Adenosine deaminase binding to human CD26 is inhibited by HIV-1 envelope glycoprotein gp120 and viral particles
Valenzuela, A.; Blanco, J.; Callebaut, C.; Jacotot, E.; Lluis, C.; Hovanessian, A.G.; Franco, R.
Journal of Immunology 158(8): 3721-3729
1997
ISSN/ISBN: 0022-1767 PMID: 9103436 Document Number: 475467
This study aimed to determine whether the physiological interaction between cell surface adenosine deaminase (ecto-ADA) and CD26 is modulated by HIV. The effect of HIV-1 gp120 on the binding of 125I-labelled ADA to CD26 expressed on different types of cells, which were CD4+ and CD4-, was investigated. It was shown that, irrespective of CD4 expression, 3 recombinant gp120 preparations inhibit the binding of ADA to CD26. The motif in the gp120 molecule responsible for the inhibition appeared to be located in the C3 region between the V3 and V4 loops. HIV-1 Lai, a T cell line-adapted HIV-1 isolate, was able to inhibit the binding of ADA to CD26 in a dose-dependent manner. This HIV-induced disruption of the ADA-CD26 interaction might have functional consequences in lymphocytes and in other cell types where the cell surface ADA-CD26 complex is present.