| CD1 molecules area family of beta2-microglobulin (beta2m)-associated, nonpolymorphic cell surface glycoproteins which are capable of presenting lipid antigens. However, unlike the molecules involved in peptide antigen presentation, which have been extensively characterized, the components of CD1 antigen-presenting pathway are largely unknown. This dissertation has successfully used retrovirus insertion mutagenesis to generate a library of mutants which had lost one or more CD1 isoforms on cell surface, implying a deficiency in molecules that may be important in CD1 antigen presentation. In one of the mutants selected for further characterization, the heavy chains of all four CD1 molecules and class I MHC were missing from the cell surface, and two viral insertions were localized near beta2m, which a 12-kDa protein. Our present study has shown conclusively that all four CD1 isoforms depend on P2m for surface expression in an immune cell. Furthermore, different CD1 isoforms may have different affinities for beta2 m. This in turn might affect the immunological functions known to be carried out by each CD1 molecule. |
