HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Data Supplement Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Dosenovic, P. Articles by Karlsson Hedestam, G. B. PubMed PubMed Citation Articles by Dosenovic, P. Articles by Karlsson Hedestam, G. B.

Selective Expansion of HIV-1 Envelope Glycoprotein-Specific B Cell Subsets Recognizing Distinct Structural Elements Following Immunization¹

Pia Dosenovic^*, Bimal Chakrabarti, Martina Soldemo^*, Iyadh Douagi^*, Mattias N. E. Forsell^*,, Yuxing Li, Adhuna Phogat, Staffan Paulie, James Hoxie, Richard T. Wyatt and Gunilla B. Karlsson Hedestam^2,*

^* Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden, and Swedish Institute for Infectious Disease Control, Solna, Sweden; Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892; Mabtech, Nacka, Sweden; and Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104

The HIV-1 envelope glycoprotein (Env) functional spike has evolved multiple immune evasion strategies, and only a few broadly neutralizing determinants on the assembled spike are accessible to Abs. Serological studies, based upon Ab binding and neutralization activity in vitro, suggest that vaccination with current Env-based immunogens predominantly elicits Abs that bind nonneutralizing or strain-restricted neutralizing epitopes. However, the fractional specificities of the polyclonal mixture of Abs present in serum, especially those directed to conformational Env epitopes, are often difficult to determine. Furthermore, serological analyses do not provide information regarding how repeated Ag inoculation impacts the expansion and maintenance of Env-specific B cell subpopulations. Therefore, we developed a highly sensitive Env-specific B cell ELISPOT system, which allows the enumeration of Ab-secreting cells (ASC) from diverse anatomical compartments directed against different structural determinants of Env. In this study, we use this system to examine the evolution of B cell responses in mice immunized with engineered Env trimers in adjuvant. We demonstrate that the relative proportion of ASC specific for defined structural elements of Env is altered significantly by homologous booster immunizations. This results in the selective expansion of ASC directed against the variable regions of Env. We suggest that the B cell specificity and compartment analysis described in this study are important complements to serological mapping studies for the examination of B cell responses against subspecificities of a variety of immunogens.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ This work was supported by grants from Karolinska Institutet, Swedish Research Council, Sida/Swedish Agency of Research Cooperation with Developing Countries, International AIDS Vaccine Initiative, Bill and Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases, and National Institutes of Health intramural research program.

² Address correspondence and reprint requests to Dr. Gunilla B. Karlsson Hedestam, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Box 280, S-171 77 Stockholm, Sweden. E-mail address: Gunilla.Karlsson.Hedestam{at}ki.se

³ Abbreviations used in this paper: Env, envelope glycoprotein; ASC, Ab-secreting cell; β-gal, β-galactosidase; BM, bone marrow; ON, overnight; RT, room temperature.

⁴ The online version of this article contains supplemental material.