Infiltrating cells and IFNgamma production in the injected eye after uniocular anterior chamber inoculation of HSV-1

After uniocular anterior chamber (AC) inoculation with HSV-1, the anterior segment of the injected eye becomes inflamed and infected; however, virus does not spread from the anterior segment and infect the retina of the injected eye. The purpose of this study was to identify early infiltrating cells and to determine whether infiltrating cells produce interferon (IFN)gamma. Euthymic, female, BALB/c mice were injected in one AC with 3 x 10(4) PFU of HSV-1 (KOS) in a volume of 2 microL. Mice from each group were killed at 12, 24, 36, 48, and 72 hours post injection (pi), the eyes were enucleated, and frozen sections were stained with antibodies specific for IFNgamma, Mac-1 (CD11b), CD49b, F4/80, CD4, CD8, and CD11c. The same antibodies were also used to stain single-cell suspensions of ocular cells for flow cytometry. In the anterior segment of the injected eye, the ciliary body, and iris were virus infected and inflamed, and infiltrating cells increased throughout the period of observation. Mac-1(+), CD49b(+), and F4/80(+) cells colocalized with IFNgamma in the anterior segment as early as 12 hours pi, and the percentage of Mac-1(+) cells increased in the injected eye beginning at 24 hours pi and continued to 72 hours pi. Taken together, these results demonstrate that Mac-1(+) cells are important IFNgamma-producing cells in the injected eye before day 3 and suggest that the IFNgamma produced by these cells is involved in inhibition of anterior to posterior spread of virus in the injected eye.