Search results for "Gamma"

Human Papillomavirus Type 33 E7 Peptides Presented by HLA-DR*0402 to Tumor-Infiltrating T Cells in Cervical Cancer

2000

ABSTRACTSeveral characteristics make human papillomavirus (HPV) amenable to vaccination. Anti-HPV-directed vaccines are based on the observation that HPV E6 and E7 oncoproteins are constitutively expressed in HPV-positive cervical cancer and may serve as tumor rejection antigens. Five HPV types (16, 18, 31, 33, and 45) account for 80% of cervical cancer. Until now, the type of immune response capable of mediating an effective antitumor response has not been defined. In order to define the anticancer-directed immune response in situ, we characterized CD4+and CD8+sorted T cells from peripheral blood lymphocytes, freshly harvested tumor tissue, and tumor-infiltrating lymphocytes (TIL) from a p…

Dendritic Cells Lose Ability to Present Protein Antigen after Stimulating Antigen-Specific T Cell Responses, despite Upregulation of MHC Class II Exp…

2000

Abstract Immature dendritic cells (DC) take up, process and present protein antigens; mature DC are specialized for stimulating primary T cell responses with increased expression of MHC class II and co-stimulatory molecules, but are incapable of processing and presenting soluble protein. The current study examined whether maturation of DC is triggered by T cell recognition of antigens presented by immature DC. Human DC derived from CD34+ progenitor cells by culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) in serum-free medium could prime naive CD4+ T cells to keyhole limpet hemocyanin (KLH) and ovalbumin (OVA). The cultured DC retained the abil…

Regulation of Protein-DNA Interactions at the Interferon-gamma Gene Promoter by Corticosteroids

1998

Docosahexaenoic acid modulates the expression of T-bet and GATA-3 transcription factors, independently of PPARα, through suppression of MAP kinase ac…

2009

The present study was conducted on CD4(+) T cells, isolated from wild type (WT) and PPARalpha(null) mice, in order to assess the mechanism of action of docosahexaenoic acid (DHA), an n-3 fatty acid, in the modulation of two transcription factors, i.e., T-bet and GATA-3, implicated in T-cell differentiation towards, respectively, T(H)1 and T(H)2 phenotype. The T-cells from PPARalpha(null) mice secreted higher IFN-gamma and lower IL-4 concentrations than WT T-cells. Furthermore, the deletion of PPARalpha gene in T-cells resulted in the upregulation of T-bet and downregulation of GATA-3 both at mRNA and protein levels. DHA exerted not only an inhibitory effect on T-cell proliferation, but also…

Change of Th0 to Th1 cell-cytokine profile following tuberculosis chemotherapy.

2000

T cells mediate protection against tuberculosis, but little is known about their role during chemotherapy of patients with active disease. Here we examined the cytokine profile of CD4 T cells before and after four months of chemotherapy in six initial skin test anergic cases. Purified protein derivative (PPD) and 16-kDa antigen-reactive CD4 T-cell clones prior to therapy resided mostly in disease-associated body fluids and were of the Th0 (interferon (IFN)-gamma + interleukin (IL)-4) secreting profile. In contrast, the majority of postchemotherapy CD4 T-cell clones originated from blood and were of the IFN-gamma secreting Th1 type. However, the recognition of several peptides derived from t…

IL-28A Is a Key Regulator of T-Cell–Mediated Liver Injury via the T-Box Transcription Factor T-Bet

2006

Background & Aims: T-cell–mediated fulminant hepatitis is a potentially life-threatening event for which the underlying pathogenic mechanisms are not fully understood. Here, we demonstrate a key regulatory role of IL-28A in T-cell–mediated hepatitis. Methods: We cloned the murine IL-28A gene by reverse-transcription polymerase chain reaction, assessed the effects of recombinant IL-28A, and generated IL-28A–transgenic mice. Results: IL-28A induced TH1 cytokine production by CD4+ T lymphocytes in a T-bet–dependent manner and was up-regulated in a murine model of T-cell–mediated hepatitis upon Con A administration. In vivo, CD4+ T cells from newly created IL-28A–transgenic animals revealed an …

Monitoring of anti-vaccine CD4 T cell frequencies in melanoma patients vaccinated with a MAGE-3 protein.

2005

Abstract Quantitative evaluation of T cell responses of patients receiving antitumoral vaccination with a protein is difficult because of the large number of possible HLA-peptide combinations that could be targeted by the response. To evaluate the responses of patients vaccinated with protein MAGE-3, we have developed an approach that involves overnight stimulation of blood T cells with autologous dendritic cells loaded with the protein, sorting by flow cytometry of the T cells that produce IFN-γ, cloning of these cells, and evaluation of the number of T cell clones that secrete IFN-γ upon stimulation with the Ag. An important criterion is that T cell clones must recognize not only stimulat…

Contrary roles of IL-4 and IL-12 on IL-10 production and proliferation of human tumour reactive T cells.

1997

The cytokine profile of tumour reactive T cells is likely to play a central role in their function. However, little is known about how cytokine patterns of tumour reactive T cells can be regulated. Here, the authors investigated the influence of exogenous regulatory cytokines in addition to interleukin-2 (IL-2) on cytokine patterns and the proliferation of T cells recognizing an autologous sarcoma cell line. In this system, IL-4 and IL-12 showed the most polarizing influences on tumour reactive T cells. Exogenous IL-4 induced a predominant production of IL-4 while decreasing the interferon-gamma (IFN-gamma) and IL-10 production by tumour reactive T cells. It also stimulated the growth of tu…

H2-M, a facilitator of MHC class II peptide loading, and its negative modulator H2-O are differentially expressed in response to proinflammatory cyto…

2000

H2-M is a major histocompatibility complex (MHC) class II-like molecule that catalyzes peptide binding to MHC class II molecules. Recently, the H2-O heterodimer, encoded by H2-Oa and H2-Ob in the MHC class II region, has been shown to be physically associated with H2-M in B cells and to downregulate H2-M function. Examination of H2-O expression in freshly isolated mouse organs revealed that H2-Oa- and H2-Ob-specific transcripts are present in both lymphoid and nonlymphoid tissues. To evaluate the gene regulation and functional impact of H2-O on antigen presentation, we examined the effects on MHCII, invariant chain (Ii), H2-M, and H2-O gene expression of interleukin (IL)-4, IL-10, and inter…

Development of a 3D CZT detector prototype for Laue Lens telescope

2010

We report on the development of a 3D position sensitive prototype suitable as focal plane detector for Laue lens telescope. The basic sensitive unit is a drift strip detector based on a CZT crystal, (similar to 19x8 mm(2) area, 2.4 mm thick), irradiated transversally to the electric field direction. The anode side is segmented in 64 strips, that divide the crystal in 8 independent sensor (pixel), each composed by one collecting strip and 7 (one in common) adjacent drift strips. The drift strips are biased by a voltage divider, whereas the anode strips are held at ground. Furthermore, the cathode is divided in 4 horizontal strips for the reconstruction of the third interaction position coord…