Since our previous studies ruled out the importance of CD86 in our model of ocular HSV-1 infection (1), this study extends those findings by showing a pathological role of CD80 in eye disease (1, 3) and further explores the importance of CD28, CTLA4, and PD-L1 binding to CD80 in HSV-1-induced immunopathology. Here, CD28 is linked to eye disorder.