Human Immune Response to Active Immunization With Rauscher Leukemia Virus. I. Cell-Mediated and Cell-Associated Immunity2

Abstract

Twenty patients were immunized with formalin-killed Rauscher leukemia virus (RLV). No untoward side effects were observed. Approximately two thirds of the patients developed cell-mediated immunity, as assessed by in vitro lymphocyte blastogenic responses to both RLV and an antigen extracted from RLV-infected BALBL/c cells by the hypertonic KCI method or as assessed in vivo by delayed hypersensitivity to the immunizing antigen. The responses were specific for the immunizing viral antigen, because lymphocytes from immunized patients showed little response to virus-free tissue culture vehicle or to a control antigen preparation from noninfected cells. Responses did not differ significantly among patients with different types of tumors or receiving different types of therapy. The data suggested that patients with metastatic cancer and acute leukemia can mount immune responses to oncogenic viruses.