HIV Flashcards
(1) Decreased immunity
(2) Increased opportunistic infections
(3) Total cases: ~50+ million; Deaths: ~20+ million (since 1970)
(4) Hot spots of infection: Southern Africa, Southern and Southeastern Asia
Acquired Immune Deficiency (AIDS)
Human Immunodeficiency Virus (HIV)
Medium sized, enveloped RNA virus
HIV
HIV is DNA/RNA? Enveloped or not?
RNA, enveloped
(a) Envelope
• Glycoprotein-41 (GP-41)
• Glycoprotein-120 (GP-120)
• Antigenically variable
(b) Capsid: Protein-24 (P-24)
(c) Core
• Two strands of RNA
• Reverse transcriptase – an enzyme which produces a DNA copy of the genomic RNA (this is an extremely unusual approach)
HIV
HIV envelope characteristics?
Glycoprotein-41
Glycoprotein-120
Antigenically variable
HIV capsid features?
Protein-24
HIV core features?
TWO strands of RNA
Reverse transcriptase?
an enzyme which produces a DNA copy of the genomic RNA (this is an extremely unusual approach)
Reverse transcriptase (in HIV core)
(1) GP-120 attaches to the ___ marker on the cell membrane [can infect cells that do not have ___ markers if they co-infect with another Retrovirus]. GP-41 attaches to a different protein, CXCR4
CD4
Unusual characteristic of HIV?
Reverse transcriptase uses the RNA strands as a template to produce new viral DNA
The new viral DNA is incorporated into the host cell’s DNA – remains latent for prolonged period of time
HIV alters the ability of CD4 cell to produce ____?
cytokines
New HIV virions released from infected cells by _____ - ultimately kills CD4 cell
budding
Types of cells infected (primary)?
CD4 Helper T-cells
Monocytes (macrophages)
Transmission of the virus (primarily inside infected cells)?
(1) Intimate sexual contact
(2) Blood and blood products (e.g. transfusion, I.V. drug use, needle sticks, cuts)
(3) Perinatally – from mother to baby
HIV virions have been isolated in ____ secretions.
all body
(1) Stage I – Primary HIV infection – lasts about 1 to 4 months
(a) Viruses are replicated and shed at a moderate rate for a short time
• The ___ antigen (capsid) may be detectable for about 2-6 weeks after infection
• Antibodies to p24
(b) Symptoms:
• “Mononucleosis-like” or “flu-like” illness. Fever, night sweats, malaise, rash, and muscle and joint pain. Lymphadenopathy may develop.
• Becomes asymptomatic after ____
p24
1 to 3 weeks
(a) Viruses are replicated and shed at a moderate rate for a short time
• p24 antigen (capsid) may be detectable for about 2-6 weeks after infection
• Antibodies to p24
(b) Symptoms:
• “Mononucleosis-like” or “flu-like” illness. Fever, night sweats, malaise, rash, and muscle and joint pain. Lymphadenopathy may develop.
• Becomes asymptomatic after 1 to 3 weeks
Stage I – Primary HIV infection – lasts about 1 to 4 months
Stage II – Latent (asymptomatic) period
(a) Patients are asymptomatic – usually lasts few to several years
(b) Viruses are replicated and shed at a low rate
(c) HIV antibodies are detectable
(d) Pathologic characteristics – Gradual decrease in ___ cells occurs
CD4
(a) Patients are asymptomatic – usually lasts few to several years
(b) Viruses are replicated and shed at a low rate
(c) HIV antibodies are detectable
(d) Pathologic characteristics – Gradual decrease in ___ cells occurs
Stage II – Latent (asymptomatic) period
(a) Virus replication and shedding occurs at a high rate – p24 antigen becomes elevated again; Antibody to p24 diminishes
(b) Pathologic characteristics – Gradual reduction of the CD4 cell count.
(c) Symptoms
• Persistent generalized lymphadenopathy (PGL) – Lymph nodes remain swollen for months with no other signs of infection. Night sweats, weight loss, diarrhea.
• Kaposi’s sarcoma
• Opportunistic infections - develop when CD4 cells are less than about 300/ mm3. Oral yeast infections, Recurrent shingles, Bacterial skin infections
Stage III – Persistent Generalized Lymphadenopathy or AIDS Related Complex (ARC)
Stage III – Persistent Generalized Lymphadenopathy or AIDS Related Complex (ARC)
(a) Virus replication and shedding occurs at a high rate – p24 antigen becomes elevated again; Antibody to p24 diminishes
(b) Pathologic characteristics – Gradual reduction of the CD4 cell count.
(c) Symptoms
• ______ – Lymph nodes remain swollen for months with no other signs of infection. Night sweats, weight loss, diarrhea.
• ____ sarcoma
• Opportunistic infections - develop when CD4 cells are less than about 300/ mm3. Oral yeast infections, Recurrent shingles, Bacterial skin infections
Persistent generalized lymphadenopathy (PGL)
Kaposi’s
Stage (#?) Pathology
• Significant decrease of CD4 cells (<200/mm3); moderate decrease of CD8 cells
• Antigen to p24 reappears – virus replication overwhelms antibody production
• Antibodies to HIV are ineffective
• Host is gradually unable to mount cell mediated or humoral immunity
(b) Opportunistic infections – become more severe as CD4 count decreases
• Tuberculosis
• Pneumocystis carinii (protozoan) – pneumonia
• Fungal infections: Histoplasmosis, Coccidioidomycosis, Cryptococcal meningitis
• Toxoplasmosis gondii (protozoan) – brain
• Herpes simplex virus, types 1 and 2
• Cryptosporidium – intestinal
• Cytomegalovirus – retina, esophagus, colon
• Mycobacterium avium complex – disseminated
(c) Central Nervous System involvement – Dementia
Stage IV – AIDS [Acquired Immune Deficiency Syndrome] (symptomatic period)
Stage IV – AIDS [Acquired Immune Deficiency Syndrome] (symptomatic period)
- Significant decrease of CD4 cells (<200/mm3); moderate decrease of CD8 cells
- Antigen to __ reappears – virus replication overwhelms antibody production
- Antibodies to HIV are ineffective
- Host is gradually unable to mount cell mediated or humoral immunity
(b) _____ infections – become more severe as CD4 count decreases
• Tuberculosis
• Pneumocystis carinii (protozoan) – pneumonia
• Fungal infections: Histoplasmosis, Coccidioidomycosis, Cryptococcal meningitis
• Toxoplasmosis gondii (protozoan) – brain
• Herpes simplex virus, types 1 and 2
• Cryptosporidium – intestinal
• Cytomegalovirus – retina, esophagus, colon
• Mycobacterium avium complex – disseminated
(c) Central Nervous System involvement – Dementia
p24
Opportunistic
- Tuberculosis
- Pneumocystis carinii (protozoan) – pneumonia
- Fungal infections: Histoplasmosis, Coccidioidomycosis, Cryptococcal meningitis
- Toxoplasmosis gondii (protozoan) – brain
- Herpes simplex virus, types 1 and 2
- Cryptosporidium – intestinal
- Cytomegalovirus – retina, esophagus, colon
- Mycobacterium avium complex – disseminated
Specifically mentioned opportunistic infections as HIV becomes AIDS
