Cell Subsets In Patients Research Articles

S2778 Ulcerative Colitis and Concomitant Pulmonary Sarcoidosis Leading to Colectomy: A Case Series

Introduction: A recent analysis of 24 cases of ulcerative colitis (UC) with concomitant sarcoidosis found a common HLA serotype (Toshiyuki 2021), however its role in disease severity is unknown. We describe 2 pulmonary sarcoidosis patients with rapidly progressing refractory UC needing colectomy. Case Description/Methods: A 45-year-old male presented with 15-20 episodes of hematochezia a day with nocturnal bowel movements. He was diagnosed with UC and started on mesalamine and vedolizumab. He did not respond and was switched to multiple biologics including ustekinumab, adalimumab and infliximab. He ultimately underwent total colectomy within 1 year of diagnosis. He was diagnosed with pulmonary sarcoidosis 10 years prior, presenting with weight loss and chest pain. Prior to his UC diagnosis, he was not taking steroids for his pulmonary disease. His annual pulmonary function tests had been normal. A 52-year-old female presented with 3 months of hematochezia and anemia. She was treated for gastroenteritis but was hospitalized due to minimal improvement. Imaging, endoscopy, and histology confirmed colitis, thought to be Crohn’s disease (CD) but later reclassified as UC. She was started on infliximab but was a primary non-responder. After 1 year of therapy she was switched to vedolizumab but received 3 doses before switching to ustekinumab. Soon after induction, her symptoms warranted hospitalization, and colectomy was performed 3 years after diagnosis. She was diagnosed with pulmonary sarcoidosis 3 years prior to her UC diagnosis and had been on daily low-dose prednisone since then. (Figure) Discussion: Our patients were diagnosed with sarcoidosis well before their UC and had rapidly progressing disease despite biologic therapy requiring colectomy. Most studies address the link between CD and sarcoidosis. Increased CD4/CD8 ratios are specific for sarcoidosis with similar expansion of T cell subsets in patients with CD. Both have been observed more often among siblings and monozygotic twins suggesting a genetic component. A similar analysis has not been performed in UC patients. To date, there is only one case that found specific HLA serotypes associated with both UC and sarcoidosis. In addition, sarcoidosis was thought to lead to less penetrative disease and fewer colectomies. This contrasts with the cases presented here, which both progressed to colectomy within 3 years of diagnosis. Thus, more studies need to be conducted in patients with UC and sarcoidosis to further elucidate the prognosis and potential complications.Figure 1.: Diffuse severe inflammation characterized by erythema, friability and deep ulcerations of the rectum (Fig 1a. and 1b.). Less severe inflammation characterized by erythema of the sigmoid colon (Fig 2a. and 2b.).

Epstein-Barr virus perpetuates B cell germinal center dynamics and generation of autoimmune-associated phenotypes in vitro.

Human B cells encompass functionally diverse lineages and phenotypic states that contribute to protective as well as pathogenic responses. Epstein-Barr virus (EBV) provides a unique lens for studying heterogeneous B cell responses, given its adaptation to manipulate intrinsic cell programming. EBV promotes the activation, proliferation, and eventual outgrowth of host B cells as immortalized lymphoblastoid cell lines (LCLs) in vitro, which provide a foundational model of viral latency and lymphomagenesis. Although cellular responses and outcomes of infection can vary significantly within populations, investigations that capture genome-wide perspectives of this variation at single-cell resolution are in nascent stages. We have recently used single-cell approaches to identify EBV-mediated B cell heterogeneity in de novo infection and within LCLs, underscoring the dynamic and complex qualities of latent infection rather than a singular, static infection state. Here, we expand upon these findings with functional characterizations of EBV-induced dynamic phenotypes that mimic B cell immune responses. We found that distinct subpopulations isolated from LCLs could completely reconstitute the full phenotypic spectrum of their parental lines. In conjunction with conserved patterns of cell state diversity identified within scRNA-seq data, these data support a model in which EBV continuously drives recurrent B cell entry, progression through, and egress from the Germinal Center (GC) reaction. This “perpetual GC” also generates tangent cell fate trajectories including terminal plasmablast differentiation, which constitutes a replicative cul-de-sac for EBV from which lytic reactivation provides escape. Furthermore, we found that both established EBV latency and de novo infection support the development of cells with features of atypical memory B cells, which have been broadly associated with autoimmune disorders. Treatment of LCLs with TLR7 agonist or IL-21 was sufficient to generate an increased frequency of IgD-/CD27-/CD23-/CD38+/CD138+ plasmablasts. Separately, de novo EBV infection led to the development of CXCR3+/CD11c+/FCRL4+ B cells within days, providing evidence for possible T cell-independent origins of a recently described EBV-associated neuroinvasive CXCR3+ B cell subset in patients with multiple sclerosis. Collectively, this work reveals unexpected virus-driven complexity across infected cell populations and highlights potential roles of EBV in mediating or priming foundational aspects of virus-associated immune cell dysfunction in disease.

Detection of rare autoreactive T cell subsets in patients with pemphigus vulgaris.

Analysis of T lymphocyte proliferation and activation after antigenic or mitogenic stimulation is a vital parameter used in the diagnosis of various immuno-deficiencies and during the monitoring of treatment responses. Most applied techniques are based on the incorporation of tritiated thymidine (3H-TdR) or ELISPOT analysis, both rely on rather time-consuming/-intensive ex vivo protocols or encompass inherent drawbacks such as the inability to distinguish specific cell populations (3H-TdR, ELISPOT) or focus on a single cytokine (ELISPOT). Here we aimed at characterizing the rapid expression of intracellular CD154 (CD40L) as a marker for rare antigen-specific CD4+ T cells in pemphigus vulgaris (PV). Upon stimulation with human desmoglein (Dsg) 3, the major autoantigen in PV, the expression of CD154 was significantly increased in PV patients compared to healthy controls (HC) and correlated with anti-Dsg3 IgG titers. Patients with active disease showed higher numbers of Dsg3-reactive CD4+ T cells in CXCR5+ T follicular helper cells. In remittent PV and HC, CXCR5+CD4+ T cells remained largely unaffected by Dsg3. IL-17 and IL-21 expression were significantly induced only in CD154+CD4+ T cells from PV patients, lending themselves as potential novel treatment targets. Additionally, stimulation with immunodominant Dsg3-derived epitopes strongly induced a CD4+ T cell response via CD40-CD154 interaction similar to the human Dsg3 protein. We here established a rapid ex vivo assay allowing the detection of Dsg3-reactive CD4+ T cells from activated systemically available PBMCs, which further supports the crucial concept of antigen-specific T cells in the pathogenesis of PV.

Aberrant expansion of follicular helper T cell subsets in patients with systemic lupus erythematosus.

ObjectiveSystemic lupus erythematosus (SLE) is a chronic and complex autoimmune disease characterized by multiple autoantibodies, resulting in multiple organ and tissue damages. These pathogenic autoantibodies produced by B cells are closely correlated with follicular helper T (Tfh) cell subsets that play a fundamental role in the pathogenesis of SLE. The aim of the present study was to study the phenotype and role of circulating Tfh (cTfh) cell subsets and associated B cell subpopulations in active and inactive SLE patients.MethodsThirty SLE outpatients and 24 healthy controls (HCs) were enrolled in this study. The frequency of cTfh cell and B cell subsets in peripheral blood mononuclear cells (PBMCs) and the plasma levels of eight cytokines were determined by flow cytometry, and plasma IL-21 levels were measured by ELISA. Meanwhile, we used MRL/lpr mice as the model of SLE to research the alterations of Tfh cells in the thymus and spleen of mice.ResultsFrequencies of CD4+CXCR5+CD45RA-effector cTfh cells, PD1+cTfh, PD1+ICOS+cTfh, PD1+cTfh1, PD1+cTfh2, PD1+cTfh17, and PD1+ICOS+cTfh1 cells as well as plasmablasts showed significant differences among HC, active and inactive SLE patients. Moreover, cytokines typically associated with cTfh cells, including IL-6 and IL-21, were elevated in active SLE patients compared to inactive SLE patients and HCs. Additionally, a positive correlation was observed between PD1+ICOS+ cTfh or PD1+ICOS+ cTfh1 cell frequencies and plasmablasts or IL-21 levels, as well as between plasmablasts. We also found PD1+ICOS+ Tfh cells expansion in both thymus and spleen of MRL/lpr mice, accompanied by increased frequencies in B cells and plasmablasts, meanwhile, cTfh1which expressing IFN-γ was increased in the peripheral blood of MRL/lpr mice.ConclusionTfh cell subsets and plasmablasts may play a fundamental role in the pathogenesis of SLE and may provide potential targets for therapeutic interventions for SLE.

Levels of Pathogenic Th17 and Th22 Cells in Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune condition characterized, among others, by tissue damage and activation/differentiation of proinflammatory lymphocytes. Accordingly, several studies have concluded that type 17 T helper (Th17) cells seem to have an important role in the pathogenesis of this condition. However, the strategy for the identification and analysis of proinflammatory Th17 cells in those studies has not been consistent and has usually been different from what was originally described. Therefore, we decided to evaluate the levels of Th17 cells in patients with RA employing an extended immune phenotype by using an eight-color multiparametric flow cytometry analysis. For this purpose, blood samples were obtained from 30 patients with RA and 16 healthy subjects, and the levels of Th17 and type 22 helper (Th22) lymphocytes were analyzed as well as the in vitro differentiation of peripheral blood mononuclear cells into Th17 lymphocytes induced by interleukin-23 (IL-23) and IL-1β. We found significant enhanced levels of total Th17 lymphocytes (defined as CD4+IL-17+) as well as enhanced numbers of their pathogenic (defined as CD4+CXCR3+IL-17+IL-22+CD243+CD161+IFN-γ+IL-10−) and nonpathogenic (CD4+CXCR3+IL-17+IL-22−CD243−CD161−IFN-γ−IL-10+) cell subsets in patients with RA. Likewise, the number of Th22 (CD4+CXCR3+/-IL-17−IL-22+) was also increased in these patients compared to healthy controls. However, the in vitro induction/differentiation of pathogenic Th17 cells showed similar results in controls and patients with RA. Likewise, no significant associations were detected in patients with RA between the levels of Th17 or Th22 cells and clinical or laboratory parameters. Our data indicate that patients with RA show enhanced blood levels of the different subsets of Th17 cells and Th22 lymphocytes tested in this study and suggest that these levels are not apparently associated with clinical or laboratory parameters.

P-049: Detection of multiple myeloma cell load by multiple-color flow cytometry as a useful approach for analyzing immune cell subsets in patients

P-049: Detection of multiple myeloma cell load by multiple-color flow cytometry as a useful approach for analyzing immune cell subsets in patients

Impact of Corticosteroids on the Proportions of Circulating Tfh Cell Subsets in Patients With Systemic Lupus Erythematous.

ObjectivesThis study aimed to analyze the distribution of T follicular helper (Tfh) cells in lupus patients, and the effects of steroids on circulating Tfh cells.MethodsCirculating Tfh cell subsets were defined by multicolor flow cytometry as Tfh17, Tfh2 or Tfh1 subpopulations of CXCR5+CD45RA–CD4+ T cells in the peripheral blood of SLE patients and healthy controls. To test the effects of corticosteroid on Tfh cells, PBMC harvested from both SLE and healthy controls were cocultured with dexamethasone, and then analyzed by Flow cytometry.ResultsThe proportion of Tfh17 cells in SLE patients was increased significantly compared with healthy controls. Additionally, patients with an active disease had reduced Tfh1 subsets than those with an inactive disease and healthy controls. The frequency of Tfh2 cells was associated with the proportion of circulating plasmablasts and the amount of anti-dsDNA. Dexamethasone reduced the percentage of Tfh2 cells while increased the proportion of Tfh17 subset in gated CXCR5+CD45RA–CD4+ T cells.ConclusionOur study investigated the distribution of circulating Tfh subsets in lupus patients. Corticosteroids treatment not only down-regulated the proportion of circulating Tfh cells, but also altered the distribution of Tfh subsets in vivo and in vitro.

Plasma Signaling Factors in Patients With Langerhans Cell Histiocytosis (LCH) Correlate With Relative Frequencies of LCH Cells and T Cells Within Lesions.

Langerhans cell histiocytosis (LCH) lesions contain an inflammatory infiltrate of immune cells including myeloid-derived LCH cells. Cell-signaling proteins within the lesion environment suggest that LCH cells and T cells contribute majorly to the inflammation. Foxp3+ regulatory T cells (Tregs) are enriched in lesions and blood from patients with LCH and are likely involved in LCH pathogenesis. In contrast, mucosal associated invariant T (MAIT) cells are reduced in blood from these patients and the consequence of this is unknown. Serum/plasma levels of cytokines have been associated with LCH disease extent and may play a role in the recruitment of cells to lesions. We investigated whether plasma signaling factors differed between patients with active and non-active LCH. Cell-signaling factors (38 analytes total) were measured in patient plasma and cell populations from matched lesions and/or peripheral blood were enumerated. This study aimed at understanding whether plasma factors corresponded with LCH cells and/or LCH-associated T cell subsets in patients with LCH. We identified several associations between plasma factors and lesional/circulating immune cell populations, thus highlighting new factors as potentially important in LCH pathogenesis. This study highlights plasma cell-signaling factors that are associated with LCH cells, MAIT cells or Tregs in patients, thus they are potentially important in LCH pathogenesis. Further study into these associations is needed to determine whether these factors may become suitable prognostic indicators or therapeutic targets to benefit patients.

Modulation of Peripheral Immune Cell Subpopulations After RapidArc/Moderate Hypofractionated Radiotherapy for Localized Prostate Cancer: Findings and Comparison With 3D Conformal/Conventional Fractionation Treatment.

Radiotherapy (RT) is an important therapeutic option in patients with localized prostate cancer (PC). Unfortunately, radiation treatment causes a decrease in peripheral lymphocytes and, consequently, influences the patients’ immune status. Our aim was to study changes in peripheral blood immune cell subpopulations after RT and during 6 months’ follow-up in 2 groups of PC patients irradiated with different techniques and dose fractions with curative intent. We also investigated the presence of correlation between immune cell modulation and genitourinary or gastrointestinal toxicity. We enrolled 44 patients treated with curative RT (RapidArc/hypofractionation regimen or 3D conformal/conventional fractionation) for localized PC. Total white blood cell (WBC), absolute lymphocyte counts (ALCs), and peripheral immune cell subpopulations were analyzed at baseline, at the end of RT, and 3 and 6 months after the end of RT. WBC and ALC greatly decreased at the end of RT with a trend to recover at 6 months’ follow-up in the hypofractionation group but not in the conventional one. Furthermore, B, total T, T CD4+, T CD8+, and NK cell values dropped significantly in both groups at the end of RT, with a minor decrease detectable in the hypofractionation group for B, total T, and T CD4+ lymphocytes with respect to the other technique/fractionation group. Double-negative T (DNT), double-positive T (DPT), and NKT cells significantly decreased at the end of RT with a slight tendency to recover values during follow-up, particularly in the hypofractionation group. No correlation with genitourinary or gastrointestinal toxicity was found. In this study, we showed, for the first time, the effects of RapidArc/moderate hypofractionation RT on immune cell subsets in patients treated for localized PC. Due to the growing interest in minority T-cell subpopulations for immunotherapy, we also reported longitudinal monitoring of the effects of RT on DNT, DPT, and NKT, which was never studied before. Our preliminary data highlight the importance of considering the effects of different RT techniques/fractionation regimens on peripheral immune cells, in the era of RT and immunotherapy combination.

The ratio of PD1+CD8+T cells in stromal area of tumor tissue is associated with the effect of neoadjuvant chemotherapy in HER2 negative breast cancer patients.

e12626 Background: For patients diagnosed with early breast cancer, surgery remains the standard of care. Early patients achieving pathological complete response (pCR) after neoadjuvant therapy have been proved to be associated with improved survival. However, the accurate prediction of pCR in a clinical setting remains challenging. Tumor infiltrating lymphocyte (TIL) levels have recently been identified as an independent predictor of pCR in breast cancer. However, due to extremely complex tumor microenvironment within tumor, the role of different immune cell subtypes in neoadjuvant chemotherapy (NAC) is inconclusive. This study aimed to explore the potentially predictive role and dynamic changes of immune cell subsets in patients with HER2 negative breast cancer receiving NAC. Methods: Since January 2020, tumor tissue samples of 12 HER2 negative breast cancer patients were collected at baseline and after NAC. Several kinds of immune cells including CD3+T cells, CD4+T cells, CD8+T cells, PD-1+CD8+T cells, Tregs, M1/M2 tumor associated macrophages(TAM), PD-L1+CD68+TAM, B cells, CD56bright NK cells and CD56dim NK cells in the tumor tissue were evaluated by multiple fluorescence immunohistochemistry (mIHC) and counted in intratumoral and stromal area for density and ratio. T test was used for the comparison of immune cells and statistical significance was set at p = 0.05. Results: We examined immune cell subtypes and PD-L1/PD-1 expression of 12 HER2 negative breast cancer patients. According to achieving pCR or not, these 12 patients were divided into two groups, pCR (n = 3) and non-pCR group (n = 9). The results showed that the ratio of PD1+CD8+T cells in stromal area of baseline tumor tissue of pCR group was significantly higher than non-pCR group (median ratio, pCR group vs. non-pCR group = 17.3% vs. 3.6%, p = 0.029).In addition, the ratio of PD1+CD8+T cells in stromal area of pCR group was still significantly higher than that of non pCR patients after NAC (median ratio, pCR group vs. non-pCR group = 20.7% vs. 2.6%, p = 0.0003). Conclusions: Whether at baseline or after NAC, the ratio of PD1+CD8+T cells in stromal area is associated with the effect of NAC in HER2 negative breast cancer.

Phenotypical changes and clinical significance of CD4+/CD8+ T cells in SLE

ObjectiveT cells display significant phenotypical changes and play multiple roles in promoting the immune response in SLE. The frequencies of T cell subpopulations in SLE are still not well understood....

Circulating T regulatory cell subsets in patients with untreated lung cancer.

Regulatory T Cells (Tregs) play an important role in carcinogenesis and tumor immunoediting by preventing the development of effective antitumor immunity. Several reports showed that circulating Tregs are increased in patients with solid tumors, including lung cancer. Treg population could be categorized into "naive," "effector," and "memory" subtypes, bearing potential unique functions. However, the data regarding the prognostic impact of these Tregs subtypes is limited in lung cancer. The aim of this study was to investigate the frequency of different circulating Tregs subtypes in lung cancer and their correlation with clinical outcomes. We analyzed the frequency of circulating CD4, CD8 and, Tregs lymphocytes in 66 patients with lung cancer and 32 healthy controls using flow cytometry. Circulating Tregs subtypes: naïve (CD3+ , CD4+ , CCR4+ , CD25+ and CD127low, CD45RO-), memory (CD3+ , CD4+ , CCR4+ , CD25+ and CD127low, CD45RO+) and the expression of the activation marker HLA-DR were correlated with overall survival. The percentage and the absolute number of total, memory and activated Tregs was significantlyhigher in lung cancer patients than healthy controls. Patients with a Tregs percentage higher than 5.4% and higher than 20% of HLA-DR + Tregs had worse overall survival than those with lower levels. Circulating Tregs and activated Tregs are a potential prognostic factor in patients with lung cancer treated with conventional therapy and could be considered a predictive biomarker in patients not eligible for immune blockade treatments. Additionally, it will be interesting to study these Tregs subsets for immune treatments in future clinical trials.

Cytotoxic T Lymphocytes Expressing GPR56 are Up-regulated in the Peripheral Blood of Patients with Active Rheumatoid Arthritis and Reflect Disease Progression

ABSTRACT Objective This study aims to elucidate the changes in the percentage of GPR56 and/or granzyme B (GZMB) positive cells in rheumatoid arthritis (RA) CD4 and CD8 T lymphocytes, and to explore their clinical value in diagnosing and reflecting the progression of RA. Methods The percentages of GPR56 and/or GZMB positive cells were analyzed in peripheral blood (PB) and spleen T cells in a collagen-induced arthritis (CIA) model established in DBA/1 mice. The percentages of GPR56+ and/or GZMB+ cells were further analyzed in PBs from RA patients and healthy controls. Correlation analysis was performed between clinical indicators and GPR56+, GZMB+, and GPR56+ GZMB+ T cells. Receiver operating characteristic (ROC) curves were used to evaluate the value of GPR56 and GZMB in differentiating active and stable remitting RA. Results GPR56+ levels were increased in CD4 and CD8 T cells in the PB of CIA mice. The percentages of GPR56+ and GZMB+ cells were increased in both CD4 and CD8 T cell subsets in patients with active RA. GPR56+, GZMB+, and GPR56+ GZMB+ cells were positively correlated with rheumatoid factor and DAS28. ROC analysis revealed that AUCs for GPR56+, GZMB+, and GPR56+ GZMB+ cell percentages to distinguish active RA from stable remission RA were 0.7106, 0.6941, 0.7024, with cut-off values of 16.35, 16.40, 14.80 in CD4 + T cells, and 0.8031, 0.8086, 0.8196 with cut-off values 60.25, 62.15, 40.15 in CD8 + T cells, respectively. Conclusions GPR56+ and/or GZMB+ T cells are up-regulated in patients with active RA and reflect their condition. The detection of GPR56 and GZMB is helpful for RA disease assessment.

Labial Gland Mesenchymal Stem Cell Derived Exosomes-Mediated miRNA-125b Attenuates Experimental Sjogren's Syndrome by Targeting PRDM1 and Suppressing Plasma Cells.

The pathogenesis of the prototypical chronic autoimmune disorder primary Sjögren syndrome (pSS) has been thought to be B-cell-centric, based on serum autoantibodies, the increased risk of B cell lymphoma, and altered B cell subsets in patients with pSS. Over the last 10 years, therapies targeting B cells have been investigated for pSS; however, current evidence for the efficacy of B cell targeted therapies in pSS is still sparse. Mesenchymal stem cells (MSCs) might represent a promising strategy for cell therapy of autoimmune diseases via regulation of immune cells. MSC-released exosomes carry various bioactive molecules and thus have been studied in MSC-based therapy. The newly discovered labial gland MSCs (LGMSCs) have exhibited enhanced performance. Herein, we aimed to determine the effects of LGMSC-derived exosomes (LGMSC-Exos) on the symptoms of a mouse model of pSS and their regulatory effect and mechanism on B cell subsets. In vivo, treatment of the spontaneous mouse model of pSS with LGMSC-Exos resulted in reduced inflammatory infiltration and restored saliva secretion in salivary glands. In vitro, coculture of LGMSC-Exos with peripheral blood mononuclear cells of patients with pSS markedly reduced the proportions of CD19+CD20-CD27+CD38+ plasma cells among peripheral blood mononuclear cells. Further investigations provided evidence that LGMSC-Exo-derived microRNA-125b affected plasma cells of pSS by directly binding to its target gene, PRDM1 (PR domain zinc finger protein 1, also known as BLIMP1), which might be developed as a target to treat pSS. Overall, these findings provided a possible exploitable therapeutic target in pSS and provide new insights into the potential therapeutic application of exosomes in pSS and other disease mediated by B-cells.

The abnormal distribution of peripheral B1 cells and transition B cells in patients with idiopathic dilated cardiomyopathy: a pilot study

BackgroundThe aberrant distribution of peripheral B cell subsets is associated with the pathogenesis of a variety of inflammatory and autoimmune diseases. However, the distribution of peripheral B cell subsets in patients with idiopathic dilated cardiomyopathy (DCM) remains to be elucidated.MethodsTwenty-seven patients with idiopathic DCM (DCM group), 18 control patients with heart failure (HF group) and 21 healthy individuals (HC group) were included in this study. Peripheral B cell subsets were analysed using multicolour flow cytometry. The plasma β1 adrenergic receptor (β1-AR) autoantibody titre was determined using ELISA. Additionally, clinical features were also collected.ResultsCompared with the HF and HC groups, the percentage of B1 cells was significantly decreased, whereas the percentage of transitional B cells (Tr) was significantly increased in the DCM group. Notably, the percentage of B1 cells was significantly lower in patients with β1-AR autoantibody-positive DCM than in β1-AR autoantibody-negative patients. The correlation analysis showed that the percentage of B1 cells was negatively correlated with N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and positively correlated with the left ventricular ejection fraction in patients with DCM.ConclusionAs shown in the present study, the percentage of B1 cells in the peripheral blood of patients with idiopathic DCM is abnormally decreased, especially in β1-AR autoantibody-positive patients, while the percentage of Tr cells is significantly increased, indicating that B1 cells and Tr cells may be implicated in the pathogenesis of idiopathic DCM. The decrease in the percentage of B1 cells is directly related to the severity of DCM.

Reduced chromatin accessibility to CD4 T cell super-enhancers encompassing susceptibility loci of rheumatoid arthritis

SummaryBackgroundRheumatoid arthritis (RA) is an inflammatory disease that manifests as a preclinical stage of systemic autoimmunity followed by chronic progressive synovitis. Disease-associated genetic SNP variants predominantly map to non-coding, regulatory regions of functional importance in CD4 T cells, implicating these cells as key regulators. A better understanding of the epigenome of CD4 T cells holds the promise of providing information on the interaction between genetic susceptibility and exogenous factors.MethodsWe mapped regions of chromatin accessibility using ATAC-seq in peripheral CD4 T cell subsets of patients with RA (n=18) and compared them to T cells from patients with psoriatic arthritis (n=11) and age-matched healthy controls (n=10). Transcripts of selected genes were quantified using qPCR.FindingsRA-associated epigenetic signatures were identified that in part overlapped between central and effector memory CD4 T cells and that were to a lesser extent already present in naïve cells. Sites more accessible in RA were highly enriched for the motif of the transcription factor (TF) CTCF suggesting differences in the three-dimensional chromatin structure. Unexpectedly, sites with reduced chromatin accessibility were enriched for motifs of TFs pertinent for T cell function. Most strikingly, super-enhancers encompassing RA-associated SNPs were less accessible. Analysis of selected transcripts and published DNA methylation patterns were consistent with this finding. The preferential loss in accessibility at these super-enhancers was seen in patients with high and low disease activity and on a variety of immunosuppressive treatment modalities.InterpretationDisease-associated genes are epigenetically less poised to respond in CD4 T cells from patients with established RA.FundingThis work was supported by I01 BX001669 from the Veterans Administration.

The role of CD8+ regulatory T cells and B cell subsets in patients with COVID-19.

Coronavirus disease 2019 (COVID-19) has a wide clinical spectrum from asymptomatic to mild, moderate, and severe cases. There are still many unknowns about the role of immunoregulatory mechanisms in COVID-19. We aimed to study regulatory T cells (Tregs) and B cell subsets and evaluate their correlations with severity of COVID-19. In total, 50 patients with COVID-19 confirmed by PCR (mean age = 49.9 ± 12.8 years) and 40 healthy control (mean age = 47.9 ± 14.7 years) were included in this study. The patients were classified as 14 mild (median age = 35.5 [24-73] years), 22 moderate (median age = 51.5 [28-67] years) and 14 severe (median age = 55.5 [42-67] years). Within 24 h of admission, flow cytometry was used to assess the lymphocyte subsets, Tregs and Bregs without receiving any relevant medication. In all patients with COVID-19, the proportion of CD3+CD8+ T cells was reduced (p = 0.004) and the CD8+ Tregs were increased compared with control (p = 0.001). While the levels of regulatory B cells, plasmablasts, and mature naive B cells were found to be significantly high, primarily memory B-cell levels were low in all patients compared with controls (p < 0.05). Total CD3+ T cells were negatively correlated with the length of stay in the hospital (r = -0.286, p = 0.044). The changes in T and B cell subsets may show the dysregulation in the immunity of patients with COVID-19. In this context, the association between CD8+ Tregs and COVID-19 severity may help clinicians to predict severe and fatal COVID-19 in hospitalized patients.

Alterations in B Cell and Follicular T-Helper Cell Subsets in Patients with Acute COVID-19 and COVID-19 Convalescents.

Background. Humoral immunity requires interaction between B cell and T follicular helper cells (Tfh) to produce effective immune response, but the data regarding a role of B cells and Tfh in SARS-CoV-2 defense are still sparse. Methods. Blood samples from patients with acute COVID-19 (n = 64), convalescents patients who had specific IgG to SARS-CoV-2 N-protein (n = 55), and healthy donors with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 44) were analyses by multicolor flow cytometry. Results. Patients with acute COVID-19 showed decreased levels of memory B cells subsets and increased proportion plasma cell precursors compared to HC and COVID-19 convalescent patients, whereas for the latter the elevated numbers of virgin naïve, Bm2′ and “Bm3+Bm4” was found if compared with HC. During acute COVID-19 CXCR3+CCR6− Tfh1-like cells were decreased and the levels of CXCR3−CCR6+ Tfh17-like were increased then in HC and convalescent patients. Finally, COVID-19 convalescent patients had increased levels of Tfh2-, Tfh17- and DP Tfh-like cells while comparing their amount with HC. Conclusions. Our data indicate that COVID-19 can impact the humoral immunity in the long-term.

Dynamics of Adaptive Immune Cell and NK Cell Subsets in Patients With Ankylosing Spondylitis After IL-17A Inhibition by Secukinumab.

Background: Anti-IL-17A therapy is generally effectively applied in patients with Ankylosing Spondylitis (AS) to achieve and maintain remission. However, the influence of anti-IL-17A on the composition of the immune system is not apparent. Our prospective study was to explore the changes in immune imbalance regarding T cell, B cell and natural killer (NK) cell subsets after secukinumab treatment in AS patients. Methods: Immune cell distribution of 43 AS patients treated with secukinumab for 12 weeks and 47 healthy controls (HC) were evaluated. Flow cytometry using monoclonal antibodies against 25 surface markers was accomplished to explore the frequencies of lineage subsets. The differences between HC, AS pre-treatment, and post-treatment were compared using the paired Wilcoxon test, Mann-Whitney U test, and ANOVA. Results: AS patients had altered immune cell distribution regarding T cell and B cell subsets. Apart from activated differentiation of CD4+ T cell, CD8+ T cell and B cell, higher levels of cytotoxic T (Tc) two cells and Tc17 cells were noted in AS patients. We confirmed that helper T (Th) one cell became decreased; however, Th17 cells and T follicular helper (Tfh) 17 cells went increased in AS. After 12 weeks of secukinumab therapy, CRP and ASDAS became significantly decreased, and meanwhile, the proportions of Th1 cells, Tfh17 cells and classic switched B cells were changed towards those of HC. A decreased CRP was positively correlated with a decrease in the frequency of naïve CD8+ T cells (p = 0.039) and B cells (p = 0.007) after secukinumab treatment. An elevated level of T cells at baseline was detected in patients who had a good response to secukinumab (p = 0.005). Conclusion: Our study confirmed that AS patients had significant multiple immune cell dysregulation. Anti-IL-17A therapy (Secukinumab) could reverse partial immune cell imbalance.

HSP90 pathway in intermediate mononuclear cells causes plaque erosion via induction of neutrophil hyper-responsiveness

Abstract Aim To explore the function(s) of HSP90 in intermediate monocyte-mediated plaque erosion. Materials and methods We used single-cell RNA sequencing to map cardiac immune response composition in patients with plaque rupture and plaque erosion. By focusing our analyses on CD14 positive monocytes, we obtained a higher resolution identification of the immune cell subsets in patients experiencing plaque erosion and rupture. We interpreted our findings with analyses using gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases and by performing receiver operating characteristic (ROC) curve analysis. Results Single-cell sequencing analysis of mononuclear cells in the peripheral blood of five ACS patients experiencing plaque erosion and rupture confirmed that CD14 positive monocytes were the main immune cells leading to ACS. Interestingly, our results suggested a significant increase in the proportion of atypical monocytes (C4 subsets) in patients with plaque rupture, which was a novel finding. This increase may be caused by increased migration of atypical monocytes into a plaque during plaque rupture. We found that intermediate monocyte activation was most obvious in patients with plaque erosion (C1, C10, and C11), and the proportion of C1 subgroup monocytes (FCGR3B/CMTM2 double strong positive; subsequently defined as intermediate monocytes) was very high. To further explore the role of C1 subgroup intermediate monocytes in plaque erosion, GO and KEGG pathway analyses were performed. GO analysis indicated that C1 subgroup intermediate monocytes are highly involved in neutrophil metabolism. Because neutrophils are the main effector cells that induce plaque erosion, we reasonably infer that intermediate monocytes can induce plaque erosion. KEGG pathway analysis indicated that all subtypes of HSP90 were highly expressed in C1 subgroup intermediate monocytes. We thus collected peripheral blood from ACS patients with plaque rupture (n=150) and plaque erosion (n=150) for mononuclear cell transcriptomics and intracellular proteomics analysis. ROC curve analysis demonstrated that the area under the curve for HSP90-based prediction was 0.86, indicating that HSP90 could be used to predict if patients would experience plaque erosion. Conclusion Activation of intermediate mononuclear HSP90 expression may be the crucial event that induces neutrophil hyper-responsiveness and leads to plaque erosion. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): China,Shanghai Science and Technology Commission