HIV Replication: How the HIV Virus spreads

Since I’m currently battling the common cold virus, I figured it’s about time I post something that is oozing with geekiness, related to the topic of viruses and diseases but at the same time something all of us all over the world are concerned, if not afraid of; the Human Immunodeficiency Virus or HIV. No, I’m not HIV positive.

Of course, some basic info about the HIV virus, the Human immunodeficiency virus (HIV) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS, a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections). Previous names for the virus include human T-lymphotropic virus-III (HTLV-III), lymphadenopathy-associated virus (LAV), or AIDS-associated retrovirus (ARV). (Source)

Why is the HIV virus so efficient or effective in infecting millions upon millions of people all over the world? It is ironic because the virus is spread via transfer of blood, semen, vaginal-fluid, pre-ejaculates even breast milk and the transfusion of these bodily fluids between humans occur in novel ways; sexual activities, medical emergencies and child rearing. Unlike the common cold virus which could be spread to a simple often amusing and seemingly harmless sneeze or clearing of the throat via a cough.

Ah but in the today’s modern times, thanks to globalization you could meet someone over the internets, have a date with them in Hong Kong, get married in Vegas and have your honeymoon in Damascus, divorce in New York and then fondle with totally some new stranger in South Africa all in one to three days.

All the time, you forget to protect yourself in every hot, steamy and wild engagement. My obvious endorsement of safe sex may irk the Rightist-conservatives but that’s for another post. Going back to the previous question of how the HIV virus could so efficient in spreading its deadly self can be best explained to us by Biology. The video below sums it all up in glorious 3D animation.

Got lost with all the scientific jargon? Worry not, for I am here to help.

Basically, there are 6 stages in the reproduction and spread of the HIV virus once it gets inside our bodies, particularly the circulatory system, where it’s target the helper T cells (specifically CD4+ T cells), macrophages and dendritic cells which are all part of our immune system.

Attachment – The HIV virus has certain types of protein receptors found on the cell’s surface. These are like the docks to your iPods, or like key holes for your keys. The HIV virus for its part has the matching protein complexes or protein structures present on the HIV virus’ envelope or outer casing. They fit or bind together like matching lock-and-key.

Entry – The viral envelope merges with the cell’s own membrane or “skin” fusing them together and facilitates the entry of the viral “core” or capsid which contains the real nasty stuff in them viruses into the cell itself.

Reverse Transcription and Biosynthesis – The viral capsid or core is like a package, a deadly package containing the viral RNA, the blueprint for making more viruses, and certain accessories that facilitate the reproduction of more HIV viruses. In the video above, they were specifically named as: integrase, protease, and reverse transcriptase.

Reverse transcriptase – this basically transcribes an RNA which is a single strand version of DNA, into its full version a double-stranded or double-helix DNA. This DNA contains the information or blueprint to make more HIV viruses.

Integrase – this prepares the viral DNA for insertion into the host cell’s nucleus where its own DNA is located. The nasty thing then inserts the HIV DNA into the host DNA, merging them as one. Once this is complete, the cell now knows how to create more HIV viruses which it does unknowingly.

Protease – once the hijacked cell begins to create more copies of the HIV RNA and other components of the virus, this protease processes them into the final parts of the virus like the capsid and complementary copies of the viral proteins.

Release – The HIV components are then assembled into the capsid which then leaves the host cell while taking part of the cell’s membrane to make its own envelope with the same set of protein complexes we talked about earlier. This virus matures and wanders off to infect other cells spreading the disease.

This whole processes occurs over millions of times a day making the virus even more deadlier.

Now, understanding each of this process is crucial because each step offers opportunities for intervention in order to stop the spread of the virus and this is where those anti-retroviral drugs comes in. You disrupt any of the processes you disrupt and stop the replication and therefore spread of the HIV virus.

This is all we could do for now while scientists work out the ultimate cure for HIV, a vaccine against the virus.

5 Replies to “HIV Replication: How the HIV Virus spreads”

  1. This is a good post, though, it's really hard to make the lay people understand HIV because we know so much about it and yet we cannot do anything about it as much 🙁 And to think the topic of HIV/AIDS run 50+ pages in Harrison's Principles of Medicine book. Sigh. But still good post 🙂

  2. nice post. you're from DLSU-D rin pala and taking up HUB (my dream course T0T). BTW, i'm reading my Medical Encyclopedia and read about Cancer and AIDS. Naiisip ko lang if HIV Viral Structure has typical viral structures (as of like what you said, common colds caused by rhinoviruses). Kasi nung nakita ko sa Science Encyclopedia, the illustration there shows that HIV has many covering layers. and i'm thinking kung yung makakapal na layers na yun yung isang reason kung bakit hindi ma-penetrate ng ilang gamot yung Virus.

    1. Natutuwa naman akong malaman na hilig at gusto mo talaga ang Human Biology. 😀

      May punto ka tungkol sa katangian ng HIV. Pero komplikadong bagay ito at hindi sa simpleng mapasok ng gamot ang virus para ito mapuksa. Ang karaniwang paraan ay mapigilan ang HIV na kumapit sa mga T-helper cells o kaya ay mapigilan silang makapagpadami sa loob ng katawan.

      1. Haha. I'm going loco over Biology. gusto ko talaga siya itake kaso ayun, naligaw ako sa course ko ngayon pero next school year, hopefully, makapag-shift ako sa HUB. Forte ko ang Microbiology and some Genetics. haha. ^^

        Anyway, nalinawan ako sa entry mo na ito. not only in HIV Virus but in other viruses. kasi ang nabasa ko, nagrerelease and re-assemble lang ang virus sa loob ng host cell pero hindi pala. Parang DNA Recombination between viral DNA at host cell's DNA tapos nagiinstruct ang viral DNA na magrelease yung host cell ng virus. Great!..

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