Ia-transfected L-cell fibroblasts present a lysozyme peptide but not the native protein to lysozyme-specific T cells
We studied the antigen-presenting capacity of mouse L fibroblasts transfected with genes encoding Ia polypeptides of the major histocompatibility complex (MHC). These cells function as efficient antigen-presenting cells (APC) in stimulating peptide antigen-specific MHC-restricted proliferation of long-term T-cell lines, thus establishing the capacity of Ia-expressing L-cell transfectants to present antigens to apparently normal T cells. However, in contrast to splenic APC, L-cell transfectants fail to present native hen egg-white lysozyme to the same T cells. Since this result is similar to that obtained with physiologic APC pretreated to prevent antigen degradation, it suggests that L-cell transfectants, without such pretreatments, may be compromised in their ability to process native lysozyme. However, since such transfectant cells have been shown to present other complex polypeptides such as keyhole limpet hemocyanin, a random copolymer of glutamic acid, alanine, and tyrosine, and influenza virus neuraminidase, this observation suggests that protein antigens differ in the stringency of processing requirements.
Additional Information© 1985 by the National Academy of Sciences. Contributed by Leroy Hood, May 6, 1985. The authors appreciate the excellent technical assistance provided by Ms. Kay Blackburn and Deborah Munt. We are grateful for the critical comments of B. Vernooy, M. Kronenberg, and J. Kobori. The manuscript was skillfully prepared by Ms. Connie Katz. This work was supported by National Institutes of Health Grant AI20317. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Published - SHApnas85.pdf