INTRODUCTION Initial evaluation of a candidate vaccine against HIV includes an assessment of the vaccine's ability to generate immune responses. However, the dynamics of vaccine-induced immune responses are unclear. We hypothesized that the IFN-γ producing cytotoxic CD8+ (CD8+ IFN-γ+) T cell responses could be predicted by early IL-2 producing CD4+ (CD4+ IL-2+) helper T cell responses, and we e...

We have examined cytotoxic responses of lymphocytes derived from the gut epithelium of mice primed systemically and enterically with alloantigens. Both gut intraepithelial (IEL) and splenic lymphocytes from alloantigen-primed mice were found to contain antigen-specific cytotoxic T cell activity. However, after priming, gut IEL also developed high levels of natural killer and spontaneous cytotox...

In healthy individuals, immune-checkpoint molecules prevent autoimmune responses and limit immune cell-mediated tissue damage. Tumors frequently exploit these molecules to evade eradication by the immune system. Over the past years, immune-checkpoint blockade of cytotoxic T lymphocyte antigen-4 and programed death-1 emerged as promising strategies to activate antitumor cytotoxic T cell response...

There are few studies on cell-mediated cytotoxicity in human Chagas' disease. In the present study, we evaluated peripheral blood mononuclear cell (PBMC) cytotoxicity activity from chagasic patients with different clinical forms of disease. To verify the cytotoxic response, we performed cell lysis assays using 51Cr-labelled K562 cells as targets. Results are reported as lytic units (LU = number...

Although alloantigen-specific suppressor T cells are generated in MLR, the cellular signals that lead to activation of suppressor T cells as opposed to cytotoxic T cells are unknown. The current study was undertaken to characterize interactions among T cell subsets involved in the generation of suppressor T cells in MLR. Human peripheral blood Leu-2+ (suppressor/cytotoxic) and Leu-3+ (helper/in...

Intracranial lymphocytic choriomeningitis virus (LCMV) infection is a widely used animal model to study virus-induced cytotoxic T cell (CTL) mediated meningitis and immunopathology. Nevertheless, this model causes severe pain and distress in mice, especially at later stages of the disease. Therefore, new treatment regimens to improve animal welfare have to be developed. In this study, we subcut...

The aim of this study was to investigate the effects of dendritic cell (DC) therapy in osteosarcoma. Bone marrow DCs from Wistar (allograft group) and Sprague Dawley (SD) (homograft group) rats were electrically fused with the SD-derived osteosarcoma cell line UMR106 to generate a DC-osteosarcoma fusion (DOF) tumor vaccine, which was co-incubated with SD T lymphocytes to stimulate T cell prolif...

Mice with congenital severe combined immunodeficiency disease (SCID) failed to mount either a T cell-independent IgM or T cell-dependent IgG anti-vesicular stomatitis virus (VSV) Indiana (IND) response. They did not generate cytotoxic T cells against lymphocytic choriomeningitis virus (LCMV) or vaccinia virus, but exhibited NK cell-like activities. When SCID mice were given bone marrow from syn...

Activation of resting Ly-2’ precursor T cells to cytotoxic T lymphocytes (CTL)’ requires stimulation by antigen or mitogen in combination with soluble mediators (1 -3). One of these antigen-nonspecific mediators is interleukin 2 (IL 2). IL 2 is released by activated Ly-l+ helper T cells and was distinguished to provide the proliferative signal (4, 5). It was only recently discovered that IL 2 i...

t regulatory cells play a crucial role in immunological unresponsiveness to self- antigens and in suppressing excessive immune responses deleterious to the host. t regulatory cells are produced in the thymus as a functionally mature subpopulation of t cells. they can be induced from naive t cells in the periphery and express their marker as a forkhead/winged helix transcription factor called fo...