Antibody Formation and Release in Ileal Loops Exposed to Enterotoxin.
Final rept. 1 Jul 74-31 Aug 77,
JOHNS HOPKINS UNIV BALTIMORE MD
Pagination or Media Count:
Formation of local antibody to cholera toxin CT was studied in fluid from Thiry-Vella intestinal loops in rabbits. IgA anti-CT production was maximal in the fluid when only intraloop i.l. immunization was used, and was minimal after subcutaneous s.c. immunization alone. Combined i.l. and s.c. routes led to intermediate production of IgA anti-CT in the fluid, suggesting suppression of local immune response to CT by the s.c. inoculations. The IgA anti-CT levels correlated with neutralizing capacity, and challenge of locally immunized loops with CT showed protection against the biologic effects excess fluid production. The protection was independent of serum IgG-anti-CT levels. In other experiments it was shown that local immunization to CT was also suppressed by s.c. inoculation with cholera toxoids choleragenoid and glutaraldehyde toxoid. This finding was consistent with an immunogenic presumably suppressor T-cell mediated suppression of local immunity by s.c. inoculation. Preliminary studies with another antigen system keyhole limpet hemocyanin also suggested that suppression of local immunity by systemic immunization may be a more general phenomenon. These observations support strongly the concept that use of local immunization for protecting human beings against enteric infections could be markedly superior to systemic immunization. Furthermore, the studies suggest that, under some circumstances, systemic immunization could be disadvantageous.
- Anatomy and Physiology
- Medicine and Medical Research