The long-term goal of this project is to identify novel monoclonal antibodies (mAbs) that broadly recognize the HIV-1 envelope glycoprotein (Env) and block infection in vitro to guide vaccine development. This goal will be pursued in local cohorts of HIV-1 infected individuals who control their infections in the absence of anti-retroviral therapy (JAIDS, 50:403-8, 2009). Approximately 13% of these individuals have circulating broadly neutralizing antibodies providing the study population for our studies. A key element of our approach is the development of a new assay to census Env-specific memory B cell clones (BMem) that allows the rapid and direct cloning of full-length molecular clones of the antibodies expressed by these cells (PNAS, 106:3952-7, 2009). This method permits clone identification using native oligomeric HIV-1 envelope glycoproteins (Env) expressed on cell surfaces and by direct neutralization of pseudoviruses. Env-reactive clones are used to produce mAbs that will be evaluated for epitope specificity and neutralization breadth. This information will be used to test the hypothesis that neutralization breadth is determined by monoclonal or pauciclonal responses comprised of one or a very few neutralizing specificities as opposed to a polyclonal response comprised of a mosaic of neutralizing specificities. There are two specific aims.
Aim 1 - To develop clonal specificity profiles of Env-specific BMem from NVS who have ongoing broadly neutralizing antibody responses- Clonal specificity profiles of anti-Env responses will be determined by limiting dilution analysis, mAb isolation, and epitope mapping to identify broadly neutralizing mAbs.
Aim -2- To compare neutralization breadth between plasma antibodies and mAbs representing a full clonal profile of BMem to determine the number of mAbs that must be pooled to reconstruct the neutralization profile of the circulating antibody pool. Neutralization breadth of mAbs will be determined using standardized pseudovirus assays. This data will be used to determine the clonality of an ongoing broadly neutralizing antibody response.
This aim will test the hypothesis that neutralization breadth is determined by monoclonal or pauciclonal responses comprised of one or a very few neutralizing specificities as opposed to a polyclonal response comprised of a mosaic of neutralizing specificities.

Public Health Relevance

This research is relevant to public health in that it seeks to understand how people who are infected with the AIDS virus make protective immune responses. This information will help guide the development of a vaccine against the AIDS virus.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI087181-02
Application #
8006391
Study Section
Special Emphasis Panel (ZRG1-AARR-C (03))
Program Officer
Miller, Nancy R
Project Start
2009-12-15
Project End
2014-11-30
Budget Start
2010-12-01
Budget End
2011-11-30
Support Year
2
Fiscal Year
2011
Total Cost
$558,285
Indirect Cost
Name
University of Maryland Baltimore
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Tolbert, William D; Gohain, Neelakshi; Veillette, Maxime et al. (2016) Paring Down HIV Env: Design and Crystal Structure of a Stabilized Inner Domain of HIV-1 gp120 Displaying a Major ADCC Target of the A32 Region. Structure 24:697-709
Kaplan, Gilad; Roitburd-Berman, Anna; Lewis, George K et al. (2016) Range of CD4-Bound Conformations of HIV-1 gp120, as Defined Using Conditional CD4-Induced Antibodies. J Virol 90:4481-93
Huang, Yunda; Ferrari, Guido; Alter, Galit et al. (2016) Diversity of Antiviral IgG Effector Activities Observed in HIV-Infected and Vaccinated Subjects. J Immunol 197:4603-4612
Veillette, Maxime; Richard, Jonathan; Pazgier, Marzena et al. (2016) Role of HIV-1 Envelope Glycoproteins Conformation and Accessory Proteins on ADCC Responses. Curr HIV Res 14:9-23
Sajadi, Mohammad M; Farshidpour, Maham; Brown, Eric P et al. (2016) λ Light Chain Bias Associated With Enhanced Binding and Function of Anti-HIV Env Glycoprotein Antibodies. J Infect Dis 213:156-64
Lewis, George K (2015) Honing a harder-hitting hammerhead improves broadly neutralizing antibody breadth and potency. J Clin Invest 125:2271-4
Gohain, Neelakshi; Tolbert, William D; Acharya, Priyamvada et al. (2015) Cocrystal Structures of Antibody N60-i3 and Antibody JR4 in Complex with gp120 Define More Cluster A Epitopes Involved in Effective Antibody-Dependent Effector Function against HIV-1. J Virol 89:8840-54
Richard, Jonathan; Veillette, Maxime; Brassard, Nathalie et al. (2015) CD4 mimetics sensitize HIV-1-infected cells to ADCC. Proc Natl Acad Sci U S A 112:E2687-94
Kulkarni, Viraj; Rosati, Margherita; Jalah, Rashmi et al. (2014) DNA vaccination by intradermal electroporation induces long-lasting immune responses in rhesus macaques. J Med Primatol 43:329-40
Lewis, George K; Guan, Yongjun; Kamin-Lewis, Roberta et al. (2014) Epitope target structures of Fc-mediated effector function during HIV-1 acquisition. Curr Opin HIV AIDS 9:263-70

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