|
||
Original Article |
Correspondence to: Gregg J. Silverman, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0663. Tel:858-534-5439 Fax:858-534-5399 E-mail:gsilverman{at}ucsd.edu.
The bacterial toxin protein A from Staphylococcus aureus (SpA) interacts with B cell antigen receptors encoded by variable region heavy chain (VH) clan III genes via a V region framework surface that has been highly conserved during the evolution of the adaptive immune system. We have investigated the consequences of exposure to this prototypic B cell superantigen, and found that treatment of neonates or adults induces a T cellindependent deletion of a large supraclonal set of susceptible B cells that includes clan III/VH S107 familyexpressing lymphocytes. In studies of different SpA forms, the magnitude of the induced deletion directly correlated with the VH-specific binding affinity/avidity. Upon cessation of SpA exposure, the representation of conventional splenic (B-2 subset) lymphocytes normalized; however, we found that the VH familyrestricted deficit of peritoneal B-1 cells persisted. SpA treatment also induced a persistent loss of splenic S107-µ transcripts, with a loss of certain natural antibodies and specific tolerance to phosphorylcholine immunogens that normally recruit protective antimicrobial responses dominated by the S107-expressing B-1 clone, T15. These studies illustrate how a B cell superantigen can exploit a primordial Achilles heel in the immune system, for which B-1 cells, an important source of natural antibodies and host immune responses, have special susceptibility.
Key Words: tolerance, repertoire, clonal selection, immunoglobulin genes, host immunity
This article has been cited by other articles:
| TABLE OF CONTENTS |
|