We have examined whether the thymus can produce immature T cell precursors for subsequent positive selection in the periphery. Using the intestine as a model system, we demonstrate that extrathymic MHC class I molecules positively select thymus-derived TCR-alpha beta CD8+ intestinal intraepithelial lymphocytes. Grafting of MHC class I+ thymus onto MHC class I- hosts resulted in the generation o...

Over the last 10 years, studies of T-cell-mediated responses in vitro have clearly demonstrated that some cancer patients have (mainly but not exclusively) CD8 cytolytic T-lymphocytes (CTL) that can recognize specifically autologous tumor cells [1]. Until 1991, however, no CTL-defined tumor antigen was characterized in molecular terms in humans. With the development of new approaches based on r...

Esophageal squamous cell carcinoma (ESCC) is a very common malignant tumor with poor prognosis in China. Chemokines secreted by tumors are pivotal for the accumulation of CD8(+) T lymphocytes within malignant lesions in several types of cancers, but the exact mechanism underlying CD8(+) T lymphocyte homing is still unknown in ESCC. In this study, we revealed that, compared with marginal tissues...

For viruses to establish persistent infections in their hosts, they must possess some mechanism for evading clearance by the immune system. When inoculated into adult immunocompetent mice, wild-type lymphocytic choriomeningitis virus (LCMV ARM) induces a CD8(+)-mediated cytotoxic T lymphocyte (CTL) response that clears the infection within 7-14 d (CTL+ [P-]). By contrast, variant viruses isolat...

The ability of two different human professional APCs, specifically macrophages (Mphi) and dendritic cells (DC), to stimulate primary responses in human CD8+ T lymphocytes was examined using both allogeneic and Ag-pulsed autologous APCs. CTL responses in CD8+ T lymphocytes isolated from HIV-uninfected donors were evaluated against six different HIV epitopes that are restricted by four different ...

A successful T cell immune response has two major products: effector T cells which directly or indirectly remove the antigens, and memory T cells, which allow a faster and more efficient recall response when challenged by related antigens. An important issue is whether costimulatory molecules on the antigen-presenting cells are involved in determining whether T cells will differentiate into eff...

Premature death of the adoptively transferred cytolytic T lymphocytes (CTL) by means of activation induced cell death (AICD) represents one of the major constraints in devising an effective anti-cancer immune intervention strategy. Understanding the mechanism of AICD is, therefore, critical for developing methods to interfere with this death process. Although the existing paradigm on AICD cente...

We have reported the identification of human gene MAGE-1, which directs the expression of an antigen recognized on a melanoma by autologous cytolytic T lymphocytes (CTL). We show here that CTL directed against this antigen, which was named MZ2-E, recognize a nonapeptide encoded by the third exon of gene MAGE-1. The CTL also recognize this peptide when it is presented by mouse cells transfected ...

Most immunopathogenesis studies of HIV-1 use peripheral blood. Most lymphocytes reside in lymphoid tissues, however, and the extent to which blood mirrors tissues is unclear. Here, we analyze lymphocytes in blood and lymph nodes of HIV-1-uninfected and -infected persons. Baseline comparison of node and blood lymphocytes in seronegative persons demonstrates a lower ratio of CD8+ versus CD4+ T ly...

Cancer vaccine development is in the process of becoming reality in future, due to successful phase II/III clinical trials. However, there are still problems due to the specificity of tumor antigens and weakness of tumor associated antigens in eliciting an effective immune response. Computational models to assess the vaccine efficacy have helped to improve and understand what is necessary for p...