{"doi":"10.3389/fimmu.2024.1476924","title":"Signal peptide exchange alters HIV-1 envelope antigenicity and immunogenicity","abstract":"Introduction: HIV-1 envelope (Env) is the key target for antibodies (Abs) against the virus and thus an important HIV-1 vaccine component. Env is synthesized from a gp160 precursor with a signal peptide (SP) at its N-terminus. This study investigated the influence of the SP on Env antigenicity and immunogenicity. Methods: Env proteins from two HIV-1 isolates, AA05 and AC02, were analyzed as gp120 and gp160 in their native wild-type (WT) forms and as chimeras with swapped SPs (AA05-02 and AC02-05). The WT and chimeric Env were assessed for antigenicity and glycosylation using monoclonal antibodies (mAbs) and glycan probes. Immunogenicity was tested in mice using three vaccine types: gp120 protein, gp120 DNA+gp120 protein, and gp120 DNA+gp160 DNA. Results: The recombinant AC02 gp120 protein was antigenically superior to AA05 as indicated by higher reactivity with most mAbs tested. When SPs were swapped, the antigenicity of the chimeric gp120s (AA05-02 and AC02-05) resembled that of the gp120s from which the SPs were derived; AA05-02 was similar to AC02 and vice versa. Glycan probe reactivity followed a similar pattern: AA05-02 and AC02 showed similar affinity to high-mannose specific mAbs and lectins. Interestingly, the antigenicity of gp160s showed an opposite pattern; membrane-bound gp160 expressed with the AA05 SP (AA05 and AC02-05) showed greater mAb binding than gp160 with the AC02 SP (AC02 and AA05-02). Mice immunized with gp120 protein showed that AA05-02 induced stronger cross-reactive binding Ab responses than AA05 WT, and AC02 elicited stronger responses than AC02-05, indicating AC02 SP enhanced gp120 immunogenicity. However, when DNA vaccines were included (gp120 DNA+gp120 protein and gp120 DNA+gp160 DNA), the use of heterologous SPs diminished the immunogenicity of the WT immunogens. Among the three vaccine regimens tested, only gp120 DNA+gp160 DNA immunization elicited low-level Tier 2 neutralizing Abs, with AA05 WT inducing Abs with greater neutralization capabilities than AA05-02. Conclusion: These data demonstrate that the SP can significantly impact the antigenicity and immunogenicity of HIV-1 Env proteins. Hence, while SP swapping is a common practice in constructing Env immunogens, this study highlights the importance of careful consideration of the effects of replacing native SPs on the immunogenicity of Env vaccines.","journal":"Frontiers in Immunology","year":2024,"id":445578,"datarank":0.32958368660043297,"base_score":2.1972245773362196,"endowment":2.1972245773362196,"self_citation_contribution":0.32958368660043297,"citation_network_contribution":0.0,"self_endowment_contribution":0.32958368660043297,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":8,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9624,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1261954,"name":"P. S. Rao","orcid":"0000-0001-6281-3531","position":1,"is_corresponding":false},{"id":1261955,"name":"Mohammad Amin Behzadi","orcid":"0000-0002-1691-6123","position":2,"is_corresponding":false},{"id":479583,"name":"Roya Feyznezhad","orcid":"0000-0002-0895-6782","position":3,"is_corresponding":false},{"id":669829,"name":"Gregory S. Lambert","orcid":"0000-0003-2808-4341","position":4,"is_corresponding":false},{"id":1056467,"name":"Rajnish Kumar","orcid":"0000-0001-7614-245X","position":5,"is_corresponding":false},{"id":1262428,"name":"Madhu Kumar","orcid":null,"position":6,"is_corresponding":false},{"id":479586,"name":"Weiming Yang","orcid":"0000-0002-5023-2155","position":7,"is_corresponding":false},{"id":427472,"name":"Xunqing Jiang","orcid":null,"position":8,"is_corresponding":false},{"id":28987,"name":"Christina C. Luo","orcid":"0000-0001-9872-7432","position":9,"is_corresponding":false},{"id":291525,"name":"Arthur Nádas","orcid":"0000-0002-6893-6759","position":10,"is_corresponding":false},{"id":367028,"name":"James Arthos","orcid":"0000-0002-6767-4267","position":11,"is_corresponding":false},{"id":228625,"name":"Xiang‐Peng Kong","orcid":"0000-0001-5773-2681","position":12,"is_corresponding":false},{"id":51843,"name":"Hui Zhang","orcid":"0000-0001-8726-7098","position":13,"is_corresponding":false},{"id":291527,"name":"Catarina E. Hioe","orcid":"0000-0002-9245-9788","position":14,"is_corresponding":false},{"id":643189,"name":"J. Andrew Duty","orcid":"0000-0003-3233-1181","position":15,"is_corresponding":false},{"id":479582,"name":"Chitra Upadhyay","orcid":"0000-0002-4524-1532","position":0,"is_corresponding":true}],"reference_count":117,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:01:46.243344Z","pmid":"39380992","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}