HIV p24 as scaffold for presenting conformational HIV Env antigens.
Heterologous protein scaffolds engrafted with structurally defined HIV Env epitopes recognized by broadly neutralizing monoclonal antibodies (MAbs) represent a promising strategy to elicit broad neutralizing antibodies. In such regards, a protein scaffold based on the HIV p24 CA protein is a highly attractive approach, providing also Gag epitopes for eliciting HIV non-neutralizing protective antibodies and specific CD4(+) and CD8(+) T cell responses. In the present study, computational techniques were employed to verify the presence of acceptor sites for conformational HIV Env epitopes and, as proof of concept, the analysis of HIV p24 CA-based scaffolds using a complete V3 loop in a MAb-bound conformation is presented. The V3-p24 epitope-scaffold proteins show the formation of capsomers made of hexamers similarly to the p24 wild type protein. Moreover, the conformational V3 loop presented on p24 scaffold is recognized by a panel of anti-V3 MAbs. The results suggest that HIV p24 CA protein has suitable acceptor sites for engrafting foreign epitopes, without disrupting the formation of capsomer hexamer structures, and that the V3 epitope does retain its antibody-bound conformation. This strongly support the feasibility of developing a scaffolding strategy based on p24 CA proteins displaying conformational minimal structural, antigenic HIV Env epitopes.
Laboratory of Molecular Biology and Viral Oncogenesis, AIDS Reference Center, Istituto Nazionale Tumori Fond G Pascale, Naples, Italy.
Maria
M
Tagliamonte
Daniela
D
Marasco
Alessia
A
Ruggiero
Angelo
A
De Stradis
Maria Lina
ML
Tornesello
Maxim
M
Totrov
Franco Maria
FM
Buonaguro
Luigi
L
Buonaguro
D000911:Antibodies, Monoclonal / Q000378:metabolism*; D057134:Antibodies, Neutralizing / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000235:genetics / Q000378:metabolism; D016655:HIV Core Protein p24 / Q000276:immunology / Q000378:metabolism*; D015699:HIV Envelope Protein gp120 / Q000276:immunology / Q000378:metabolism*; D015497:HIV-1 / Q000276:immunology*; D008854:Microscopy, Electron; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism*; D011487:Protein Conformation
D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000939:Epitopes; D016655:HIV Core Protein p24; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments