Search results for "interleukin 2"

Role of accessory cells in cytokine production by T cells in chronic B- cell lymphocytic leukemia

1995

Abstract We investigated the production of cytokines by highly purified T helper cells from B-cell chronic lymphocytic leukemia (B-CLL) patients stimulated by different activation pathways, and we studied the influence of various accessory cell populations on the pattern of the secretion of cytokines, including interleukin (IL)-2, IL-4, interferon- gamma (IFN-gamma), and IL-10. Neither a qualitative nor a quantitative difference in cytokine production and proliferative capacity was observed in CLL-derived purified T cells compared with normal individuals, when T cells were stimulated by different pathways, including CD3, CD2, and costimulation with CD28. Addition of autologous accessory cel…

Interleukin-10–Treated Human Dendritic Cells Induce a Melanoma-Antigen–Specific Anergy in CD8+ T Cells Resulting in a Failure to Lyse Tumor Cells

1999

Abstract Dendritic cells (DC) are critically involved in the initiation of primary immune processes, including tumor rejection. In our study, we investigated the effect of interleukin-10 (IL-10)–treated human DC on the properties of CD8+ T cells that are known to be essential for the destruction of tumor cells. We show that IL-10–pretreatment of DC not only reduces their allostimulatory capacity, but also induces a state of alloantigen-specific anergy in both primed and naive (CD45RA+) CD8+ T cells. To investigate the influence of IL-10–treated DC on melanoma-associated antigen-specific T cells, we generated a tyrosinase-specific CD8+ T-cell line by several rounds of stimulation with the sp…

T helper cell populations: As flexible as the skin?

2011

T helper cells can be defined by the cytokines they produce and are divided into Th1, Th2, Th17, T(FH) or regulatory T cells. Th17 cells have been shown to produce, in addition to IL-17, IL-22. In the current issue of the European Journal of Immunology, an article by Larsen et al. (Eur. J. Immunol. 2011. 41: 2596-2605) provides evidence that human T helper cells, like murine cells, can also express IL-22 in the absence of the other T helper cell signature cytokines. Moreover, they show that these IL-22-producing cells, namely Th22 cells, can be found in the skin of psoriasis patients, where they might contribute to the pathogenesis of this inflammatory skin disease. Finally, they show that,…

T cell directives for transcriptional regulation in asthma.

2003

Allergic asthma frequently starts in childhood, and environmental factors such as viruses, allergens and occupational exposure can regulate the evolution of the disease. The development of allergen-specific Th2 lymphocytes represents the triggering event for the recruitment and activation of IgE-producing B cells and fibroblasts, followed by the release of soluble factors, thus giving rise to the inflammatory reaction observed in this disease. GATA-3 was identified as a cell lineage-specific factor selectively expressed and activated in the Th2 lineage as a consequence of STAT-6 activation. However, recent literature indicates that blockade of CTLA-4-directed inhibitory signals is sufficien…

Inhibition of anti-GD3-ganglioside antibody-induced proliferation of human CD8+ T cells by CD16+ natural killer cells

1994

The ganglioside GD3 has been described as a membrane component of human T cells which is involved in T cell growth. In the present study the activating function of GD3 for human CD4+ and CD8+ T cells was analyzed by five different monoclonal antibodies (mAb) directed against the GD3 molecule. Three mAb U5, Z21 and R24 induced strong proliferation of peripheral blood mononuclear cells and purified CD8+ and CD4+ T cells of normal donors containing less than 5% CD16+ natural killer (NK) cells. In contrast to CD4+ T cells, CD8+ T cells proliferated only weakly in the presence of 15% CD16+ NK cells. The proliferative response of purified CD4+ and CD8+ T cells (< 5% NK cells) correlated with the …

Peptide-specific CD8+ T-cell evolutionin vivo: Response to peptide vaccination with Melan-A/MART-1

2002

Monitoring of CD8+ T-cell responses in cancer patients during peptide vaccination is essential to provide useful surrogate markers and to demonstrate vaccine efficacy. We have longitudinally followed CD8+ T-cell responses in 3 melanoma patients who were immunized with peptides derived from Melan-A/MART-1. Recombinant HLA-A2 tetramers loaded with the naturally presented Melan-A/MART-1 nonamer peptide (AAGIGILTV) and the Melan-A/MART-1 analog (ELAGIGILTV) were used in combination with phenotypical analysis for different T-cell subsets including naive T cells, effector T cells, "true memory" T cells and "memory effector" T cells, based on CD45RA/RO and CCR7-expression. At least in a single pat…

2004

Altered CD94/NKG2A and perforin expression reduce the cytotoxic activity in malignant pleural effusions.

2010

CD94/NKG2A is an inhibitory receptor expressed by NK cells and cytotoxic lymphocytes and, upon activation by HLA-E, downregulates the cytolytic activities of these cells thus representing a tumour immune escape mechanism. This study was aimed at assessing whether cytotoxic lymphocytes (CD8+) and NK cells from malignant pleural effusions have a deregulated expression of CD94/NKG2A. The expression of membrane CD94/NKG2A and perforin was evaluated by flow-cytometry in CD8+ and NK cells from pleural effusions and autologous peripheral blood of cancer (n=19) and congestive heart failure (CHF) (n=11) patients. Intracellular CD94/NKG2A expression was evaluated by flow-cytometry in pleural effusion…

Human FOXP3 and cancer.

2010

FOXP3 is a transcription factor necessary and sufficient for induction of the immunosuppressive functions in regulatory T lymphocytes. Its expression was first considered as specific of this cell type, but FOXP3 can also be transiently expressed in T-cell antigen receptor-activated human nonregulatory T cells. Recent data indicate that FOXP3 is also expressed by some nonlymphoid cells, in which it can repress various oncogenes that are restored following FOXP3 deletion or mutation. This review summarizes major advances in (1) the understanding of Foxp3 functions in human regulatory T cells, (2) the prognostic significance of Foxp3-expressing T cells in human malignancies and (3) the signifi…

Blockade of PD-L1 (B7-H1) augments human tumor-specific T cell responsesin vitro

2006

Human tumors frequently escape immune destruction, despite the presence of cytotoxic T cells (CTL) recognizing tumor-associated antigens (TAA). We have previously shown that programmed death ligand-1 (PD-L1), a recently identified ligand of the B7 superfamily, is expressed on murine tumors and can inhibit antitumor immune responses. To evaluate the clinical relevance of our animal model findings, we examined human tumors and tumor-specific T cells. We found PD-L1 to be constitutively expressed on human renal cell carcinoma (RCC) cell lines and upregulated on human melanoma cell lines upon exposure to interferon-gamma. Similarly, we found binding of anti-PD-L1 monoclonal antibody (mAb) on fr…