Characterization of an early cytotoxicity-inducing factor in sera of Japanese quails after inoculation with Rous sarcoma virus

Interferon and cell-mediated immunity

The thesis is introduced that the phenomena of cell-mediated immunity proceed with the necessary involvement of interferon. In view of this thesis various examples of cell-mediated cytotoxicity both antibody-dependent, and antibody-independent are analyzed. The role of interferon in transplantation, allergic diseases and the treatment of cancer is also discussed. Based on this analysis it is concluded that interferon provides for the cytotoxicity of immune and non-immune leukocytes. It is suggested that interferon is responsible for the cytotoxic effect in itself, since it facilitates lethal hybridization. Recognition of the important role of interferon in the mechanism of cell-mediated immunity leads to some practical conclusions: a) The selective inhibition of the activity of type II interferon may be a sufficient measure in cases where now total immunosuppression is applied. b) Periodic treatment of healthy population by lymphokine stimulants may be a method of prevention of cancer. c) Transplantation, allergic diseases, immunotherapy of cancer should be considered in terms of the role of interferon in these processes.

Continuous lines of RSV-transformed embryo cells and peritoneal macrophages of Japanese quails

Four continuous lines of RSV-transformed quail cells were established; QERC-31F and QERC-31N cells derived from quail embryo cells and PERP and PERY cells from adult quail peritoneal macrophages. Marked morphological difference was noted between QERC-31F and QERC-31N; the former showed fusiform shape and the latter nodular shape. Both PERP and PERY showed macrophage-like morphology with phagocytic capacity. All four cell lines contained gs antigen and gp 85. Production of transforming virus was found in QERC-31N, PERP and PERY. In spite of failure in production of transforming virus, EQRC-31F was demonstrated to produce C-type particles by electron microscopy and to contain tumor-specific surface antigen by in vivo immunization and in vitro microcytotoxicity tests.

Lysis of RSV-transformed Japanese quail cells by a factor from normal quail serum

Normal sera of Japanese quails caused lysis of tumor cells from a Rous sarcoma virus (RSV)-induced quail tumor (QT cells). Other tumor cell lines, including RSV-transformed quail embryo cells and methylcholanthrene-induced quail tumors, were not lysed. This naturally occurring cytolytic factor (NCLF) was sensitive to heating at 56 degrees C, zymosan, and inulin, and it required magnesium but not calcium for the expression of its activity. These results suggested that NCLF activity was mediated by complement activated through an alternative pathway. This possible complement activation occurred in the absence of specific antibodies to the target cells.