Intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) contribute to the elimination of equine herpesvirus type 1 (EHV-1) from the lungs of intranasally infected BALB/c mice.

The role of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) on equine herpesvirus type 1 (EHV-1) infection in BALB/c mice produced by intranasal inoculation was studied. Infected mice were found to lose bodyweight (BW) during the acute phase of infection (i.e., within 1 week of inoculation) but to regain it during the convalescent phase. The intraperitoneal administration of monoclonal antibodies (mAbs) against ICAM-1 and LFA-1 one day before EHV-1 infection reduced the BW loss in the acute phase and retarded the recovery of BW in the convalescent phase. When mice pretreated with mAbs were killed 21 days after infection, the epithelial cells of the bronchi and bronchioles were found to contain viral antigens and to show degeneration and necrosis. In non-pretreated control mice, no viral antigens were detected and lesions were mild or absent. It was concluded that ICAM-1 and LFA-1 contributed to the elimination of EHV-1 from the lung, and to recovery. These findings may be relevant to EHV-1 infection in the horse.