An inhibitor of glycosphingolipid metabolism blocks HIV-1 infection of primary T-cells.
OBJECTIVE
HIV-1 uses CD4 and chemokine receptors to enter cells. However, other target membrane components may also be involved. This study examines the role of glycosphingolipids (GSL) in HIV-1 entry into primary lymphocytes and its modulation by an inhibitor of GSL biosynthesis.


METHODS
CD4 lymphocytes purified from normal or the p-group subtype individuals that were defective in Gb3 synthesis were treated with a GSL biosynthesis inhibitor, 1-phenyl-2-hexadecanoylamino-3-morpholino-1-propanol (PPMP). The PPMP-treated cells were tested for HIV-1 replication by measuring p24 antigen production for 7-14 days post-infection and for susceptibility to HIV-1 Env-mediated fusion monitored by a fluorescent dye transfer assay. The effects of PPMP treatment on HIV-1 binding to CD4 lymphocytes were also examined by measuring HIV-1 p24.


RESULTS
CD4 lymphocytes from p donors that are devoid of Gb3, but have elevated levels of GM3 were highly susceptible to HIV-1 fusion/entry. Pre-treatment of primary human CD4 lymphocytes from normal or p-sub-group type with PPMP, significantly reduced HIV-1 replication with no change in CD4 and CXCR4 levels. Inhibition of HIV-1 infection was due to the block in HIV-1 Env-mediated plasma membrane fusion. Binding of HIV-1 to CD4 lymphocytes was not affected by PPMP treatment.


CONCLUSIONS
Manipulation of glycosphingolipid metabolic pathways may alter susceptibility of CD4 lymphocytes to HIV-1 entry.
Puri
Anu
A
Laboratory of Experimental and Computational Biology, SAIC-Frederick Inc., NCI Frederick, Frederick, MD 21702, USA.
Rawat
Satinder S
SS
Lin
Han-Ming Joseph
HM
Finnegan
Catherine M
CM
Mikovits
Judy
J
Ruscetti
Francis W
FW
Blumenthal
Robert
R
D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000821:virology*; D002478:Cells, Cultured; D006028:Glycosphingolipids / Q000037:antagonists & inhibitors*; D016655:HIV Core Protein p24 / Q000032:analysis; D023581:HIV Fusion Inhibitors / Q000627:therapeutic use*; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D008561:Membrane Fusion / Q000187:drug effects; D009025:Morpholines / Q000627:therapeutic use*; D019718:Receptors, CXCR4 / Q000032:analysis; D013107:Sphingolipids / Q000627:therapeutic use*; D014779:Virus Replication / Q000187:drug effects
C095823:1-phenyl-2-palmitoylamino-3-morpholino-1-propanol; D006028:Glycosphingolipids; D016655:HIV Core Protein p24; D023581:HIV Fusion Inhibitors; D009025:Morpholines; D019718:Receptors, CXCR4; D013107:Sphingolipids