Antibody response and acquired tolerance of A/J mice: age- and immunogen-related isotype differences.

In earlier work we have observed strain- and age-related diversity of immunological ageing in inbred mice pretreated with tolerogen or left without pretreatment and then immunized. Different isotypes show different age- and strain-related changes. Here, we extend this isotype analysis from C57BL/6 and SJL to A/J. By comparison with the first two of these, animals of strain A/J show very little age-related change, as judged by indirect plaque-forming response. We have found that in A/J, as in SJL and C57BL/6 mice, age-related changes are isotype-dependent. The age-related changes in isotype predominance and magnitude differ for different determinants. They depend on the structural relation between the tolerance-inducing or -sensitizing macromolecule and the immunogen.