Maternal-fetal transfer of a state of idiotypic suppression

Trypanosoma cruzi infection in offspring born to chagasic C3H/He mice

This study reports the effects of Trypanosoma cruzi infection induced in C3H/He male and female mice born to chagasic mice. An experimental model was established infecting female C3H/He mice with a low virulent T. cruzi clone. In this model, mating, fertilization, pregnancy evolution and delivery was carried out successfully. The offspring was infected at four, six and eighth weeks of age. The results showed that the offspring born to chagasic mothers present decreased resistance to acquired T. cruzi infection. This decreased resistance was expressed by higher levels of parasitaemia and higher mortality rates in offspring born to chagasic mothers than in controls. Age and sex were shown to be important factors of this phenomenon. The results suggest that maternal immune system products can modulate the immune response of the offspring.

Inhibition of offspring response to HEL-CFA by administration of anti-HEL MAB to the mother is not related to the predominant idiotype, IdXE, or specificity of the MAB

In the neonatal suckling mouse, the antibody response to HEL-CFA can be inhibited by administration of certain anti-HEL monoclonal antibodies to the mother. The murine primary response to hen egg-white lysozyme (HEL), which can be elicited in A/J mice as early as 7 days of age, is characterized by a predominant specificity that includes the 3 N-terminal amino acids of HEL (TIP-dependence) and by a predominant idiotype, IdXE. A panel of murine IgG1 anti-HEL mAbs was administered to the suckling offspring via the mother. These mAbs were not equivalent in their effects on the offspring. Only two of six IgG1 mAbs, 2F4/2E5 (IdXE-positive, TIP-dependent) and 2D1 (IdXE-negative, TIP-independent), consistently induced suppression of the response of A/J offspring when immunized at 16-20 days of age with HEL-CFA. Suppression averaged 71% for 2F4/2E5 and 74% for 2D1 and was always statistically significant (P less than .05) when 275 micrograms mAb was administered IP to the mother within 24 hr postpartum. Since 2D1 is IdXE-negative and TIP-independent, neither of these properties appears to be crucial for suppression. Differences in transfer of the mAbs from the mother to the offspring or differences in catabolism of the mAbs in the offspring were not detected. When various characteristics of the mAbs such as affinity, idiotypy, and fine specificity were considered, there was no single factor which determined suppression. One of the two mAbs that suppressed the offspring response, 2D1, is idiotypically highly connected in the anti-HEL mAb panel. This observation suggests that idiotypic interactions in the developing neonatal repertoire with subsequent perturbation of T and B cell repertoire development may be an area for future investigation.

Maternal antibodies to Ro (SS-A) are associated with both early onset of disease and male sex among children with systemic lupus erythematosus

In this study of 71 children with systemic lupus erythematosus (SLE) and 188 of their first-degree relatives, we demonstrated that the development of SLE in male children younger than age 18, and in all children younger than age 10 at the time of diagnosis, is strongly correlated with the presence of antibodies to Ro (SS-A) in the mother's serum. When the relative antibody concentration was quantified, increased quantities of antibody to Ro (SS-A) were also found in mothers of male probands and mothers of probands whose SLE was diagnosed before age 10. No similar association was found for the presence or amount of antibody to Ro (SS-A) in other first-degree relatives or for antibody to La (SS-B) or nuclear RNP in any relative. The explanation for the association of maternal anti-Ro (SS-A) antibodies and early diagnosis of SLE or male sex is not apparent. These findings extend the association of maternal antibodies to Ro (SS-A) from transient "neonatal" SLE to SLE in childhood, and suggest that maternal antibodies to Ro (SS-A) may be of fundamental importance in the pathogenesis of some cases of childhood SLE.