TLR2 engagement on memory CD8(+) T cells improves their cytokine-mediated proliferation and IFN-gamma secretion in the absence of Ag.

Persistence of memory CD8(+) T cells is known to be largely controlled by common gamma chain cytokines, such as IL-2, IL-7 and IL-15. However, other molecules may be involved in this phenomenon. We show here that TLR2(-/-) mice have a decreased frequency of memory phenotype CD8(+) T cells when compared with WT mice.

Abnormal cellular reactivity to microbial antigens in patients with uveitis.

Purpose: The purpose of the present study was to evaluate the cellular response to microbial antigens in patients with idiopathic uveitis.

Methods: Blood lymphocytes from 31 patients with uveitis and 24 healthy controls were cultivated with microbial antigens and analyzed by flow cytometry after staining with monoclonal antibodies against CD3, CD4, and activation markers CD69 and CD25.

Results: Although no difference was noted in circulating lymphocytes, the activation of T cells, detected with CD69, was higher in 24-hour blood culture from uveitis patients with Candida albicans antigen (Ca-Ag) than from controls, especially in posterior uveitis and panuveitis.