Recent evidence has shown that cloned, murine CTL cell lines are resistant to the cytotoxic components of the toxic granules they release upon specific interaction with their target cells. Inasmuch as the resistance might be due to selection in culture over many months by repeated exposure to these cytolytic components (which are released repeatedly as a result of the cultured CTL being periodi...

The connection between innate and adaptive immunity is best exemplified by antigen presentation. Although antigen-presenting cells (APCs) are required for antigen receptor-mediated T-cell activation, how T-cells feedback to APCs to sustain an antigen-specific immune response is not completely clear. Here we show that CD8+ T-cell (also called cytotoxic T lymphocytes, CTL) feedback activates the ...

Mycosis Fungoides (MF) is the most common type of Cutaneous T-Cell Lymphoma (CTCL) and represents nearly 50% of all primary cutaneous lymphomas [1]. MF is characterized by an epidermotropic skin infiltrate of atypical CD4+ phenotype lymphocytes. In a minority of MF cases, the atypical infiltrate is CD8 positive. The later form of CTCL generally follows a rapid, aggressive clinical course [2]. H...

The cellular basis o f immunological memory has been a debated issue. It is not clear whether CD8 T cell memory is maintained by long-lived cells or by specific or nonspecific restimulation. Here, we have approached the question from a different angle, asking whether the cellular interactions that are required to maintain memory are the same as those necessary to activate cytotoxic T lymphocyte...

The polarized response of T helper-2 (Th2) lymphocytes to an allergen is considered to be the main cause of the pathogenesis of asthma. In this study, we asked a question whether M. bovis BCG mycobacteria which are known for the preferential stimulation of T helper-1 (Th1) immunity, diminish the effector functions of Th2 cells from allergic patients upon stimulation with a common house dust mit...

Infection elicits CD4(+) memory T lymphocytes that participate in protective immunity. Although memory cells are the progeny of naïve T cells, it is unclear that all naïve cells from a polyclonal repertoire have memory cell potential. Using a single-cell adoptive transfer and spleen biopsy method, we found that in mice, essentially all microbe-specific naïve cells produced memory cells during i...

Intravenous immunoglobulin (IVIg) is a polyclonal immunoglobulin G preparation with potent immunomodulatory properties. The mode of action of IVIg has been investigated in multiple disease states, with various mechanisms described to account for its benefits. Recent data indicate that IVIg increases both the number and the suppressive capacity of regulatory T cells, a subpopulation of T cells t...

The response of T cells to liver Ags sometimes results in immune tolerance. This has been proposed to result from local, intrahepatic priming, while the expression of the same Ag in liver-draining lymph nodes is believed to result in effective immunity. We tested this model, using an exogenous model Ag expressed only in hepatocytes, due to infection with an adeno-associated virus vector. T cell...