Regulatory T cells (Tregs) are a subset of immune cells that suppress the immune response. Treg therapy for inflammatory diseases is being tested in the clinic, with moderate success. However, it is difficult to isolate and expand Tregs to sufficient numbers.
View Article and Find Full Text PDFPurpose: Poor preoperative nutritional status is associated with a higher complication rate after radical cystectomy in patients with bladder cancer. Given the short interval between diagnosis and radical cystectomy, we compared the effect of short-term specialized immunonutrition to that of a standard oral nutritional supplement on the acute inflammatory response and arginine status in patients treated with radical cystectomy.
Materials And Methods: In this prospective, randomized study in 29 men 14 received specialized immunonutrition and 15 received oral nutritional supplement.
J Clin Cell Immunol
April 2017
Regulatory T (Treg) cells are a subset of immune cells that maintain homeostasis by promoting immune tolerance and suppressing the immune response via a variety of mechanisms such as secreting cytokines, killing reactive immune cells, and inducing anergy. Dysfunction of Treg cells has been implicated in inflammatory diseases such as autoimmunity and transplant rejection. Conversely, too many or hyperresponsive Treg cells has been observed in cancer and chronic infections.
View Article and Find Full Text PDFThe Ikaros family of transcription factors includes five highly homologous members that can homodimerize or heterodimerize in any combination. Dimerization is essential for their ability to bind DNA and function as transcription factors. Previous studies showed that eliminating the function of the entire family blocks lymphocyte development while deletion of individual family members has relatively minor defects.
View Article and Find Full Text PDFBackground: Pediatric T cell acute lymphoblastic leukemia (T-ALL) is a highly heterogeneous disease in which the cells share phenotypic characteristics with normal human thymocytes. The Ikaros family of transcription factors includes five members that are required for normal T cell development and are implicated in leukemogenesis. The goal of this work was to correlate the pattern of expression of Ikaros family members with the phenotype of the T-ALL cells.
View Article and Find Full Text PDFThe Ikaros family of transcription factors is essential for normal T-cell development, but their expression pattern in human thymocytes remains poorly defined. Our goal is to determine how protein levels of Ikaros, Helios and Aiolos change as human thymocytes progress through the positive selection and lineage commitment stages. To accomplish this goal, we used multi-parameter flow cytometry to define the populations in which positive selection and lineage commitment are most likely to occur.
View Article and Find Full Text PDFUnlabelled: After radical cystectomy (RC), patients are at risk for complications including infections. The expansion of myeloid-derived suppressor cells (MDSCs) after surgery may contribute to the lower resistance to infection. Immune response and postoperative complications were compared in men consuming either specialized immunonutrition (SIM; n=14) or an oral nutrition supplement (ONS; n=15) before and after RC.
View Article and Find Full Text PDFIn human T cell development, the mechanisms that regulate cell fate decisions after TCRβ expression remain unclear. We defined the stages of T cell development that flank TCRβ expression and found distinct patterns of human T cell development. In half the subjects, T cell development progressed from the CD4(-)CD8(-) double-negative stage to the CD4(+)CD8(+) double-positive (DP) stage through an immature single-positive (ISP) CD4(+) intermediate.
View Article and Find Full Text PDFGRB2 related adaptor protein downstream of Shc (GADS) is a member of the GRB2 family of adaptors and is critical for TCR-induced signaling. The current model is that GADS recruits SLP-76 to the LAT complex, which facilitates the phosphorylation of SLP-76, the activation of PLC-γ1, T cell adhesion and cytokine production. However, this model is largely based on studies of disruption of the GADS/SLP-76 interaction and murine T cell differentiation in GADS deficient mice.
View Article and Find Full Text PDFBackground: Gastric disturbances such as dyspepsia are routinely encountered by multiple sclerosis (MS) patients, and these conditions are often treated with gastric acid suppressors such as proton pump inhibitors, histamine H2 receptor antagonists, or antacids. The proton pump inhibitor omeprazole can alter the gut flora and immune responses, both of which can influence the course of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The objective of the current study was to examine the effect of omeprazole treatment on the development of EAE.
View Article and Find Full Text PDFThe Gads adaptor protein is an essential component of the T cell signaling complex critical for T cell receptor-mediated calcium mobilization. After expression of TCRβ in T cell precursors, Gads is required for optimal Bcl-2 expression and cell survival. Similarly, the IL-7 receptor chain CD127 is also necessary for optimal Bcl-2 expression and cell survival in TCRβ-expressing thymocytes.
View Article and Find Full Text PDFAmong the milestones that occur during T-cell development in the thymus is the expression of T-cell receptor-β (TCR-β) and the formation of the pre-TCR complex. Signals emanating from the pre-TCR trigger survival, proliferation and differentiation of T-cell precursors. Although the pre-TCR is essential for these cell outcomes, other receptors, such as Notch and CXCR4, also contribute.
View Article and Find Full Text PDFThe Gads adaptor protein is critical for TCR-mediated Ca(2+) mobilization. We investigated the effect of Gads deficiency on the proliferation of CD8(+) T cells following peptide stimulation and in the context of infection with an intracellular pathogen. We stimulated CD8(+) T cells from Gads(+/+) OT-I and Gads(-/-) OT-I mice with cognate Ag (SIINFEKL) or altered peptide ligand.
View Article and Find Full Text PDFEarly in T-cell development, cells proceed through stages that are critically dependent on signaling through the Notch receptor. As cells mature, thymocytes transition from being Notch dependent to being Notch independent, but the stage of development during which this transition occurs is unknown. We used an in vitro differentiation system in which thymocytes can be cultured in the presence or absence of a Notch ligand to identify the stage of development in which thymocytes transition from being Notch responsive to Notch non-responsive.
View Article and Find Full Text PDFHuman parvovirus B19 (B19V) infection shows a strong erythroid tropism and drastically destroys erythroid progenitor cells, thus leading to most of the disease outcomes associated with B19V infection. In this study, we systematically examined the 3 B19V nonstructural proteins, 7.5 kDa, 11 kDa, and NS1, for their function in inducing apoptosis in transfection of primary ex vivo-expanded erythroid progenitor cells, in comparison with apoptosis induced during B19V infection.
View Article and Find Full Text PDFThe failure to reject the semi-allogeneic fetus suggests that maternal T lymphocytes are regulated by potent mechanisms in pregnancy. The T cell immunoinhibitory receptor, Programmed Death-1 (PD-1), and its ligand, B7-H1, maintain peripheral tolerance by inhibiting activation of self-reactive lymphocytes. Here, we investigated the role of the PD-1/B7-H1 pathway in maternal tolerance of the fetus.
View Article and Find Full Text PDFPositive selection of T-cell precursors is the process by which a diverse T-cell repertoire is established. Positive selection begins at the CD4(+)CD8(+) double positive (DP) stage of development and involves at least two steps. First, DP thymocytes down-regulate CD8 to become transitional single positive (TSP) CD4(+) thymocytes.
View Article and Find Full Text PDFLive-attenuated viruses derived from SIV and SHIV have provided the most consistent protection against challenge with pathogenic viruses, but concerns regarding their long-term safety and efficacy have hampered their clinical usefulness. We report a longitudinal study in which we evaluated the long-term safety and efficacy of DeltavpuSHIV(PPC), a live virus vaccine derived from SHIV(PPC). Macaques were administered two inoculations of DeltavpuSHIV(PPC), three years apart, and followed for eight years.
View Article and Find Full Text PDFTCRbeta expression in CD4(-)CD8(-) double-negative (DN) thymocytes induces signaling pathways that promote survival and proliferation, as well as differentiation into CD4(+)CD8(+) double-positive thymocytes. The signaling pathways that regulate survival, proliferation, and differentiation remain unclear. We used Gads-deficient mice to investigate the signaling pathways that regulate these cell fates.
View Article and Find Full Text PDFNearly all hematopoietic receptors are dependent on adaptor proteins for the activation of downstream signaling pathways. The Gads adaptor protein is expressed in many hematopoietic tissues, including bone marrow, lymph node, and spleen. Using intracellular staining, we detected Gads protein in a number cells, including B cells, T cells, NK cells, monocytes, and plasmacytoid DC, but not in macrophages, neutrophils, or monocyte-derived DC.
View Article and Find Full Text PDFLittle is known about the role of the Gads (GrpL) adaptor protein in mature T cell populations. In this study we show that the effects of Gads deficiency on murine CD4(+) and CD8(+) T cells are markedly different. Gads(-/-) CD4(+) T cells were markedly deficient in the spleen and had an activated phenotype and a rapid turnover rate.
View Article and Find Full Text PDFAdapter proteins play a critical role in regulating signals triggered by Ag receptor cross-linking. These small molecules link receptor proximal events with downstream signaling pathways. In this study, we explore the expression and function of the Grb2-related protein of the lymphoid system (GrpL)/Grb2-related adaptor downstream of Shc adapter protein in human B cells.
View Article and Find Full Text PDFThe B cell antigen receptor (BCR) is coupled to the mobilization of Ca(2+) by the protein-tyrosine kinase, Syk. Syk, recruited to the clustered BCR, becomes phosphorylated on three tyrosines (Tyr-317, Tyr-342, and Tyr-346) located within the linker region that separates the C-terminal catalytic domain from the N-terminal tandem Src homology 2 domains. Phosphorylation within the linker region can be either activating or inhibitory to Ca(2+) mobilization depending on the sites that are modified.
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