Monoclonal Antibodies to Murine Retrovirus Protein p30

Abstract

SUMMARYHybrid cell lines were prepared by the fusion of mouse myeloma cells with the spleen cells of Wistar-Furth rats that had been immunized with a Moloney sarcoma virus (MoMuSV)-induced tumour, MFU. Two immunization protocols were designed. In the first, the animals received several injections of irradiated (10 000 rad) cells of a tumour cell line established in vitro, MFU-67. The rats received a booster injection 3 days prior to fusion. In the second protocol, immunization was the result of simple tumour growth, and no booster was given. Hybrids were tested by immunofluorescence for the production of immunoglobulins reacting with mouse cells acutely infected with MoMuSV. Over 20 ~ of reactive hybrids were observed in the tumour growth protocol, and about 10 ~o in the irradiated cell protocol when the last injection of the series was given 2 weeks before fusion. After 6 months, the proportion fell to 3~. Hybrid lines producing antibody to p30, the major core polypeptide of murine retroviruses, were obtained by cloning. Three of these were selected for closer study and were found to recognize three non-overlapping epitopes on p30. By direct and competitive binding in ELISA tests, the three epitopes were found to have very different distribution patterns among the various strains and isolates of murine retroviruses.

Antigenic and Structural Variation of the p28 Core Polypeptide of Goat and Sheep Retroviruses

“…Monoclonal antibody 8B1 bound all CAEV isolates and VV, but not PPV. Demonstration of antigenic differences among the p28s from goat and sheep retrovirus isolates is similar to findings with murine retroviruses (Chuat et al, 1985).…”

Differences in the pI Heterogeneity of Virion and Intracellular Moloney Murine Leukaemia Virus p30s

“…Thcy may be due to as yct uncharacterized post-translational modifications of the major p30 with pI 6.3 or thcy could bc derived from minor gag precursors such as PrlS0 ~ao-p°~ (Jamjoom et al, 1977;Kopchick et al, 1978Kopchick et al, , 1979 or gPr800og (Ledbetter et al, 1978;Edwards & Fan, 1979;Lcdbetter, 1979). It is of interest to note in this regard that thc usc of monoclonal antibodies to p30 suggests there arc at least three different p30 epitopes which can be identified (Chuat et al, 1985). The use of such sera may assist us in identifying which, if any, of the gag precursors arc the source of the minor p30s.…”