Search results for "Lymphocyte"
showing 10 items of 2280 documents
Longitudinal analysis of Mycobacterium tuberculosis 19-kDa antigen-specific T cells in patients with pulmonary tuberculosis: association with disease…
2003
CD8(+) T cells play a central role in immune protection against infection with Mycobacterium tuberculosis. One of the target epitopes for anti-M. tuberculosis directed CD8(+) T cells is the HLA-A2-restricted 19-kDa lipoprotein peptide VLTDGNPPEV. T cell clones directed against this epitope recognized not only the nominal peptide ligand, but also a closely related peptide (VPTDPNPPEV) from the HIV envelope gp120 (HIV(env) gp120) protein characterized by IFN-gamma release. This cross-reactivity was confirmed in ex vivo in M. tuberculosis 19-kDa tetramer-sorted T cells from patients with tuberculosis and in HIVgp120 tetramer-reactive T cells sorted from HIV(+) patients. M. tuberculosis 19-kDa …
Th0 to Th1 switch of CD4 T cell clones specific from the 16-kDa antigen of Mycobacterium tuberculosis after successful therapy: lack of involvement o…
2005
Abstract In this study, we have examined the influence of HLA-DR molecules and the structure of the epitope repertoire of the 16-kDa protein of Mycobacterium tuberculosis on the acquisition of the cytokine secretion pattern of CD4 T cell clones, obtained from tuberculous patients before and after anti-mycobacterial therapy. Our data indicate that TB patients have a predominant Th0 response against the 16-kDa protein and its epitopes and that healing, induced by anti-mycobacterial therapy, is associated with a shift toward a predominant Th1 phenotype. Moreover, both HLA-DR molecules restricting the clone specificity and the nature of the recognized epitope do not play any role in the generat…
Biology of gama delta T Cells in Tuberculosis and Malaria
2002
Tuberculosis and malaria remain the leading causes of mortality among human infectious diseases in the world. It is estimated that 3 to 5 million people die from tuberculosis and malaria each year. Although it is traditionally believed that CD4 and CD8 alphabeta T lymphocytes are mandatory for protective immune responses against Mycobacterium tuberculosis and Plasmodium falciparum (the ethiologic agents of tuberculosis and the most severe form of malaria, respectively), there is still incomplete understanding of the mechanisms of immune protection and of the causes of its failure in the affected patients. Several studies in humans and animal models have suggested that Vgamma9/Vdelta2 T cell…
Mycobacterium tuberculosis secretory proteins downregulate T cell activation by interfering with proximal and downstream T cell signalling events
2015
Background Mycobacterium tuberculosis (M. tuberculosis) modulates host immune response, mainly T cell responses for its own survival leading to disease or latent infection. The molecules and mechanisms utilized to accomplish immune subversion by M. tuberculosis are not fully understood. Understanding the molecular mechanism of T cell response to M. tuberculosis is important for development of efficacious vaccine against TB. Methods Here, we investigated effect of M. tuberculosis antigens Ag85A and ESAT-6 on T cell signalling events in CD3/CD28 induced Peripheral blood mononuclear cells (PBMCs) of PPD+ve healthy individuals and pulmonary TB patients. We studied CD3 induced intracellular calc…
Plasmacytoid dendritic cells are inefficient in activation of human regulatory T cells
2011
BACKGROUND: Dendritic cells (DC) play a key role in initiation and regulation of immune responses. Plasmacytoid DC (pDC), a small subset of DC, characterized as type-I interferon producing cells, are critically involved in anti-viral immune responses, but also mediate tolerance by induction of regulatory T cells (Treg). In this study, we compared the capacity of human pDC and conventional DC (cDC) to modulate T cell activity in presence of Foxp3(+) Treg. PRINCIPAL FINDINGS: In coculture of T effector cells (Teff) and Treg, activated cDC overcome Treg anergy, abrogate their suppressive function and induce Teff proliferation. In contrast, pDC do not break Treg anergy but induce Teff prolifera…
p53 Isoform D133p53a: A Novel Transcriptional Enhancer of T-Cell Effector Function to Improve T-Cell Based Cancer Immunotherapy
2018
Abstract Background: Adoptive transfer of genetically modified T lymphocytes with tumor antigen-specific receptor has proven efficacy in cancer immunotherapy. However, in many patients the overall benefit is still limited due to various tumor escape mechanisms. Cell damage and metabolic/hypoxic stress in the tumor microenvironment (TME) can lead to a dysfunctional anti-tumor T cell response called T cell senescence. The tumor suppressor TP53 is a master molecule in the regulation of cell cycle and senescence. Few studies have demonstrated the critical role of p53 isoforms in the regulation of cellular senescence mainly in tumor cells. However, their role in tumor infiltrating lymphocytes (T…
Tumor infiltration by chemokine receptor 7 (CCR7)+ T-lymphocytes is a favorable prognostic factor in metastatic colorectal cancer
2012
The immune interactions occurring within the tumor microenvironment have a critical role in determining the outcome of colorectal cancer patients. We carried-out an immunohistochemical analysis of tumor infiltrating T-lymphocytes expressing chemokine receptor 7 (CCR7) in a series of colorectal cancer patients enrolled in a prospective clinical trial. We demonstrated that a high tumor infiltration score of this lymphocyte subset is predictive of longer progression free survival and overall survival. © 2012 Landes Bioscience.
The tumor suppressor CYLD controls the function of murine regulatory T cells.
2012
Abstract CYLD was originally identified as a tumor suppressor gene mutated in familial cylindromatosis, an autosomal dominant predisposition to multiple benign neoplasms of the skin known as cylindromas. The CYLD protein is a deubiquitinating enzyme that acts as a negative regulator of NF-κB and JNK signaling through its interaction with NEMO and TNFR-associated factor 2. We have previously described a novel mouse strain that expresses solely and excessively a naturally occurring splice variant of CYLD (CYLDex7/8). In this study, we demonstrate that CYLD plays a critical role in Treg development and function. T cells of CYLDex7/8 mice had a hyperactive phenotype manifested by increased prod…
Tumor-infiltrating lymphocytes and breast cancer: Beyond the prognostic and predictive utility
2017
The importance of the immune system as a potent anti-tumor defense has been consolidated in recent times, and novel immune-related therapies are today demonstrating a strong clinical benefit in the setting of several solid neoplasms. Tumor-infiltrating lymphocytes reflect the attempt of the host to eradicate malignancies, and during the last decades, they have been shown to possess an interesting prognostic utility for breast cancer, especially in case of HER2 positive and triple-negative molecular subtypes. In parallel, the clinical evaluation of tumor-infiltrating lymphocytes has been shown to effectively predict treatment outcomes in both neoadjuvant and adjuvant settings. Currently, tu…
A tyrosinase nonapeptide presented by HLA-B44 is recognized on a human melanoma by autologous cytolytic T lymphocytes
1996
The human tyrosinase gene has been reported previously to code for two distinct antigens recognized on HLA-A2 melanoma cells by autologous cytolytic T lymphocytes (CTL). By stimulating lymphocytes of melanoma patient MZ2 with a subclone of the tumor cell line of this patient, we obtained a CTL clone that lysed this subclone but did not lyse other subcloncs of the Same melanoma cell line. The sensitive melanoma subclone was found to express a much higher level of tyrosinase than the others, suggesting that the antigen recognized bv the CTL might be encoded by tyrosinase. Transfection of a tyrosinase cDNA demonstrated that the CTL clone indeed recognized a tyrosinase product presented by HLA-…