Engineered Human Cells: STOP HIV
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AIDS epidemic
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AIDS (Acquired ImmunoDeficiency Syndrome) is one of the most striking problems of modern world. It is a consequence of HIV (human immunodeficiency virus) infection which attacks and damages the immune system. It is identified by counting the number of CD4+ T-cells – decreased number of these cells is typical for development of AIDS. During the progression of the disease patients become more sensitive to different opportunistic infections which can be lethal.
HIV primarily infects cells that are important in human immune response; CD4+ T-cells, macrophages, dentritic cells... By replicating itself in human T-cells it destroys them and thus weaken the immune system. AIDS is a consequence of HIV infection; main problem and cause of AIDS mortality are opportunistic infections that can defeat weakened immune system.
Primary infection is the first step – soon after the entry of HIV into host cells HIV replicates itself intensively. Flu-like symptoms are common at this stage. Approximately one month later specific immune response is formed, number of viral particles is decreased. When viral RNA is transcribed into DNA and integrated into host cell genome, latent period occurs. This period can vary between individuals; it can be over 20 years before AIDS develops in infected individuals. AIDS is caused by intense transcription of integrated viral DNA into mRNA and its rapid translation to viral polyproteins. They travel to membrane where polyproteins are cut into functional proteins and new viral particles are formed.
If HIV replication cycle is not interrupted at some point, virus spreads all over the infected individual's body and weakens immune system. Infected T-cells can be destroyed in numerous ways; infection with HIV can cause apoptosis in infected cells, cell membrane can be damaged during exodus of new viral particles, cells of immune system (killer cells) can recognize and destroy infected cells... This stage is identified as AIDS.
AIDS was first recognized in 1981 and has killed more than 25 million people up to now. It claims around 3 million lives per year; more than 40 million are believed to be living with AIDS and even more are infected with HIV. The most critical is Sub-Saharan Africa where around 30 million people are believed to be infected with HIV which is more than 60% of all HIV infections.
In spite of serious struggle to find an ultimate cure for AIDS there is no efficient treatment that could totally eliminate HIV. Main reason is lack of proofreading enzymes in HIV – because mutations are frequent and are not repaired resistance evolves quickly which makes a lot of existing drugs useless. Nevertheless, there are certain therapeutics and 'drug cocktails' that can slow down progression of AIDS and provide better life for those infected with HIV. One of the problems in AIDS treatment is also the price of the therapeutics; only a small amount of infected population can afford the expensive treatment.