Age-Dependent Changes of Isotype and Idiotype Expression in the Antibody Response to the Phosphorylcholine Hapten in BALB/c Mice

Abstract

The distribution of antibodies among different isotypes in an immune response to a given antigen reflects the immunoregulatory linkage of T and B cell compartments, the genetic background of an individual and the functional state of its immune system. In addition, idiotypes are markers for the clonal origin of antibodies and their genetic relationship. Therefore, we have analyzed the isotype patterns and development of the major idiotype (T15) in BALB/c mice of different ages, immunized with a T-cell-dependent phosphorylcholine conjugate. The response was dominated by µ, γ3 and γ1 isotypes. The proportion of these antibodies changed in the progress of immunization but not with age in the primary response. An age-dependent change of the isotype distribution was observed only in the memory response. The T15 idiotype was dominantly expressed in the primary response and decreased in the memory response by 80–95% independently of the age of the mice. The results demonstrate that 2 populations of anti-phosphorylcholine antibodies which both prefer particular isotypes are expressed according to the functional state of the T and B cell compartments with age.

Heterogeneity and immunogenicity of theTrichinellaTSL‐1 antigen gp53

“…The reason why US5‐recognized and non‐US5‐recognized species‐specific epitopes are more important in BALB/c than in Swiss CD‐1 mice is unclear at present. However, another Trichinella epitope that plays a key role in the primary antibody response induced by the parasite during the intestinal phase, phosphorylcholine (31,32), is also differentially recognized in BALB/c mice, in which (unlike in other mouse strains) more than 90% of anti‐PC antibodies belong to the T15 idiotype family (33,34). As the infective capability of Trichinella species is lower in BALB/c than in Swiss CD‐1 mice, one might speculate that the preferential recognition of species‐specific epitopes on gp53 in BALB/c mice is advantageous in terms of protection against infection, but current available information suggests that the presence of these epitopes on gp53 from T. spiralis is not detrimental to the parasite.…”