Immunological studies on certain albuminoids.

Abstract

Under the term “albuminoids” a group of substances are classified whose chief properties appear to consist in insolubility in all neutral solvents and resistance to enzymatic digestion. Solubility can be effected only through the agency of strong acids and alkalies. No work on the ability of these substances to act as antigens appears to have been carried out. Since solubility is an essential factor in the production of immune bodies as well as in the demonstration of their presence it might, a priori, be assumed that the members of this group are non-antigenic. The experiments herein described were carried out for the purpose of obtaining experimental data relative to the ability of several members of this group to act as antigens.

The fibroin was obtained from silk cocoons. The water-soluble proteins were extracted by repeatedly washing the silk in cold water, then autoclaving, and repeatedly washing with fresh portions of boiling water. The spongin was similarly treated. In order to induce production of immune bodies, 50 to 100 mgs. of fibroin were placed in the peritoneal cavity of each of three rabbits, and four rabbits were similarly treated with spongin. Attempts to demonstrate the presence of fixation antibodies at the end of a month were wholly negative. In carrying out the test a small arbitrary amount of “antigen” was employed. After addition of serum and alexin the mixture was incubated for several hours to give the maximum opportunity for the fixation of alexin, and allowances for the mechanical absorption of the added constituents by the spongin were made by the aid of a large number of control determinations with normal sera. Attempts to demonstrate immune bodies by skin tests were likewise negative.