EFFECTOR CELL BLOCKADE

Open Access
Publisher Website
Google Scholar
Abstract
This study describes the effects of incubating antibody-forming cells (AFC), either as mass cell suspensions, or as single AFC in microdroplets, with antigens against which the cells display specificity. Most of the work was done with hapten-specific anti-DNP-AFC, but AFC with specificity against flagellar antigens or fowl gamma globulin (FGG) were also included. It was noted that 30-min incubation of AFC with highly multivalent forms of antigen caused a substantial partial suppression of the antibody-forming performance of the AFC as measured by a hemolytic plaque test. Thus, when cell suspensions containing anti-DNP plaque-forming cells (PFC), were incubated for 30 min at 37°C with 100 µg of DNP-polymerized flagellin (DNP-POL), the number of plaques appearing after washing of the cells and placing them in plaque-revealing erythrocyte monolayers was reduced to 50% or less compared with the number of plaques observed with control portions preincubated with medium alone. Preincubation with DNP-lysine, with oligovalent DNP-protein conjugates, or with irrelevant antigens produced no such inhibition. Studies where preinhibited PFC suspensions were mixed with control suspensions before assay showed that a nonspecific carryover of antigen into the assay system was not involved. The inhibitory effect could also be initiated by holding cells at 0°C with DNP-POL, but in that case, inhibition only became manifest after cells were incubated for 30 min at 37°C before being placed in plaque-revealing monolayers. This suggested that inhibition was initiated by adsorption of multivalent antigen onto PFC-surface Ig, but required some active process before secretion actually slowed down. The effect was dose- and time-dependent, antigen-specific, and generalized for all antigens studied.