engineering modifications. Recent studies have highlighted the ability of tumour cell-derived exosomes (TDEs) to interact with immune cells or modify the immune microenvironment to suppress host immune responses, as well as their unique homing ability to parental cells. The core question of this study is whether this immunomodulatory property of TDEs can be utilised for the immunotherapy of inflammatory diseases. In our experiments, we prepared exosomes derived from murine colon cancer cells CT26 (CT26 exo) using ultracentrifugation, characterised them, and conducted proteomic analysis. The therapeutic potential of CT26 exo was evaluated in our dextran sulphate sodium salt (DSS)-induced inflammatory bowel disease (IBD) mouse model. Compared to the control and 293 T exo treatment groups, mice treated with CT26 exo showed a reduction in the disease activity index (DAI) and colon shortening rate, with no noticeable weight loss. Haematoxylin and eosin (H&E) staining of colon paraffin sections revealed reduced inflammatory infiltration and increased epithelial goblet cells in the colons of CT26 exo-treated group. Furthermore, we conducted preliminary mechanistic explorations by examining the phenotyping and function of CD4+ T cells and dendritic cells (DCs) in the colonic lamina propria of mice. The results indicated that the ameliorative effect of CT26 exosomes might be due to their inhibition of pro-inflammatory cytokine secretion by colonic DCs and selective suppression of Th17 cell differentiation in the colon. Additionally, CT26 exo exhibited good biosafety. Our findings propose a novel exosome-based therapeutic approach for IBD and suggest the potential application of TDEs in the treatment of inflammatory diseases.

Regulation of memory CD4+ T-cell generation by intrinsic and extrinsic IL-27 signaling during malaria infection.

The generation and maintenance of memory T cells are regulated by various factors, including cytokines. Previous studies have shown that IL-27 is produced during the early acute phase of Plasmodium chabaudi chabaudi AS (Pcc) infection and inhibits the development of Th1-type memory CD4+ T cells. However, whether IL-27 acts directly on its receptor on Plasmodium-specific CD4+ T cells or indirectly via its receptor on other immune cells remains unclear. We aimed to determine the role of IL-27 receptor signaling in different immune cell types in regulating the generation and phenotype of memory CD4+ T cells during Plasmodium infection. We utilized Plasmodium-specific T-cell antigen receptor (TCR) transgenic mice, PbT-II, and Il27rα-/- mice to assess the direct and indirect effects of IL-27 signaling on memory CD4+ T-cell generation. Mice were transferred with PbT-II or Il27rα-/- PbT-II cells and infected with Pcc. Conditional knockout mice lacking the IL-27 receptor in T cells or dendritic cells were employed to discern the specific immune cell types involved in IL-27 receptor signaling. High levels of memory in PbT-II cells with Th1-shift occurred only when both PbT-II and host cells lacked the IL-27 receptor, suggesting the predominant inhibitory role of IL-27 signaling in both cell types. Furthermore, IL-27 receptor signaling in T cells limited the number of memory CD4+ T cells, while signaling in both T and dendritic cells contributed to the Th1 dominance of memory CD4+ T cells. These findings underscore the complex cytokine signaling network regulating memory CD4+ T cells during Plasmodium infection.

Metabolic Plasticity of Regulatory T Cells in Health and Autoimmunity.

Immunometabolism has been demonstrated to control immune tolerance and the pathogenic events leading to autoimmunity. Compelling experimental evidence also suggests that intracellular metabolic programs influence differentiation, phenotype, proliferation, and effector functions of anti-inflammatory CD4+CD25+Foxp3+ regulatory T (Treg) cells. Indeed, alterations in intracellular metabolism associate with quantitative and qualitative impairments of Treg cells in several pathological conditions. In this review, we summarize the most recent advances linking how metabolic pathways control Treg cell homeostasis and their alterations occurring in autoimmunity. Also, we analyze how metabolic manipulations could be employed to restore Treg cell frequency and function with the aim to create novel therapeutic opportunities to halt immune-mediated disorders.

Impairment of Gal-9 and Tim-3 crosstalk between Tregs and Th17 cells drives tobacco smoke-induced airway inflammation.

Overexpression of T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) on T cells has been observed in smokers. However, whether and how galectin-9 (Gal-9)/TIM-3 signal between T-regulatory cells (Tregs) and type 17 helper (Th17) cells contributes to tobacco smoke-induced airway inflammation remains unclear. Here, we aimed to explore the role of the Gal-9/TIM-3 signal between Tregs and Th17 cells during chronic tobacco smoke exposure. Tregs phenotype and the expression of TIM-3 on CD4+ T cells were detected in a mouse model of experimental emphysema. The role of TIM-3 in CD4+ T cells was explored in a HAVCR2-/- mouse model and in mice that received recombinant anti-TIM3. The crosstalk between Gal-9 and Tim-3 was evaluated by coculture Tregs with effector CD4+ T cells. We also invested the expression of Gal-9 in Tregs in patients with COPD. Our study revealed that chronic tobacco smoke exposure significantly reduces the frequency of Tregs in the lungs of mice and remarkably shapes the heterogeneity of Tregs by downregulating the expression of Gal-9. We observed a pro-inflammatory but restrained phenotypic transition of CD4+ T cells after tobacco smoke exposure, which was maintained by TIM-3. The restrained phenotype of CD4+ T cells was perturbed when TIM-3 was deleted or neutralised. Tregs from the lungs of mice with emphysema displayed a blunt ability to inhibit the differentiation and proliferation of Th17 cells. The inhibitory function of Tregs was partially restored by using recombinant Gal-9. The interaction between Gal-9 and TIM-3 inhibits the differentiation of Th17 cells and promotes apoptosis of CD4+ T cells, possibly by interfering with the expression of retinoic acid receptor-related orphan receptor gamma t. The expression of Gal-9 in Tregs was reduced in patients with COPD, which was associated with Th17 response and lung function. These findings present a new paradigm that impairment of Gal-9/Tim-3 crosstalk between Tregs and Th17 cells during chronic tobacco smoke exposure promotes tobacco smoke-induced airway/lung inflammation.

Antigen-specific profiling for neoadjuvant anti-PD-1 therapy in melanoma.

9576 Background: Anti-PD-1 therapy (aPD-1) has had significant clinical success in extending survivability of melanoma patients. However, two-third of the patients do not achieve long-lasting benefits, and currently, there exists no reliable method for predicting clinical response. We test whether monitoring melanoma-specific CD8 T cells in blood, lymph node, and tumor enables us to gain insights into the mechanism of clinical resistance, and identify potential predictive biomarkers. Methods: We leveraged a phase 2 clinical trial of neoadjuvant PD-1 blockade at University of Pennsylvania where patients with stage III melanoma patients receive a pre-treatment biopsy, treatment with a single dose of the aPD-1 therapy, followed by tumor and lymph node resection 4 weeks later, allowing for access to paired blood and tumor samples. We used a combinatorial tetramer system to track panels of 10 HLA-restricted melanoma and viral-specific CD8 T cell populations simultaneously. Results: Out of 35 patients analyzed, 53% of patients had detectable melanoma-specific CD8 T cells. Notably, these cells exhibited exhausted phenotypes both in blood and tumor, whereas viral-specific T cells displayed features resembling effector and memory CD8 T cells in blood and tumor, respectively. Thus. the presence of tumor antigen emerges as a crucial determinant in shaping the phenotype of melanoma-specific CD8 T cells, above that of the tissue microenvironment. Analysis of resected lymph node samples following PD-1 blockade reveals their supportive role in activating and proliferating anti-tumor T cells. Finally, pathologic responders to PD-1 blockade are characterized by both a higher quantity and a less exhausted phenotype of tumor-specific CD8 T cells. This suggests that assessing both the quantity and quality of these T cells can serve as a predictive indicator to distinguish responders from non-responders. Conclusions: These findings highlight the feasibility of antigen-specific profiling in a clinical trial setting, the importance of melanoma-specific CD8 T cells in checkpoint blockade responses, and their potential use an early on-treatment biomarker of clinical outcomes.

Cellular immunity in women aged 20–40 living in different climatic and geographic regions

The aim. To identify phenotypic features of adaptive cellular immune responses in young women living in different climatic and geographic regions.Materials and methods. We examined 63 apparently healthy women, including 25 residents of Sovpolye settlement, Arkhangelsk region (Arctic region) and 38 residents of Tskhinvali (Republic of South Ossetia) aged 20–40. The content of lymphocytes, their phenotypes CD4+, CD8+, CD3+, CD5+, CD16+, CD10+, CD71+, CD25+, HLA-DR+ and CD95+, CEA (carcinoembryonic antigen) glycoprotein, and interleukin (IL) 6 and IL-10 cytokines was studied. Lymphocytes phenotyping was performed by indirect immunoperoxidase reaction using monoclonal antibodies (MedBioSpektr, Moscow) on “dried drop” lymphocyte sample with peroxidase conjugate and chromogen solution staining for immersion microscopy analysis (Nicon 50i, Japan). The content of CEA glycoprotein and cytokines was determined using ELISA.Results. In women living in Arctic region, a deficiency of CD5+, CD3+, CD10+, CD95+, CD71+, CD25+, HLA-DR+ cells, CEA and IL-6 concentrations is associated with high concentrations of CD8+ and IL-10. In women living in Southern region, a slight deficiency of CD5+, CD8+ and CD95+ cells is associated with high concentrations of CEA, IL-6, IL-10 and CD10+, CD16+ and HLA-DR+ cells.Conclusion. In inhabitants of different climatic regions, the features of formation of adaptive immune reactions are determined by different quantitative and qualitative composition of lymphocytes and cytokines phenotypes. Reduction of reserve capabilities of immune homeostasis is detected 3 times more often in inhabitants of the Arctic region.

Glycolysis inhibition induces anti-tumor central memory CD8+T cell differentiation upon combination with microwave ablation therapy

Minimally invasive thermal therapy is a successful alternative treatment to surgery in solid tumors with high complete ablation rates, however, tumor recurrence remains a concern. Central memory CD8+ T cells (TCM) play important roles in protection from chronic infection and cancer. Here we find, by single-cell RNA analysis of human breast cancer samples, that although the memory phenotype of peripheral CD8+ T cells increases slightly after microwave ablation (MWA), the metabolism of peripheral CD8+ T cells remains unfavorable for memory phenotype. In mouse models, glycolysis inhibition by 2-deoxy-D-glucose (2DG) in combination with MWA results in long-term anti-tumor effect via enhancing differentiation of tumor-specific CD44hiCD62L+CD8+ TCM cells. Enhancement of CD8+ TCM cell differentiation determined by Stat-1, is dependent on the tumor-draining lymph nodes (TDLN) but takes place in peripheral blood, with metabolic remodeling of CD8+ T cells lasting the entire course of the the combination therapy. Importantly, in-vitro glycolysis inhibition in peripheral CD8+ T cells of patients with breast or liver tumors having been treated with MWA thrice leads to their differentiation into CD8+ TCM cells. Our work thus offers a potential strategy to avoid tumor recurrence following MWA therapy and lays down the proof-of-principle for future clinical trials.

Anti-interleukin-18 as therapy against atherosclerosis

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Established Investigator of the Dutch Heart Foundation Background Interleukin-18 (IL-18) is a pro-inflammatory cytokine and is secreted by macrophages after NLRP3-inflammasome activation. IL-18 is important for the induction of the Th1 response and overexpression of IL-18 aggravates atherosclerosis, suggesting that inhibition of IL-18 may act atheroprotective. In this study, we investigated the therapeutic potential of an IL-18 neutralizing antibody (anti-IL18) on atherosclerosis development. Methods and results Female ApoE-/- mice were fed a Western-type diet for 8 weeks and simultaneously received an antibody against IL-18 (100 µg/mouse; n=15) or a rat IgG2a control (100 µg/mouse; n=15) 3x per week intraperitoneally, after which the mice were sacrificed. First, we assessed macrophage phenotype in the peritoneal cavity. Expression of the proinflammatory markers CD80 (control: 46.3±1.4 *103; p&amp;lt;0.05 vs. anti-IL18: 40.4 ±1.7 *103) and iNOS (control: 15.5±1.8 *102 vs. anti-IL18: 8.0±1.9 *102; p&amp;lt;0.01) were reduced. In the aorta, MFIs of anti-inflammatory macrophage markers Arginase-1 (control: 389±99 vs. anti-IL18: 654±85; p=0.06) and CD206 (control: 55.2±2.4 *103 vs. anti-IL18: 62.8±3.7 *103; p=0.1) tended to be increased expression in the ascending aorta of anti-IL18 mice compared to controls. In addition, anti-IL18 treatment promoted the number of CD4 T cells (control: 20±1% vs. anti-IL18: 28±1%; p&amp;lt;0.0001) in the mediastinal lymph node and increased it’s regulatory phenotype (Tregs; Foxp3+) of CD4 (control: 23±1% vs. anti-IL18: 26±1%; p=0.07) and CD8 T cells (control: 0.4±0.02% vs. anti-IL18: 0.9±0.09%; p&amp;lt;0.0001). These effects however, did not translate into an effect on plaque size in the aortic root, as measured using an Oil-Red-O staining, which did not differ between the control and anti-IL18 treatment group (control: 47.1±2.4 *104 µm2 vs. anti-IL18: 43.4±2.3 *104 µm2). Conclusions Anti-IL18 treatment reduced the proinflammatory phenotype of peritoneal macrophages and promoted Tregs in the mediastinal lymph node. Further analyses on plaque stability and intraplaque macrophage subsets are currently being performed.

Priming with LSD1 inhibitors promotes the persistence and antitumor effect of adoptively transferred T cells

The antitumor efficacy of adoptively transferred T cells is limited by their poor persistence, in part due to exhaustion, but the underlying mechanisms and potential interventions remain underexplored. Here, we show that targeting histone demethylase LSD1 by chemical inhibitors reshapes the epigenome of in vitro activated and expanded CD8+ T cells, and potentiates their antitumor efficacy. Upon T cell receptor activation and IL-2 signaling, a timely and transient inhibition of LSD1 suffices to improve the memory phenotype of mouse CD8+ T cells, associated with a better ability to produce multiple cytokines, resist exhaustion, and persist in both antigen-dependent and -independent manners after adoptive transfer. Consequently, OT1 cells primed with LSD1 inhibitors demonstrate an enhanced antitumor effect in OVA-expressing solid tumor models implanted in female mice, both as a standalone treatment and in combination with PD-1 blockade. Moreover, priming with LSD1 inhibitors promotes polyfunctionality of human CD8+ T cells, and increases the persistence and antitumor efficacy of human CD19-CAR T cells in both leukemia and solid tumor models. Thus, pharmacological inhibition of LSD1 could be exploited to improve adoptive T cell therapy.

Abstract PS03-01: Single cell analysis of paired lymph nodes and primary tumors in breast cancer patients

Abstract A sentinel lymph node (SN) is the primary node draining the tumor and is assumed to be affected early in the metastatic process. The sentinel node holds a key position in the immune response against tumor in breast, and represents a unique connection between the tumor and the host immune response. We hypothesize that the immune profile in the primary tumor and the paired lymph node (LN) is different during tumor progression. 3.7 million single cells from paired primary tumor and lymph nodes from 33 breast cancer patients (Oslo2 cohort) was analyzed by single cell mass cytometry (CyTOF) with a 47 antibody immune panel and characterized by a semi-automatic gating approach (FlowSOM). Tumor cells were found in 11 LN. When analyzing the leucocytes from LN we identified a significant difference in immune cell type skewing towards higher abundance of memory CD4 and CD8 T cells expressing an exhausted phenotype in LN with metastasis. In addition, a higher abundance of activated Tregs and significantly lower abundance of resting Tregs was found in the metastatic LNs compared to the sentinel lymph nodes. The change in immune composition and exhaustion was correlated to the metastatic tumor burden. The skewing towards an exhausted immune profile was also found in larger primary tumors compared to smaller primary tumors. We further analyzed tumor cells from 8 patients with paired primary tumor and LN. No differences were identified in the primary tumor when stratified by LN status, but LNs with smaller metastasis expressed lower levels of epithelial markers essential in the Epithelial-to-Mesenchymal Transition such as E-cadherin, Pan Cytokeratin and EpCAM – this in contrast to the LN with manifested metastasis in the axilla which expressed higher levels of epithelial markers and lower levels of mesenchymal markers such as Vimentin and CD44. We identified a skewing in the immune profile from a naive phenotype towards a memory and exhausted phenotype in CD8 and CD4 T cell population in LN with manifested metastasis, as well as in larger primary tumors. We also identified that tumor cells in smaller metastatic tumors resembled a “mesenchymal like” phenotype compared to in the larger manifested tumors. These results suggest that the immune suppression is correlated with the tumor burden. Citation Format: Marit Fjørtoft, Inga Rye, Kanutte Huse, June Myklebust, Hege Russnes, Margit Riis, Ole Christian Lingjærde, Øystein Garred, Karin Teien Lande, Inger Riise Bergheim, Ellen Schlichting. Single cell analysis of paired lymph nodes and primary tumors in breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS03-01.

Abstract PO2-08-06: Metformin may improve the outcome of patients with breast cancer and type 2 diabetes mellitus through the effect of tumor immune microenvironment

Abstract Metformin, an anti-diabetic drug, is known to have anti-tumor effects. We examined the outcome of 177 patients with type 2 diabetes mellitus (T2DM) who received surgery for breast cancer. Among them, 49 patients were treated with drugs including metformin. In those patients, recurrence in distant organs was less frequent and postoperative disease-free survival (DFS) tended to be better than those without metformin intake. In patients who received preoperative systemic therapy (PST), rate of pathological complete response (pCR) was significantly more frequent in patients with metformin treatment (p &amp;lt; 0.05). Multiplex immunohistochemical staining of resected tumors revealed that the density of tumor associated macrophages (TAM), especially of CD68(+)CD163(+) M2-type TAM, was significantly lower in tumors with metformin treatment. In contrast, the rate of CD8(+) phenotype in CD3(+) tumor infiltrating lymphocytes (TILs) was significantly higher in metformin group. The results suggest that metformin can change the immune microenvironment from pro-tumorigenic to anti-tumorigenic status, which leads to the favorable outcome of the patients with breast cancer and T2DM. Citation Format: Satomi Shiba, Michiko Harao, Kasumi Ogihara, Takayo Fukuda, Masako Sakuragi, Kitayama Joji, Naohiro Sata. Metformin may improve the outcome of patients with breast cancer and type 2 diabetes mellitus through the effect of tumor immune microenvironment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-08-06.

Abstract 1030: Zeb2 Regulates Senescence And Cytotoxic Phenotype In Atherosclerotic Plaque CD8 T Cells

Circulating senescent CD8 + CD57 + T cells have been implicated in reduced post-myocardial infarction survival and impaired glucose homeostasis in type 2 diabetes (T2D) patients. Despite these associations, their specific role in human atherosclerotic plaques, particularly in the context of aggravated plaque pathology in T2D remains unknown. In this study, we analyzed single-cell transcriptomic data from 75,049 immune cells obtained from plaques from 12 T2D and 10 no diabetes patients enrolled in the ATHERO-IN study. We identified 14 clusters of CD8 + T cells clusters, revealing distinct subsets such cytotoxic CD8 + T cells with a terminally differentiated effector memory phenotype, cytotoxic/exhausted, naïve/CM and regulatory CD8 + T cells. These clusters expressed varying degrees of senescent genes, with a notable heightened senescent transcriptional signature in T2D patients. Fibrocalcific plaques, which were prevalent in T2D patients, showed significantly enrichment in cytotoxic, inflammatory, naïve/CM, and interferon response CD8 T cell clusters. In contrast, fibroatheroma samples were predominantly enriched in MAIT-like CD8 T cells and cytotoxic/exhausted clusters. Aged CD8 T cells expanded in T2D patients exhibited elevated senescence and cytotoxic score, manifested a senescence-associated secretory phenotype expressing cytotoxic, pro-inflammatory and proatherogenic genes. Trajectory analysis and regulatory network analysis, highlighted ZEB2— a GWAS gene associated to coronary artery disease and myocardial infarction— as a potential transcription factor driving the senescence phenotype. CRISPR-based studies corroborated this, demonstrating that ZEB2 KO CD8 T cells reduced senescence, cytotoxicity, and activation markers, underscoring the pivotal role of ZEB2 in driving the terminal differentiation and aging phenotype. In conclusion, our findings shed light on the intricate interplay between senescent CD8+ T cells and atherosclerotic plaque pathology in the context of T2D. The identification of ZEB2 as a key regulator of T cell senescence offers a potential target for therapeutic interventions aimed at mitigating the senescence-associated effects on plaque pathology and cardiovascular outcomes in T2D patients.

Lineage tracing reveals heterogeneity within tumor-reactive CD8 T cells in mismatch repair-proficient (MMR-p) CRC

Abstract While CRC develop in the colon and rectum, little is known about the relationship between tissue resident memory (TRM) CD8 T cells and newly recruited tumor-reactive T cells. We compared the phenotype of CD8 T cells from paired adjacent normal colon (NC) and tumor by flow cytometry and observed a higher T cell infiltration in the tumor with an enrichment in CD8 T cells. Interestingly, a subset of CD103+ CD8 T cells in NC expressed CD39, a phenotype reminiscent of tumor-reactive T cells, but those cells lacked PD-1 and Ki-67. To better understand the relationship between T cells from NC and tumor and to uncover the differentiation path of tumor-reactive CD8 T cells, we performed scRNA-seq and scTCR-seq together with CITE-seq on paired NC and tumor from five patients. We confirmed that DP CD8 T cells from NC were distinct from tumor-infiltrating DP CD8 T cells (DP CD8 TILs). In contrast, the latter represented an heterogenous population with cells at different stages of differentiation as illustrated by the detection of cells sharing the same TCRs in multiple cell clusters. To further appreciate the differentiation path of neoantigen-reactive CD8 TILs, we performed neoantigen discovery on three of the five patients. We are now evaluating whether T cell differentiation and activation are linked to functional avidity and cellular location in the tumor. This work provides essential information regarding the differentiation of tumor-reactive CD8 TILs in MMR-p CRC tumors.

Unveiling the immune responses of ferrets inoculated with Ebola virus

Abstract Animal-based models continue to be important for investigating the immunological pathways involved with infections of emerging infectious diseases. Inoculation of Ebola virus (EBOV) in ferrets results in nearly uniformly fatal disease while also recapitulating numerous additional aspects associated with EBOV infection of nonhuman primates or humans. However, the underlying immune responses of EBOV-associated disease in ferrets is largely unknown due to a lack of available reagents. Thus, we designed and optimized a 10-color flow cytometry panel to investigate the adaptive and innate immune components of ferrets. Animals were inoculated with EBOV or mock virus, and circulating immune responses in whole blood were longitudinally examined by flow cytometry. Appreciable alterations in both the innate and adaptive immune responses during late-stage disease were observed. Animals were euthanized at 3 or 6-d post-exposure, and terminal tissues were examined. As expected, marked increases in the number and frequency of apoptotic and necrotic cells were noted. Interestingly, a significant loss of memory phenotype CD8+ T cells and activated CD11b+ cells was associated with advanced disease. In plasma, elevated circulating protein levels of multiple cytokines, commonly associated with EBOV infection, were found in a stepwise manner. Altogether, these tools add significant illumination of underlying immune responses in the ferret model.

Metabolic Reprogramming of Tumor-Associated Macrophages Using Glutamine Antagonist JHU083 Drives Tumor Immunity in Myeloid-Rich Prostate and Bladder Cancers.

Glutamine metabolism in tumor microenvironments critically regulates antitumor immunity. Using the glutamine-antagonist prodrug JHU083, we report potent tumor growth inhibition in urologic tumors by JHU083-reprogrammed tumor-associated macrophages (TAMs) and tumor-infiltrating monocytes. We show JHU083-mediated glutamine antagonism in tumor microenvironments induced by TNF, proinflammatory, and mTORC1 signaling in intratumoral TAM clusters. JHU083-reprogrammed TAMs also exhibited increased tumor cell phagocytosis and diminished proangiogenic capacities. In vivo inhibition of TAM glutamine consumption resulted in increased glycolysis, a broken tricarboxylic acid (TCA) cycle, and purine metabolism disruption. Although the antitumor effect of glutamine antagonism on tumor-infiltrating T cells was moderate, JHU083 promoted a stem cell-like phenotype in CD8+ T cells and decreased the abundance of regulatory T cells. Finally, JHU083 caused a global shutdown in glutamine-utilizing metabolic pathways in tumor cells, leading to reduced HIF-1α, c-MYC phosphorylation, and induction of tumor cell apoptosis, all key antitumor features. Altogether, our findings demonstrate that targeting glutamine with JHU083 led to suppressed tumor growth as well as reprogramming of immunosuppressive TAMs within prostate and bladder tumors that promoted antitumor immune responses. JHU083 can offer an effective therapeutic benefit for tumor types that are enriched in immunosuppressive TAMs.

KLRB1 defines an activated phenotype of CD4+ T cells and shows significant upregulation in patients with primary Sjögren's syndrome

ObjectiveThis study aimed to investigate the role of KLRB1 (CD161) in human CD4+ T cells and elucidate its significance in primary Sjögren's syndrome (pSS). MethodsPeripheral blood samples from 37 healthy controls and 44 pSS patients were collected. The publicly available single-cell RNA-Seq data from pSS patient PBMCs were utilized to analyse KLRB1 expression in T cells. KLRB1-expressing T lymphocyte subset proportions in pSS patients and healthy controls were determined by flow cytometry. CD25, Ki-67, cytokine secretion, and chemokine receptor expression in CD4+ KLRB1+ T cells were detected and compared with those in CD4+ KLRB1- T cells. Correlation analysis was conducted between KLRB1-related T-cell subsets and clinical indicators. ROC curves were generated to explore the diagnostic potential of KLRB1 for pSS. ResultsKLRB1 was significantly upregulated following T-cell activation, and Ki-67 and CD25 expression was significantly greater in CD4+ KLRB1+ T cells than in CD4+ KLRB1- T cells. KLRB1+ CD4+ T cells exhibited greater IL-17A, IL-21, IL-22, and IFN-γ secretion upon stimulation, and there were significantly greater proportions of CCR5+, CCR2+, CX3CR1+, CCR6+, and CXCR3+ cells among CD4+ KLRB1+ T cells than among CD4+ KLRB1- T cells. Compared with that in HCs, KLRB1 expression in CD4+ T cells was markedly elevated in pSS patients and significantly correlated with clinical disease indicators. ConclusionKLRB1 is a characteristic molecule of the CD4+ T-cell activation phenotype. The increased expression of KLRB1 in the CD4+ T cells of pSS patients suggests its potential involvement in the pathogenesis of pSS and its utility as an auxiliary diagnostic marker for pSS.

Gluten-Free Diet Induces Rapid Changes in Phenotype and Survival Properties of Gluten-Specific T Cells in Celiac Disease

Background and AimsThe treatment of celiac disease (CeD) with gluten-free diet (GFD) normalizes gut inflammation and disease-specific antibodies. CeD patients have HLA-restricted, gluten-specific T cells persisting in the blood and gut even after decades of GFD, which are re-activated and disease driving upon gluten exposure. Our aim was to examine the transition of activated gluten-specific T cells into a pool of persisting memory T cells concurrent with normalization of clinically relevant biomarkers during the first year of treatment. MethodsWe followed 17 CeD patients during their initial GFD year, leading to disease remission. We assessed activation and frequency of gluten-specific CD4+ blood and gut T cells with HLA-DQ2.5:gluten tetramers and flow cytometry, disease-specific serology, histology and symptom scores. We assessed gluten-specific blood T cells within the first three weeks of GFD in six patients and serology in additional nine patients. ResultsGluten-specific CD4+ T cells peaked in blood at day 14 while upregulating Bcl-2 and downregulating Ki-67, then decreased in frequency within 10 weeks of GFD. CD38, ICOS, HLA-DR and Ki-67 decreased in gluten-specific cells within three days. PD-1, CD39 and OX40 expression persisted even after 12 months. IgA-TG2 decreased significantly within four weeks. ConclusionGFD induces rapid changes in phenotype and number of gluten-specific CD4+ blood T cells, including a peak of non-proliferating, non-apoptotic cells at day 14. Subsequent alterations in T-cell phenotype associate with the quiescent but chronic nature of treated CeD. The rapid changes affecting gluten-specific T cells and disease-specific antibodies offer opportunities for clinical trials aiming at developing non-dietary treatments for newly diagnosed CeD patients.

High frequencies of alpha common cold coronavirus/SARS-CoV-2 cross-reactive functional CD4+ and CD8+ memory T cells are associated with protection from symptomatic and fatal SARS-CoV-2 infections in unvaccinated COVID-19 patients.

Cross-reactive SARS-CoV-2-specific memory CD4+ and CD8+ T cells are present in up to 50% of unexposed, pre-pandemic, healthy individuals (UPPHIs). However, the characteristics of cross-reactive memory CD4+ and CD8+ T cells associated with subsequent protection of asymptomatic coronavirus disease 2019 (COVID-19) patients (i.e., unvaccinated individuals who never develop any COVID-19 symptoms despite being infected with SARS-CoV-2) remains to be fully elucidated. This study compares the antigen specificity, frequency, phenotype, and function of cross-reactive memory CD4+ and CD8+ T cells between common cold coronaviruses (CCCs) and SARS-CoV-2. T-cell responses against genome-wide conserved epitopes were studied early in the disease course in a cohort of 147 unvaccinated COVID-19 patients who were divided into six groups based on the severity of their symptoms. Compared to severely ill COVID-19 patients and patients with fatal COVID-19 outcomes, the asymptomatic COVID-19 patients displayed significantly: (i) higher rates of co-infection with the 229E alpha species of CCCs (α-CCC-229E); (ii) higher frequencies of cross-reactive functional CD134+CD137+CD4+ and CD134+CD137+CD8+ T cells that cross-recognized conserved epitopes from α-CCCs and SARS-CoV-2 structural, non-structural, and accessory proteins; and (iii) lower frequencies of CCCs/SARS-CoV-2 cross-reactive exhausted PD-1+TIM3+TIGIT+CTLA4+CD4+ and PD-1+TIM3+TIGIT+CTLA4+CD8+ T cells, detected both ex vivo and in vitro. These findings (i) support a crucial role of functional, poly-antigenic α-CCCs/SARS-CoV-2 cross-reactive memory CD4+ and CD8+ T cells, induced following previous CCCs seasonal exposures, in protection against subsequent severe COVID-19 disease and (ii) provide critical insights into developing broadly protective, multi-antigen, CD4+, and CD8+ T-cell-based, universal pan-Coronavirus vaccines capable of conferring cross-species protection.