Histocompatibility typing and course of canine venereal tumors transplanted into unmodified random dogs.

Abstract

The clinical course following transplantation and the histocompatibility specificities were compared for two cell lines of the canine transmissible venereal tumor. The naturally occurring tumors originated in dogs from Malaya and Chicago. All of the 71 dogs challenged with either the Malayan or Chicago cell line developed tumors. The clinical courses of both tumor lines were similar and included periods of logarithmic growth, stability, and regression. Four dogs showed accelerated growth or metastatic disease. Histocompatibility antigenic specificity was tested on tumor cells by the cytotoxicity reaction with the use of a panel of 64 canine allotypic antisera. Specificities for histocompatibility Groups 3, 10, and 8 were interpreted to be present on both cell lines. Cells reacted identically with 62 of the 64 antisera. Four sera obtained from animals following tumor regression showed associated allotypic specificities when tested against the lymphocytes of normal dogs. Elution and immunofluorescent studies demonstrated membrane-associated IgG on tumor cells 7 days following transplantation which increased with tumor age and decreased with dissemination. It was concluded that cells obtained from tumor sources of widely disparate geographical origin present similar clinical and immunogenic characteristics. The tumor system may be useful for studies of immunological mechanisms involved in tumor growth in unmodified recipients of a randomly bred species.