Microarray Profiling of Antibody Responses against Simian-Human Immunodeficiency Virus: Postchallenge Convergence of Reactivities Independent of Host Histocompatibility Type and Vaccine Regimen

Abstract

We developed antigen microarrays to profile the breadth, strength, and kinetics of epitope-specific antiviral antibody responses in vaccine trials with a simian-human immunodeficiency virus (SHIV) model for human immunodeficiency virus (HIV) infection. These arrays contained 430 distinct proteins and overlapping peptides spanning the SHIV proteome. In macaques vaccinated with three different DNA and/or recombinant modified vaccinia virus Ankara (rMVA) vaccines encoding Gag-Pol or Gag-Pol-Env, these arrays distinguished vaccinated from challenged macaques, identified three novel viral epitopes, and predicted survival. Following viral challenge, anti-SHIV antibody responses ultimately converged to target eight immunodominant B-cell regions in Env regardless of vaccine regimen, host histocompatibility type, and divergent T-cell specificities. After challenge, responses to nonimmunodominant epitopes were transient, while responses to dominant epitopes were gained. These data suggest that the functional diversity of anti-SHIV B-cell responses is highly limited in the presence of persisting antigen.

Immunogenicity of recombinant human immunodeficiency virus type 1-like particles expressing gp41 derivatives in a pre-fusion state

“…On the other hand, NAbs that target the MPER of gp41 are rare in infected individuals, suggesting that such epitopes are weakly immunogenic [28,[63][64][65][66]. Many gp41 antibodies are raised against the membrane-distal immunodominant epitope I (residue 597-613) and immunodominant epitope II (residue 644-663) regions and are incapable of mediating viral neutralization [67][68][69]. This may be explained by the fact that the non-covalent interaction of gp120 with gp41 is labile and CD4 binding to gp120 stimulates further shedding of gp120 from the functional envelope spike.…”

An array of possibilities for the study of autoimmunity

“…38), allergies 39 and autoimmunity 40 . Arrays are composed of known antigens, including intact antigenic particles, proteins, lipids, carbohydrates, linear peptides and constrained peptides in which disulphide bonds between cysteine residues provide secondary structure to the peptide 40,41 .…”

“…Arrays of antigens have been used to design and guide development of antigen-specific DNA vaccines for the treatment of multiple sclerosis and HIV infection 38 . More specifically, arrays of autoantigens or viral antigens are printed and probed using serum derived from animal models of multiple sclerosis (mice with experimental allergic encephalomyelitis) or HIV (macaques with a simian version of HIV), then the antibody response is compared before and after a therapeutic intervention with a DNA vaccine encoding autoantigens or viral proteins, respectively.…”

“…Multiplexed bead-based flow-cytometry assays represent an active altered as a result of therapy 38,43 . This technique can be applied to any autoimmune disease in which one or more candidate target antigens have been identified.…”

Current perspectives in protein array technology

“…Placing reference features, or landmarks, on an array usually ensures unambiguous orientation.Various materials have been used to create these features, including Cy3-labelled or biotinylated protein. 72,74 Following con¢rmation of array orientation and spot identi¢cation, spot quantitation is undertaken. Signal intensity is usually estimated using either the total integrated or average spot intensity.…”