scholarly journals Case Report: Sustained Remission Due to PD-1-Inhibition in a Metastatic Melanoma Patient With Depleted B Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Lena Margarethe Wulfken ◽  
Jürgen Christian Becker ◽  
Rami Hayajneh ◽  
Annette Doris Wagner ◽  
Katrin Schaper-Gerhardt ◽  
...  
Keyword(s):  
Case Report ◽  
B Cells ◽  
Metastatic Melanoma ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Flow Cytometric Analysis ◽  
Sustained Remission ◽  
Regulatory B Cells ◽  
Double Positive ◽  
Peripheral Blood Mononuclear

IntroductionCheckpoint-Inhibition (CPI) with PD-1- and PD-L1-inhibitors is a well-established therapy for advanced stage melanoma patients. CPI mainly acts via T-lymphocytes. However, recent literature suggests also a role for B cells modulating its efficacy and tolerability of CPI.Case ReportWe report a 48-year-old female patient with metastatic melanoma affecting brain, lung, skin and lymph nodes. A preexisting granulomatosis with polyangiitis was treated with rituximab over five years prior to the diagnosis of melanoma, resulting in a complete depletion of B cells both in peripheral blood as well as the tumor tissue. In the absence of the mutation of the proto-oncogene b-raf, treatment with the PD-1 inhibitor nivolumab was initiated. This therapy was well tolerated and resulted in a deep partial response, which is ongoing for 14+ months. Flow cytometric analysis of peripheral blood mononuclear cells revealed 15% IL-10 producing and 14% CD24 and CD38 double positive regulatory B cells.ConclusionThe exceptional clinical response to nivolumab monotherapy in our patient with depleted B cells sheds a new light on the relevance of B cells in the modulation of immune responses to melanoma. Obviously, B cells were not required for the efficacy of CPI in our patient. Moreover, the depletion of regulatory B cells may have improved efficacy of CPI.

scholarly journals Defective Regulatory B Cells Are Associated With Thyroid-Associated Ophthalmopathy

2019 ◽  
Vol 104 (9) ◽  
pp. 4067-4077 ◽  
Author(s):  
Guo Chen ◽  
Yungang Ding ◽  
Qian Li ◽  
Yanbing Li ◽  
Xiaofeng Wen ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Healthy Controls ◽  
Regulatory B Cells ◽  
Peripheral Blood Mononuclear ◽  
Thyroid Associated Ophthalmopathy ◽  
Ifn Γ

Abstract Purpose To investigate the change in IL-10–producing regulatory B cells (Breg), which suppress peripheral immune responses, in patients with thyroid-associated ophthalmopathy (TAO). Methods Peripheral blood mononuclear cells (PBMCs) were isolated from healthy controls (n = 54), patients with Graves disease (n = 26), and patients with TAO (N=125), and stimulated with CpG/CD40L. The frequency of IL-10–producing Bregs and the expression of IL-10 in response to TSH stimulation were measured by flow cytometry. CD4+ T cells were cultured with Breg-depleted PBMCs to elucidate the function of Bregs in patients with TAO. The potential immunoregulatory mechanism was also investigated by Western blot and chromatin immunoprecipitation assays. Results Patients with active TAO had higher baseline levels of Bregs in their peripheral blood than both healthy controls and inactive patients. TSH promoted Bregs. Bregs from patients with TAO were defective in suppressing the activation of interferon (IFN)-γ+ and IL-17+ T cells in vitro. Conclusions Regulatory B cells in patients with TAO are functionally defective, suggesting that the defective Bregs might be responsible for the pathogenesis of TAO.

scholarly journals Circulating CD19+CD24hiCD38hi regulatory B cells as biomarkers of response to methotrexate in early rheumatoid arthritis

Rheumatology ◽  
2020 ◽  
Vol 59 (10) ◽  
pp. 3081-3091
Author(s):  
Paula Fortea-Gordo ◽  
Alejandro Villalba ◽  
Laura Nuño ◽  
María José Santos-Bórnez ◽  
Diana Peiteado ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Clinical Response ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Regulatory B Cells ◽  
Cell Frequency ◽  
Peripheral Blood Mononuclear ◽  
Inflammatory Conditions

Abstract Objective The protagonism of regulatory B cells seems to vary along the course of the disease in murine models of inflammatory conditions. Decreased numbers of circulating regulatory CD19+CD24hiCD38hi transitional (cTr) B cells have been described in patients with long-standing RA, thus our objective was to examine the frequency and evolution of cTr B cells in the peripheral blood of early RA (ERA) patients. Methods Freshly isolated peripheral blood mononuclear cells from 48 steroid- and DMARD-naïve ERA patients with a disease duration of <24 weeks and 48 healthy controls (HCs) were examined by flow cytometry. Co-cultures of isolated memory B cells were established with autologous T cells in the absence or presence of Tr B cells. Results As compared with HCs, ERA patients demonstrated an increased frequency of cTr B cells. cTr B cells of ERA patients and HCs displayed an anti-inflammatory cytokine profile and were able to downregulate T cell IFN-γ and IL-21 production, together with ACPA secretion in autologous B/T cell co-cultures. Basal frequencies of cTr B cells above the median value observed in HCs were associated with a good EULAR response to MTX at 12 months [relative risk 2.91 (95% CI 1.37, 6.47)]. A significant reduction of cTr B cells was observed 12 months after initiating MTX, when the cTr B cell frequency was no longer elevated but decreased, and this was independent of the degree of clinical response or the intake of prednisone. Conclusion An increased frequency of regulatory cTr B cells is apparent in untreated ERA and the baseline cTr B cell frequency is associated with the clinical response to MTX at 12 months.

scholarly journals Distribution of integrins on human peripheral blood mononuclear cells

Blood ◽  
1989 ◽  
Vol 74 (4) ◽  
pp. 1348-1354 ◽  
Author(s):  
HG Klingemann ◽  
S Dedhar
Keyword(s):  
T Cells ◽  
B Cells ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Peptide Sequence ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Beta 1 Integrin

Abstract The receptors for fibronectin (FN-R) and vitronectin (VN-R) belong to a family of integral membrane glycoproteins known to be involved in cell- extracellular matrix and cell-cell interactions named integrins (FN-R = beta 1 integrin and VN-R = beta 3 integrin). Adhesion studies using FN- coated plastic dishes and highly purified subpopulations of peripheral blood mononuclear cells (PBMCs) showed a strong binding of monocytes and T lymphocytes to FN but virtually no binding of B cells to FN. Binding of monocytes and T cells to FN could be partially inhibited by a hexapeptide (GRGDSP) containing the adhesive peptide sequence Arg-Gly- Asp (RGD) as well as by an anti-FN-R antibody. The distribution of beta 1 and beta 3 integrin complexes on PBMCs was characterized by immunoprecipitation of detergent extracts of 125I-labeled cells using polyclonal antibodies against these two receptors. Two surface polypeptides corresponding to the alpha and beta chains of FN-R and VN- R were found on all three cell types. To characterize these receptors further, monoclonal antibodies (MoAbs) against the very late antigens (VLAs) 1, 3, and 5 were used for immunoprecipitation studies. Monocytes and T cells reacted with VLA 5 that was previously identified as the human FN receptor, whereas no labeling with anti-VLA 5 could be shown for B cells. When cell populations were cultured in 10% human serum for 24 hours, an increase in beta 1-integrin+ monocytes and T cells was observed. The number of beta 3-integrin+ cells remained essentially unchanged. The presence of beta 1 and beta 3 integrins on monocytes as well as on T and B lymphocytes may be of significance in the ability of these cells to interact with each other and participate in hematopoiesis and certain immune reactions.

scholarly journals Oropouche Virus Infects, Persists and Induces IFN Response in Human Peripheral Blood Mononuclear Cells as Identified by RNA PrimeFlow™ and qRT-PCR Assays

Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 785
Author(s):  
Mariene Ribeiro Amorim ◽  
Marjorie Cornejo Pontelli ◽  
Gabriela Fabiano de Souza ◽  
Stéfanie Primon Muraro ◽  
Daniel A. Toledo-Teixeira ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Peripheral Blood Mononuclear ◽  
Human Leukocytes ◽  
Qrt Pcr ◽  
Viral Antigens ◽  
Blood Mononuclear Cells

Oropouche orthobunyavirus (OROV) is an emerging arbovirus with a high potential of dissemination in America. Little is known about the role of peripheral blood mononuclear cells (PBMC) response during OROV infection in humans. Thus, to evaluate human leukocytes susceptibility, permissiveness and immune response during OROV infection, we applied RNA hybridization, qRT-PCR and cell-based assays to quantify viral antigens, genome, antigenome and gene expression in different cells. First, we observed OROV replication in human leukocytes lineages as THP-1 monocytes, Jeko-1 B cells and Jurkat T cells. Interestingly, cell viability and viral particle detection are maintained in these cells, even after successive passages. PBMCs from healthy donors were susceptible but the infection was not productive, since neither antigenome nor infectious particle was found in the supernatant of infected PBMCs. In fact, only viral antigens and small quantities of OROV genome were detected at 24 hpi in lymphocytes, monocytes and CD11c+ cells. Finally, activation of the Interferon (IFN) response was essential to restrict OROV replication in human PBMCs. Increased expression of type I/III IFNs, ISGs and inflammatory cytokines was detected in the first 24 hpi and viral replication was re-established after blocking IFNAR or treating cells with glucocorticoid. Thus, in short, our results show OROV is able to infect and remain in low titers in human T cells, monocytes, DCs and B cells as a consequence of an effective IFN response after infection, indicating the possibility of leukocytes serving as a trojan horse in specific microenvironments during immunosuppression.

scholarly journals Single cell resolution landscape of equine peripheral blood mononuclear cells reveals diverse immune cell subtypes including T-bet+ B cells

2020 ◽  
Author(s):  
Roosheel S. Patel ◽  
Joy E. Tomlinson ◽  
Thomas J. Divers ◽  
Gerlinde R. Van de Walle ◽  
Brad R. Rosenberg
Keyword(s):  
B Cells ◽  
Immune Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Model Organisms ◽  
Traditional Model ◽  
Cell Type ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

ABSTRACTTraditional laboratory model organisms represent a small fraction of the diversity of multicellular life, and findings in any given experimental model often do not translate to other species. Immunology research in non-traditional model organisms can be advantageous or even necessary (e.g. for host-pathogen interaction studies), but presents multiple challenges, many stemming from an incomplete understanding of potentially species-specific immune cell types, frequencies and phenotypes. Identifying and characterizing immune cells in such organisms is frequently limited by the availability of species-reactive immunophenotyping reagents for flow cytometry, and insufficient prior knowledge of cell type-defining markers. Here, we demonstrate the utility of single cell RNA sequencing (scRNA-Seq) to characterize immune cells for which traditional experimental tools are limited. Specifically, we used scRNA-Seq to comprehensively define the cellular diversity of equine peripheral blood mononuclear cells (PBMCs) from healthy horses across different breeds, ages, and sexes. We identified 30 cell type clusters partitioned into five major populations: Monocytes/Dendritic Cells, B cells, CD3+PRF1+ lymphocytes, CD3+PRF1- lymphocytes, and Basophils. Comparative analyses revealed many cell populations analogous to human PBMC, including transcriptionally heterogeneous monocytes and distinct dendritic cell subsets (cDC1, cDC2, plasmacytoid DC). Unexpectedly, we found that a majority of the equine peripheral B cell compartment is comprised of T-bet+ B cells; an immune cell subpopulation typically associated with chronic infection and inflammation in human and mouse. Taken together, our results demonstrate the potential of scRNA-Seq for cellular analyses in non-traditional model organisms, and form the basis for an immune cell atlas of horse peripheral blood.

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