Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 1980 | Published
Journal Article Open

Abelson murine leukemia virus-induced tumors elicit antibodies against a host cell protein, P50

Abstract

When BALB/c mice were injected with a syngeneic cell line transformed by Abelson murine leukemia virus (A-MuLV), the tumor was usually lethal. In sera from tumor-bearing mice, and at highest levels in sera from mice that reject their tumors, was an antibody that immunoprecipitates a specific protein from [35S]-methionine-labeled A-MuLV-transformed BALB/c cells. This protein was not the previously characterized A-MuLV-specific protein (P120) but a 50,000-molecular-weight protein (P50). Such sera may also immunoprecipitate P120, but no other protein was reproducibly precipitated by them. A monoclonal antibody (RA3-2C2) that has been shown to stain normal B-lymphocytes also selectively immunoprecipitated P50. P50 was present in A-MuLV-transformed lymphoid and fibroblastic cells of a variety of mouse strains. One A-MuLV-transformed cell line had a very low P50 level, the L1-2 tumor of C57L origin. This tumor was previously shown to be rejected by C57L mice and is used to produce anti-P120 (anti-AbT) sera. P50 was not a Moloney MuLV protein and was found at low levels in normal cells of cells transformed by agents other than A-MuLV; thus, it was probably a host cell protein whose concentration was selectively accentuated by A-MuLV transformation. P50 was phosphorylated and, by using indirect immunofluorescence, anti-P50 serum stained live A-MuLV-transformed cells. The protein was not glycosylated and did not label by lactoperoxidase-catalyzed iodination. Thus, P50 was very like P120 in its cellular localization and properties, but it did not exhibit proptein kinase activity in vitro. The selective accentuation of this protein in A-MuLV transformants and its strong antigenicity in syngeneic animals suggest that it is a unique and functionally important protein.

Additional Information

© 1980 by the American Society for Microbiology. We are grateful to Irving Weissman for his interest and thoughtful discussions throughout the course of this work. This work was supported by Public Health Service grants CA-09302 from the National Cancer Institute (to R.C.), Al-09072 from the National Institutes of Health (to R.C.) and CA-14051 from the National Cancer Institute (core grant to S. E. Luria) and grant MV-34K from the American Cancer Society (to D.B.). V.R. was supported by Public Health Service international research fellowship TW02765. O.N.W. was a postdoctoral fellow of the Helen Hay Whitney Foundation. D.B. is an American Cancer Society research professor.

Attached Files

Published - ROTjvir80.pdf

Files

ROTjvir80.pdf
Files (1.8 MB)
Name Size Download all
md5:6b8f88471fb20d73c4b80168f4677369
1.8 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023