PURPOSE To determine whether iris pigment epithelium (IPE)-induced T regulatory (Treg) cells can suppress the activation of bystander T cells with cell contact via costimulatory interactions. METHODS CD8(+) T cells were cocultured with IPE, x-irradiated, and then used as regulators (IPE-induced Treg cells). The target CD4(+) T cells from wild-type control or knockout donors were used for the ...

The activation of lymphocytes is a central event of the adaptive immune response. Physiologically, this activation is carefully controlled. Productive stimulation of T cells is necessary for all T-cell-dependent immune responses and requires two distinct intracellular signals. The first signal is antigen specific; it is delivered via the antigen-specific T-cell surface receptor (TCR) when antig...

Binding of Ag by the Ag receptor in combination with other stimuli provided by costimulatory receptors triggers the expansion and differentiation of T lymphocytes. However, it is unclear whether the time when costimulatory molecules interact with their counterreceptors with regards to Ag recognition leads to different T cell responses. Provided that the coreceptor molecule CD43 is a very abunda...

The human autologous mixed lymphocyte reaction (AMLR) consists of a proliferative response of primarily CD4+ T lymphocytes stimulated by autologous non-T cells expressing class II MHC-encoded gene products and is thought to represent a self-recognitive mechanism that might be important in regulating the cellular interactions involved in the generation of normal immune responses. To further defi...

Following immunization with acetylcholine receptor (AChR), MHC class II-restricted, AChR-specific CD4 cell activation is critical for the development of experimental autoimmune myasthenia gravis (EAMG) in C57BL/6 mice. To study the contributions of B7-1 and B7-2 costimulatory molecules in EAMG, B7-1, B7-2, and B7-1/B7-2 gene knockout (KO) mice were immunized with Torpedo AChR in CFA. Compared w...