Detection of H‐2D d and H‐2K d molecules in purified rauscher leukemia virus

Evidence is presented that an H‐2 antigenic activity is associated with Rauscher murine leukemia virions grown in vitro. Purified Rauscher MuLV grown in fibroblasts of BALB/c (H‐2 d ), C57BL6 (H‐2 d ) or (BALB/c × C57BL/6)F 1 (H‐2 d/b ) were used to absorb the activity of anti‐D d , anti‐K d , anti‐D d , or anti‐D b anti‐K b antisera tested against H‐2‐related targets by cellular radioimmunoassay. The results show that D d and K d activities were associated with the virions grown in H‐2 d or H‐2 d/b fibroblasts. No H‐2 b antigenic activity was detected in the virions grown in C57BL/6 or F 1 fibroblasts. Immunoprecipitation of surface‐labelled spleen cells revealed that Rauscher MuLV grown in BALB/c or F 1 , fibroblasts inhibited the precipitation of the 48 000 dalton peaks characteristic of the D d and K d molecules whereas the precipitation of H‐2 b molecules was not modified by Rauscher MuLV grown in the different cell lines. Class II molecules (la) were not detected in Rauscher virions. Comparison of the absorbing activities of intact and disrupted viruses suggests that the H‐2 activity was localized at the viral surface. Taken together, these results confirm the possible non‐random association of H‐2 molecules to type‐C viral particles whatever the nature of this association and its possible cellular or extracellular origin. However, the H‐2 antigens found in the virions being a non‐restricting element of anti‐viral cytolytic T lymphocytes in the same system, these results give no particular support to the “altered self” hypothesis.