beta2 Microglobulin on the envelope of urinary cytomegalovirus is not associated with host class I human leukocyte antigen {alpha} chain

Previous studies have shown that ₂ microglobulin (₂m) is associated with glycoproteins present on the envelope of urinary human cytomegalovirus (CMV). ₂m is non-covalently associated with the α chain of human leukocyte antigen (HLA) class I antigens and therefore it was of interest to determine whether the class I α chain is also associated with the ₂mCMV complex. Using a panel of monoclonal antibodies recognizing different conformational determinants on the HLA class I heterodimer or free ₂m, we have shown that ₂m but not the α 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 α chains are not associated with ₂m on the envelope of urinary CMV.

^† Present address: National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar EN6 3QG, U.K.