Cell surface interactions between the T cell costimulatory receptors, CD28 and cytotoxic T-lymphocyte antigen-4 (CTLA4), with their cognate ligands, CD80 and CD86, on antigen-presenting cells play an important role in T cell activation. Although CD80 and CD86 are induced on T cells after activation, not much is known about their role in modulating T cell function. We show that CD80, CD86, and C...

The use of mAbs to abrogate costimulatory interactions has attracted much attention with regard to prevention and modulation of adverse (auto)immune-like reactions. However, the role of costimulatory molecules and possible therapeutic use of Ab-treatment in drug-induced immunostimulation is poorly elucidated. In the present studies, we show that CD28/CTLA-4-CD80/CD86 costimulatory interactions ...

The expression of the costimulatory molecules CD80 and CD86 was increased on synovial fluid CD19+ B cells as compared to peripheral blood. CD80/CD86 expression on these B cells could be shown to induce alloreactive T cell proliferation in vitro. Most of the synovial fluid B cells belonged to the CD27+IgDclass-switched memory B cell subset. However, almost half of the CD27 negative synovial B ce...

CD8+CD28- human T suppressor cells (Ts) act on APC, inhibiting their ability to elicit Th activation and proliferation. This effect is due to inhibition of the CD40 pathway which normally leads to CD80 and CD86 up-regulation. To determine whether Ts inhibit expression of B7 molecules by blocking transcription, we cloned and characterized the CD86 promoter. Mutational analysis revealed that Ts i...

The interaction of CD28 with one of the B7 molecules (CD80 and CD86) on professional antigen-presenting cells (APC) is generally considered to be the most important co-stimulatory signal for T cell activation. Several lines of evidence suggest that dendritic cells (DC), the most potent antigen presenting cells known, play a role in the immunological control of herpes simplex virus (HSV) infecti...

Although prognosis for patients with multiple myeloma has improved over the past decade, research toward discovery of new therapeutic avenues is important and could lead to a cure for this plasma cell malignancy. Here we show that blocking the CD28-CD86 pathway via silencing of either CD28 or CD86 leads to myeloma cell death. Inhibiting this pathway leads to downregulation of integrins and IRF4...

Objective(s) Recent studies on human indicate that the introduction of therapeutic use of tolerogenic dendritic cell (DC) for chronic inflammatory conditions is imminent. For the purpose of defining CGRP potency in tolerogenic DC production, we investigated the phenotype and IL-'2 production of DCs generated from the monocytes of rheumatoid arthritis (RA) patients in the presence of the calcit...

PURPOSE Allergic asthma (AA) and rheumatoid arthritis (RA) are immune tolerance-related diseases, and immune tolerance is known to be influenced by costimulatory molecules. In this study, we sought to identify common genetic susceptibility in AA and RA. METHODS Two hundred cases of AA, 184 cases of RA, and 182 healthy controls were recruited at the Seoul National University Hospital, Seoul, K...

Lipid mediators are emerging as important regulators of the immune system. Based on our previous result that shows strong expression of prostacyclin synthase in the germinal center, we investigated whether prostacyclin would regulate the APC function of B cells. Owing to the very short half-life of prostacyclin in experimental conditions, we used a more stable analog, beraprost. Beraprost incre...

Influenza A virus (IAV) infection in the respiratory tract triggers robust innate and adaptive immune responses, resulting in both virus clearance and lung inflammation and injury. After virus clearance, resolution of ongoing inflammation and tissue repair occur during a distinct recovery period. B7 family co-stimulatory molecules such as CD80 and CD86 have important roles in modulating T cell ...