Immunological Reactions with a Virus Causing Papillomas in Rabbits* I. Demonstration Oy a Complement Fixation Reaction: Rela- Tion of Virus-neutralizing and Complement- Binding Antibodies

The immunological study of the Shope papilloma virus (1) has exceptional interest, for the virus causes enduring, proliferative growths that have the character of tumors (2). In the work now to be reported a complement fixation reaction has been used in addition to the neutralization test previously employed (3). Special attention has been paid to the relation of the virus and the complement-binding antigen in extracts of the growths, and to the relation of the virus-neutralizing and complement-binding antibodies in the sera of animals carrying the tumors. In the present paper the complement fixation test will be described, and the results presented of experiments to determine its specificity. Tests will also be reported that deal with the relation of the complement-binding and virus-neutralizing antibodies, and with the amount of antibody in the sera of cottontail and domestic rabbits bearing the virus-induced papillomas. In two papers that follow, the properties of the complement-binding antigen will be considered, as also its relation to the virus; and some observations will be reported on the yield of virus, and of the complement-binding antigen, from the papillomas of domestic and cottontail rabbits.