Abstract
We have used cell surface radioiodination, biosynthetic incorporation of [ 35S]methionine, and flow cytometry to analyze the effects of interferon γ and/or phorbol esters (PMA) on the turnover and expression of class I antigens of a human leukemia B cell line. Our results demonstrated that although both IFN-γ and PMA enhance HLA expression, they act synergistically to increase by eightfold the amount of HLA polypeptides synthesized by the acute lymphoblastic leukemia cells and acted additively to augment the cell surface expression of HLA as quantified by flow cytometry. We observed a cyclic increase or decrease in the expression or class 1 antigens as a function of time in cell culture. IFN-γ and/or PMA modulated this effect inducing more cells to express HLA maximally. These results suggest that there is a physiologic limit for the expression of major histocompatibility complex class 1 antigens.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
