A Heat-labile Skin Sensitizing Activity of Mouse Serum

Abstract

EARLIER my colleagues and I reported that, although mice actively sensitized to egg albumin may suffer a marked local and systemic hypersensitive reaction when challenged intradermally with egg albumin 7–9 days after the sensitizing injection, it is difficult to demonstrate antibody activity in sera obtained from sensitized mice at this time¹. The mouse is known to produce two immunoglobulins capable of transferring passive cutaneous anaphylaxis (PCA)^2,3: 7Sγ₁, which sensitizes homologous skin, and 7$S{\text{γ}}_{{\text{2}}^a}$, which will sensitize the skin of guinea-pigs. In both species the test is carried out using a 3–4 h latent period. Neither activity is reported to be diminished by heat. Treatment with mercaptoethanol slightly reduces the skin sensitizing activity of 7Sγ₁ Both classes of immunoglobulin increase in concentration with time after sensitization, even though the sensitivity of the donor animal to intradermal challenge decreases (unpublished data).