Jacalin, a lectin with anti-HIV-1 properties, and HIV-1 gp120 envelope protein interact with distinct regions of the CD4 molecule.
Jacalin is a multimeric plant lectin able to interact with the lymphocyte cell-surface molecule CD4, a known receptor for the human immunodeficiency virus type 1 (HIV-1). Moreover, jacalin is able to block HIV-1 infection of CD4+ lymphoblastoid cells. Here we studied whether jacalin prevents HIV-1 gp120-CD4 interactions. We found (i) that jacalin did not inhibit HIV-1 Lai-induced syncytium formation that requires gp120-CD4 interactions; (ii) that jacalin prevented neither rgp120 binding to cell-surface CD4 nor sCD4 binding to viral envelope proteins expressed at the surface of HIV-1-infected lymphoblastoid cells; (iii) that jacalin did not compete for binding to CD4 with anti-CD4 mAb specific for the CDR2- or CDR3-like regions of the D1 domain of CD4; (iv) that jacalin did not bind a recombinant soluble molecule containing the D1/D2 domains of CD4; and, (iv) that jacalin binding to CD4 is inhibited by sugars known to interact with the lectinic-site of jacalin. These data have implications for the understanding of the mechanism by which jacalin blocks HIV-1 infection of CD4+ cells.
Corbeau
P
P
CRBM-UPR 9008 du CNRS, Institut de Biologie-Faculté de Médecine, Montpellier, France.
Haran
M
M
Binz
H
H
Devaux
C
C
D000116:Acetylgalactosamine / Q000378:metabolism; D000998:Antiviral Agents / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D015704:CD4 Antigens / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D002461:Cell Line, Transformed; D015699:HIV Envelope Protein gp120 / Q000378:metabolism*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D009598:Nitrophenylgalactosides / Q000378:metabolism; D037121:Plant Lectins
D000998:Antiviral Agents; D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120; D037102:Lectins; D037121:Plant Lectins; C043696:jacalin; D009598:Nitrophenylgalactosides; C059200:4-nitrophenylgalactoside; D000116:Acetylgalactosamine