Strain-specific differences in LFA-1 induction on measles virus-infected monocytes and adhesion and viral transmission to endothelial cells.

Measles virus (MV) infection of monocytes induces leukocyte function-associated antigen-1 (LFA-1), an integrin that mediates intercellular adhesion to the endothelium. Thus, an increase in LFA-1 expression could lead to enhanced monocyte adherence and virus dissemination to endothelial cells (ECs) and potentially be an important means of distinction between MV strains. We identified both vaccine and wild-type strains that induced LFA-1 and others that failed to induce. Although adhesion of MV-infected monocytes and viral transmission to ECs was demonstrated, strain-specific differences were not correlated with LFA-1 induction. MV infection of ECs was dramatically reduced in the absence of cell contact, suggesting virus dissemination by cell-cell transmission.