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Definition
group of RNA viruses that infect animals and humans "Retro, Grow and Blow" Retro - carry reverse transcriptase to convert viral RNA into DNA -Sticky ends allow it to integrate into the host's DNA Grow - cause normal cells to become malignant due to oncogenes Blow -are cytotoxic to certain cells and destroy them (like HIV to t helper lymphocytes) |
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Definition
inactive oncogenes present in humans and animals that are normally present. Essentially are time bombs awaiting activation from carcinogen-induced DNA mutation or retrovirus infection. |
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Definition
| -loss of contact inhibition between cells which causes mass pile-ups of malignant cells |
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Term
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Definition
Human Immunodeficiency Virus dimer of two ssRNA pieces has a surrounding RNA dimer with a capside sheel made up of capside protins (p24 is major one) |
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| 3 essential retroviral enzymes present in HIV |
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Definition
integrase reverse transcriptase protease |
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Term
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Definition
Two ending long terminal repeat (LTR) sequences gag gene pol gen env gene LTR - GAG - POL - EVN - LTR same in all retroviruses (I think) |
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Definition
act as sticky ends - that are recognized by intergrase and inserted into the host DNA also modifies viral DNA transcription |
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Definition
sequences code for proteins inside the evelope these include: nucleocapsid protein p24 protein matrix protein |
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Definition
encode sequences for enzymes these include: integrase, reverse transcriptase and protease these enzymes are needed to cause disease |
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Definition
| codes for the envelope proteins |
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Definition
are encoded by regulatory genes known as: tat, rev or nef genes |
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Term
| acute transforming retrovirus |
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Definition
these carry intact oncogenes integrate into host DNA and cause Malignancies |
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Term
| Non-acute transforming retrovirus |
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Definition
activate host cell proto-oncogenes by integrating viral DNA into a key regulatory area -often have a full genome for viral replication |
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Term
| three important enzymes for HIV reproduction, etc |
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Definition
| integrase, reverse transcriptase, protease |
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Term
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Definition
44 million infected (90% in developing countries) 14 million dead |
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Term
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Definition
Western world - homosexuals and IV users therefore, more men infected then women Developing world - equal male:female infection ratio because it is spread via sexual activity |
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Term
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Definition
HIV virion enters blood stream and it's gp160 glycoprotein binds to CD4 receptors on target cells |
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Definition
-cells that have CD4 receptors include T-helper lymphocytes, macrophages, monocytes and dendritic cells (in CNS) |
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Term
| Corecptors that aid in the attachment of HIV to host cell |
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Definition
CCR5or CXCR4 Therefore, patients who lack normal CCR5 are resistant to HIV |
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Term
| HIV once in the cytoplasm |
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Definition
in the cytoplasm, viral RNA is reverse transcriped into DNA -dsDNA taken to nucleus -integrase used to integrate it into host DNA |
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Term
| Outcomes of integrated DNA |
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Definition
a. remains inactive (latent) b.are cleaved by HIV proteases and assembled into new virions |
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Term
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Definition
Healthy person - 1000 T helper cells/mL of blood HIV causes a decline of about 60 T cells/mL per year 7 years - 400-200/mL 8 years - <200/mL (constitutional symptoms) |
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Term
| T cell count less than 200/mL |
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Definition
results in Serious opportunistic killers opportunistic cillers such as Pneumocystis carinii pneumonia, crytococcus neoformans and toxoplasma gondii move ie. |
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Term
| T cell count less than 60/mL |
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Definition
Immune system is completely down get cytomegalovirus infection and mycobacterium avium - intracellulare |
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Term
| Significance of T cell death |
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Definition
-normally recruit macrophages, neutrophils and B-lymphocytes -w/o B-lymphocytes - reduces ability to produce antibodies Multinucleated giant cells formed by T-cell fusion: this allows viruses to pass between infected cells without having to contact antibodies.
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Term
| Cells that can serve as reservoirs of HIV |
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Definition
monocytes and macrophages this is b/c HIV does not destroy these cells |
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Term
| Two initial outcomes of HIV infection |
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Definition
1. immediate viral replication. Acute illness
2. Virus replicates slowly (latency). Chronic illness
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Term
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Definition
Symptoms include -fever, lymphadenopathy, pharyngitis.... -virus spreads to lymph nodes and macrophages |
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Term
| Chronic Illness due to HIV |
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Definition
-Often follows initial acute illness -HIV replicates in lymphoid tissue -steady destruction of CD4 - T - Lymphocytes Symptoms: fever, weight loss, night sweats... Overall, a weakened immune system leading to AIDS
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Term
| Formal Definition of AIDS |
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Definition
| -A CD4 count less than 200 |
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Term
| Two types of 'diseases' caused by AIDS |
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Definition
1. Direct viral disease: fever like symptoms, weight loss, neurological disease (which affects cognitive function, etc). 2. Secondary Diseases: diseases caused as a result of the immune deficient state. eg. opportunistic pathogen infections, malignancies.
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| Common Malignancies seen due to diseases secondary to immune deficiency state |
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Definition
B-cell lymphomas (present as a brain mass) Kaposi's sarcoma - red to purple nodules |
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Term
| Opportunistic infections common to AIDS patients |
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Definition
Bacterial - S. aureus, S. epidermidis, H. influenza and S. pneumoniae Fungal - candida albicans, cryptococcus neoformans Viral -herpes Zoster and Simplex, Epstein Barr Virus and cytomegalovirus Protozoal - Pneumocystis carinii (fungus?), toxoplasma gondii |
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| Most common opportunistic pathogen in AIDS |
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Definition
Pneumocystis carinii causes cough and hypoxia, fine reticular opacification |
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Term
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Definition
ELISA test - detects antibodies CD4 T-helper counts (if less than 200) Viral RNA antigens |
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