Down-modulation of the CXCR4 co-receptor by intracellular expression of a single chain variable fragment (SFv) inhibits HIV-1 entry into primary human brain microvascular endothelial cells and post-mitotic neurons.
Our laboratories previously demonstrated that expression of a single chain variable antibody fragment (SFv), anti-CXCR4 SFv, in human lymphoid cells suppresses surface display of the chemokine co-receptor CXCR4 and inhibits infectious entry of human immunodeficiency virus type I (HIV-1). We now sought to extend these results to two types of central nervous system (CNS) cells, primary isolated human brain microvascular endothelial cells (MVECs), and post-mitotic differentiated human neurons, both of which normally express significant levels of CXCR4. The anti-CXCR4 SFv expression construct was delivered using an HIV-1-based vector, and control cells received LacZ-expressing viral particles. Upon intracellular expression of the anti-CXCR4 SFv, immunostaining revealed a marked reduction in surface display of CXCR4 on both cell types. Consequently, post-mitotic neurons expressing the anti-CXCR4 SFv were significantly protected from HIV-1 infection, as measured by HIV-1 p24 antigen production, and partial protection was observed in human brain MVECs. The ability to selectively down-modulate the surface expression of CXCR4 in CNS cells may allow for the development of clinical molecular therapy strategies against HIV-1-related neurodegenerative disorders and neuroinvasion.
Mukhtar
Muhammad
M
The Dorrance H. Hamilton Laboratories, Center for Human Virology and Biodefense, Division of Infectious Diseases and Environmental Medicine, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Acheampong
Edward
E
Khan
Muhammad Ayub
MA
Bouhamdan
Mohammed
M
Pomerantz
Roger J
RJ
D000941:Antigens / Q000378:metabolism; D001921:Brain / Q000166:cytology / Q000821:virology; D002478:Cells, Cultured; D015536:Down-Regulation; D004622:Embryo, Mammalian; D042783:Endothelial Cells / Q000821:virology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005455:Fluorescent Antibody Technique / Q000379:methods; D016655:HIV Core Protein p24 / Q000378:metabolism; D015658:HIV Infections; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000378:metabolism*; D007424:Intracellular Fluid / Q000378:metabolism / Q000821:virology; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008938:Mitosis / Q000502:physiology; D009474:Neurons / Q000821:virology*; D019718:Receptors, CXCR4 / Q000276:immunology / Q000378:metabolism*; D013997:Time Factors; D014161:Transduction, Genetic / Q000379:methods; D014779:Virus Replication; D014841:von Willebrand Factor / Q000276:immunology
D000941:Antigens; D016655:HIV Core Protein p24; D007135:Immunoglobulin Variable Region; C489788:MAP2 protein, human; D008869:Microtubule-Associated Proteins; D019718:Receptors, CXCR4; C029417:Von Willebrand antigen; D014841:von Willebrand Factor