Loss of tumorigenicity following in vitro MuLV infection is associated with induction of peritoneal natural killer cell activity.
Infection by an attenuated replication-competent murine retrovirus (Friend leukemia virus-FLV4), but not other non-transforming retroviruses, stimulated rejection of transplantable thymomas (RL-cell line) and subsequent tumor immunity in syngeneic mouse recipients. FLV-infected RL-cells (RL-FLV) were unaltered in their in vitro growth, and grew progressively to kill sublethally irradiated animals and nude mice. Primary RL-FLV rejection was due to induction of increased natural killer (NK)-cell activity limited to peritoneal sites of tumor inoculation with a minor cytolytic macrophage population. Syngeneic mutant beige (NK-deficient) mice similarly rejected RL-FLV cells with increased peritoneal NK-cell activity and acquired immunity to the parental RL-tumor. While RL-FLV stimulated far greater peritoneal NK activity than did other tested retrovirus-infected RL-cells, the inherent susceptibility of these cells to lysis by normal NK cells was not altered by virus. RL-FLV induced NK effectors showed an indiscriminate lysis pattern that was independent of target cell type and retrovirus expression.
Thiel
K
K
Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710.
Genovesi
E V
EV
Iglehart
J D
JD
Bolognesi
D P
DP
Weinhold
K J
KJ
D000818:Animals; D000956:Antigens, Viral / Q000008:administration & dosage; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005260:Female; D005622:Friend murine leukemia virus / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D009052:Leukemia Virus, Murine / Q000276:immunology*; D007953:Leukemia, Radiation-Induced / Q000276:immunology / Q000628:therapy; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013953:Thymus Neoplasms / Q000276:immunology / Q000628:therapy
D000956:Antigens, Viral