Th Cell Subsets Research Articles

Mass cytometry reveals cellular correlates of immune response heterogeneity to SARS-CoV-2 vaccination in the elderly

Heterogeneity in vaccine response, particularly in vulnerable populations like the elderly, represents a significant public health challenge. We conducted an in-depth examination of immune cell profiles before and after SARS-CoV-2 vaccination utilizing mass cytometry in a cohort of healthy Norwegian seniors (65–80 years). We have demonstrated that higher pre-vaccination frequencies of CD27+IgD- class-switched memory B cells and subsets of CD27-CD24+CD38+ transitional B cells were associated with a robust vaccine response. Post-vaccination, high responders exhibited increased frequencies of IFN-γ+CD4+ T cells with antigen recall and a concurrent decrease in CCR6(+) TH cell subset frequencies compared to low responders. The presence of a γδ T cell subset displaying polyfunctional cytokine responses was also associated with better vaccine response in the elderly. This in-depth profiling sheds light on inherent differences in immune cell frequencies and functions that may offer insights for targeted vaccination strategies in older populations.

Virus-specific Th17 Cells Are Induced by Human Cytomegalovirus after Renal Transplantation.

CMV infection and Th17 cells are independently associated with increased risk for late allograft loss after renal transplantation. Although CMV-specific Th17 cells are detectable in animal models and nontransplant clinical populations, evidence linking CMV and Th17 cells after renal transplantation remains unclear. This prospective observational study evaluated a cohort of renal transplant recipients during 12 mo posttransplant to assess the presence of CMV-specific Th17 cells in peripheral blood and their relationship to pretransplant CMV serostatus and CMV DNAemia. CMV-specific Th17 cells were identified among CMV serostatus donor (D)+ and/or recipient (R)+ recipients and expanded during both primary (D+/R-) and reactivated (D+/R+, D-/R+) CMV DNAemia. A subset of CMV-specific Th17 cells coexpressed IFN-γ, indicating a Th1/17 phenotype. These Th17 and Th1/17 cells expressed CCR6, CCR5, activation and terminal differentiation markers (CD95, OX40, HLA-DR, CD57), and a central/effector memory phenotype. CMV-specific Th1/17 cells expressed activating/inhibitory receptors (CD57, 4-1BB, CD160, CTLA-4, PD-1) at higher frequencies than Th17 cells. In contrast, staphylococcal enterotoxin B-induced Th17 cells did not expand during CMV DNAemia, did not differ between CMV serostatus groups over time, expressed CCR6, predominantly coexpressed TNF-α, and had lower expression of activating and inhibitory receptors than pp65-specific Th17 and Th1/17 cells. These data show that CMV-specific Th17 cells expand during episodes of CMV DNAemia among renal transplant recipients, and that these virus-specific Th17 and Th1/17 cells have distinct phenotypes from global circulating Th(1)/17 cells. These results suggest a potential proinflammatory pathway by which CMV-induced Th17 cells may contribute to allograft injury, increasing risk for late allograft loss.

A Paradigm Shift in Tumor Immunology: Th17 Cells and TGF-β in Intestinal Cancer Initiation.

Cancer remains one of the most complex challenges in modern medicine, with intricate relationships between immune responses and tumor development. This article examines a groundbreaking study by Fesneau, Thevin and colleagues, published in Nature Immunology. This elegant body of work explores the link between chronic inflammation and cancer, particularly focusing on Th17 cells involved in intestinal cancer initiation. Th17 cells, known for their dual roles in immunity, can promote or inhibit tumor growth depending on their environment. This study reveals that a specific subset of Th17 cells, derived from IL-17-producing cells, can transition to a tumorigenic state when TGF-β signaling is impaired. Surprisingly, TGF-β acts as a crucial regulatory factor, maintaining the balance between immune tolerance and tumorigenesis by preventing Th17 cells from becoming tumorigenic. This research highlights the potential for therapeutic interventions targeting TGF-β signaling to prevent cancer initiation in chronic inflammatory conditions. The findings have clinical implications for improving cancer immunotherapies, including immune checkpoint inhibitors and adoptive T cell therapies, by enhancing the efficacy of treatments and mitigating the risk of tumorigenic transformations. Overall, this study provides insights into the mechanisms linking inflammation and cancer, paving the way for innovative strategies to harness the immunity in cancer treatment.

Coinhibitory Molecule VISTA Play an Important Negative Regulatory Role in the Immunopathology of Bronchial Asthma.

To investigatethesignificanceofVISTAinbronchialasthma and its impact on the disease. Human peripheral blood of asthma children was gathered. The expressionconcentrationsofVISTA,IL-4,IL-6,CD25,CD40L,andPD-L2 in peripheral blood plasma were detected by ELISA. We established the mouse model of asthma and intervened with agonistic anti-VISTAmAb(4C11) and VISTA fusion protein. ELISA, flow cytometry, and Western blottingwereperformed todetectthe expressionlevels ofTh1,Th2,and Th17 cell subsets and related characteristic cytokines, as well as the protein levels of MAPKs, NF-κB, and TRAF6 in lung tissues. In addition, the infiltration of eosinophils and inflammatory cells, airway mucus secretion, and VISTA protein expression in lung histopathological sections of different groups of mice were analyzed. The concentration of VISTA in human asthma group decreased significantly (p < 0.05); A positive correlation was observed between VISTA and CD40L. The intervention of 4C11mAband fusion protein respectively during the induction period increase the differentiation of Th1cellsandthesecretionofIFN-γ,andinhibitthedifferentiationofTh2 and Th17cells, aswell as the secretion of IL-4, IL-5, IL-13 and IL-17, partially reduce the pathological changes of asthma in mouse lungs and correct the progress of asthma. The MAPK, NF-κB, and TRAF6 protein levels were the middle rangein the4C11mAbandfusion proteingroups (p < 0.05). ThefindingssuggestVISTAmayplayanegativeregulatory role in the occurrence and development of bronchial asthma.

Generation of antigen-specific memory CD4 T cells by heterologous immunization enhances the magnitude of the germinal center response upon influenza infection.

Current influenza vaccine strategies have yet to overcome significant obstacles, including rapid antigenic drift of seasonal influenza viruses, in generating efficacious long-term humoral immunity. Due to the necessity of germinal center formation in generating long-lived high affinity antibodies, the germinal center has increasingly become a target for the development of novel or improvement of less-efficacious vaccines. However, there remains a major gap in current influenza research to effectively target T follicular helper cells during vaccination to alter the germinal center reaction. In this study, we used a heterologous infection or immunization priming strategy to seed an antigen-specific memory CD4+ T cell pool prior to influenza infection in mice to evaluate the effect of recalled memory T follicular helper cells in increased help to influenza-specific primary B cells and enhanced generation of neutralizing antibodies. We found that heterologous priming with intranasal infection with acute lymphocytic choriomeningitis virus (LCMV) or intramuscular immunization with adjuvanted recombinant LCMV glycoprotein induced increased antigen-specific effector CD4+ T and B cellular responses following infection with a recombinant influenza strain that expresses LCMV glycoprotein. Heterologously primed mice had increased expansion of secondary Th1 and Tfh cell subsets, including increased CD4+ TRM cells in the lung. However, the early enhancement of the germinal center cellular response following influenza infection did not impact influenza-specific antibody generation or B cell repertoires compared to primary influenza infection. Overall, our study suggests that while heterologous infection or immunization priming of CD4+ T cells is able to enhance the early germinal center reaction, further studies to understand how to target the germinal center and CD4+ T cells specifically to increase long-lived antiviral humoral immunity are needed.

An intestinal TH17 cell-derived subset can initiate cancer

Approximately 25% of cancers are preceded by chronic inflammation that occurs at the site of tumor development. However, whether this multifactorial oncogenic process, which commonly occurs in the intestines, can be initiated by a specific immune cell population is unclear. Here, we show that an intestinal T cell subset, derived from interleukin-17 (IL-17)-producing helper T (TH17) cells, induces the spontaneous transformation of the intestinal epithelium. This subset produces inflammatory cytokines, and its tumorigenic potential is not dependent on IL-17 production but on the transcription factors KLF6 and T-BET and interferon-γ. The development of this cell type is inhibited by transforming growth factor-β1 (TGFβ1) produced by intestinal epithelial cells. TGFβ signaling acts on the pretumorigenic TH17 cell subset, preventing its progression to the tumorigenic stage by inhibiting KLF6-dependent T-BET expression. This study therefore identifies an intestinal T cell subset initiating cancer.

The role of CD20+ T cells: Insights in human peripheral blood.

CD20+ T cells constitute a small subset of T cells. These are found among CD4+, CD8+, CD4+CD8+, CD4-CD8- T, and TCRγδ+ T cells, and have been poorly characterized. The aim of this study was to characterize peripheral blood (PB) CD20+ T cells and compare them to their PB CD20- T cell counterparts. PB from 17 healthy individuals was collected. The distribution of CD20+ T cells among maturation-associated T cells compartments (naïve, central memory, transitional memory, effector memory, and effector T cells), their polarization, activation status, and expression of immune-regulatory proteins were evaluated by flow cytometry. Their function was also assessed, by measuring IFN-γ, TNF-α, and IL-17 production. Compared with CD20- T cells, CD20+ T cells represent a higher proportion of transitional memory cells. Furthermore, CD20+ T cells display a proinflammatory phenotype, characterized by the expansion of Th1, Th1/17, and Tc1 cell subsets , associated to a high expression of activation (CD25) and exhaustion (PD-1) markers. In addition, the simultaneous production of the proinflammatory cytokines IFN-γ, TNF-α, and IL-17 was also detected in CD4+CD20+ T cells. Our results show that CD20+ T cells are phenotypically and functionally different from CD20- T cells, suggesting that these cells are a distinct subset of T cells.

Metabolism of Inflammatory T helper 17 cells from Type 2 Diabetic Patients

Abstract Around 90% of the 537 million global diabetic adults suffer from type 2 diabetes (T2D), a metabolic disorder marked by heightened blood glucose due to insulin resistance or inadequate insulin production. T2D onset involves chronic systemic inflammation, predominantly influenced by T-helper 17 (Th17) cells. In T2D patients, defective fatty acid metabolic pathways contribute to Th17-driven inflammation. While lipid metabolism's role is established in in vitro Th17 cells, in vivo differentiated Th17 cells remain underexplored due to their low abundance. We addressed this challenge with a novel Th17 cell enrichment assay, capturing CD4+ T cells and magnetically purifying them based on IL-17A/17F/21 secretion for scRNAseq. From this transcriptomic data we established that the subsets of Th17 cells found in mice - pathogenic and non-pathogenic, are also present in humans, and that in vivo differentiated Th17 cells have a unique lipid metabolic phenotype from in vitro differentiated Th17 cells. We also characterized the metabolic state of these Th17 cells by utilizing the metabolic modeling algorithm Compass. Overlaying scRNAseq data from diabetic and control patients, we identified key lipid pathways driving Th17 inflammation in T2D. This pioneering study on endogenous Th17 cells in healthy and T2D patients, coupled with functional validation, unveils potential targets for developing immunotherapy for T2D.

High dimensional proteomic mapping of bone marrow immune characteristics in immune thrombocytopenia.

To investigate the role of co-stimulatory and co-inhibitory molecules on immune tolerance in immune thrombocytopenia (ITP), this study mapped the immune cell heterogeneity in the bone marrow of ITP at the single-cell level using Cytometry by Time of Flight (CyTOF). Thirty-six patients with ITP and nine healthy volunteers were enrolled in the study. As soluble immunomodulatory molecules, more sCD25 and sGalectin-9 were detected in ITP patients. On the cell surface, co-stimulatory molecules like ICOS and HVEM were observed to be upregulated in mainly central memory and effector T cells. In contrast, co-inhibitory molecules such as CTLA-4 were significantly reduced in Th1 and Th17 cell subsets. Taking a platelet count of 30×109 L-1 as the cutoff value, ITP patients with high and low platelet counts showed different T cell immune profiles. Antigen-presenting cells such as monocytes and B cells may regulate the activation of T cells through CTLA-4/CD86 and HVEM/BTLA interactions, respectively, and participate in the pathogenesis of ITP. In conclusion, the proteomic and soluble molecular profiles brought insight into the interaction and modulation of immune cells in the bone marrow of ITP. They may offer novel targets to develop personalized immunotherapies.

Bhlhe40 Promotes CD4+ T Helper 1 Cell and Suppresses T Follicular Helper Cell Differentiation during Viral Infection.

In response to acute infection, naive CD4+ T cells primarily differentiate into T helper 1 (Th1) or T follicular helper (Tfh) cells that play critical roles in orchestrating cellular or humoral arms of immunity, respectively. However, despite the well established role of T-bet and BCL-6 in driving Th1 and Tfh cell lineage commitment, respectively, whether additional transcriptional circuits also underlie the fate bifurcation of Th1 and Tfh cell subsets is not fully understood. In this article, we study how the transcriptional regulator Bhlhe40 dictates the Th1/Tfh differentiation axis in mice. CD4+ T cell-specific deletion of Bhlhe40 abrogates Th1 but augments Tfh differentiation. We also assessed an increase in germinal center B cells and Ab production, suggesting that deletion of Bhlhe40 in CD4+ T cells not only alters Tfh differentiation but also their capacity to provide help to B cells. To identify molecular mechanisms by which Bhlhe40 regulates Th1 versus Tfh lineage choice, we first performed epigenetic profiling in the virus specific Th1 and Tfh cells following LCMV infection, which revealed distinct promoter and enhancer activities between the two helper cell lineages. Furthermore, we identified that Bhlhe40 directly binds to cis-regulatory elements of Th1-related genes such as Tbx21 and Cxcr6 to activate their expression while simultaneously binding to regions of Tfh-related genes such as Bcl6 and Cxcr5 to repress their expression. Collectively, our data suggest that Bhlhe40 functions as a transcription activator to promote Th1 cell differentiation and a transcription repressor to suppress Tfh cell differentiation.

Single-cell molecular signature of pathogenic T helper subsets in type 2-associated disorders in humans.

To unravel the heterogeneity and molecular signature of effector memory Th2 cells (Tem2), we analyzed 23 individuals' PBMCs of filaria-infected (Filaria+) and 24 healthy volunteers (Filaria-), with or without coincident house dust mite (HDM) allergic sensitization. Flow cytometry revealed 3 CD4+ Tem subsets - CCR4+CCR6+CRTH2- Tem17, CCR4+CCR6-CRTH2+ Tem2, and CCR6+CCR4+CRTH2+ Tem17.2 - markedly enriched in Filaria+ individuals. These subsets were sorted and analyzed by multiomic single-cell RNA immunoprofiling. SingleR-annotated Th2 cells from Tem2 and Tem17.2 cell subsets had features of pathogenic Th2 effector cells based on their transcriptional signatures, with downregulated CD27 and elevated expression levels of ITGA4, IL17RB, HPGDS, KLRB1, PTGDR2, IL9R, IL4, IL5, and IL13 genes. When the Filaria+ individuals were subdivided based on their allergic status, Tem2 cells in HDM+Filaria+ individuals showed an overall reduction in TCR diversity, suggesting the occurrence of antigen-driven clonal expansion. Moreover, HDM+Filaria+ individuals showed not only an expansion in the frequency of both Tem2 and Tem17.2 cell subsets, but also a change in their molecular program by overexpressing GATA3, IL17RB, CLRF2, and KLRB1, as well as increased antigen-induced IL-4, IL-5, and IL-13 production, suggesting that aeroallergens reshape the transcriptional and functional programming of Th2 cell subsets in human filarial infection toward a pathogenic immunophenotype.

Off-label use of Baricitinib improves moderate and severe atopic dermatitis in China through inhibiting MAPK and PI3K/Akt/mTOR pathway via targeting JAK-STAT signaling of CD4+ cells.

As an inflammatory disease with a disrupted immune system, cytokine disorders in atopic dermatitis (AD) are closely related to the abnormal activation of JAK-STAT signal pathway. The critical relevance of the JAK-STAT signaling pathway to the pathogenesis of AD provides a strong rationale for JAK inhibitor research. Baricitinib, a small-molecule oral JAK inhibitor, has been proven to inhibit JAK-STAT signaling in a variety of diseases, including AD. It is currently available in China for off-label use. However, its efficacy in China and its mechanism are rarely reported. In our study, we found that the immune status of patients with moderate and severe AD was hyperactive. Among the 49 known immunotherapy targets, JAK1 and JAK2 genes on lymphocytes of AD patients were significantly upregulated, which was closely related to the symptom severity in moderate and severe AD patients. Baricitinib can improve immune hyperresponsiveness and clinical symptoms in moderate and severe AD by inhibiting the activation of Th2 cell subsets and the secretion of Th2-type cytokines through MAPK, mTOR and PI3K-Akt signaling pathways, providing an important theoretical basis for clinical off-label use of Baricitinib to treat moderate and severe AD.

Therapeutic Potential of IL-1 Antagonism in Hidradenitis Suppurativa.

The immunopathogenesis of HS is partially understood and exhibits features of an autoinflammatory disease; it is associated with the potential involvement of B cells and the contribution of Th1 or Th17 cell subsets. Recently, the pathogenic role of both innate immunity and IL-1 family cytokines in HS has been deeply investigated. Several agents targeting the IL-1 family pathway at different levels are currently available and under investigation for the treatment of HS. HS is still characterized by unmet clinical needs and represents an expanding field in the current scientific research. The aim of this narrative review is to describe the pathological dysregulation of IL-1 family members in HS and to provide an update on therapeutic strategies targeting IL-1 family cytokine signaling. Further clinical and preclinical data may likely lead to the enrichment of the therapeutic armamentarium of HS with IL-1 family cytokine antagonists.

Th-Cell Subsets of Submandibular Lymph Nodes in Peri-Implantitis.

Implant surgery is a popular operation in craniomaxillofacial surgery, but the occurrence of peri-implantitis affects the success and survival rate of the implant. Research has found that Th-cell-related cytokines are associated with peri-implantitis. However, the distribution and proportions of Th-cell subsets in submandibular lymph nodes' immune environments during the progression of peri-implantitis remain unclear. Forty-eight rats were randomly divided into 4 groups: the control group, the 1-week ligation peri-implantitis induction (Lig 1w) group, the Lig 2w group, and the Lig 4w group (n=12). Ligation was maintained for different times to induce peri-implantitis 4 weeks after implantation. Inflammation and bone resorption were examined by clinical probing and micro-CT. The submandibular lymph nodes were harvested for quantitative real-time polymerase chain reaction and flow cytometry to obtain the Th-cell profiles. With increasing ligation time, more redness and swelling in the gingiva and more bone resorption around the implant were observed ( P <0.05). The proportions of Th1 and Th17 cells increased, the proportion of Th2 cells decreased, and the proportion of Treg cells first increased and then decreased in the lymph nodes ( P <0.05). This study provided a preliminary characterization of the temporal distribution of Th cells in lymph nodes of peri-implantitis. Persistent elevation of Th1 and Th17 proportions and decrease of Treg proportion may be the cause of bone resorption in peri-implantitis. Lymphatic drainage may be a bridge between craniomaxillofacial diseases and systemic diseases. Early immune support against T cells may be a potential therapeutic idea for the prevention of implant failure and the potential risk of systemic disease.

Cirrhosis-downregulated LSECtin can be retrieved by cytokines, shifts the TLR-induced LSECs secretome and correlates with the hepatic Th response.

We evaluated tolerogenic C-type lectin LSECtin loss in cirrhosis and its potential regulation by cytokines. Liver tissue from patients with cirrhosis and healthy controls, immortalised and generated LSECtin-CRISPR immortalised LSECs, and murine primary LSECs from the CCl4 model were handled. LSECtin expression was reduced in liver tissue from cirrhotic patients, and it decreased from compensated to decompensated disease. Increased phosphorylation of MAPK, Akt and NFkB was observed upon LSECtin stimulation in LSEC murine cell line, showing a pattern of inflammatory and chemotactic cytokines either restrained (IL-10, CCL4) or unrestrained (TNF-α, IL-1β, IL-6, CCL2). CD44 attenuated whereas LAG-3 increased all substrates phosphorylation in combination with TLR4 and TLR2 ligands except for NFkB. TNF-α, IL-1 β, IL-6 and CCL2 were restrained by LSECtin crosslinking on TLRs studied. Conversely, IL-10 and CCL4 were upregulated, suggesting a LSECtin-TLRs synergistic effect. Also, LSECtin was significantly induced after IL-13 stimulation or combined with anti-inflammatory cytokines in cirrhotic and immortalised LSECs. Th17 and regulatory T cells were progressively increased in the hepatic tissue from compensated to decompensated patients. A significant inverse correlation was present between gene expression levels of CLEC4G/LSECtin and RORγT and FOXP3 in liver tissues. LSECtin restrains TLR proinflammatory secretome induced on LSECs by interfering immune response control, survival and MAPKs signalling pathways. The cytokine-dependent induction of LSECtin and the association between LSECtin loss and Th17 cell subset expansion in the liver, provides a solid background for exploring LSECtin retrieval as a mechanism to reprogram LSEC homeostatic function hampered during cirrhosis.

High-parameter phenotypic characterization reveals a subset of human Th17 cells that preferentially produce IL-17 against M. tuberculosis antigen.

Interleukin-17-producing CD4 T cells contribute to the control of Mycobacterium tuberculosis (Mtb) infection in humans; whether infection with human immunodeficiency virus (HIV) disproportionately affects distinct Th17-cell subsets that respond to Mtb is incompletely defined. We performed high-definition characterization of circulating Mtb-specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by liquid chromatography-mass spectrometry (LC/MS) on plasma and tested the hypothesis that tryptophan catabolism influences Th17-cell frequencies in this context. We identified two subsets of Th17 cells: subset 1 defined as CD4+Vα7.2-CD161+CD26+and subset 2 defined as CD4+Vα7.2-CCR6+CXCR3-cells of which subset 1 was significantly reduced in latent tuberculosis infection (LTBI) with HIV-ART, yet Mtb-responsive IL-17-producing CD4 T cells were preserved; we found that IL-17-producing CD4 T cells dominate the response to Mtb antigen but not cytomegalovirus (CMV) antigen or staphylococcal enterotoxin B (SEB), and tryptophan catabolism negatively correlates with both subset 1 and subset 2 Th17-cell frequencies. We found differential effects of ART-suppressed HIV on distinct subsets of Th17 cells, that IL-17-producing CD4 T cells dominate responses to Mtb but not CMV antigen or SEB, and that kynurenine pathway activity is associated with decreases of circulating Th17 cells that may contribute to tuberculosis immunity.

Significance of Tim-3 and Its Ligand Galectin-9 in Th1/Th2 Imbalance in Patients with Multiple Myeloma

To investigate the significance of Tim-3 and Galectin-9 in Th1/Th2 imbalance in patients with multiple myeloma (MM). 55 newly diagnosed MM patients and 20 healthy controls were included. Flow cytometry was used to detect the expression of Tim-3 on CD4+T cells, the proportion of Th1, Th2, Tim-3+Th1 and Tim-3+Th2 cells in peripheral blood. ELISA was used to detect the levels of cytokines IFN-γ and IL-4 in serum, and PCR was used to detect the level of Galectin-9 mRNA. Then the correlations between Galectin-9 mRNA expression and Th-cell subsets and related cytokine levels, as well as the relationship between Tim-3+Th1/Tim-3+Th2 ratio and corresponding clinical features were analyzed. Compared with the control group, the expression of Tim-3 on CD4+T cells in peripheral blood of MM patients was significantly increased (P<0.05), the proportions of Tim-3+Th1 cells, Tim-3+Th2 cells and Tim-3+Th1/Tim-3+Th2 ratio in MM patients were also increased (P<0.05), while the proportion of Th1 cells and Th1/Th2 ratio in MM patients were significantly decreased (P<0.05). The level of cytokine IFN-γ and IFN-γ/IL-4 ratio in MM patients were significantly decreased (P<0.05), while the level of cytokine IL-4 was increased (P<0.05). The mRNA levels of Galectin-9 in MM patients were significantly increased (P<0.05). The levels of Galectin-9 mRNA were positively correlated with Tim-3+CD4+T cells (r=0.663), Tim-3+Th2 cells (r=0.492) and IL-4 (r=0.470), while negatively correlated with IFN-γ (r=-0.593). The ratios of Tim-3+Th1/Tim-3+Th2 in MM patients were positively correlated with ISS stage (r=0.511), osteolytic damage (r=0.556) and chromosome abnormality (r=0.632). These results suggest that Tim-3 and Galectin-9 are involved in Th1/Th2 imbalance in MM patients, and the high ratio of Tim-3+Th1/Tim-3+Th2 is associated with poor clinical prognosis.

Immune cell profiles of idiopathic inflammatory myopathy patients expressed anti-aminoacyl tRNA synthetase or anti-melanoma differentiation-associated gene 5 autoantibodies

BackgroundPatients with idiopathic inflammatory myopathy (IIM) often express a different type of myositis-specific autoantibodies (MSAs), each associated with different clinical symptoms. Understanding the immunopathogenesis of various IIM subgroups can help improve the diagnosis and prognosis of IIM patients with different MSAs. However, the immune cell profiles of these IIM patients with anti-aminoacyl tRNA synthetase (ARS) or anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies remain unclear. We focused on the immune cell profiles of IIM patients with anti-ARS or anti-MDA5 autoantibodies.ResultsThe peripheral blood from IIM patients with anti-MDA5 autoantibody (MDA5 + group, n = 24) or one of the anti-ARS autoantibodies (ARS + group, n = 40) autoantibodies, and healthy controls (HC group, n = 60) were collected and examined. We found that IIM patients had a lower CD3 T cell population compared to the HC group. IIM patients showed a significantly lower TN cell population and a higher TEMRA cell population. Higher Th17 and Treg cell populations were found in these IIM patients than in the HC group. In these IIM patients, the MDA5 + group exhibited the higher percentages of Th17 and Treg cells than the ARS + group. It is noteworthy that the percentage of Th1 cells in the survival subgroup was higher than in the death subgroup in IIM patients with ARS + or MDA5 + . Furthermore, in the MDA5 + group, the percentage of Treg cells was higher in the survival subgroup compared to the death subgroup.ConclusionsOur study demonstrated that elevated Th1 may be a good prognostic indicator in IIM patients with ARS + or MDA5 + . Elevated Treg may also help predict a good prognosis in MDA5 + IIM patients. However, more large-scale studies and clinical samples are needed to verify the significance of Th1 and Treg cell subsets in clinical outcomes for these IIM patients with ARS + or MDA5 + . These data may help design a therapeutic approach that specifically targets the pathogenic immune molecular responsible for autoimmune attacks in IIM.

T-cell subsets in allergy and tolerance induction.

Antigen-specific T lymphocytes are the central regulators of tolerance versus immune pathology against otherwise innocuous antigens and key targets of antigen-specific immune therapy. Recent advances in the understanding of T cells in tolerance and allergy resulted from improved technologies to directly characterize allergen-specific T cells by multiparameter flow cytometry or single-cell sequencing. This unravelled phenotypically and functionally distinct populations, such as Type 2a T helper cells (Th2a), follicular Th cells (Tfh), regulatory T cells (Treg),Type 1 regulatory T cells (Tr1), and follicular T regulatory cells. Here we will discuss the role of the different Th-cell subsets in the healthy state, during sensitization and development of allergy, and in tolerance induction by allergen immunotherapy (AIT). To date, the mechanisms of AIT as the only causal treatment of allergy are not completely understood. The analyses of allergen-specific T cells directly ex vivo during AIT support the concept of specific-Th2(a) cell deletion rather than an expansion of allergen-specific Tr1 or Treg cells as underlying mechanism.

An Intestinal Th17 Subset is Associated with Inflammation in Crohn's Disease and Activated by Adherent-invasive Escherichia coli.

IFNγ-producing ex-Th17 cells ['Th1/17'] were shown to play a key pathogenic role in experimental colitis and are abundant in the intestine. Here, we identified and characterised a novel, potentially colitogenic subset of Th17 cells in the intestine of patients with Crohn's disease [CD]. Human Th17 cells expressing CCR5 ['pTh17'] co-expressed T-bet and RORC/γt and produced very high levels of IL-17, together with IFN-γ. They had a gene signature of Th17 effector cells and were distinct from established Th1/17 cells. pTh17 cells, but not Th1/17 cells, were associated with intestinal inflammation in CD, and decreased upon successful anti-TNF therapy with infliximab. Conventional CCR5[-]Th17 cells differentiated to pTh17 cells with IL-23 in vitro. Moreover, anti-IL-23 therapy with risankizumab strongly reduced pTh17 cells in the intestine. Importantly, intestinal pTh17 cells were selectively activated by adherent-invasive Escherichia coli [AIEC], but not by a commensal/probiotic E. coli strain. AIEC induced high levels of IL-23 and RANTES from dendritic cells [DC]. Intestinal CCR5+Th1/17 cells responded instead to cytomegalovirus and were reduced in ulcerative colitis [UC], suggesting an unexpected protective role. In conclusion, we identified an IL-23-inducible subset of human intestinal Th17 cells. pTh17 cells produced high levels of pro-inflammatory cytokines, were selectively associated with intestinal inflammation in CD, and responded to CD-associated AIEC, suggesting a key colitogenic role.