Alterations In CD4 Research Articles

EXPRESS: Unlocking the Immune Puzzle: T Cell exhaustion in cirrhosis and implication for immunotherapy.

Cirrhosis, an advanced stage of liver diseases, induces Cirrhosis-Associated Immune Dysfunction Syndrome (CAIDS) characterized by both innate and adaptive immune dysfunction. Inflammation triggered by factors such as alcohol, viruses, toxins, and cholesterol induce metabolic reprogramming of both innate and adaptive immune cells. Our study specifically sought to investigate the compromised adaptive immune response in cirrhosis by focusing on assessing T-cell exhaustion and activation markers on helper and cytotoxic T cells. A prospective observational study involving 19 liver cirrhosis patients and 36 healthy controls was conducted. Hepatic decompensation degree was assessed using various parameters including serum bilirubin, albumin, international normalized ratio, ascites and hepatic encephalopathy. T cell activation (CD38, CD44, CD69, HLADR), and exhaustion markers (CTLA-4, PD-1, TIM-3, LAG-3) were assessed on helper and cytotoxic T cells by flow cytometry. Cirrhosis patients showed reduced T cells with no alteration in CD4:CD8 T cell ratio. Among activation markers, HLADR showed increased expression on CD8+ T cells (P=0.031). Regarding exhaustion markers LAG-3 and TIM-3 exhibited increased expression in cirrhotic patients compared to controls in both CD4 and CD8 T cells (P=0.004, P=0.016, P=0.001, P=0.004, respectively). Neither cirrhotic nor healthy controls showed CTLA expression. PD-1 did not differ significantly between the two groups. Co-expression of PD-1/TIM-3 on CD8+ T cells was notably higher in cirrhotic patients (P<0.002). The observation of impaired adaptive immunity with notable T cell exhaustion and activation in cirrhosis underscores the potential relevance of immunotherapy.

Decreased T helper 1cell function underlies recurrent sinopulmonary infections in the 17q12 deletion syndrome.

The 17q12 deletion syndrome (17q12DS) is a heterozygous deletion of a 1.4 megabase‒spanning DNA sequence on chromosome 17. The clinical characteristics of 17q12DS include neurodevelopmental disorders, kidney and urinary tract abnormalities. In our cohort of 37 subjects with 17q12DS, we observed increased atopic disorders and recurrent sinopulmonary infections, raising the possibility of immune dysregulation in 17q12DS, a feature that has not been previously reported. We tested the hypothesis that individuals with 17q12DS have altered T-cell function, contributing to recurrent infections and atopy. Alteration of CD4+ T-cell functions was assessed on FACS sorted CD4+ T-cells using RNA-seq analysis, and flow cytometry and multiplex assays. We found that individuals with 17q12DS had a substantially decreased frequency of CD4+ T-cells producing the T helper (Th) 1 cytokine IFN-γ but not Th2 and Th17 cytokines when compared to age-matched healthy controls (HCs). RNA-seq analysis of CD4+ T-cells from subjects with 17q12DS, when compared to HCs, revealed decreased levels of TBX21 encoding the Th1 transcription factor T-bet, IFNG, and other Th1 chemokine genes. These findings were validated using flow cytometry and multiplex assay. Our study is the first to demonstrate immune alterations in 17q12DS characterized by decreased T-bet and its downstream effector cytokines such as IFN-γ. These findings warrant further investigation into underlying mechanisms, which would inform precision therapy for individuals with 17q12DS. National Institutes of HealthKL2 TR001862 to JJS, T35DK104689 to AG, 5T32AR007107 to JPY and LO, 1R01AG056728 to IK, and 1R21AI161838 to IK and JJS.

Enhanced ROS Production and Mitochondrial Metabolic Shifts in CD4+ T Cells of an Autoimmune Uveitis Model.

Equine recurrent uveitis (ERU) is a spontaneously occurring autoimmune disease and one of the leading causes of blindness in horses worldwide. Its similarities to autoimmune-mediated uveitis in humans make it a unique spontaneous animal model for this disease. Although many aspects of ERU pathogenesis have been elucidated, it remains not fully understood and requires further research. CD4+ T cells have been a particular focus of research. In a previous study, we showed metabolic alterations in CD4+ T cells from ERU cases, including an increased basal oxygen consumption rate (OCR) and elevated compensatory glycolysis. To further investigate the underlying reasons for and consequences of these metabolic changes, we quantified reactive oxygen species (ROS) production in CD4+ T cells from ERU cases and compared it to healthy controls, revealing significantly higher ROS production in ERU-affected horses. Additionally, we aimed to define mitochondrial fuel oxidation of glucose, glutamine, and long-chain fatty acids (LCFAs) and identified significant differences between CD4+ T cells from ERU cases and controls. CD4+ T cells from ERU cases showed a lower dependency on mitochondrial glucose oxidation and greater metabolic flexibility for the mitochondrial oxidation of glucose and LCFAs, indicating an enhanced ability to switch to alternative fuels when necessary.

Differential T-cell profiles determined by Hepatitis B surface antigen decrease among people with Human Immunodeficiency Virus /Hepatitis B Virus coinfection on treatment

BackgroundSeveral studies have reported that combination antiretroviral therapy (cART) enhances the hepatitis B surface antigen (HBsAg) clearance rate in Human Immunodeficiency Virus-1/Hepatitis B Virus (HIV/HBV) coinfected patients, yet the associated immunological characteristics remain unclear.MethodsGlobal and specific immune phenotypic profiles were examined in 48 patients with HIV/HBV coinfection before cART and at 1-year, and 3-year after cART using flow cytometry. In addition, 61 patients with HBV monoinfection were included for comparison.ResultsHBsAg response (sAg-R) was defined as > 0.5 log decrease within six months of cART initiation, and 16 patients achieved it. Patients with sAg-R (the sAg-R group) exhibited distinct immune phenotypes compared to those of HBsAg-retained patients (the sAg-NR group). Notably, patients with sAg-R had lower CD4+ T cell counts and a higher number of HBcAg-specific T cells. Further, the sAg-R group exhibited upregulation of HLA-DR, Ki67, and PD-1 in CD4+ T cells and heightened HLA-DR and T-bet in CD8+ T cells. However, the sAg-R group had fewer TEMRA cells but more TEM and Th17 cells than those in the sAg-NR group. Expression of various markers, including HLA-DR+CD4+, Ki67+CD4+, PD-1+CD4+, CD38+CD8+, HLA-DR+CD8+, TIM-3+CD8+, HBV-specific CD4+ T cell secreting IFN-γ and IL-2, and specific CD8+ T cell secreting IFN-γ and IL-2, correlated with HBsAg decrease.ConclusionThe decline in HBsAg levels during cART in HIV/HBV coinfection involves significant alterations in CD4+ and CD8+ T cells phenotypes, offering a novel perspective on a functional HBV cure.

Changes in Phenotypic and Molecular Features of Naïve and Central Memory T Helper Cell Subsets following SARS-CoV-2 Vaccination.

Molecular changes in lymphocytes following SARS-CoV-2 vaccination are incompletely understood. We hypothesized that studying the molecular (transcriptomic, epigenetic, and T cell receptor (TCR) repertoire) changes in CD4+ T cells following SARS-CoV-2 vaccination could inform protective mechanisms and refinement of future vaccines. We tested this hypothesis by reporting alterations in CD4+ T cell subsets and molecular features of CD4+ naïve and CD4+ central memory (CM) subsets between the unvaccinated and vaccinated groups. Compared with the unvaccinated, the vaccinated had higher HLA-DR expression in CD4+ T subsets, a greater number of differentially expressed genes (DEGs) that overlapped with key differentially accessible regions (DARs) along the chromatin linked to inflammasome activation, translation, regulation (of apoptosis, inflammation), and significant changes in clonal architecture beyond SARS-CoV-2 specificity. Several of these differences were more pronounced in the CD4+CM subset. Taken together, our observations imply that the COVID-19 vaccine exerts its protective effects via modulation of acute inflammation to SARS-CoV-2 challenge.

Direct and Abscopal Antitumor Responses Elicited by AlPcNE-Mediated Photodynamic Therapy in a Murine Melanoma Model.

Melanoma, the most aggressive form of skin cancer, presents a major clinical challenge due to its tendency to metastasize and recalcitrance to traditional therapies. Despite advances in surgery, chemotherapy, and radiotherapy, the outlook for advanced melanoma remains bleak, reinforcing the urgent need for more effective treatments. Photodynamic therapy (PDT) has emerged as a promising alternative, leading to targeted tumor destruction with minimal harm to surrounding tissues. In this study, the direct and abscopal antitumor effects of PDT in a bilateral murine melanoma model were evaluated. Although only one of the two tumors was treated, effects were observed in both. Our findings revealed significant changes in systemic inflammation and alterations in CD4+ and CD8+ T cell populations in treated groups, as evidenced by blood analyses and flow cytometry. High-throughput RNA sequencing (RNA-Seq) further unveiled shifts in gene expression profiles in both treated and untreated tumors. This research sheds light on the novel antitumor and abscopal effects of nanoemulsion of aluminum chloride phthalocyanine (AlPcNE)-mediated PDT in melanoma, highlighting the potential of different PDT protocols to modulate immune responses and to achieve more effective and targeted cancer treatments.

Alterations in CD4+ T Cell Cytokines Profile in Female Patients with Hashimoto's Thyroiditis Following Vitamin D Supplementation: A Double-blind, Randomized Clinical Trial.

Hashimoto's thyroiditis (HT) is an autoimmune disease characterized by the destruction of thyroid cells through immune processes involving T helper (Th)1 cytokines. This clinical trial investigates the impact of vitamin D supplementation on serum cytokine levels and gene expression in CD4+ T cells from HT patients, aiming to understand its effects on Th-1, Th-2, Th-17, and regulatory T (Treg) cell-associated factors. Female patients were randomly assigned in a double-blind design to either a vitamin D-supplemented group, which received cholecalciferol (1, 25(OH)2D3) at a dose of 50,000 IU, or the placebo group, which received a weekly placebo for a duration of three months. Serum cytokine levels were assessed using enzyme-linked immunosorbent assay (ELISA), while genes' expression levels were measured using real-time PCR. Serum 25-hydroxyvitamin D and levels exhibited a significant increase following vitamin D supplementation, in comparison to the placebo group. Additionally, the vitamin D supplementation resulted in a significant elevation of serum calcium (Ca) levels compared to baseline. In the vitamin D group, there was a significant decrease in both serum levels and expression of the interleukin (IL)-17 gene when compared to baseline, although no statistical difference was observed between the placebo and vitamin D groups. The gene expression of transforming growth factor-beta (TGFβ) was significantly increased in the vitamin D group compared to baseline, with no significant difference between the two study groups. Vitamin D treatment had no effect on serum levels of interferon-gamma (IFNϒ) and IL-4. While the gene expression of IL-4 in the vitamin D group did not exhibit a statistically significant increase, the level of GATA3 transcription factor increased significantly when compared to the placebo group. The expression of IFNϒ and transcription factors, T-bet, RORc, and forkhead box protein 3 (FOXP3) in genes did not show significant changes following vitamin D supplementation. The findings suggest that vitamin D supplementation may hold potential benefits for autoimmune diseases, such as HT. However, further longitudinal clinical trials are necessary to gain a more comprehensive understanding of the specific effects of vitamin D on HT.

Influenza-induced alveolar macrophages protect against death by malaria-associated acute lung injury.

Lower respiratory tract infections are common in malaria-endemic areas, and there is some evidence that co-infections between various bacteria/viruses and Plasmodium may affect disease prognosis. In this study, we report the novel finding that co-infection with influenza/A/X31 protects mice from death by Plasmodium berghei NK65-Edinburgh, a model of severe malarial pulmonary leak which underpins malaria-associated acute lung injury (MA-ALI) and malaria-associated acute respiratory distress (MA-ARDS). Co-infected mice exhibit equivalent parasitemia as mice with malaria only, suggesting that the survival phenotype is due to differences in immune kinetics. We demonstrated that the pulmonary leak typical of Pb E is attenuated in co-infected mice without alteration in CD8 T cell activation and recruitment to the lung. Upon further examination of the immune response to influenza/A/X31 we identified a population of arginase 1-expressing alveolar macrophages that traffic to the lungs early during infection. In vitro these macrophages inhibit CD8 T cell activation and proliferation better than non-arginase expressing cells. Removal of arginase-1 expressing alveolar macrophages in vivo via administration of the antimetabolite gemcitabine removed the protective effects of influenza/A/X31co-infection on MA-ALI. This study opens a route to better understanding of how to modulate the immunopathology observed in pulmonary leak associated with severe malaria, which must be achieved to rationally design therapeutic interventions for MA-ARDS / MA-ALI.

Temporal Alterations in CD8+ T Cells During the Progression from Stage 1 to Stage 3 Type 1 Diabetes.

CD8+ T cells are perceived to play a major role in the pathogenesis of type 1 diabetes (T1D). In this study, we characterized the function and phenotype of circulating CD8+ memory T cells in samples from individuals at different stages of T1D progression using flow cytometry and single-cell multiomics. We observed two distinct CD8+ T-cell signatures during progression of T1D within the highly differentiated CD27-CD8+ memory T cell subset. A proinflammatory signature, with an increased frequency of IFN-γ+TNF-α+ CD27-CD8+ memory T cells, was observed in children with newly diagnosed T1D (stage 3) and correlated with the level of dysglycemia at diagnosis. In contrast, a co-inhibitory signature, with an increased frequency of KLRG1+TIGIT+ CD27-CD8+ memory T cells, was observed in islet autoantibody-positive children who later progressed to T1D (stage 1). No alterations within CD27-CD8+ memory T cells were observed in adults with established T1D or in children during the initial seroconversion to islet autoantibody positivity. Single-cell multiomics analyses suggested that CD27-CD8+ T cells expressing the IFNG+TNF+ proinflammatory signature may be distinct from those expressing the KLRG1+TIGIT+ co-inhibitory signature at the single-cell level. Collectively, our findings suggest that distinct blood CD8+ T-cell signatures could be employed as potential biomarkers of T1D progression.

T cell specific Eomes Deletion Does Not Protect Against High Fat Diet Induced Large Artery Stiffening

We have found that T cells contribute to age-related large artery stiffness. The T-box transcription factor, Eomes is an important regulator of CD8+ (Cytotoxic) T cell differentiation from a naïve to a memory phenotype. We previously reported that these effector memory CD8+ T cells accumulate in the aorta of old mice. We aimed to investigate whether inhibiting CD8+ T cell memory differentiation in mice, specifically through T cell-specific Eomes deletion, would protect these animals from high-fat diet (HFD)-induced large artery stiffness. Mice with a CD8 driven Cre Recombinase were bred with mice with loxp sites surrounding the Eomes gene resulting in wild type (CD8 Eomes+/+) and T cell specific Eomes deleted (CD8 Eomesf/f) mice. Mice were randomly divided into a normal chow (NC) and HFD. Resulting in 8 mice of each genotype and diet. The NC group was given a normal diet containing 4% fat and the HFD group was given a high-fat diet containing 60% fat. At 4-8 months of age, doppler pulse wave velocity was used to assess large artery stiffness. Following euthanasia, aortic T cell phenotype was assessed using flow-cytometry. Group differences were assessed by two-way ANOVA and Tukey’s post-hoc test. Data shown as mean ± SD. Regardless of genotype, HFD had a significant impact on pulse wave velocity (PWV), indicating elevated aortic stiffness. In the HFD group, both CD8 Eomesf/f and CD8 Eomes+/+ mice exhibited higher PWV values (330.08±72.33 cm/s;312.5±53.74 cm/s) compared to their counterparts in the NC group (256.4±63.67 cm/s;259.2±66.36 cm/s, p=0.0172). To determine whether HFD-induced increases in aortic stiffness are accompanied by changes in aortic T cell phenotype, flow cytometric analysis was performed on the aorta. First, we observed, regardless of mouse genotype, HFD had a significant impact on CD4+ (Helper T) naïve cells, resulting in a blunted percentage of these cells. This dietary effect was observed in both CD8 Eomesf/f and CD8 Eomes+/+ mice (NCD CD8 Eomesf/f: 70.92±5.912%; NCD CD8 Eomes+/+ mice: 56.46±20.62%; HFD CD8 Eomesf/f: 47.5±7.865%; HFD CD8 Eomes+/+ mice: 50.58±13.907%; p=0.0206). In contrast, the percentages of CD8+ naïve cells did not display a significant change in response to the high-fat diet (p=0.6303). HFD significantly influenced CD4+ memory cells, resulting in an increase in percentages, regardless of mouse genotype (NCD CD8 Eomesf/f: 29.09± 5.909%; NCD CD8 Eomes+/+ mice: 44.27±19.17%; HFD CD8 Eomesf/f: 52.47±7.875%; HFD CD8 Eomes+/+ mice: 49.44±13.9%; p=0.02). However, HFD did not produce any significant alterations in CD8+ memory cell percentages (p=0.6). These results suggest that contrary to our hypothesis, T cell specific Eomes deletion is not suffcient to protect against diet induced large artery stiffness. However, this may be due to greater proportions of CD4+ memory cells in the aorta with high fat feeding. Funding: AHA 940023, NIH R01AG060395, K01AG061271. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Alterations in CD4+ T-cell Subsets in Living Donor Liver Transplantation Associated With Graft Rejection

Background and ObjectivesRegulatory T-cells (Tregs) play a key role in immune homeostasis after organ transplantation. However, the role of CD4+ T cell subsets in early acute rejection is still not well understood. Therefore, our aim was to determine changes in CD4+ T-cell subsets in living donor liver transplantation (LDLT). MethodsLDLT patients were assessed for T-cell subsets, Tregs frequencies and their functionality by flow-cytometry at peri and post-transplant in the span of 1year. Results33 patients were followed-up and 11 (33%) patients have developed early acute cellular rejection (ACR). At peri-transplant time point, MFI of Foxp3+ Tregs was significantly increased compared to HC (P=0.04). However, CD4+CD25+Foxp3+/CD127- Tregs numbers and IL-10, IL-17 and TGF-β secreting functional Tregs were significantly decreased at 3-month compared to peri-transplant (P=0.003). But in patients with rejection, CD4+CD25+FOXP3+ and CD4+CD25+CD127-Tregs were significantly decreased at day 3 compared to no rejection group (P=0.048). Patients with rejection also showed significantly decreased numbers of IL-17 and TGF-β secreting CD4+CD25+FOXP3+ Tregs at peri-transplant time (P=0.04, P=0.03) compared to no rejection. Further, rejection group showed decreased terminally differentiated effector memory (TEMRA) at peri-transplant and day 7 (P=0.048 and P=0.01). Additionally, CD4+ central memory (CM) was decreased at peri-transplant (P=0.05), 1-month (P=0.04), 3 to 6-month (P=0.02). Interpretation and ConclusionTregs frequencies were significantly decreased in peri-TX in rejection patients. Further, decreased frequencies of CD4+ TEMRA and CD4+ CM at day 7 and 1month were associated with rejection.

Chronic Viral Infection Compromises the Quality of Circulating Mucosal-Associated Invariant T Cells and Follicular T Helper Cells via Expression of Inhibitory Receptors.

Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we compared the quality of T-cell responses among chronic hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV)-infected individuals by examining the levels of expression of selected immune activation and exhaustion molecules on circulating MAIT cells and Tfh cells. Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and phenotypic alterations in CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based on markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression. The activation marker CD69 was significantly increased in CD4+hi T cells, while CD8+ MAIT cells producing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+hi T cells, PD-1+CD8+ T cells, and Ki67+CD4+ MAIT cells, were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL. Chronic viral infection negatively impacts the quality of peripheral MAIT cells and Tfh cells via differential expression of both activating and inhibitory receptors.

Artesunate-loaded thermosensitive chitosan hydrogel promotes osteogenesis of maxillary tooth extraction through regulating T lymphocytes in type 2 diabetic rats.

Type 2 diabetes mellitus (T2DM) causes severe bone loss after tooth extraction as a hyperglycemic environment causes aberrant bone homeostasis. Artesunate (ART) is known to possess anti-inflammation and osteogenic properties. However, its osteogenesis property in alveolar bone remains unclear. This study aimed to explore the osteogenic and immunoregulatory effects of artesunate-loaded thermosensitive chitosan hydrogel (ART-loaded TCH) on maxilla tooth extraction in T2DM rats. T2DM rats were induced by a high-fat diet and streptozotocin. Different concentrations of ART-loaded TCH were applied in tooth extraction sockets. Bone loss and the expression of osteogenic regulatory factors (OPG, ALP, RANK) were evaluated. The immunoregulatory effects of ART-loaded TCH were observed through detecting the infiltration of T lymphocytes and their cytokines. The underlying mechanisms were explored. Results showed that the 150mg/ml ART-loaded TCH group significantly ameliorated maxilla bone height and bone mineral density when compared with the T2DM group (p < 0.05). It also improved the expression of OPG, ALP, and RANK. Although the alteration of CD4+ T, CD8+ T, and CD4+:CD8+ T ratio has no significant difference among groups, the release of Th1 and Th2 in the 150mg/ml ART-loaded TCH group has been significantly regulated than in the T2DM group (p < 0.05). Besides, ART-loaded TCH treatment inhibited the expression of p38 MAPK and ERK1 in T2DM maxilla. Therefore, the results indicated that 150mg/ml ART-loaded TCH could be an effective method to prevent bone loss in T2DM tooth extraction rats by modulating the immunoregulation of Th1 and Th2 and the MAPK signaling pathway.

P106 Single-cell transcriptomic analysis reveals insights into the mechanism of action of Granulocyte-monocyte apheresis

Abstract Background Granulocyte-monocyte apheresis (GMA) is a non-pharmacological treatment approved for the management of ulcerative colitis (UC), particularly steroid-dependent cases. The exact mechanism of action and immunological changes associated with GMA remain undescribed. Gene expression analysis at the single-cell level (through scRNA-Seq) has emerged as a key tool of choice to characterize drug response at the molecular level. We used scRNA-Seq to characterize the transcriptomic effects and immune cell population alterations in GMA. Methods We generated scRNA-Seq from peripheral blood mononuclear cells (PBMC) of two ulcerative colitis (UC) patients undergoing GMA treatment. We compared the gene expression profile before and after 5 sessions of GMA treatment. The analytical pipeline included quality control and classical filtering steps, cell-type annotation, differential gene expression analysis and pathway enrichment profiling. Results We report three main results. First, we observed significant reductions of cell types directly affected by GMA treatment in UC patients. This includes classical CD14+ monocytes and Natural killers, which are central components of the innate system. Of note, we observed a remarkable increase in Double-negative T cells (dnT) after 5 sessions of GMA treatment, suggesting potential expansion of protective populations involved in decreased inflammation. Second, we observe a variety of genes and regulatory pathways altered by GMA treatment. In total, we detect 86 differentially expressed genes (DEGs), which overall are biased towards downregulation (63%). Of note, we detected dnT-s exhibiting upregulation of NEFL that is associated with the MAPK cascade and downregulation of genes related to immune response and signaling pathways. Finally, the effects of GMA treatment extend beyond the above mentioned populations, with particular alterations in CD4+ T cell populations such as CD4+ central memory and CD4+ Naive (7 and 13 DEGs, respectively). Conclusion For the first time, we generated single-cell transcriptomic profiles to characterize the effects of GMA treatment in peripheral blood of UC patients. Our preliminary analysis detects important alterations in the gene regulation and cell type composition in samples obtained after 5 sessions of GMA. Through expansion of this dataset to include more time points and profiles for more individuals, we will discuss the longitudinal changes and molecular mechanisms involved in response to GMA treatment.

CD8+ Treg cells play a role in the obesity-associated insulin resistance

Obesity-related chronic low-grade inflammation may trigger insulin resistance and type 2 diabetes (T2D) development. Cells with regulatory phenotype have been shown to be reduced during obesity, especially CD4+ Treg cells. However, little is known about the CD8+ Treg cells. Therefore, we aim to characterize the CD8+ Treg cells in human peripheral blood and adipose tissue, specifically, to address the effect of obesity and insulin resistance in this regulatory immune cell population. A group of 42 participants with obesity (OB group) were recruited. Fourteen of them were evaluated pre- and post-bariatric surgery. A group of age- and sex-matched healthy volunteers (n = 12) was also recruited (nOB group). CD8+ Treg cell quantification and phenotype were evaluated by flow cytometry, in peripheral blood (PB), subcutaneous (SAT), and visceral adipose tissues (VAT). The OB group displayed a higher percentage of CD8+ Treg cells in PB, compared to the nOB. In addition, they were preferentially polarized into Tc1- and Tc1/17-like CD8+ Treg cells, compared to nOB. Moreover, SAT displayed the highest content of CD8+ Tregs infiltrated, compared to PB or VAT, while CD8+ Tregs infiltrating VAT displayed a higher percentage of cells with Tc1-like phenotype. Participants with pre-diabetes displayed a reduced percentage of TIM-3+CD8+ Tregs in circulation, and PD-1+CD8+ Tregs infiltrated in the VAT. An increase in the percentage of circulating Tc1-like CD8+ Treg cells expressing PD-1 was observed post-surgery.In conclusion, obesity induces significant alterations in CD8+ Treg cells, affecting their percentage and phenotype, as well as the expression of important immune regulatory molecules.

Memory T Cells Discrepancies in COVID-19 Patients.

The immune response implicated in Coronavirus disease 2019 (COVID-19) pathogenesis remains to be fully understood. The present study aimed to clarify the alterations in CD4+ and CD8+ memory T cells' compartments in SARS-CoV-2-infected patients, with an emphasis on various comorbidities affecting COVID-19 patients. Peripheral blood samples were collected from 35 COVID-19 patients, 16 recovered individuals, and 25 healthy controls, and analyzed using flow cytometry. Significant alterations were detected in the percentage of CD8+ T cells and effector memory-expressing CD45RA CD8+ T cells (TEMRA) in COVID-19 patients compared to healthy controls. Interestingly, altered percentages of CD4+ T cells, CD8+ T cells, T effector (TEff), T naïve cells (TNs), T central memory (TCM), T effector memory (TEM), T stem cell memory (TSCM), and TEMRA T cells were significantly associated with the disease severity. Male patients had more CD8+ TSCMs and CD4+ TNs cells, while female patients had a significantly higher percentage of effector CD8+CD45RA+ T cells. Moreover, altered percentages of CD8+ TNs and memory CD8+CD45RO+ T cells were detected in diabetic and non-diabetic COVID-19 patients, respectively. In summary, this study identified alterations in memory T cells among COVID-19 patients, revealing a sex bias in the percentage of memory T cells. Moreover, COVID-19 severity and comorbidities have been linked to specific subsets of T memory cells which could be used as therapeutic, diagnostic, and protective targets for severe COVID-19.

A tryptophan metabolite made by a gut microbiome eukaryote induces pro-inflammatory T cells.

The large intestine harbors microorganisms playing unique roles in host physiology. The beneficial or detrimental outcome of host-microbiome coexistence depends largely on the balance between regulators and responder intestinal CD4+ T cells. We found that ulcerative colitis-like changes in the large intestine after infection with the protist Blastocystis ST7 in a mouse model are associated with reduction of anti-inflammatory Treg cells and simultaneous expansion of pro-inflammatory Th17 responders. These alterations in CD4+ T cells depended on the tryptophan metabolite indole-3-acetaldehyde (I3AA) produced by this single-cell eukaryote. I3AA reduced the Treg subset in vivo and iTreg development in vitro bymodifying their sensing of TGFβ, concomitantly affecting recognition of self-flora antigens by conventional CD4+ T cells. Parasite-derived I3AA also induces over-exuberant TCR signaling, manifested by increased CD69 expression and downregulation of co-inhibitor PD-1. We have thus identified a new mechanism dictating CD4+ fate decisions. The findings thus shine a new light on the ability of the protist microbiome and tryptophan metabolites, derived from them or other sources, to modulate the adaptive immune compartment, particularly in the context of gut inflammatory disorders.

Comparison of CD4+/CD8+ Lymphocytic Subpopulations Pre- and Post-Antituberculosis Treatment in Patients with Diabetes and Tuberculosis.

Is there a CD4+ and CD8+ immunity alteration in patients with pulmonary tuberculosis (TB) and diabetes (DM) that does not recover after antituberculosis treatment? This prospective comparative study evaluated CD4+ and CD8+ lymphocytic subpopulations and antituberculosis antibodies in patients with diabetes and tuberculosis (TB-DM), before and after antituberculosis treatment. CD4+ T cell counts were lower in patients with TB-DM compared to those with only TB or only DM, and these levels remained low even after two months of anti-TB treatment. Regarding the CD8+ T cell analysis, we identified higher blood values in the DM-only group, which may be explained by the high prevalence of latent tuberculosis (LTBI) in patients with DM. IgM antituberculosis antibodies levels were elevated in patients with only TB at baseline, and 2 months post-anti-TB treatment, IgG did not express any relevant alterations. Our results suggest an alteration in CD4+ immunity in patients with TB-DM that did not normalize after antituberculosis treatment.

The Effect of Tunnel versus Conventional Phototherapy on the T Lymphocytes in Full Term Neonates with Hyperbilirubinemia

Background Neonatal jaundice is one of the most common conditions. Phototherapy has been accepted as the standard treatment for neonatal jaundice and the decline in the number of exchange transfusions in recent years is, at least in part, likely a direct reflection of the effectiveness of phototherapy at treating hyperbilirubinemia. However, this treatment modality also has some complications. One possible harmful consequence is potential immunotoxic effects by affection of lymphocytes subtypes which can affect the immune system functions in infants. Aim of the Work current study was performed to compare the effect of both conventional and tunnel phototherapy on lymphocytes subsets in term neonates (≥37weeks) with unconjugated hyperbilirubinemia. Patients and Methods The present study was conducted on 60 term neonates (≥37weeks) 40 of them with unconjugated hyperbilirubinemia admitted to NICUs in Ain-Shams University hospital during the period from January 2019 to July 2019. They were randomly assigned to 3 groups: 20 patients were exposed to conventional phototherapy and 20 patients were exposed to tunnel phototherapy and the other 20 healthy full term were assigned as control group. Total serum bilirubin (TSB), direct serum bilirubin (DSB), CBC, CD4 and CD8 percentages and absolute count were measured before and 48 h after phototherapy in the phototherapy groups. Baseline lab was done in the control group at once. Results significant decrease in total and direct bilirubin post-phototherapy in both phototherapy groups proved that tunnel phototherapy is as effective as conventional phototherapy as both provided rapid decrease in bilirubin levels. As regards the effect of phototherapy on lymphocytic count, we found that lymphocytic count significantly decreased post-phototherapy in both phototherapy groups. As regards the effect of phototherapy on CD4+ and CD8+ percentages, we found that CD4+ % significantly decreased postphototherapy in conventional phototherapy group. Moreover, when we measured CD4+ and CD8+ absolute counts, we found that CD4+ and CD8+ absolute counts significantly decreased post-phototherapy in both phototherapy groups. In the view of the effect of phototherapy on CD4/CD8 ratio, we found that the ratio significantly increased in tunnel phototherapy group. Conclusion Conventional and tunnel phototherapy which are used in the treatment of neonatal hyperbilirubinemia, affects the function of the immune system in newborns via alterations in CD4+ and CD8+ absolute counts.

Prognostic Immune Effector Signature in Adult Acute Lymphoblastic Leukemia Patients Is Dominated by γδ T Cells.

The success of immunotherapy has highlighted the critical role of the immune microenvironment in acute lymphoblastic leukemia (ALL); however, the immune landscape in ALL remains incompletely understood and most studies have focused on conventional T cells or NK cells. This study investigated the prognostic impact of circulating γδ T-cell alterations using high-dimensional analysis in a cohort of newly diagnosed adult ALL patients (10 B-ALL; 9 Philadelphia+ ALL; 9 T-ALL). Our analysis revealed common alterations in CD8+ T cells and γδ T cells of relapsed patients, including accumulation of early stage differentiation and increased expression of BTLA and CD73. We demonstrated that the circulating γδ T-cell signature was the most discriminating between relapsed and disease-free groups. In addition, Vδ2 T-cell alterations strongly discriminated patients by relapse status. Taken together, these data highlight the role of ɣδ T cells in adult ALL patients, among whom Vδ2 T cells may be a pivotal contributor to T-cell immunity in ALL. Our findings provide a strong rationale for further monitoring and potentiating Vδ2 T cells in ALL, including in the autologous setting.