Human immunodeficiency virus type 1 Negative Factor protein (Nef) (Nef)

The Human immunodeficiency virus type 1 (HIV-1) Negative Factor (Nef) protein is a 27-35 kDa myristoylated accessory protein that is essential for viral pathogenesis and high-titer replication (UniProt P03406). Expressed early in the viral life cycle, Nef functions as a critical virulence factor by hijacking host cellular machinery to downregulate key surface receptors, including CD4 and Major Histocompatibility Complex class I (MHC-I) (Wikipedia). By reducing MHC-I expression, Nef allows HIV-infected cells to evade detection and destruction by cytotoxic T lymphocytes (CTLs), facilitating persistent infection (NIH). In vaccine development, such as those utilizing the Modified Vaccinia Ankara (MVA) vector (e.g., MVA-B), Nef is included as a key antigen to stimulate broad and polyfunctional T-cell responses (PubMed). Nef also enhances viral infectivity by counteracting host restriction factors like SERINC3 and SERINC5 (UniProt). Furthermore, it modulates T-cell signaling pathways to create an environment conducive to viral production while preventing premature apoptosis of the host cell (Reactome). Therapeutic approaches targeting Nef include both immunotherapies designed to enhance the host's immune recognition and small-molecule inhibitors, such as lovastatin or hydroxypyrazole analogs, that block Nef's interactions with host proteins like Src kinases and adaptor protein complexes (MDPI). While no Nef-specific inhibitors are currently approved for clinical use, they represent a promising strategy for achieving a functional cure by restoring the immune system's ability to clear the latent viral reservoir (NIH).

Other names

Negative FactorF-proteinHIV-1 Nef27 kDa myristoylated proteinNef protein

Induction of antigen-specific T-cell responses (vaccines) or inhibition of Nef-mediated protein trafficking and signaling (small molecules).