Local and regional immune function of vitamin A-deficient rats with ocular herpes simplex virus (HSV) infections

Experimental ocular herpes virus (HSV) infections are more severe in vitamin A-deficient rats (-A) compared with normal pair-fed controls (+A). In an effort to determine whether alterations in specific or nonspecific immune responses were responsible for the increased susceptibility of -A rats, cell-mediated responses and natural killer cell (NK) activity were monitored during the course of ocular herpetic infections in -A and +A rats. Prior to infection the concanavalin A (Con A)-induced response of splenic lymphocytes from -A rats was significantly less than that of +A animals. Three days following topical application of HSV to abraded corneas, the Con A-induced splenic response decreased in both -A and +A animals and remained at low levels for 10 d following infection. The cervical lymph node (CLN) response to Con A was depressed 7 d following infection but was higher in the -A group than in the +A group at all time points. In vitro response to inactivated HSV antigen appeared on d 7 in the spleen and d 10 in the CLN. The responses were higher in -A animals compared with +A pair-fed controls and were related to the severity of the disease rather than to dietary treatment. Splenic NK cytotoxic responses were higher in +A than -A animals and decreased in both groups during the 10-d post-infection period. Cervical lymph node NK responses were unaffected by diet or ocular HSV infection.