scholarly journals IL-21 signaling promotes early dissemination of KSHV infection in B lymphocytes

2021 ◽  
Author(s):  
Nedaa Alomari ◽  
Farizeh Aalasm ◽  
Romina Nabiee ◽  
Jesus Ramirez Castano ◽  
Jennifer Totonchy

AbstractKaposi’s sarcoma-associated herpesvirus (KSHV) extensively manipulates the host immune system and the cytokine milieu, and cytokines are known to influence the progression of KSHV-associated diseases. However, the precise role of cytokines in the early stages of KSHV infection remains undefined. Here, using our unique model of KSHV infection in tonsil lymphocytes, we investigate the influence of host cytokines on the establishment of KSHV infection in B cells. Our data demonstrate that KSHV manipulates the host cytokine microenvironment during early infection and susceptibility generally associated with downregulation of multiple cytokines. However, we show that IL-21 signaling promotes KSHV infection by promoting both plasma cell numbers and increasing KSHV infection in plasma cells. Our data reveal that IL-21 producing T cells, particularly Th17/Tc17 and central memory CD8+ T cells may represent immunological factors that modulate host-level susceptibility to KSHV infection. These results suggest that IL-21 plays a significant role in the early stages of KSHV infection in the human immune system and may represent a novel mechanism to be further explored in the context of preventing KSHV transmission.Author SummaryVery little is known about how KSHV is transmitted and how it initially establishes infection in a new human host and this lack of information limits our ability to prevent KSHV-associated cancers by limiting its person-to-person transmission. Saliva is thought to be the primary route of person-to-person transmission for KSHV, making the tonsil a likely first site for KSHV replication in a new human host. In particular, the tonsil is likely to be the first place KSHV is able to enter B cells, which are thought to be a major site of persistent infection. Our previous work identified plasma cells as a highly targeted cell type in early KSHV infection in cultured cells from human tonsil. In this study, we show that the human cytokine IL-21 promotes both overall KSHV infection and the establishment of infection in plasma cells. We also investigate the immunological mechanisms underlying this effect. Our results demonstrate that IL-21 and IL-21-producing cells are a novel factor that influences the initial establishment of KSHV infection in humans.

1999 ◽  
Vol 73 (8) ◽  
pp. 6468-6473 ◽  
Author(s):  
Kim J. Hasenkrug

ABSTRACT The study of genetic resistance to retroviral diseases provides insights into the mechanisms by which organisms overcome potentially lethal infections. Fv-2 resistance to Friend virus-induced erythroleukemia acts through nonimmunological mechanisms to prevent early virus spread, but it does not completely block infection. The current experiments were done to determine whether Fv-2 alone could provide resistance or whether immunological mechanisms were also required to bring infection under control. Fv-2-resistant mice that were CD4+ T-cell deficient were able to restrict early virus replication and spread as well as normalFv-2-resistant mice, but they could not maintain control and developed severe Friend virus-induced splenomegaly and erythroleukemia by 6 to 8 weeks postinfection. Mice deficient in CD8+ T cells and, to a lesser extent, B cells were also susceptible to late Friend virus-induced disease. Thus,Fv-2 resistance does not independently prevent FV-induced erythroleukemia but works in concert with the immune system by limiting early infection long enough to allow virus-specific immunity time to develop and facilitate recovery.


PEDIATRICS ◽  
1975 ◽  
Vol 55 (2) ◽  
pp. 157-160
Author(s):  
Robert C. Seeger ◽  
E. Richard Stiehm

The two major subpopulations of lymphocytes, T cells (thymus-dependent lymphocytes) and B cells (bursal equivalent or thymus-independent lymphocytes) have multiple roles in the immune system. In general, T cells are the functioning cells in the cellular immune system (delayed hypersensitivity, graft rejection, graft-versus hostreaction); and B cells, the precursors of plasma cells which form specific antibodies, are the functioning cells in the antibody immune system. It is now well recognized, however, that these cell types and immune systems usually do not function independently, but interact with one another in multiple ways and also with other, cells such as macrophages. For example, T cells may increase or suppress the production of antibodies by the B cell system, and macrophages may increase or suppress the response of T and B cells to antigens.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 231.1-231
Author(s):  
F. Liu ◽  
H. Zhang ◽  
X. Wang ◽  
J. Feng ◽  
Y. Cao ◽  
...  

Background:Donor-specific anti-HLA antibodies (DSAs) are antibodies in the recipient directed against donor class I/II HLA antigens. The existence of DSAs before allogenic hematopoietic stem cell transplantation (AHSCT) are known to cause primary graft failure. Currently there’s no established method of DSA desensitization due to the long half-life of plasma cells.Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease involving in multiple organ systems mediated by numerous autoantibodies. Recent results have shown that depletion of B cells by CD19 CAR-T cells effectively reversed some manifestations in two SLE mouse models. However, plasma cells could be spared with single CD19 CAR-T cells, and peripheral circulating anti-DNA IgG and IgM autoantibodies remain elevated or increased in treated mice.Objectives:We present the efficacy of BCMA-CD19 compound CAR (cCAR), which target on antibody- producing “root”, both B cells and plasma cells in preclinical study and in our first-in-human phase 1 clinical trial.Methods:We constructed a BCMA-CD19 cCAR composed of a complete BCMA-CAR fused to a complete CD19 CAR, separated by a self-cleaving P2A peptide. We assessed the functional activity of cCAR in co-culture assay with multiple cell lines. We also verified cCAR efficacy with two mouse models, injected with either BCMA-expressing MM.1S cells or CD19-expressing REH cells. In our phase 1 clinical trial, we enrolled patients with hematologic malignancies with antibody mediated disorders.Results:BCMA-CD19 cCAR exhibited robust cytotoxic activity against the K562 cells engineered to express either CD19 or BCMA in co-culture assays, indicating the ability of each complete CAR domain to specifically lyse target cells. In mouse model study, cCAR-T cells were able to eliminate tumor cells in mice injected with MM.1S cells and REH cells, indicating that both BCMA and CD19 are specifically and equally lysing B cells and plasma cells in vivo, making BCMA-CD19 cCAR a candidate for clinical use.In our first-in-human clinical trial, the first case is a 48-year-old female patient having resistant B-ALL with high DSA titers. She exhibited complete remission of B-ALL at day 14 post-CAR T treatment. MFI of DSA dropped from 7800 to 1400 at 8 weeks post cCAR treatment, the reduction percentage was approximately 80% (Figure 1). The patient had no CRS, and no neurotoxicity was observed.Figure 1.1. A) MFI of DSA and other HLA antibodies before and at different time points after cCAR T infusion. B) the percent reduction post-transfusion of cCAR T cells at different time points.The second case is a 41-year-old female patient having a refractory diffuse large B cell lymphoma with bone marrow (BM) involvement. Furthermore, she has a 20 years of SLE, with manifestation of fever dependent of corticosteroids. On day 28 after cCAR treatment, PET/CT scan showed CR, and BM turned negative. In addition, she is independent of steroids, has no fever and other manifestations, C3/C4 are within normal ranges, and all the ANA dropped significantly, especially the nuclear type ANA, which turned from> 1:1000 to be negative at day 64. She had Grade 1 CRS but with no neurotoxicity observed. The absence of B cells and plasma cells persisted more than 5 months post CAR therapy.Conclusion:Our first in human clinical trial on BCMA-CD19 cCAR demonstrated profound efficacy in reducing DSA levels in an AHSCT candidate and ANA titer in a SLE patient. There was strong clinical evidence of depletion of antibody-producing roots, B-cells and plasma cells in both patients. Our results further suggested that BCMA-CD19 cCAR has the potential to benefit patients receiving solid organ transplants or those with other antibody-mediated diseases.Figure 2.Reduction of different type of ANA titer at different time points.Acknowledgments:patients and their familiesDisclosure of Interests:Fang liu: None declared, Hongyu Zhang: None declared, Xiao Wang: None declared, Jia Feng: None declared, Yuanzhen cao Employee of: Employee of iCell Gene Therapeutics LLC, Yi Su: None declared, Masayuki Wada Employee of: employee of iCell Gene Therapeutics LLC, Yu Ma Employee of: employee of iCAR Bio Therapeutics Ltd, Yupo Ma Shareholder of: shareholder of iCell Gene Therapeutics LLC


2021 ◽  
pp. 1-19
Author(s):  
Sonia George ◽  
Trevor Tyson ◽  
Nolwen L. Rey ◽  
Rachael Sheridan ◽  
Wouter Peelaerts ◽  
...  

Background: α-Synuclein (α-syn) is the predominant protein in Lewy-body inclusions, which are pathological hallmarks of α- synucleinopathies, such as Parkinson’s disease (PD) and multiple system atrophy (MSA). Other hallmarks include activation of microglia, elevation of pro-inflammatory cytokines, as well as the activation of T and B cells. These immune changes point towards a dysregulation of both the innate and the adaptive immune system. T cells have been shown to recognize epitopes derived from α-syn and altered populations of T cells have been found in PD and MSA patients, providing evidence that these cells can be key to the pathogenesis of the disease. Objective To study the role of the adaptive immune system with respect to α-syn pathology. Methods: We injected human α-syn preformed fibrils (PFFs) into the striatum of immunocompromised mice (NSG) and assessed accumulation of phosphorylated α-syn pathology, proteinase K-resistant α-syn pathology and microgliosis in the striatum, substantia nigra and frontal cortex. We also assessed the impact of adoptive transfer of naïve T and B cells into PFF-injected immunocompromised mice. Results: Compared to wildtype mice, NSG mice had an 8-fold increase in phosphorylated α-syn pathology in the substantia nigra. Reconstituting the T cell population decreased the accumulation of phosphorylated α-syn pathology and resulted in persistent microgliosis in the striatum when compared to non-transplanted mice. Conclusion: Our work provides evidence that T cells play a role in the pathogenesis of experimental α-synucleinopathy.


2008 ◽  
Vol 32 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Michele Bolan ◽  
Daniele de Almeida Lima ◽  
Cláudia Pinto Figueiredo ◽  
Gabriella Di Giunta ◽  
Maria José de Carvalho Rocha

BACKGROUND: The periapical lesion is the result of a local inflammatory reaction caused by bacteria and its products present on the root canal. The interaction between inflammatory cells and bacteria elicit both specific and non-specific immune responses. OBJETIVE: Due to the lack of studies evaluating the role of the immune system in periapical lesions of primary teeth and considering the potentially systemic effects that these infections can cause in children, especially because of the immaturity of their immune system, we sought to evaluate the presence of T cells, B cells and macrophages on periradicular lesions in primary teeth. STUDY DESIGN: 14 periradicular lesions were analyzed. The immunohistochemistry technique was performed using CD45RO, CD20, CD68 monoclonal antibodies aiming to identify T cells, B cells and macrophages, respectively. Cells were quantified by microscopic analysis of histological sections. RESULTS: Mean percentage of positive cells CD45RO was 11.76; CD20 was 5.25; CD68 was 10.92. Our results showed that T and B cells and macrophages comprise the majority of the inflammatory infiltrate. CONCLUSION: We concluded that both humoral and cell mediated immune reactions take place in periradicular lesions of primary teeth. The immune system plays an important role on the periradicular inflammatory processes in primary teeth.


2021 ◽  
Vol 12 ◽  
Author(s):  
Emily E. Radke ◽  
Zhi Li ◽  
David N. Hernandez ◽  
Hanane El Bannoudi ◽  
Sergei L. Kosakovsky Pond ◽  
...  

Staphylococcus aureus, a common cause of serious and often fatal infections, is well-armed with secreted factors that disarm host immune defenses. Highly expressed in vivo during infection, Staphylococcal protein A (SpA) is reported to also contribute to nasal colonization that can be a prelude to invasive infection. Co-evolution with the host immune system has provided SpA with an Fc-antibody binding site, and a Fab-binding site responsible for non-immune superantigen interactions via germline-encoded surfaces expressed on many human BCRs. We wondered whether the recurrent exposures to S. aureus commonly experienced by adults, result in the accumulation of memory B-cell responses to other determinants on SpA. We therefore isolated SpA-specific class-switched memory B cells, and characterized their encoding VH : VL antibody genes. In SpA-reactive memory B cells, we confirmed a striking bias in usage for VH genes, which retain the surface that mediates the SpA-superantigen interaction. We postulate these interactions reflect co-evolution of the host immune system and SpA, which during infection results in immune recruitment of an extraordinarily high prevalence of B cells in the repertoire that subverts the augmentation of protective defenses. Herein, we provide the first evidence that human memory responses are supplemented by B-cell clones, and circulating-antibodies, that bind to SpA determinants independent of the non-immune Fc- and Fab-binding sites. In parallel, we demonstrate that healthy individuals, and patients recovering from S. aureus infection, both have circulating antibodies with these conventional binding specificities. These findings rationalize the potential utility of incorporating specially engineered SpA proteins into a protective vaccine.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kristian Assing ◽  
Christian Nielsen ◽  
Marianne Jakobsen ◽  
Charlotte B. Andersen ◽  
Kristin Skogstrand ◽  
...  

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Wei Li ◽  
Zheng Zhang ◽  
Zuo-min Wang

Abstract Background Host immunity plays an important role against oral microorganisms in periodontitis. Methods This study assessed the infiltrating immune cell subtypes in 133 healthy periodontal and 210 chronic periodontitis tissues from Gene Expression Omnibus (GEO) datasets using the CIBERSORT gene signature files. Results Plasma cells, naive B cells and neutrophils were all elevated in periodontitis tissues, when compared to those in healthy controls. In contrast, memory B cells, resting dendritic, mast cells and CD4 memory cells, as well as activated mast cells, M1 and M2 macrophages, and follicular helper T cells, were mainly present in healthy periodontal tissues. Furthermore, these periodontitis tissues generally contained a higher proportion of activated CD4 memory T cells, while the other subtypes of T cells, including resting CD4 memory T cells, CD8 T cells, follicular helper T cells (TFH) and regulatory T cells (Tregs), were relatively lower in periodontitis tissues, when compared to healthy tissues. The ratio of dendritic and mast cells and macrophages was lower in periodontitis tissues, when compared to healthy tissues. In addition, there was a significant negative association of plasma cells with most of the other immune cells, such as plasma cells vs. memory B cells (γ = − 0.84), plasma cells vs. resting dendritic cells (γ = − 0.64), plasma cells vs. resting CD4 memory T cells (γ = 0.50), plasma cells versus activated dendritic cells (γ = − 0.46), plasma cells versus TFH (γ = − 0.46), plasma cells versus macrophage M2 cells (γ = − 0.43), or plasma cells versus macrophage M1 cells (γ = − 0.40), between healthy control and periodontitis tissues. Conclusion Plasma cells, naive B cells and neutrophils were all elevated in periodontitis tissues. The infiltration of different immune cell subtypes in the periodontitis site could lead the host immunity against periodontitis.


1998 ◽  
Vol 23 (6) ◽  
pp. 724-727 ◽  
Author(s):  
K. G. GUDMUNDSSON ◽  
R. ARNGRÍMSSON ◽  
S. ARINBJARNARSON ◽  
A. OLAFSSON ◽  
T. JONSSON

Previous reports have indicated that inflammatory mechanisms may be involved in the pathogenesis of Dupuytren’s disease and it has even been suggested that this condition is a T-cell mediated autoimmune disorder. We investigated peripheral blood lymphocyte subsets from 21 patients with Dupuytren’s disease and compared them with ten healthy blood donors. The Dupuytren’s patients had an increase in DR+ T-cells compared with healthy controls. Furthermore, patients with both palmar and plantar involvement had a higher percentage of DR+ T-cells than those with only the palm affected. The percentage of circulating CD5+ B-cells was lower in the Dupuytren’s patients compared with the control group; this feature was marginally significant for the whole group of Dupuytren’s patients but was strongest in the group of patients with both palmar and plantar involvement. These findings support previous suggestions that immunological mechanisms, involving activated T-cells and probably also B-cells, are involved in the pathogenesis of Dupuytren’s disease.


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