135 Flashcards
what molecule on a tc cell distinguishes it
CD8+
What molecule on th distinguishes it
CD4
antibody elimination of pathogen (b-cell mediated) steps
- pathogen opsonised, faster phagocytosis
- antibodies recruit complement proteins
- causes formation of MAC
- hole forms in membrane
-pathogen destroyed
what cell is crucial in acquired immune response
t helper
how does HIV infect T helper cells
GP120 binds to CD4
GP41 binds CXCR4 on surface of Th
what does AIDS stand for
Acquired Immune Deficiency Syndrome
most common opportunistic infections in AIDS
toxoplasmosis
tuberculosis
pneumonia
other fungal infections
infection-related cancers
methods for detection of HIV infection
- antibodies to HIV (seroconversion)
- Viral RNA
- fall in t helper cell numbers
antibodies to HIV detection method
develop 2-8 weeks after infection
often binds to p24 or gp41
detection via ELISA, immunichromatography, latex particle agglutination
viral RNA as HIV detection
genome of HIV is RNA
RT-PCR (Reverse Transcription Polymerase Chain Reaction) detection
fall in t helper cell numbers as a HIV detection method
Flow cytometry and Fluorescence-Activated Cell Sorting
can be used to identify T Helper cells on basis of CD4
ELISA
- HIV antigen bound to well
- patient serum added.
- antibody binds to antibodies. enzyme-linked
4substrate added, colour produced by enzyme
chromogenic substrates
Antibody conjugated (linked) to:
ALKALINE PHOSPHATASE (AP) ENZYME
Substrate may be BCIP (5-bromo-4-chloro-3-indolyl phosphate)
immunochromatography
Detection of antibodies to HIV
Serum, plasma or whole blood added to absorbent pad
Any anti-HIV antibodies bind HIV antigen in test
HIV test line = antibody which binds antigen/antibody complex
Control line binds HIV antigen
latex particle agglutination
Latex particle agglutination
Visual clumping
Quick, simple and cheap
