Immune Analytics Core (IAC)

Weill Medical Coll Of Cornell Univ, New York NY

Investigators

Abstract

ABSTRACT - IMMUNE ANALYTICS CORE (IAC) The Immune Analytics Core (IAC) is an essential component of this P01 Program by developing and providing relevant immunogens and by performing standardized assays to assess vaccine-induced immune responses in rhesus macaque and human studies proposed in Projects 1 and 2. To support the overall goal of the Program “Translating germline-targeting HIV Env SOSIP immunization of infants: targeting bnAbs in early life”, the IAC will pursue three Specific Aims. Aim 1 will focus on the development and production of germline-targeting or standard SOSIP trimers. The trimers will not only be essential for the proposed immunization, but also for the analysis of vaccine-induced antibody responses. The trimer production team leader, Dr. John Moore, is an expert on trimer design both for preclinical and clinical studies. Dr. Moore’s long-standing track record in trimer development and optimization is deemed critical for the success of the Program. The immunogens generated in Aim 1 will also be a critical tool for the analysis of vaccine-induced immune responses in Aim 2 of the IAC. Aim 2 will define the phenotype of vaccine-induced HIV Env-specific B cells by flow cytometry, with a particular focus on memory B cells targeting the CD4bs and enumeration of plasma cells. At selected time points, we will perform single cell BCR sequencing to define the somatic hypermutation rate and the heavy and light chain usage of bNAbs. The induction of bNAbs will be correlated to follicular T helper cell responses to the various vaccine regimens tested in Project 1 and by the combination of active and passive immunization in Project 2. Expanding upon data in Aim 2, Aim 3 will apply electron microscopy-based polyclonal epitope mapping (EMPEM) to identify the epitope specificity of vaccine- induced antibodies. Immune sera from vaccinees will be examined by EMPEM to track antibodies to the CD4 binding site. High resolution analysis of the CD4bs responses will provide information on the molecular features of such responses. Additionally, the generated data can be used to further optimize vaccine candidates to reduce unwanted responses and enrich for on-target functional antibodies to neutralizing epitopes. The approach is to subject polyclonal antibody complexes to negative stain EMPEM, determine the most interesting candidates and apply cryoEM analysis to predict the sequences of the antibodies using a combination of the cryoEM data and B-cell sequencing data. To ensure rigor and reproducibility, all methods in Aims 1-3 are well established and will be conducted according to standard operating procedures with built-in quality control measures. In summary, the IAC will provide immunogens and assess vaccine immunogenicity and the maturation of bNAbs by applying complementary immune, molecular, and structural biology technologies and analytic tools.