The Proliferative and Anamnestic Antibody Response of Rabbit Lymphoid Cells in Vitro

Abstract

Popliteal lymph nodes were obtained from rabbits 4 days to 9 months after a primary injection of diphtheria toxoid or bovine γ-globulin into the footpad. The ability of cells from these nodes to proliferate upon reexposure to antigen in vitro was compared to the height of the secondary response produced by tissue fragments. In addition, a comparison was made between the responsiveness of draining and contralateral lymph nodes. While the secondary antibody response in vitro increased markedly with the time after immunization at which the lymph nodes were taken from the animals, the degree of proliferation induced by antigen was highest with cells from lymph nodes taken early after priming (peak day 7) and was very much lower with lymph node cells taken longer than 3 wk after priming. This striking difference between these two responses has been discussed. Contralateral lymph nodes were much inferior to draining nodes in their ability to give a secondary antibody response in vitro, and never gave a detectable proliferative response. This difference became less marked with time after priming, but could still be demonstrated after 4 months. These results suggest a concentration of primed cells in the lymphoid tissue draining the site of injection, and a slow release of these cells into the circulation, to be distributed to the remaining lymphoid tissue.

Characteristics of immunological memory in mice. II. Resistance of nonrecirculating memory cells to antigen‐mediated suppression of the secondary antibody response

“…The observations reported here support the hypothesis that two classes of memory cells exist in primed mice [7]. One of these forms a part of the recirculating lymphocyte pool, and the response given by this population was shown t o be as susceptible t o preemption as the response in unprimed animals.…”

“…Although they may have been in transit through the nodes at the time of challenge, the resistant lymphocytes were most probably nonrecirculating cells which had been retained at the site of antigenic stimulation. A sessile population of memory cells within primed nodes has been proposed by a number of authors t o account for the superior secondary response which these organs give when compared with unprimed (contralateral) nodes [7,9,10,271, although others have maintained that memory cells are mainly recirculating [28]. It seems likely that nonrecirculation and resistance to preemption are characteristics of the same lymphocyte population in primed mice, and also that these properties are related.…”

“…Although primed cells may be identified in the circulation, it has also been established that some remain for long periods of time within the stimulated lymphoid organ. It has been shown, for instance, that secondary responses in lymph nodes draining the original site of antigen injection were superior t o those in contralateral nodes for several months [7,81, and that this finding could be associated both with the persistence of a sessile population of memory cells and with the persistence of antigen 19, lo]. It is therefore apparent that memory cells may be divided into two subpopulations on the basis of their mobility or affinity for lymphoid tissues [ 1 I], although there is little information on the properties of the recirculating and sessile populations, or on their relationship t o each other.…”

Induction, Maintenance and Regulation of Antibody Responses Due to Persistent Antigen and Accessory Cells

“…There was relatively little information about the comparative localization of the cells involved in antibody synthesis and in immunologic memory in the rabbit. Jacobson & Thorbecke (1969) injected diphteria toxoid into one hind foot pad of rabbits and at various times removed the draining and contralateral nodes for preparation of fragments which were challenged with antigen in vitro. Upon addition of KLH to cells, memory was detected mainly in the cells of the popliteal lymph node which drained the site of injection or in the cells of the spleen after intravenous injection.…”