{"doi":"10.1128/jvi.02268-24","title":"Development and optimization of human T-cell leukemia virus-specific antibody-dependent cell-mediated cytotoxicity (ADCC) assay directed to the envelope protein","abstract":"ABSTRACT An estimated 10–20 million people worldwide are infected with the deltaretrovirus human T-cell leukemia virus type 1 (HTLV-1). Although most infected individuals remain asymptomatic, some progress to develop the fatal and debilitating disease adult T-cell leukemia/lymphoma (ATLL) or HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or develop a plethora of other inflammatory disorders. In addition, HTLV-1 infection is associated with immunosuppression and a shorter lifespan. Although a protective role for neutralizing antibodies has been suggested, the role of non-neutralizing antibody-dependent cell-mediated cytotoxicity (ADCC) remains unclear, largely because an assay to measure this response has not been established. Here, we developed a high-throughput flow cytometry-based assay system to measure HTLV-1 envelope-specific ADCC. We used a natural killer cell-resistant T-lymphoblastoid cell line stably expressing the green fluorescent protein GFP to construct a target cell line expressing HTLV-1 envelope protein and using monoclonal antibodies and plasma samples from HTLV-infected or uninfected individuals, validating the specificity and sensitivity of the assay. We detected high ADCC activity in samples from HTLV-1-infected humans. In the plasma of experimentally infected macaques, ADCC activity was measured and a correlation between ADCC activity and HTLV-1 envelope antibody titers was observed. Further, we observed a significant increase in ADCC titer over time; as HTLV-1 infection persists, a higher ADCC response is generated, potentially influencing disease outcome. ADCC titer in HTLV-1-infected macaques also positively correlated with FLT3LG, IL-17F, CD4 + T cells, and lymphocytes but negatively correlated with monocyte frequency and classical monocyte frequency. In conclusion, these findings detail the generation of a cell line that enabled development of an HTLV-specific ADCC assay, which can be employed in large clinical studies as well as research involving humans or non-human primates. IMPORTANCE This approach measures human T-cell leukemia virus (HTLV)-specific envelope antibody-dependent cell-mediated cytotoxicity responses, provides a critical tool to investigate the role of envelope-specific binding antibodies in the immune control of HTLV infection and pathogenesis, and may help guide the development of both therapeutic and preventative vaccine approaches.","journal":"Journal of Virology","year":2025,"id":543549,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.959,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":383714,"name":"Mohammad Arif Rahman","orcid":"0000-0002-6120-8943","position":1,"is_corresponding":false},{"id":383799,"name":"Daniel C. Masison","orcid":"0000-0003-3516-8850","position":2,"is_corresponding":false},{"id":893927,"name":"Anna Gutowska","orcid":"0000-0002-9873-6432","position":3,"is_corresponding":false},{"id":409300,"name":"Ramona Moles","orcid":"0000-0001-8576-2394","position":4,"is_corresponding":false},{"id":397733,"name":"Massimiliano Bissa","orcid":"0000-0003-3455-3992","position":5,"is_corresponding":false},{"id":409301,"name":"Sarkis Sarkis","orcid":"0000-0002-3876-5733","position":6,"is_corresponding":false},{"id":397732,"name":"Luca Schifanella","orcid":"0000-0002-6123-536X","position":7,"is_corresponding":false},{"id":105631,"name":"Tongqing Zhou","orcid":"0000-0002-3935-4637","position":8,"is_corresponding":false},{"id":226807,"name":"Jennifer Jones","orcid":"0000-0002-9488-7719","position":9,"is_corresponding":false},{"id":545343,"name":"Steve Jacobson","orcid":null,"position":10,"is_corresponding":false},{"id":397737,"name":"Genoveffa Franchini","orcid":"0000-0003-2851-6589","position":11,"is_corresponding":false},{"id":893930,"name":"Cynthia A. Pise-Masison","orcid":"0000-0003-2788-235X","position":0,"is_corresponding":true}],"reference_count":68,"raw_metadata":null,"created_at":"2026-07-19T02:53:04.088079Z","pmid":"40152593","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":[]}