Cytokinetics of IGG vs IGM PFU Response in the Lungs of C3H Mice 1

Abstract

The hemolytic plaque assay procedure developed by Jerne 1 and by Ingraham and Bussard 2 has been used to evaluate the relative number of antibody-producing cells in the population. The number of plaque-forming cells detected during the primary and secondary responses is related to the levels of antibody titers attained in the circulation which in turn determines the immune status of the animal. The contribution of antibodies to the circulation by antibody-forming cells residing in extralymphoidal tissues is not known. The possibility that significant amounts may come from this source cannot be ignored.

If, in the course of preliminary stimulation, immunocompetent cells seed or are stimulated in situ in nonlymphoid organs, activation of these cells and their progeny by secondary stimulation will indicate their whereabouts.

These studies were initiated to determine the presence of antibody-forming cells in the lung of hyperimmunized mice.

Materials and Methods. C₃H strain mice were injected with 0.1 ml of a 50% suspension of sheep erythrocytes (SRBC) and sacrificed at periodic intervals. The spleens from such animals were tested in vitro as follows: single cell suspensions were obtained by teasing with a 23-gauge needle in Hanks' solution. One-tenth milliliter of the suspension was mixed with 3 ml of 0.8% agar containing 1 mg diethylaminoethyl dextran. To this mixture 0.2 ml of a 14% SRBC suspension was added, and the mixture was plated in petri dishes containing 10 ml of 1.4% agar. All plates were incubated at 37° for 2 hr and then layered with 3 ml of complement. Incubation was continued for 1 hr at 37°, the plates were decanted, washed with saline, and stained with benzidine.

The peripheral blood cells were isolated according to the method of Möller 3 with slight modification.