EXPRESSION OF MYCOBACTERIUM-LEPRAE 18-KDA ANTIGEN IN YEAST IN A GPI-ANCHORED FORM

The 18-kDa protein from Mycobacterium leprae is a major target for the immune response in leprosy. We have developed a system to express thi s antigen in yeast as a fusion protein with the C-terminal region of t he yeast membrane protein GAS1, which would render the recombinant pro tein anchored to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor. Cells lacking the GAS1 gene and transformed with the hy brid 18-kDa-GAS1 construct express a polypeptide that reacts with an 1 8-kDa-specific monoclonal antibody. In addition, these cells react wit h an alpha-CRD antibody after GPI-PLC treatment. The non-transformed c ells are negative. These data indicate that our system may be suitable for the expression of foreign proteins in yeast in a GPI-anchored for m.