although the structure of human t lymphoptropic virus type i (htlv-i) has been known well, the function of some proteins encoded by htlv-i px region is not fully understood. furthermore, the responses of the immune system to htlv-i remain still unknown. most of htlv-i-infected individuals show a strong and persistently activated cytotoxic t-cell (ctl) response to the virus. the frequency of htl...

We investigated the feasibility of generating cytotoxic T cell clones against autologous human melanoma cells using a melanoma cell line (VIP) and a spontaneously transformed autologous fibroblast line (VIP-F:T). Cytotoxic lymphocytes (CL) generated against the VIP melanoma cells in one-way mixed lymphocyte-tumor cell interactions were expanded in interleukin 2 for 2 wk. The expanded CL were cl...

The role of the humoral and cellular arms of the immune response in protection against respiratory syncytial virus (RSV) infection and in the pathogenesis of the severe forms of this disease is poorly understood. The recent demonstration that some inbred mouse strains can be infected with RSV has opened the way to a detailed investigation of RSV immunity. We report here the finding of major his...

A large number of CD4+ T cell clones, obtained from peripheral blood T lymphocytes by direct limiting dilution, allowed us to address the question whether functional heterogeneity exists within the human CD4+ T cell subset. Cytotoxic capacity of cloned T cells was analyzed with the use of anti-CD3 antibodies and target cells bearing FcR for murine IgG. 6 of 12 CD4+ clones obtained were able to ...

Vaccination with a nucleopeptide (NP 118; amino acids 118 to 132) representing a cytotoxic T-cell epitope of lymphocytic choriomeningitis virus (LCMV) can modulate immunopathology. Immunization with NP 118 protected H-2d mice against intracerebral infection with the LCMV-ARMSTRONG isolate. However, when NP 118-primed H-2d mice were challenged intracerebrally with an intermediate dose (5 x 10(4)...

We have shown previously that the inactivation of macrophages in nonobese diabetic (NOD) mice results in the prevention of diabetes; however, the mechanisms involved remain unknown. In this study, we found that T cells in a macrophage-depleted environment lost their ability to differentiate into beta cell-cytotoxic T cells, resulting in the prevention of autoimmune diabetes, but these T cells r...

perforin(p) is the primary mediator of short term cytotoxicity, it is accumulated in response to proinflammatory  cytokines and stored in t lymphocyte , nk cells and nkt cells are released upon activation. perforin is a prototypical cytotoxic molecule involved in cell mediated immunity against various pathogens , alloantigens and particularly different tumors.the purpose of this study was to de...

A major role that cytotoxic T lymphocytes (CTLs) play in the immune response is the specific destruction of viral-infected cells and tissue from foreign grafts. Class I molecules encoded within the major histocompatibility complex are the target structures for these CTLs. Recently, viral-restricted CTLs have been shown to recognize viral peptides in association with class I molecules, while sev...

The presence of poliovirus (PV)-specific CD4(+) T cells in individuals vaccinated against polio has been shown, but CD8(+) T-cell responses have not been described. Here, we functionally characterize the CD4(+) T-cell response and show for the first time that dendritic cells and macrophages can stimulate PV-specific CD8(+) T-cell responses in vitro from vaccinees. Both CD4(+) T and CD8(+) T cel...

Following infection by human T cell lymphotrophic virus-I (HTLV-I), high frequencies of polyclonal Tax11-19-reactive CD8(+) T cells can be detected in the peripheral blood. To investigate whether there are differences in the effector functions of these cells, we generated a panel of Tax11-19-reactive T cell clones by single cell sorting of HLA-A2/Tax11-19 tetramer binding CD8(+) T cells followe...