Both CD4+ and CD8+ T cells are involved in protection against HSV-1 induced corneal scarring

AIM—To determine the relative impact of CD4+ T cells and CD8+ T cells in protecting mice against ocular HSV-1 challenge. METHODS—CD4+ T cell knockout mice (CD4−/− mice), CD8+ T cell knockout mice (CD8−/− mice), and mice depleted for CD4+ or CD8+ T cells by antibody (CD4+ depleted and CD8+ depleted mice), were examined for their ability to withstand HSV-1 ocular challenge. The parental mice for both knockout mice were C57BL/6J. RESULTS—These results suggest that: (1) both CD4+ deficient mice (CD4−/− and CD4+ depleted mice) and CD8+ deficient mice (CD8−/−, and CD8+ depleted mice) developed significantly more corneal scarring than their C57BL/6J parental strain; (2) the duration of virus clearance from the eyes of the CD4+ deficient mice was 4 days longer than that of the CD8+ deficient mice; and (3) the severity of corneal scarring in the CD4+ deficient mice was approximately twice that of the CD8+ deficient mice. CONCLUSIONS—It was reported here that: (1) CD4+ and CD8+ T cells were both involved in protection against lethal ocular HSV-1 infection; and (2) CD4+ and CD8+ T cells were both involved in protection against HSV-1 induced corneal scarring.