Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates
NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD
Pagination or Media Count:
We studied the induction of antigen-specific lgA memory B cells BM in volunteers who received live attenuated Shigella flexneri 2a vaccines. Subjects ingested a single oral dose of 107 , 108 or 109 CFU of S. flexneri 2a with deletions in guaBA CVD 1204 or in guaBA, set and sen CVD 1208. Antigen-specific serum and stool antibody responses to LPS and lpa B were measured on days 0, 7, 14, 28 and 42. lgA BM cells specific to LPS, lpa Band totallgA were assessed on days 0 and 28. We show the induction of significant LPS-specific lgA BM cells in anti-LPS lgA seroresponders. Positive correlations were found between anti-LPS lgA BM cells and anti-LPS lgA in serum and stool lgA BM cell responses to lpaB were also observed. These BM cell responses are likely play an important role in modulating the magnitude and longevity of the humoral response.
- Medicine and Medical Research