Effect of pretreatment with immune serum on murine sarcoma virus (Moloney) tumour induction and growth

Abstract

Summary.-Regressor serum from MSV-M-infected mice markedly reduced MSV-M oncogenesis when administered i.p. (0-1 ml/mouse) as much as 30 days before i.m. MSV-M infection in adult BALB/c mice. The regressor serum activity appeared to be directly dependent on the amount of IgG, as shown by: (1) inactivity of sera which have low virus-neutralizing antibody content; (2) high effectiveness only of the IgG serum fraction; (3) inactivity of regressor serum incubated with anti-mouse gamma-globulin serum. The regressor serum activity was specific and could not be ascribed to interferon or interferon-inducing factors, antigenantibody complexes or free antigen. The activity was not suppressed by sublethal irradiation (380 rad) of recipient mice. These results suggest that the activity of regressor serum administered before MSV-M infection is mediated through sensitization of host cells which are not radiosensitive.

Immunopathology

“…In the MSV system, serum from tumor-bearing animals was shown to inhibit tumor growth in vivo (Fefer et al, 1967b;Pierce, 1971;Pearson et al, 1973;Giuliani et al, 1977), contain complement-dependent activity in the MCA (Tamerius and , and mediate ADCC (Lamon et al, 1975a,b;Harada et al, 1975;Miller and Feldman, 1977). Activity was mostly in regressor sera in some reports, and in both regressor and progressor sera in others.…”

Activation of K cells in mice with transplanted tumours differing in immunogenicity and metastasizing capacity

“…Tumours.-MSV-induced sarcomas T-MSV and MS2 have previously been described in detail (Giuliani, Casazza and Di Marco, 1974;Di Marco et al, 1976;Giuliani et al, 1977 Evans and Alexander, 1977) and has a macrophage content of 3900.…”