Abstract
Saline suspensions of virus-induced rabbit papillomas may stimulate the production of specific antiviral antibody when injected in-traperitoneally into normal rabbits, as Shope found, even though they contain no pathogenic virus demonstrable by the ordinary test. 1 In experiments of the same sort we found that saline extracts containing infectious papilloma virus in quantity elicited the antibody in much higher titer than extracts in which little or none was present. 2 Other studies already reported from this laboratory have shown that the antibody often extravasates into the large, disorderly papillomas of cottontail rabbits in such quantity as to “mask” the causative virus, 3 and that the antibody can be identified as such in extracts of the growths. 4 With these findings in mind, experiments were undertaken to determine whether the antibody, which accumulates in the papillomas in various amounts depending upon the titer of it in the blood and upon the local vascular conditions determining its extravasation, may not influence the anti-genicity of extracts of the growths.
The antigenicity of the papilloma virus, as determined by its capacity to elicit antibody upon intraperitoneal injection into normal rabbits, was found to be markedly reduced when antibody was mixed with it in vitro in amounts sufficient to neutralize it. When an excess of antibody was added to a filtrate containing highly infectious virus, the mixture elicited no antibody upon repeated intraperitoneal injections into normal rabbits, although the control mixture containing saline and the same amount of virus (approximately 20,000 infectious doses for each animal) proved highly antigenic.
To procure virus-induced papillomas that were certain to contain the extravasated antibody in quantity, a number of cottontail and domestic rabbits carrying vigorous confluent growths of 2 to 4 weeks' duration were injected intraperitoneally with large quantities of active virus.
Get full access to this article
View all access options for this article.