The Rate of Division of Antibody-Forming Cells During the Early Primary Immune Response

Abstract

There is conflicting evidence about the relative roles of division and "recruitment" of responding ceils during the early primary immune response. The cells primarily releasing "19S" hemolysin for sheep erythrocytes may be enumerated using the plaque-forming cell technique developed by Jeme and Nordin (1, 2) and independently by Ingraham (3). An exponential increase in plaque-forming cells occurs during the early primary response; doubling times vary from about 5 to 10 hr depending on the dose of antigen and other experimental variables (4-14).A method using mitotic blocking agents to estimate cell cycle times of antibody-formlng cells, in vivo and in vitro, is presented. Results with this method indicate that the increase in numbers of antibody-forming cells which occurs during the early primary response is due primarily to exponential division of responding cells. Increased responses produced by larger antigen doses or adjuvant appear to result from an increased rate of division of responding cells. These findings are contrary to the view that the observed increase in antibody-producing ceils can be attributed to continued activation or recruitment of potential antibody-producing cells (9-14). Materials and MethodsYoung adult Sprague Dawley rats were used. The antigen was washed whole erythrocytes prepared from sterile sheep's blood. A single sample of blood stored in Alsever's solution was used in each experiment both for ;mmunization and for titrating immune respo~es. The sheep erythroc~es were washed four times in large volumes of freshly prepared pyrogenfree saline and used immediately. Doses of sheep erythrocytes were standardized by ceil *

Induction and mode of action of suppressor cells generated against human gamma globulin. II. Effects of colchicine.

“…In contrast, in the present studies, Col did not depress immune responsiveness when injected up to 24 h before assessment of the PFC response ( Figs. 1 and 2), and it has been reported to be immunodepressive in vivo only when injected repeatedly (59,60) or at nearly toxic doses (61,62). In the present work as in previous reports (46,47), Col possessed adjuvant properties at concentrations approaching toxicity, and at concentrations that were toxic for individual animals, the surviving animals exhibited heightened immune responses.…”

Maturation of Hemolysin-Producing Cell Clones

“…The observation that the number of precursor units/culture remains stable throughout a 4 day experiment indicates that recruitment of additional cells capable of producing clones of PFC does not occur in this system. This data is in agreement with the recent findings of Rowley et al (13).…”

“…This may be explained by the fact that during their development in culture PFC are in constant contact with antigen and it would appear logical therefore that this antigen acts like a sponge to draw antibody from the cell surface of producing cells as soon as it is released. In addition, during and shortly after cell division the rate of antibody synthesis is probably quite low (13). In order to insure maximum PFC survival it was also found very important to keep the agarose-medium-cell suspension mixture at no more than 48°C and to pour this mixture onto the Petri dish as quickly as possible.…”

Antibody and Immunoglobulin Production at the Cellular Level in Bursectomized-Irradiated Chickens

“…We examined a total of 80 X l0 s spleen cells, approximately 1/~ 0 of the total spleen cell number, with both the direct and indirect techniques. Assuming a doubling time for the chicken IgM hemolysin producing cell of at the most 9 hr, as has been shown for the corresponding mouse cell (23), and an exponential increase of the number of chicken spleen PFC in the primary immune response to SRBC, we should have been able to detect the progeny of one precursor cell for either the IgM or IgG antibody producing cells. It is therefore possible that the precursors for the antibody forming cells are absent in the hypogammaglobulinemic bursectomized-irradiated chicken.…”