scholarly journals Differential survival of leukocyte subsets mediated by synovial, bone marrow, and skin fibroblasts: Site-specific versus activation-dependent survival of T cells and neutrophils

2006 ◽  
Vol 54 (7) ◽  
pp. 2096-2108 ◽  
Author(s):  
Andrew Filer ◽  
Greg Parsonage ◽  
Emily Smith ◽  
Chloe Osborne ◽  
Andrew M. C. Thomas ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.


Author(s):  
Tatsuya Suwabe ◽  
Yasuhiko Shibasaki ◽  
Hiroyuki Sato ◽  
Suguru Tamura ◽  
Takayuki Katagiri ◽  
...  

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S81-S81
Author(s):  
J Lanceta ◽  
W Xue ◽  
M Hurford ◽  
H Wu

Abstract Casestudy Epstein-Barr virus (EBV)-associated peripheral T-cell lymphomas are a group of aggressive neoplasms with a geographic predilection for South America and Asia, but are very rare in Western populations. Results We report a case of a 74-year-old Caucasian female who presented with pancytopenia and B symptoms with EBV-IgG detected on admission. Past medical history included: ITP, chronic urticaria, and recently diagnosed myelodysplastic syndrome (MDS) on bone marrow biopsy one month prior to admission. Excisional biopsies of an enlarged right neck lymph node (repeated within 6 months) and right axillary lymph node five years ago were negative for a lymphoproliferative disorder at the time. Repeated bone marrow biopsy, performed during the current admission, confirmed the diagnosis of MDS, with scattered T-cells without aberrant immunophenotype. Despite aggressive treatment from multiple specialties, the patient deteriorated and expired four weeks later from complications of MDS. At autopsy, there was diffuse lymphadenopathy involving the mediastinum, axilla, pelvis and peripancreatic fat. Lymph node sections demonstrated nodal architecture effacement by diffuse, vaguely nodular lymphoid infiltrates. Histologically, the infiltrates were composed of medium to large lymphocytes with round to slight irregular nuclei, rare Reed-Sternberg-like multinucleated cells, clumped chromatin, and indistinct nucleoli. Individual cell necrosis was abundant with mitotic figures readily identifiable. Immunohistochemistry revealed CD2+ CD3+ neoplastic T-cells that co-express MUM1 and a subset of CD30, while negative for CD4, CD5, CD8, CD56, ALK1, and TDT. EBV-encoded RNA in-situ hybridization was focally positive. The final postmortem diagnosis was peripheral T-cell lymphoma, not otherwise specified (NOS), with focal EBV positivity. Conclusion Co-existence of a de-novo MDS and non-Hodgkin lymphoma without any prior chemotherapeutic exposure is a highly unusual finding, although MDS-like presentations can occur with EBV-associated lymphomas. Peripheral T-cell lymphoma, NOS is an aggressive lymphoma and EBV positivity has been found correlated with a poor prognosis. This case demonstrates how postmortem examination remains an important tool in clinical- pathological correlation and highlights the potential pathogenetic role EBV plays in MDS and T-cell lymphoma.


Sign in / Sign up

Export Citation Format

Share Document