Cell Reports (Dec 2017)

Structural Determination of the Broadly Reactive Anti-IGHV1-69 Anti-idiotypic Antibody G6 and Its Idiotope

  • Yuval Avnir,
  • Kristina L. Prachanronarong,
  • Zhen Zhang,
  • Shurong Hou,
  • Eric C. Peterson,
  • Jianhua Sui,
  • Hatem Zayed,
  • Vinodh B. Kurella,
  • Andrew T. McGuire,
  • Leonidas Stamatatos,
  • Brendan J. Hilbert,
  • Markus-Frederik Bohn,
  • Timothy F. Kowalik,
  • Jeffrey D. Jensen,
  • Robert W. Finberg,
  • Jennifer P. Wang,
  • Margaret Goodall,
  • Roy Jefferis,
  • Quan Zhu,
  • Nese Kurt Yilmaz,
  • Celia A. Schiffer,
  • Wayne A. Marasco

DOI
https://doi.org/10.1016/j.celrep.2017.11.056
Journal volume & issue
Vol. 21, no. 11
pp. 3243 – 3255

Abstract

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The heavy chain IGHV1-69 germline gene exhibits a high level of polymorphism and shows biased use in protective antibody (Ab) responses to infections and vaccines. It is also highly expressed in several B cell malignancies and autoimmune diseases. G6 is an anti-idiotypic monoclonal Ab that selectively binds to IGHV1-69 heavy chain germline gene 51p1 alleles that have been implicated in these Ab responses and disease processes. Here, we determine the co-crystal structure of humanized G6 (hG6.3) in complex with anti-influenza hemagglutinin stem-directed broadly neutralizing Ab D80. The core of the hG6.3 idiotope is a continuous string of CDR-H2 residues starting with M53 and ending with N58. G6 binding studies demonstrate the remarkable breadth of binding to 51p1 IGHV1-69 Abs with diverse CDR-H3, light chain, and antigen binding specificities. These studies detail the broad expression of the G6 cross-reactive idiotype (CRI) that further define its potential role in precision medicine.

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