Introduction to HIV and Its Classification

A category of viruses characterized by their ability to integrate their genetic material into the host cell's genome.

The process of copying RNA into DNA.

The enzyme responsible for converting RNA into DNA in retroviruses.

A specific group of retroviruses known for their ability to cause long-term infections and immune deficiency.

A type of lentivirus that causes AIDS in humans.

A viral protein that allows the HIV genome to integrate into the host cell's DNA.

A viral protein that breaks down the HIV genome into smaller pieces, allowing it to be packaged into new virions.

The process of how HIV replicates and spreads within a host.

The presence of other sexually transmitted diseases, such as syphilis, gonorrhea, or herpes simplex type 2, increases the risk of sexual HIV transmission as much as a 100-fold because the inflammation and sores facilitate the transfer of HIV across mucosal barriers.

The process of transmitting HIV from a mother to her child during pregnancy, childbirth, or breastfeeding.

High levels of HIV in the blood are associated with a higher risk of transmission, especially during breastfeeding.

HIV can be transmitted through contact with contaminated blood or blood products.

The amount of HIV in the blood is measured to assess the effectiveness of treatment.

A permanent state where the virus's genetic material becomes integrated into the host cell's DNA. This means the infected cell will continuously produce new viral particles unless a cure is found.

A form of a virus that exists within a host cell but is not actively replicating. It can remain dormant for years, waiting for the right conditions to reactivate.

The ability of a virus to persist in the body for a long time, often causing recurring symptoms or disease.

The complete and active reproduction of a virus within a host cell, leading to the release of new viral particles and potentially cell death.

A group of cells or tissues where a virus can reside and replicate, allowing it to persist in the body.

A key type of immune cell that is targeted by HIV. It helps to fight off infections by helping coordinate the immune response.

The body's initial line of defense against pathogens. This includes cells like macrophages and NK cells that can directly attack invaders.

The adaptive immunity triggered by exposure to a specific pathogen. It involves cells like T lymphocytes (T cells) that can recognize and destroy specific invaders.

Special cells that present pieces of pathogens to T lymphocytes, triggering the adaptive immune response.

A type of immune cell responsible for killing infected cells and activating the adaptive immune response.

A type of white blood cell that directly kills HIV-infected cells.

A protein produced by CD8+ T-lymphocytes that creates an antiviral state.

Mutations in HIV that allow it to escape recognition by the immune system.

Antibodies that neutralize HIV by binding to the virus and preventing it from infecting cells.

A key protein on the surface of HIV that helps it enter cells, and is a target for neutralizing antibodies.

Special white blood cells that help other immune cells fight infection by producing substances called cytokines.

HIV can spread directly from one cell to another, avoiding detection by antibodies.

HIV's high mutation rate allows it to constantly change its appearance, evading the immune system’s memory.

HIV can interfere with the production of important signaling molecules (cytokines) that help the immune system function.

HIV can hide within the host's DNA, making it difficult for the immune system to eliminate it completely.

Virus uses CD4 molecule found on macrophages and T lymphocytes as a receptor for entry into cells.

A second receptor besides CD4 is required for HIV to fuse with the cell membrane and gain entry. This protein is important for the fusion process.

HIV uses chemokine receptors as the second receptor for entry. CCR5 is the main receptor for macrophage-tropic HIV strains, while CXCR4 is the coreceptor for lymphocyte-tropic strains.

The viral envelope glycoprotein gp120 binds to CD4, and this binding triggers conformational changes in the envelope, activating the gp41 fusion peptide which leads to membrane fusion and entry of the virus.

The HIV envelope protein gp120 binds to CD4, a receptor found on the surface of immune cells. This sets off a chain of events allowing the virus to enter the cell.

After binding to CD4, HIV uses another receptor called a coreceptor, typically CCR5 or CXCR4, to further activate the fusion process and enter the cell.

HIV reverse transcriptase creates a DNA copy of the viral RNA genome, which is then integrated into the host cell's DNA through the action of integrase.

The HIV RNA genome is released into the cytoplasm after the virus enters. Reverse transcriptase, an enzyme carried by the virus, creates a DNA copy of the viral RNA genome.

The newly formed DNA copy is then integrated into the host cell's DNA by integrase, an enzyme that helps the viral DNA become part of the host's genetic material.

The provirus, the integrated viral DNA, can now direct the host cell to produce new HIV particles, continuing the cycle of infection.