Antigen-independent selection of T15 idiotype during B-cell ontogeny in mice.

Abstract

Precursors of B cells capable of responding to a T-independent form of phosphorylcholine (PC) in splenic focus assays were detected in the spleens of neonatal mice as early as 4 days after birth. The earliest anti-PC B cells were T15-. T15+ foci-forming B cells were first detected 6 days after birth and expanded rapidly to constitute greater than 80% of the total PC-specific foci by day 10. Injection of heat-killed S. pneumoniae (R36A) into neonatal mice resulted in priming of the antibody response to PC, with an idiotype profile reflecting that of precursors of foci-forming B cells at the time of antigen administration. Priming of 2-day-old mice with 2 x 10(6) and 2 x 10(7) R36A induced a five- and ten-fold increase in the antibody response to phosphorylcholine 6 to 8 weeks later. However, only 10 to 15% of the serum antibodies expressed the normally dominant T15 idiotype. Doses below 2 x 10(5) R36A showed no detectable priming activity. PC-specific hybridomas derived from mice injected with 2 x 10(7) R36A 2 days after birth lacked the idiotypic and molecular characteristics typical of T15+ antibodies. Antibodies to phosphorylcholine, raised by immunization of 6-week-old mice are normally protective against pneumococcal infection. However, serum antibodies from mice treated with R36A 2 days after birth and responding to phosphorylcholine following challenge with R36A at 6 weeks of age failed to protect against deliberate infection with virulent S. pneumoniae. These observations imply that the antigen phosphorylcholine does not play a role in the selective expansion and dominant expression of the T15 idiotype.

• Authors: M Vakil, D E Briles, J F Kearney
• Journal: Developmental immunology (Dev Immunol) Vol. 1 Issue 3 Pg. 203-12 ( 1991) ISSN: 1044-6672 [Print] England
• PMID: 1821697 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antibodies, Bacterial
• Antigens, Bacterial
• Antigens, T-Independent
• Immunoglobulin Idiotypes
• Phosphorylcholine

Topics

• Animals
• Animals, Newborn (growth & development, immunology)
• Animals, Suckling (growth & development, immunology)
• Antibodies, Bacterial (biosynthesis, classification, immunology)
• Antigens, Bacterial (immunology)
• Antigens, T-Independent (immunology)
• B-Lymphocytes (cytology, immunology)
• Cell Differentiation
• Clone Cells (immunology)
• Immunization
• Immunoglobulin Idiotypes (immunology)
• Mice (growth & development, immunology)
• Mice, Inbred BALB C (growth & development, immunology)
• Mice, Inbred CBA (growth & development, immunology)
• Mice, Inbred DBA (growth & development, immunology)
• Phosphorylcholine (immunology)