NEUTRALIZATION OF HUMAN CYTOMEGALOVIRUS BY HUMAN CD13-SPECIFIC ANTIBODIES

The mechanisms of inhibition of cytomegalovirus (CMV) infection by hum an CD13 (aminopeptidase N)-specific antibodies were studied, These ant ibodies protect CD13-negative and -positive cells from CMV infection o nly if incubated with the virus inoculum, suggesting they bind to CMV virions, The association of a CD13-like molecule with virions was furt her supported by the transfer of CD13 immunoreactivity to the surface of CD13-negative cells upon binding of CMV; the binding of CD13-specif ic antibodies directly to the surface of CMV virions; and the presence of anti-CD13 immunoreactive bands, including one with mobility simila r to that of native cellular CD13 on immunoblots of proteins of purifi ed CMV particles, Importantly, CD13-specific antibodies neutralize CMV in urine of neonates with congenital CMV, indicating that the CD13-li ke molecule is associated with natural CMV and not acquired in vitro, These studies demonstrate that a CD13-like molecule is associated with CMV particles and may be important in CMV pathogenesis.