Regulatory B Cells Research Articles

B-Cell-Activating Factor Contributes to Elevation of the Content of Regulatory B Cells in Neonatal Sepsis.

We studied the role of B cell-activating factor (BAFF) in PI3K/AKT/mTOR signaling pathway in promoting proliferation and maintaining survival of regulatory B lymphocytes (Breg) in newborns with sepsis. The peripheral blood samples were collected from preterm neonates (n=40) diagnosed with sepsis on the day of diagnosis and on days 7, 14, and 21 after diagnosis, as well as from the matched preterm neonates without sepsis (n=40; control group). The peripheral blood mononuclear cells and B cells were isolated, cultured, and stimulated with LPS and immunostimulant CpG-oligodeoxynucleotide (CpG-ODN). Proliferation and differentiation of B-cells into CD19+CD24hiCD38hi Breg cells and the role of the PI3K/AKT/mTOR signaling pathway in these processes were studied by flow cytometry, real-time quantitative reverse transcription PCR (qRT-PCR), and Western blotting. BAFF levels in the peripheral blood of neonates with sepsis were significantly increased at one week after diagnosis in parallel with increasing trend of expression of BAFF receptor. When applied with LPS and CpG-ODN, BAFF promoted differentiation of B cells into CD19+CD24hiCD38hi Breg cells. Phosphorylation of 4E-BP1 factor and 70S6K kinase located downstream in PI3K/AKT/mTOR signaling pathway was significantly up-regulated when stimulated with BAFF in combination with LPS and CpG-ODN. Thus, increased level of BAFF activates PI3K/AKT/mTOR signaling pathway and induces in vitro differentiation of peripheral blood B cells into CD19+CD24hiCD38hi Breg cells.

Leveraging the tolerogenic potential of TNF-α and regulatory B cells in organ transplantation.

A subset of B-cells with tolerogenic functions, termed B-regulatory cells or Bregs, is characterized by the expression of anti-inflammatory/tolerogenic cytokines, namely IL-10, TGF-β, and IL-35, that contribute to their regulatory functions. Breg regulation favors graft acceptance within a tolerogenic milieu. As organ transplantation invariably triggers inflammation, new insights into the crosstalk between cytokines with dual properties and the inflamed milieu are needed to tailor their function toward tolerance. Using TNF-α as a proxy of dual-function cytokines involved in immune-related diseases and transplantation settings, the current review highlights the multifaceted role of TNF-α. It focuses on therapeutic approaches that have revealed the complexity of TNF-α properties tested in clinical settings where total TNF-α inhibition has proven ineffective and often detrimental to clinical outcomes. To improve the efficacy of current TNF-α inhibiting therapeutics, we propose a three-prong strategy to upregulate the tolerogenic pathway engaging the TNFR2 receptor while simultaneously inhibiting the inflammatory mechanisms associated with TNFR1 engagement. When combined with additional administrations of Bregs-TLR that activate Tregs, this approach may become a potential therapeutic in overcoming transplant rejection and promoting graft tolerance.

Immunological Signatures Associated With Ocrelizumab Treatment in Early RRMS: 12-Month Interim Analysis From the Ocrelizumab Phase IIIb (ENSEMBLE; NCT03085810) Immunological Substudy (S16.003)

Immunological Signatures Associated With Ocrelizumab Treatment in Early RRMS: 12-Month Interim Analysis From the Ocrelizumab Phase IIIb (ENSEMBLE; NCT03085810) Immunological Substudy (S16.003)

A Subset of Breg Cells, B10, Contributes to the Development of Radiation-Induced Pulmonary Fibrosis

Radiation-induced pulmonary fibrosis (RIPF) is a serious side effect of radiotherapy, but the underlying mechanisms are unknown. B10 cells, as negative B regulatory cells, play important roles in regulating inflammation and autoimmunity. However, the role of B10 cells in RIPF progression is unclear. The aim of this study was to determine the role of B10 cells in aggravating RIPF and the underlying mechanism. The role of B10 cells in RIPF was studied by constructing mouse models of RIPF and depleting B10 cells with an anti-CD22 antibody. The mechanism of B10 cells in RIPF was further explored through cocultivation of B10 cells and MLE-12 or NIH3T3 cells and administration of an IL-10 antibody to block IL-10. B10 cell numbers increased significantly during the early stage in the RIPF mouse models compared with the controls. In addition, depleting B10 cells with the anti-CD22 antibody attenuated the development of lung fibrosis in mice. Subsequently, we confirmed that B10 cells induced EMT and the transformation of myofibroblasts via activation of STAT3 signaling in vitro. After blockade of IL-10, it was verified that IL-10 secreted by B10 cells mediates the EMT of myofibroblasts, thereby promoting RIPF. Our study uncovers a novel role for IL-10-secreting B10 cells that could be a new target of research for relieving RIPF.

Abstract 5785: A pan-cancer single-cell tumor micro-environment atlas predictive of immunotherapy response

Abstract The tumor microenvironment (TME) shapes response to immune checkpoint blockade (ICB). Several pan-cancer single-cell RNA-sequencing (scRNA-seq) analyses have reported how TME heterogeneity profoundly differs between cancer types. These studies mainly focused on one cell type (e.g., T-cells) and combined different technologies and bioinformatics pipelines with data being collected from both published and newly generated datasets. A comprehensive pan-cancer scRNA-seq map of the TME involving all cell types is therefore still lacking. We obtained scRNA-seq (10x Genomics) on 234 fresh tissue samples from 161 treatment-naïve patients. Samples were collected from 9 cancer types and subjected to a uniform in-house optimized protocol of tissue dissociation, sequencing and bioinformatics analysis. Abundancies of cell types and subtypes were correlated with each other and a tumor-reactive T-cell signature. From 683,184 high-quality single cells, we identified 9 cell types and 71 subtypes of T-cells, B-cells, dendritic cells (DCs), monocytes/macrophages and endothelial-cells (ECs), shared between cancer types. PDCD1 (PD1) was expressed by differentiated T-cells subtypes (e.g., CD8+ exhausted and CD4+ T-helper-1 subclusters), while CD274 and PDCD1LG (PDL-1/PDL-2) were mainly expressed by regulatory B-cells, immune-regulatory DCs, CXCL10+ and CCL2+ monocyte-derived macrophages as well as inflammatory ECs. Pairwise analyses showed positive correlations between PD1-expressing T-cell subclusters, CD4+ T-regulatory cells, plasma B-cells (plasmablasts, IgA and IgG plasma cells), immune-regulatory DCs, CXCL10+ and CCL2+ macrophages and lymphatic ECs. On the other hand, negative correlations were observed with naïve T- and B-cells, conventional DC2 (cDC2), monocytes, CX3CR1+ macrophages, as well as arterial and capillary ECs. When ranking individual tumors based on a tumor-reactive T-cell signature, we found reactive tumors to correlate with positively interacting subtypes, while they anti-correlated with subclusters negatively interacting with PD1-expressing differentiated T-cells. Upon deconvolution of bulk RNA-seq data using gene signatures derived from each subcluster, these correlations were replicated in TCGA datasets across cancers. These signature scores correlated with tumor mutation burden (TMB) and other immunological features, while they were also predictive of response in clinical trials involving ICB. We provide insights into the TME complexity at unprecedented level, identifying numerous subclusters enriched in immune-reactive (hot) or -suppressive (cold) tumors across cancer types. We validate these observations in TCGA by deconvolution of bulk RNA-seq data, and show that already pre-treatment several TME subclusters predict response to ICB. Citation Format: Francesca Lodi, Sam Vanmassenhove, Elena Donders, Pierre Van Mol, Amelie Franken, Sarah Cappuyns, Ayse Bassez, Siel Olbrecht, Liselore Loverix, Michel Bila, Hanne Vos, Joanna Pozniak, Kevin Punie, Diether Lambrechts. A pan-cancer single-cell tumor micro-environment atlas predictive of immunotherapy response. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5785.

Abstract 4458: Single cell landscape of multicentric Castleman disease in identical twins

Abstract Idiopathic Multicentric Castleman Disease (iMCD) is a rare IL-6-driven hematological disorder characterized by systemic lymphadenopathy, elevated immunoglobulin levels, and prominent plasmacytosis in the bone marrow and lymph nodes. An unusual occurrence of iMCD in identical twins provided a unique opportunity to answer genetic and molecular features of this disease, including the cell-of-origin of IL-6 signals, and the immune milieu within affected lymphoid organs and in circulation. Germline whole genome sequencing of the affected twins identified pathogenic homozygous mutations of NCOA4 c.G1322A and monoallelic mutations of TRAF3 c.G1504A - both genes recently implicated in IL-6 signaling and B-cell regulation. Their unaffected sister was heterozygous mutant for NCOA4 and homozygous wildtype for TRAF3 loci. Via single cell sequencing of 63,519 cells from bone marrow, lymph node, and peripheral blood mononuclear cells, we identified nodal endothelial cells and fibroblastic reticular cells (FRC) as the source of IL-6 signals. The latter are composed of mainly T-cell zone FRCs (CCL19+/CCL21+/IL7+/PDPN+/MADCAM1-) and a minor population of follicular dendritic cells (FDCs) (CD21+/CD35+/CXCL13+). An “inflammatory” peripheral monocytosis enriched for the expression of S100A family genes was evident in both twins, as well as a group of monocytes expressing cytotoxic gene signatures in the affected twin with milder clinical manifestations. Their unaffected sister mainly carried monocytes enriched for expression of major histocompatibility complex (MHC) class II genes. In conclusion, we provided evidence of a genetic cause of iMCD, identified the putative cell-of-origin of IL-6 signals in this rare disease, and described a distinct monocytic immune response phenotype. Citation Format: Jason Yongsheng Chan, Jui Wan Loh, Jing Quan Lim, Herty Liany, Elizabeth Chun Yong Lee, Jing Yi Lee, Bavani Kannan, Boon Yee Lim, Kerry Lim, Jeslin Chian Hung Ha, Cedric Chuan-Young Ng, Tun Kiat Ko, Dachuan Huang, Dominique Yuan Bin Seow, Chee Leong Cheng, Sock Hoai Chan, Joanne Ngeow, Bin Tean Teh, Soon Thye Lim, Choon Kiat Ong. Single cell landscape of multicentric Castleman disease in identical twins. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4458.

Intracellular Levels of IL-10 and STAT3 in Patients with Chronic Lymphocytic Leukemia

Objective: Chronic Lymphocytic Leukemia (CLL) is characterized by the accumulation of CD5+CD19+ B cells in the bone marrow and peripheral blood. Recent studies indicated that expression of IL-10, AID and mir-155 which are regulated by STAT3 are increased in CLL patients. CD5+CD19+ regulator B (Breg) cells secrete IL-10 and suppress the immune system. While the CLL cells show similar immunophenotypic properties to Breg cells, they are also thought to be functionally similar. In this study, STAT3 and IL-10 levels of CLL patients were investigated.
 Methods: Peripheral blood samples obtained from patients (n:24) and healthy controls (n:14). Peripheral blood mononuclear cells were cultured for 48 hours in the presence and absence of CpG for IL-10 expression and cultured with and without PMA for STAT3 expression. IL-10 and STAT3 expression were analyzed with anti-CD5, anti-CD19, anti-CD38, anti-STAT3 and anti-IL-10 monoclonal antibodies by using flow cytometry.
 Results: Compared to healthy subjects, increased IL-10+, IL-10+CD19+, STAT3+CD19+ were obtained in lymphocyte population of patients. Increased IL-10 was showed CD19+ B cells of CLL patients. Our results showed that IL-10 levels had no significant difference between CD5+CD19+ cells, whereas STAT3 levels were found lower in patient compared to healthy controls.
 Conclusion: These results made us thought that the levels of IL-10 and STAT3 expression in CLL B cells is clearly different from normal B lymphocytes might have a role in the biology of CLL. It is believed that the presented data will contribute to the studies that scrutinize the similarity of CLL cells to Breg cells.

International Society for Cell & Gene Therapy Stem Cell Engineering Committee: Cellular therapies for the treatment of graft-versus-host-disease after hematopoietic stem cell transplant

Background aimsAllogeneic hematopoietic stem cell transplant is a curative approach for many malignant and non-malignant hematologic conditions. Despite advances in its prevention and treatment, the morbidity and mortality related to graft-versus-host disease (GVHD) remains. The mechanisms by which currently used pharmacologic agents impair the activation and proliferation of potentially alloreactive T cells reveal pathways essential for the detrimental activities of these cell populations. Importantly, these same pathways can be important in mediating the graft-versus-leukemia effect in recipients transplanted for malignant disease. This knowledge informs potential roles for cellular therapies such as mesenchymal stromal cells and regulatory T cells in preventing or treating GVHD. This article reviews the current state of adoptive cellular therapies focused on GVHD treatment. MethodsWe conducted a search for scientific literature in PubMed® and ongoing clinical trials in clinicaltrial.gov with the keywords “Graft-versus-Host Disease (GVHD),” “Cellular Therapies,” “Regulatory T cells (Tregs),” “Mesenchymal Stromal (Stem) Cells (MSCs),” “Natural Killer (NK) Cells,” “Myeloid-derived suppressor cells (MDSCs),” and “Regulatory B-Cells (B-regs).” All the published and available clinical studies were included. ResultsAlthough most of the existing clinical data focus on cellular therapies for GVHD prevention, there are observational and interventional clinical studies that explore the potential for cellular therapies to be safe modalities for GVHD treatment while maintaining the graft-versus-leukemia effect in the context of malignant diseases. However, there are multiple challenges that limit the broader use of these approaches in the clinical scenario. ConclusionsThere are many ongoing clinical trials to date with the promise to expand our actual knowledge on the role of cellular therapies for GVHD treatment in an attempt to improve GVHD-related outcomes in the near future.

Regulatory B cells are reduced in the blood in patients with granulomatosis with polyangiitis, and fail to regulate T-cell IFN-γ production.

Regulatory B (Breg) cells can dampen inflammation, autoreactivity, and transplant rejection. We investigated the frequencies, phenotypes, and function of Breg cells in granulomatosis with polyangiitis (GPA) to gain further knowledge as to whether there are numerical alterations or limitations of their ability to regulate T-cell function. Frequencies and phenotypes of CD24hiCD27+ and CD24hiCD38hi B-cells in the blood were determined with flow cytometry in 37 GPA patients (22 in remission and 15 with active disease) and 31 healthy controls (HC). A co-culture model was used to study the capacity of Breg cells to regulate T-cell activation and proliferation in cells from 10 GPA patients in remission and 12 HC. T-cell cytokine production in vitro and levels in plasma were determined with enzyme-linked immunosorbent assay. Frequencies of CD24hiCD27+ B-cells were reduced both during active disease and remission compared with HC (P = 0.005 and P = 0.010, respectively), whereas CD24hiCD38hi B-cells did not differ. Patient CD24hiCD27+ B-cells exhibited decreased expression of CD25 but increased expression of PD-L1 and PD-L2 during remission. B-cells from GPA patients regulated T-cell proliferation but failed to regulate interferon (IFN)-γ production (median T-cells alone 222 ng/ml vs. T-cells + B-cells 207 ng/ml, P = 0.426). IFN-γ was also elevated in patient plasma samples (P = 0.016). In conclusion, GPA patients exhibit altered numbers and phenotypes of CD24hiCD27+ B-cells. This is accompanied by a disability to control T-cell production of Th1-type cytokines during remission, which might be of fundamental importance for the granulomatous inflammation that characterizes the chronic phase of this disease.

Regulatory B cells protect against chronic hypoxia-induced pulmonary hypertension by modulating the Tfh/Tfr immune balance.

Hypoxia-induced pulmonary hypertension (HPH) is a progressive and lethal disease characterized by the uncontrolled proliferation of pulmonary artery smooth muscle cells (PASMCs) and obstructive vascular remodelling. Previous research demonstrated that Breg cells were involved in the pathogenesis of pulmonary hypertension. This work aimed to evaluate the regulatory function of Breg cells in HPH. HPH mice model were established and induced by exposing to chronic hypoxia for 21 days. Mice with HPH were treated with anti-CD22 or adoptive transferred of Breg cells. The coculture systems of Breg cells with CD4+ T cells and Breg cells with PASMCs in vitro were constructed. Lung pathology was evaluated by HE staining and immunofluorescence staining. The frequencies of Breg cells, Tfh cells and Tfr cells were analysed by flow cytometry. Serum IL-21 and IL-10 levels were determined by ELISA. Protein levels of Blimp-1, Bcl-6 and CTLA-4 were determined by western blot and RT-PCR. Proliferation rate of PASMCs was measured by EdU. Compared to the control group, mean PAP, RV/(LV + S) ratio, WA% and WT% were significantly increased in the model group. Anti-CD22 exacerbated abnormal hemodynamics, pulmonary vascular remodelling and right ventricle hypertrophy in HPH, which ameliorated by adoptive transfer of Breg cells into HPH mice. The proportion of Breg cells on day 7 induced by chronic hypoxia was significantly higher than control group, which significantly decreased on day 14 and day 21. The percentage of Tfh cells was significantly increased, while percentage of Tfr cells was significantly decreased in HPH than those of control group. Anti-CD22 treatment increased the percentage of Tfh cells and decreased the percentage of Tfr cells in HPH mice. However, Breg cells restrained the Tfh cells differentiation and expanded Tfr cells differentiation in vivo and in vitro. Additionally, Breg cells inhibited the proliferation of PASMCs under hypoxic condition in vitro. Collectively, these findings suggested that Breg cells may be a new therapeutic target for modulating the Tfh/Tfr immune balance in HPH.

Single-cell RNA sequencing identifies precise tolerogenic cellular and molecular pathways induced by depigmented-polymerized grass pollen allergen extract

Immunologic mechanism of action of allergoids remains poorly understood. Previous models of allergenicity and immunogenicity have yielded suboptimal knowledge of these immunotherapeutic vaccine products. Novel single-cell RNA sequencing technology offers a bridge to this gap in knowledge. We sought to identify the underpinning tolerogenic molecular and cellular mechanisms of depigmented-polymerized Phleum pratense (Phl p) extract. The molecular mechanisms underlying native Phl p, depigmented Phl p (DPG-Phl p), and depigmented-polymerized (DPG-POL-Phl p) allergoid were investigated by single-cell RNA sequencing. Allergen-specific TH2A, T follicular helper (Tfh), and IL-10+ regulatory B cells were quantified by flow cytometry in peripheral blood mononuclear cells from 16 grass pollen-allergic and 8 nonatopic control subjects. The ability of Phl p, DPG-Phl p, and DPG-POL-Phl p to elicit FcεRI- and FcεRII-mediated IgE responses was measured by basophil activation test and IgE-facilitated allergen binding assay. Analysis revealed that DPG-POL-Phl p downregulated genes associated with TH2 signaling, induced functional regulatory T cells exhibiting immunosuppressive roles through CD52 and Siglec-10, modulated genes encoding immunoproteasome that dysregulate the processing and presentation of antigens to T cells and promoted a shift from IgE toward an IgA1 and IgG responses. In grass pollen-allergic subjects, DPG-POL-Phl p exhibited reduced capacity to elicit proliferation of TH2A, IL-4+ Tfh and IL-21+ Tfh cells while being the most prominent at inducing IL-10+CD19+CD5hi and IL-10+CD19+CD5hiCD38intCD24int regulatory B-cell subsets compared to Phl p (all P< .05). Furthermore, DPG-POL-Phl p demonstrated a hypoallergenic profile through basophil activation and histamine release compared to Phl p (31.54-fold, P< .001). Single-cell RNA sequencing provides an in-depth resolution of the mechanisms underlying the tolerogenic profile of DPG-POL-Phl p.

Primary head and neck cancer cell cultures are susceptible to proliferation of Epstein-Barr virus infected lymphocytes

BackgroundNew concepts for a more effective anti-cancer therapy are urgently needed. Experimental flaws represent a major counter player of this development and lead to inaccurate and unreproducible data as well as unsuccessful translation of research approaches into clinics. In a previous study we have created epithelial cell cultures from head and neck squamous cell carcinoma (HNSCC) tissue.MethodsWe characterize primary cell populations isolated from human papillomavirus positive HNSCC tissue for their marker expression by RT-qPCR, flow cytometry, and immunofluorescence staining. Their sensitivity to MDM2-inhibition was measured using cell viability assays.ResultsPrimary HNSCC cell cultures showed the delayed formation of spheroids at higher passages. These spheroids mimicked the morphology and growth characteristics of other established HNSCC spheroid models. However, expression of epithelial and mesenchymal markers could not be detected in these cells despite the presence of the HNSCC stem cell marker aldehyde dehydrogenase 1 family member A1. Instead, strong expression of B- and T-lymphocytes markers was observed. Flow cytometry analysis revealed a heterogeneous mixture of CD3 + /CD25 + T-lymphocytes and CD19 + B-lymphocytes at a ratio of 4:1 at passage 5 and transformed lymphocytes at late passages (≥ passage 12) with CD45 + CD19 + CD20 + , of which around 10 to 20% were CD3 + CD25 + CD56 + . Interestingly, the whole population was FOXP3-positive indicative of regulatory B-cells (Bregs). Expression of transcripts specific for the Epstein-Barr-virus (EBV) was detected to increase in these spheroid cells along late passages, and this population was vulnerable to MDM2 inhibition. HPV + HNSCC cells but not EBV + lymphocytes were detected to engraft into immunodeficient mice.ConclusionsIn this study we present a primary cell culture of EBV-infected tumor-infiltrating B-lymphocytes, which could be used to study the role of these cells in tumor biology in future research projects. Moreover, by describing the detailed characteristics of these cells, we aim to caution other researchers in the HNSCC field to test for EBV-infected lymphocyte contaminations in primary cell cultures ahead of further experiments. Especially researchers who are interested in TIL-based adopted immunotherapy should exclude these cells in their primary tumor models, e.g. by MDM2-inhibitor treatment. BI-12-derived xenograft tumors represent a suitable model for in vivo targeting studies.

AT-101 Enhances the Antitumor Activity of Lenalidomide in Patients with Multiple Myeloma.

Bcl-2 and Mcl-1 proteins play a role in multiple myeloma (MM) cell survival, for which targeted inhibitors are being developed. AT-101 is an oral drug, which disrupts Bcl-2 and Mcl-1 function, impedes mitochondrial bioenergetic processes and induces apoptosis in MM cells. When combined with lenalidomide and dexamethasone (Rd), AT-101 significantly reduced tumor burden in an in vivo xenograft model of MM. These data provided rationale for a phase I/II study to establish the effective dose of AT-101 in combination with Rd (ARd regimen) in relapsed/refractory MM. A total of 10 patients were enrolled, most with high-risk cytogenetics (80%) and prior stem cell transplant (70%). Three patients were lenalidomide-refractory, 2 were bortezomib-refractory and 3 were daratumumab-refractory. The ARd combination was well tolerated with most common grade 3/4 adverse events being cytopenia's. The overall response rate was 40% and clinical benefit rate was 90%. The median progression free survival was 14.9 months (95% CI 7.1-NE). Patients responsive to ARd showed a decrease in Bcl-2:Bim or Mcl-1:Noxa protein complexes, increased CD8+ T and NK cells and depletion of T and B-regulatory cells. The ARd regimen demonstrated an acceptable safety profile and promising efficacy in patients with relapsed/refractory MM prompting further investigation in additional patients.

Using Treg, Tr1, and Breg Expression Levels to Predict Clinical Responses to csDMARD Treatment in Drug-naive Patients With Rheumatoid Arthritis.

Regulatory T cells (Treg) play a crucial role in maintaining immune tolerance and preventing autoimmune diseases. Recent data also indicate that type 1 regulatory T (Tr1) and regulatory B (Breg) cells play an inhibitory (i.e., protective) role in autoimmune diseases. Conventional synthetic disease-modifying antirheumatic drugs (csDMARD) are a first-line therapy for rheumatoid arthritis (RA), and our aim was to predict clinical responses of this treatment using immunophenotyping. We first detected the presence of immune cells in fresh blood from 16 healthy controls (HC) and 26 patients with RA (14 drug-naive and 12 csDMARD-experienced). Then, we recorded immunophenotypic changes in 14 drug-naive RA (naive RA) patients prior to csDMARD treatment (i.e., day 0) and after receiving treatment for 6 months. The observed changes were also compared with other clinical indicators, including the presence of anti-citrullinated peptide antibodies (anti-CCP), rheumatoid factor (RF) levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels. Naive RA patients had significantly lower Tregs than HC and csDMARD-experienced patients (both p<0.0001) and the number of Tregs correlated with the diagnosis of RA and therapeutic efficacy of csDMARD treatment. Furthermore, lower baseline levels of Treg, memory Treg, Tr1, and higher PD-1+ Marginal B, Breg cells were significantly associated with decreased development of the 28-joint Disease Activity Score (DAS28) (all p<0.05), revealing better medical response. Multiple regression and principal component analysis identified Treg, Tr1, and Breg as potential predictors of csDMARD responses (Area under curve: 0.9; Accuracy: 92.86%). Furthermore, elevated Treg, Tr1, and Breg cells were associated with decreased DAS28, ESR, and CRP (all p<0.05); changes in Treg and Breg cell expression were also more pronounced among double negative anti-CCP and RF in RA patients with better outcomes (p<0.05). Immunophenotyping can be an adjunct clinical tool to identify patients who are poor candidates for csDMARD therapy. Alternative therapeutic interventions in the early stages of disease should be formulated for these patients.

Multiple human B cell subsets give rise to regulatory B cells

Multiple human B cell subsets give rise to regulatory B cells

Tumor-Associated CD19+CD39- B Regulatory Cells Deregulate Class-Switch Recombination to Suppress Antibody Responses.

B cells are an essential component of humoral immunity. Their primary function is to mount antigen-specific antibody responses to eliminate pathogens. Despite an increase in B-cell number, we found that serum-IgG levels were low in patients with breast cancer. To solve this conundrum, we used high-dimensional flow cytometry to analyze the heterogeneity of B-cell populations and identified a tumor-specific CD19+CD24hiCD38hi IL10-producing B regulatory (Breg)-cell subset. Although IL10 is a Breg-cell marker, being an intracellular protein, it is of limited value for Breg-cell isolation. Highly expressed Breg-cell surface proteins CD24 and CD38 also impede the isolation of viable Breg cells. These are hurdles that limit understanding of Breg-cell functions. Our transcriptomic analysis identified, CD39-negativity as an exclusive, sorting-friendly surface marker for tumor-associated Breg cells. We found that the identified CD19+CD39‒IL10+ B-cell population was suppressive in nature as it limited T helper-cell proliferation, type-1 cytokine production, and T effector-cell survival, and augmented CD4+FOXP3+ regulatory T-cell generation. These tumor-associated Breg cells were also found to restrict autologous T follicular helper-cell expansion and IL21 secretion, thereby inhibiting germinal transcript formation and activation-induced cytidine deaminase expression involved in H-chain class-switch recombination (CSR). This isotype-switching abnormality was shown to hinder B-cell differentiation into class-switched memory B cells and subsequent high-affinity antibody-producing plasma B cells, which collectively led to the dampening of IgG-mediated antibody responses in patients with cancer. As low IgG is associated with poor prognosis in patients with cancer, Breg-cell depletion could be a promising future therapy for boosting plasma B cell-mediated antibody responses.

Unraveling the role of Breg cells in digestive tract cancer and infectious immunity.

Over the past two decades, regulatory B cells (Breg cells or Bregs) have emerged as an immunosuppressive subset of B lymphocytes playing a key role in inflammation, infection, allergy, transplantation, and cancer. However, the involvement of Bregs in various pathological conditions of the gastrointestinal tract is not fully understood and is the subject of much recent research. In this review, we aimed to summarize the current state of knowledge about the origin, phenotype, and suppressive mechanisms of Bregs. The relationship between the host gut microbiota and the function of Bregs in the context of the disturbance of mucosal immune homeostasis is also discussed. Moreover, we focused our attention on the role of Bregs in certain diseases and pathological conditions related to the digestive tract, especially Helicobacter pylori infection, parasitic diseases (leishmaniasis and schistosomiasis), and gastrointestinal neoplasms. Increasing evidence points to a relationship between the presence and number of Bregs and the severity and progression of these pathologies. As the number of cases is increasing year by year, also among young people, it is extremely important to understand the role of these cells in the digestive tract.

Evaluation of innate and adaptive immune system interactions in the tumor microenvironment via a 3D continuum model

Immune cells in the tumor microenvironment (TME) are known to affect tumor growth, vascularization, and extracellular matrix (ECM) deposition. Marked interest in system-scale analysis of immune species interactions within the TME has encouraged progress in modeling tumor-immune interactions in silico. Due to the computational cost of simulating these intricate interactions, models have typically been constrained to representing a limited number of immune species. To expand the capability for system-scale analysis, this study develops a three-dimensional continuum mixture model of tumor-immune interactions to simulate multiple immune species in the TME. Building upon a recent distributed computing implementation that enables efficient solution of such mixture models, major immune species including monocytes, macrophages, natural killer cells, dendritic cells, neutrophils, myeloid-derived suppressor cells (MDSC), cytotoxic, helper, regulatory T-cells, and effector and regulatory B-cells and their interactions are represented in this novel implementation. Immune species extravasate from blood vasculature, undergo chemotaxis toward regions of high chemokine concentration, and influence the TME in proportion to locally defined levels of stimulation. The immune species contribute to the production of angiogenic and tumor growth factors, promotion of myofibroblast deposition of ECM, upregulation of angiogenesis, and elimination of living and dead tumor species. The results show that this modeling approach offers the capability for quantitative insight into the modulation of tumor growth by diverse immune-tumor interactions and immune-driven TME effects. In particular, MDSC-mediated effects on tumor-associated immune species’ activation levels, volume fraction, and influence on the TME are explored. Longer term, linking of the model parameters to particular patient tumor information could simulate cancer-specific immune responses and move toward a more comprehensive evaluation of immunotherapeutic strategies.

IL-10‒Producing Potency from Blood B Cells Correlates with the Prognosis of Alopecia Areata

IL-10‒Producing Potency from Blood B Cells Correlates with the Prognosis of Alopecia Areata

Highlights from Recent Cancer Literature

Breaking Insights| December 02 2022 Highlights from Recent Cancer Literature Author & Article Information Online ISSN: 1538-7445 Print ISSN: 0008-5472 ©2022 American Association for Cancer Research2022American Association for Cancer Research Cancer Res (2022) 82 (23): 4301–4302. https://doi.org/10.1158/0008-5472.CAN-82-23-BI Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Article Versions Icon Versions Version of Record December 2 2022 Citation Highlights from Recent Cancer Literature. Cancer Res 1 December 2022; 82 (23): 4301–4302. https://doi.org/10.1158/0008-5472.CAN-82-23-BI Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest Search Advanced Search Stimulator of interferon genes (STING) agonists rapidly moved into clinical trials with great optimism but have only shown mediocre therapeutic efficacy in patients. Li and colleagues revealed that STING activation in B cells drives immunosuppression that counteracts the stimulatory activity of these drugs, and that blocking regulatory B-cell function can improve STING-based cancer immunotherapy. Using specific deletion of STING (TMEM173) in B cells, they first showed that systemic delivery of STING agonists is more effective in controlling multiple cancer models, most importantly pancreatic ductal adenocarcinomas (PDAC). Next, they found that in response to STING activation, B cells take on a regulatory phenotype and produce two suppressive cytokines, IL35 and IL10. They found that IL35 production is essential for their suppressive nature, acting to suppress natural killer (NK) cell antitumor responses specifically in response to STING agonists. Finally, they showed that a combination of blocking anti-IL35 antibodies in combination... You do not currently have access to this content.