How AIDS take place in body?

Answer 1

Life cycle of HIV
HIV enters a CD4+ helper T-cell by bonding with either CXCR4 or both CXCR4 and CCR5 depending on what stage the HIV infection is in. A cofactor protein (fusin) is required to assist binding of the viron to the membrane of the T-cell. During the early phases of an HIV infection typically both CCR5 and CXCR4 are bound while late stage infection often involve HIV mutations that only bind to CXCR4.
Once HIV has bound to the CD4+ T-cell a viral protein known as GP41 penetrates the cell membrane and the HIV RNA and various enzymes including but not limited to reverse transcriptase, integrase and protease are injected into the cell.

The host T-cell can process RNA into proteins (as in Polio virus) but this doesn't happen with HIV. Instead, HIV is stabilised by copying it into DNA and inserting it into the host cell's chromosomes. This means the virus can perform more subtle functions by using the host transcription machinery. The virus generates DNA from the HIV RNA using the reverse transcriptase enzyme to perform reverse transcription. This process can be inhibited by drugs. If this succeeds the pro-viral DNA must then be integrated into the host cell DNA using the integrase enzyme. If the pro-viral DNA becomes integrated into the host cell's DNA the cell is now fully infected but not actively producing HIV proteins. This is the latent stage of an HIV infection during which the infected cell can be an "unexploded bomb" for potentially a long time.

To actively produce virus, certain transcription factors need to be present in the cell. The most important is called NF-kB (NF Kappa B) and is present once the T cells becomes activated. This means that those cells most likely to be killed by HIV are in fact those currently fighting infection.

The production of the virus is regulated, like that of many viruses. Initially the integrated provirus is copied to mRNA which is then spliced into smaller chunks. These small chunks produce the regulatory proteins Tat (which encourages new virus production) and Rev. As Rev accumulates it gradually starts to inhibit mRNA splicing. At this stage the structural proteins Gag and Env are produced from the full-length mRNA. Additionally the full-length RNA is actually the virus genome, so it binds to the Gag protein and is packaged into new virus particles.

Interestingly HIV-1 and HIV-2 appear to package their RNA differently - HIV-1 will bind to any appropriate RNA whereas HIV-2 will preferentially bind to the mRNA which was used to create the Gag protein! This may mean that HIV-1 is better able to mutate (HIV-1 causes AIDS faster than HIV-2 and is the majority species of the virus).

The virus starts to form under the cell membrane, in special cholesterol-rich regions, and gradually buds outside. Once outside it has to undergo a maturation step or else it isn't infectious. The virus protease enzyme cleaves Gag into several smaller proteins (Matrix, Capsid, p2, Nucleocapsid, p1 and P6) and this step can be inhibited by drugs. The virus is then able to infect a further cell.

Structure of the virus
HIV looks quite different to the classic retroviruses described in the 1960s. It is around 120nm in diameter (120 billionths of a meter - a red blood cell is around 60 times larger at 7 millionths of a meter) and roughly spherical. There are two forms of the virus. They both consist of a lipid envelope surrounding a protein/RNA core.
Immature form: When the virus leaves the cell it is not infectious and the inner part of the virus particle contains a spherical core (stains dark on electron micrographs). There are also spikes on the outer membrane that are the Env proteins (gp120 and gp41). Sometimes a virus can be seen during the process of budding, when it looks like a dark arc sitting under the cell membrane - this observation meant that HIV was originally classed as a type C retrovirus. The Env proteins link together in groups of three (trimers).Mature form: Once the virus protease has cleaved the Gag proteins, the core rearranges into a truncated cone (imagine a traffic cone sliced at an angle across the top!) Some reports also show a small filament linking the core to the membrane. The envelope spikes are often much rarer on mature particles since they are easily dislodged. It is the mature conical core that makes HIV so easily identifiable.

Inside the virus there are two identical strands of RNA, in the same way that we have two identical copies of each chromosome. The RNA is coated by the CA protein (formed from Gag) and is not easily seen unless the virus particles are broken apart. The reverse transcriptase enzyme, which includes integrase, is also packaged into the virus along with certain other important proteins (some from the virus, some captured from the cell) and a tRNA molecule that initiates the reverse transcription process. Because the virus contains certain proteins it needs to replicate, injection of the pure RNA will not result in a successful infection.

HIV has several major genes coding for structural proteins that are found in all retroviruses, and several non-structural or "accessory" genes that are unique to HIV.

General retrovirus genes
gag. gag-derived proteins make up the cone-shaped viral capsid (p24, i.e. a 24 Kilodalton protein, CA) the nucleocapsid proteins (p6 and p7, NC) and a matrix protein (p17, MA).
pol. The pol gene codes for the virus enzymatically active proteins. Most important is the so-called reverse transcriptase (RT) which performs the unique reverse transcription of the viral RNA into double-stranded DNA. The latter is integrated into the genome of the host, which means into a chromosome of an infected cell of an HIV-positive person by the pol-encode integrase (IN). Also, pol encodes a specific viral protease (PR). This enzyme cleaves gag- and gag-pol-derived proteins into functional pieces.
env. env stands for "envelope". The proteins derived from env are a surface (gp120) and a transmembrane protein (gp41). They are located at the outer part of the virus particle and enable the virus to attach to and to fuse with the target cells to initiate the infectious cycle. The gene-product has a knoblike structure.

Answer 2

AIDS is caused by the HIV virus. Not all people with HIV have AIDS, but everyone with AIDS has HIV. The HIV virus gradually deteriorates immune function; this decrease in immunity, characterized as AIDS, causes infection in the body's major organs which eventually shut down. Yet, most people who die from AIDS die from simple colds and infections that their bodies couldn't fight off due to the immunosuppression.

Answer 3

So what happened to the 'body fluid' did it all dry up? You don't just get aids from semen. My question would be...why are you having sex with someone with aids in the first place let alone unprotected sex....they obviously got it somehow...i wouldnt want any of that crap

Answer 4

Through many things. In my opinion :
1. sex with so many personl.
2. through blood
3. Use of use syringe
4. sex without condom