Beta 2 microglobulin on the envelope of urinary cytomegalovirus is not associated with host class I human leukocyte antigen alpha chain.

Previous studies have shown that beta 2 microglobulin (beta 2m) is associated with glycoproteins present on the envelope of urinary human cytomegalovirus (CMV). beta 2m is non-covalently associated with the alpha chain of human leukocyte antigen (HLA) class I antigens and therefore it was of interest to determine whether the class I alpha chain is also associated with the beta 2m-CMV complex. Using a panel of monoclonal antibodies recognizing different conformational determinants on the HLA class I heterodimer or free beta 2m, we have shown that beta 2m but not the alpha chain of HLA class I could be immunoprecipitated from 125I-surface-labelled virions purified directly from urine. We therefore conclude that host class I HLA alpha chains are not associated with beta 2m on the envelope of urinary CMV.