Objective: To investigate the inhibition by CTLA-4Ig on herpetic stromal keratitis (HSK).
Methods: BALB/c mice infected with HSV-1 Mckrae strain by corneal scarification were injected intraperitoneally with murine CTLA-4Ig given on days 0, +2, +4 after the infection. The effects of CTLA-4Ig on HSK were evaluated.
Results: As measured by flow cytometry, in the mice treated with CTLA-4Ig, 81.6% of CD4(+)T cells and 67.9% of CD8(+)T cells were reduced. CTLA-4Ig halted the onset of HSK, reduced the corneal stromal opacification of HSK, prevented extensive cellular infiltration in cornea, impaired the delayed type hypersensitivity and inhibited splenocytes producing Th1 cytokines.
Conclusions: The results provide evidence that blockade of B7:CD28/CTLA-4 costimulation by CTLA-4Ig can inhibit the proliferation of T cells and Th1 response and impair onset and severity of HSK.