Saturday, July 2, 2011

30th Anniversary of Identification of AIDS

The year 2011 marks the 30th anniversary of the HIV virus discovery and, at the same time, 30 years of fight against this global plague. Between 8 and 10 June, the activities of the UN General Assembly High Level Meeting on fight against HIV/AIDS will be conducted at the UN Headquarters in New York. Romania issued a commemorative stamp on 8 June for this event, featuring the red ribbon signifying the fight against AIDS, and the representative structure of the AIDS virus.
As shown on the stamp, the AIDS virus structure is roughly spherical with a diameter of about 120 nm. It is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24. The single-stranded RNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion such as reverse transcriptase, proteases, ribonuclease and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle. This is, in turn, surrounded by the viral envelope that is composed of two layers of fatty molecules called phospholipids. Embedded in the viral envelope are proteins from the host cell and about 70 copies of a complex HIV protein that protrudes through the surface of the virus particle. This protein, known as Env, consists of a cap made of three molecules called glycoprotein (gp) 120, and a stem consisting of three gp41 molecules that anchor the structure into the viral envelope. This glycoprotein complex enables the virus to attach to and fuse with target cells to initiate the infectious cycle.
The Serbian Post released on 1 June the commemorative stamp with an artist's impression of the virus, with the external glycoprotein structures shown.

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