The hiv virus life cycle

Isentress raltegravir , Tivicay dolutegravir , and Vitekta elvitegravir are three commonly prescribed integrase inhibitors. Once integration has occurred, HIV must manufacture protein building blocks that it uses to assemble new virus. It does so with the protease enzyme, which chops protein into smaller bits and then assembles the pieces into new, fully formed HIV virions.

A class of drugs called protease inhibitors can effectively block the assembly process. Prezista darunavir and Reyataz atazanavir are two of the newer class protease inhibitors able to prevent viral assembly. One the virions are assembled, they go through the final stage in which the mature virions literally buds from the infected host cell. Once released into free circulation, these virions go on to infect other host cell and begin the replication cycle yet again.

There are no drugs that can prevent the maturation and budding process. The average life span of virus-producing host cells is short, around two days. Each infected cell can produce an average of new HIV virions by before it fails and dies. Get information on prevention, symptoms, and treatment to better ensure a long and healthy life. The HIV life cycle. Updated September 28, J Virol. Maraviroc: a review of its use in HIV infection and beyond. Drug Des Devel Ther. HIV replication cycle.

Updated June 19, Multifaceted action of Fuzeon as virus-cell membrane fusion inhibitor. Biochim Biophys Acta. Rawle DJ, Harrich D. PLoS Pathog. Patel PH, Zulfiqar H. Not everyone who gets HIV will immediately show symptoms of the condition. Generally, people show symptoms after 2—4 weeks. Learn more here. There are many types of HIV medications, including antiretroviral drugs, which stop the virus from replicating.

Learn more about the many HIV…. HIV is a virus that targets the immune system. Without treatment, HIV can lead to other infections and affect the whole body. Medication can prevent…. HIV medications include antiretroviral drugs, which suppress viral activity in the body. Learn more about the types and side effects of these drugs…. What to know about the HIV life cycle. What is a life cycle? The structure of HIV. What the life cycle means for HIV medication.

The timeline of HIV infection. New biomarker may help improve depression treatment. Dementia cases set to triple by Related Coverage. Please note that the animation shown here is a work-in-progress, and will be further updated, refined and augmented over the coming years.

Additional animations will illustrate how antiretroviral drugs impact the life cycle, and how innate immunity can block HIV infection. Click here to view a version of this animation without narration.

To combat viral infections, the mammalian immune system has developed many defenses against it, some of which works against HIV and other retroviruses, targeting different aspects of their life cycle, restricting their replication. The following restriction factors are some of the most well-studied examples. After these viruses infect a new host cell, A3G produces a large number of changes in the HIV genome, which causes the virus to become non-infectious due to catastrophic errors in its genetic sequence.

This process is shown in the animation on the left. As shown in the animation above, HIV counteracts A3G restriction by encoding a protein called viral infectivity factor Vif. The tripartite-motif protein TRIM5 proteins are restriction factors that block retroviral infections by binding to viral capsids soon after entry into the host cell and preventing reverse transcription. TRIM5 is a mammalian restriction factor that can potently block viral replication. It is part of the innate immune system.

Structural studies have shown that TRIM5 can form a cage-like structure surrounding the capsid. There are three proposed mechanisms by which TRIM5 can inhibit HIV infection: 1 causing premature uncoating of the viral capsid, 2 recruiting ubiquitin, which leads to non-productive uncoating of the virus, 3 virophagy in which the TRIM5 cage directs the viral capsid to get degraded by digested enzymes contained in a membrane structure called lysosome.

Skip to content. The HIV life cycle. The small green dot to the left of the T cell is a HIV particle, shown to scale. About HIV. Integration and Transcription HIV is a retrovirus, and one of the characteristics of this type of virus is the integration of their genome into that of the host. HIV Assembly, Budding, and Maturation Once the different viral components are built by the infected cell, they must be assembled and released at the plasma membrane.

The formation of a new HIV virus consists of three major stages: 1 Assembly. Craigie R, Bushman FD. Cold Spring Harb Perspect Med. HIV-1 assembly, budding, and maturation. HIV: cell binding and entry. Immune Defense - Restriction Factors. Viral Infectivity Factor Vif. Embo j. RNA is typically made up of one long chain of genetic information, while DNA is made up of a double strand.

At this point, the infection is still considered latent and is difficult to detect even with sensitive laboratory tests. During this time, it can also produce more of its genetic material RNA. These two things allow it to create more viral particles. These viruses are non-infectious in their current form. During the budding stage, the immature viruses push out of your CD4 cell.

They then release an enzyme called protease that modifies proteins in the virus and creates a mature and infectious version. At least two different drug classes are used during antiretroviral therapy. Each medication typically has two or three of the drugs in it. Post-attachment inhibitors bind to the receptors on CD4 cells. Fusion inhibitors block the ability of the HIV envelope to combine itself with the membrane of a CD4 cell.

This action prevents the virus from entering your cells. Reverse transcriptase allows the virus to convert its RNA to DNA in the reverse transcription stage of its life cycle. They work in a similar way to NRTIs by stopping the virus from replicating itself. Integrase strand transfer inhibitors block the enzyme integrase that HIV uses to combine its reverse-transcribed DNA with the DNA of your cell during the integration stage.