AEGiS-4IAC: [1007] SYNTHESIS OF EXCRETED 26KDa PROTEINS BY HIV-1 INFECTED CELLS APPARENTLY DIFFERENT FROM THE CORE PROTEIN OF HIV

4th International AIDS Conference

Stockholm, Sweden. — June 12-16, 1988

[TITLE:] SYNTHESIS OF EXCRETED 26KDa PROTEINS BY HIV-1 INFECTED CELLS APPARENTLY DIFFERENT FROM THE CORE PROTEIN OF HIV

Int Conf AIDS. 1988 Jun 12-16;4:1.114 (abstract no. 1007)

AG Laurent, L Montagnier, AG Hovanessian
Unité d'Oncologie Virale, Institut Pasteur Paris, France

Synthesis of HIV-1 proteins was studied in infected CEM cells metabolicaly labeled with (³⁵S) methionine.

Low levels of newly-synthesized, viral proteins are detectable 24 hr after the infection with a maximal synthesis on days 4 and 5. During this period, there is a dramatic inhibition of cellular protein synthesis which is concomitant with a significant increase of a series of proteins of 25-26KDa. The amount of these proteins might reach as much as 25% of total proteins synthesized in HIV-infected cells. Analysis of these 25-26KDa proteins by two-dimensional gel electrophoresis revealed that they are composed of at least four species with different isoelectric points (pI) : two 25KDa species with pI values more basic than two 26KDa species. Only the 25KDa species are recognized by immunoblotting using monoclonal antibodies specific for three different epitopes in the n25 of HIV-1. Subcellular localization studies have indicated that the 25KDa species and as well as their precursors (p40 and, p55) are associated with the rough microsomal pellet whereas the 26KDa species remain in the Post-ribosomal supernatant fraction. The 26KDa species are not incorporated into virus particles but they are excreted by virus producing cells.

These observations provide evidence for the first time for the synthesis and excretion of 26KDa proteins by HIV-1 infected cells. The function of these 26KDa proteins, their origin (viral or cellular) and their relation to the HIV-1 p25 remain to be elucidated.

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