00:00 / 00:00
Viral structure and functions
Hepatitis B and Hepatitis D virus
Epstein-Barr virus (Infectious mononucleosis)
Herpes simplex virus
Human herpesvirus 6 (Roseola)
Human herpesvirus 8 (Kaposi sarcoma)
Varicella zoster virus
BK virus (Hemorrhagic cystitis)
JC virus (Progressive multifocal leukoencephalopathy)
Poxvirus (Smallpox and Molluscum contagiosum)
Lymphocytic choriomeningitis virus
Hepatitis C virus
West Nile virus
Yellow fever virus
Human parainfluenza viruses
Respiratory syncytial virus
Hepatitis A and Hepatitis E virus
Human T-lymphotropic virus
Eastern and Western equine encephalitis virus
Prions (Spongiform encephalopathy)
0 / 45 complete
0 / 8 complete
HIV CD4+ 100
HIV CD4+ 200
HIV CD4+ 500
HIV Prophylaxis Medications
Human Immunodeficiency Virus (HIV) Assessment
Human Immunodeficiency Virus (HIV) Diagnosis
Human Immunodeficiency Virus (HIV) Interventions
Human Immunodeficiency Virus (HIV) Stages
Retrovirus - HIV/AIDs
AIDS retinitis p. 162
AIDS and p. 180
HIV, or human immunodeficiency virus, is a virus that targets cells in the immune system.
Over time, the immune system begins to fail which is called immunodeficiency, and this increases the risk of infections and tumors that a healthy immune system would usually be able to fend off.
These complications are referred to as AIDS, or acquired immunodeficiency syndrome.
Now there are two distinct types of HIV—HIV-1 and HIV-2.
HIV-1 is the more commonly associated with AIDS in the US and worldwide, HIV-2 is more rare, and typically restricted to areas in western Africa and southern Asia.
HIV-2 is so uncommon that “HIV” almost always refers to HIV-1.
Alright HIV targets CD4+ cells, meaning cells that have this specific molecule called CD4 on their membrane. Macrophages, T-helper cells, and dendritic cells are all involved in the immune response and all have CD4 molecules; therefore they can be targeted by HIV.
The CD4 molecule helps these cells attach to and communicate with other immune cells, which is particularly important when the cells are launching attacks against foreign pathogens.
So this little molecule is pretty important for our immune system, but it’s also extremely important for HIV. HIV targets and attaches to the CD4 molecule via a protein called gp120 found on its envelope.
HIV then again uses gp120 to attach to another receptor, called a co-receptor.
HIV needs to bind to both the CD4 molecule and a coreceptor to get inside the cell.
The most common co-receptors that HIV uses are the CXCR4 co-receptor, which is found mainly on T-cells, or the CCR5 co-receptor which is found on T-cells, macrophages, monocytes, and dendritic cells.
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