Studies on antibody affinity in mice

Abstract

The plaque inhibition method of measuring the affinity of single antibody‐forming cells (AFC) developed by Andersson has been modified for use with haptens. Using this method, it was possible to make simultaneous determinations of the relative affinities of IgG and IgM plaques during the primary and secondary responses. It was shown that there was no maturation of the affinity of antibody‐released IgM AFC in the primary response in mice. There was an increase in affinity of the antibody released from IgG AFC, which was antigen dose‐ and time‐dependent, confirming results obtained by others. Furthermore, at any time during the course of the primary response, the affinity of the IgM antibody released by AFC was always lower than that of IgG plaque‐forming cells. This difference averaged about 10‐fold. The same factors were shown to influence the affinity changes of IgG AFC observed during the secondary response. In addition the booster, or secondary dose of antigen used, was important. Highest affinity antibody was produced in response to intermediate antigen doses. The maturation of affinity affects the generation of memory cells to the same degree as the antibody‐secreting cells during the primary response, since similar affinity changes occurred in the absence of detectable primary responses. Finally, when the period between primary stimulation and challenge is 5 months, there is a decrease of between 2 and 2.6 log10 in the concentrations of DNP lysine needed to inhibit 50 % of the IgG antibody‐forming cells depending on the doses used for priming. The variation of affinity of IgM antibody was much less obvious, with a 6‐fold difference at the maximum, which was independent of the doses of antigen used for priming or boosting, and of the time elapsed between the two antigenic stimuli.

The avidity of specific IgM detected in primary rubella and reinfection

“…These have generally considered the avidity of specific IgG. Little work has been done on the relative avidity of specific IgM and most has been done on animals and for primary responses only [8][9][10]. We know of only one report [15] of studies on the avidity of human rubella-specific IgM.…”

“…However, because of the pentavalent structure of the molecule, it may be that IgM has a high functional affinity or avidity [7]. Most studies on IgM avidity have been done on the primary immune response in animals [8][9][10]. It has been claimed that there is no maturation of the IgM response [10,11] although others [9] have claimed that there is but that the maturation is antigen-dose dependent.…”

“…Most studies on IgM avidity have been done on the primary immune response in animals [8][9][10]. It has been claimed that there is no maturation of the IgM response [10,11] although others [9] have claimed that there is but that the maturation is antigen-dose dependent. Specific IgM is either not produced in secondary responses or is produced in such small amounts that it has generally not been possible to draw conclusions about the avidity of IgM in the secondary response.…”

Analysis of affinity of monoclonal antibody responses by inhibition of plaque‐forming cells

“…This reflects cell selection during the initiation of local monoclonal responses, which may prevent the effective expansion of clones producing plaques relatively refractory toward inhibition by free antigen. These clones were resolved by deduction from the biphasic curve of a Scatchard plot, using measurements from the Stupp-Farr assay, as having affinities of 2.4 x and 9 x mole/l (90 % of antibody) motell (10 % of antibody). Table 3.…”

Antigen‐initiated B Lymphocyte Differentiation. Characterisation of the Primary and Secondary Immune Responses of Normal and Athymic Mice to the Hapten 4‐hydroxy‐3‐iodo‐5‐nitrophenylacetic Acid Presented on the Carrier Polymerised Bacterial Flagellin

“…Whereas the maximal nimibcr of AFC against SRC was observed on day 4 or day 5 (Wortis et al, 1966;Wortis et al, 1969), the nnL\iiiial number of AFC against the NIP determinant was observed on day 3. This does not correlate with other T cell independent antigens including POL or even DNP-POL where the maximal response occurred on day 4 or day 5 (Diener, 1968;Britton and Moller, 1968;Baker and Stashak, 1969;' Miranda] 1972;Huchet and Feldmann, 1973), indicating that this is a unique feattire of the response to the NIP determinant itself rather than to its mode of presentation or related T cell independence. The early sharp response was also obser\'ed in nude mice, indicating that T cells do not play a role in this phenomenon.…”