The structural basis of repertoire shift in an immune response to phosphocholine

McKay Brown, Maria A. Schumacher, Gregory D. Wiens, Richard G. Brennan, Marvin B. Rittenberg

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


The immune response to phosphocholine (PC)-protein is characterized by a shift in antibody repertoire as the response progresses. This change in expressed gene combinations is accompanied by a shift in fine specificity toward the carrier, resulting in high affinity to PC-protein. The somatically mutated memory hybridoma, M3C65, possesses high affinity for PC-protein and the phenyl-hapten analogue, p-nitrophenyl phosphocholine (NPPC). Affinity measurements using related PC-phenyl analogues, including peptides of varying lengths, demonstrate that carrier determinants contribute to binding affinity and that somatic mutations alter this recognition. The crystal structure of an M3C65-NPPC complex at 2.35-Å resolution allows evaluation of the three light chain mutations that confer high-affinity binding to NPPC. Only one of the mutations involves a contact residue, whereas the other two have indirect effects on the shape of the combining site. Comparison of the M3C65 structure to that of T15, an antibody dominating the primary response, provides clear structural evidence for the role of carrier determinants in promoting repertoire shift. These two antibodies express unrelated variable region heavy and light chain genes and represent a classic example of the effect of repertoire shift on maturation of the immune response.

Original languageEnglish (US)
Pages (from-to)2101-2111
Number of pages11
JournalJournal of Experimental Medicine
Issue number12
StatePublished - Jun 19 2000


  • Affinity maturation
  • Antibody affinity
  • Immunoglobulin
  • Somatic mutation
  • X-ray crystallography

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


Dive into the research topics of 'The structural basis of repertoire shift in an immune response to phosphocholine'. Together they form a unique fingerprint.

Cite this