Immunity Flashcards
describe how pregnancy test can detect presence of HCG
- stick dipped in urine sample
- hCG antigen in urine = pregnant
- antibody bound to indicator
- hCG moves up strip
-binds to mobilized antibody - gold complex on VR - complimentry to antigen binding site on antibody
- moves up test strip to 1st window
- immbobolized antibody complimentry to hCG
- hCG antibody complex formed
- colored band = pregnant
Drug cocktail for HIV
- virus may be resistant to one or more drugs
- resistance due to change in AS
- HIV high mutation rate/ANTIGENIC SHIFT
- drugs inhibiting 2 enzymes so more effective
- drugs have diff targets + actions
- prevents gene passed on
WHY ANTIBIOTICS DO NOT WORK AGAINST HIV
- virus acellular so no peptidoglycan cell wall/ribosomes
- antibiotics only work against bacteria
- ionised rifampicin for 6-12 months
mode of HIV
- glycoprotein spikes complimntry to CD4 receptords on Th cell
- injects RNA into Th cell w REVERSE TRANSCRIPTASE
- REVERSE TRANSCRIPTASE converts RNA to cDNA
- cDNA enters nucleus
- cDNA uses host Th DNA polymerase = double stranded HIV gene
- HIjacks nucleus
- Uses host lysosome to make hole in CM
- Burst cell/cell lysis
- Th dies + Th reduced, cytokines etc
- Immunosupressed
mode of penicillin
- bacteriocidal antibiotic
- penicllin acts when bacteria growing
- stops cross link forming between peptidoglycan mol in CW
- inhibits glycoprotein peptidase enzyme by binding to AS (CI)
- water enters cell via osmosis
- cell lysis + cannot withstand turgor pressure
- bacteriostatic = inhbits growth of bacteria
- bacteriocidal = kills bacteri a
- selectivly toxic= acts only on peptidoglycan CW
ANTIBIOTIC RESISTANCE
- Uncompleted antibiotic + not all bacteria killed
- selective pressure is penicillin
- increases chance of mutation
- making penicillinase
- survive + reproduce to pass on advantageous RESISTANT allele to next generation
-by horizontal transmission conjugation - allele frequency increases + evolution change
phagocytosis
- macrophage
- non specific receptors on CSM
- engluf/ednd/phagocytosis of bacteria
- which contain protease/hydrolytic enzyme
- lysosome fuses w vacuole + releases lysosome enzymes
- diguest bacteria
- antigens removed from bac + placed on CSM of macrophage = APC
- activates b + t cells
Early making of antibodies
- phagocytosis
- macrophage engulf bacteria
- APC made
B lymo speceific reptor/antibody on its CSM bind to APC - clonal selection
monoclonal antibodies
- antigen injected into mouse
- B plasma cells made against it + wait for primary immune reponse
- kill mouse
- remove spleen + remove B plasma cells from spleen
- ++ Antigen and identify B plasma cells that make specific antibodies
- seperate B plasma + fuse w B plasma of myeloma cell w FUSOGEN
- forming hybriodema + add antigen not hybrideoma
- large conc of antibodies produced
- antigen marker/ Antigen A to detect antibody produced
describe HIV ss
- core of RNA/DNA
- surronded by capsid
- 10nm to 300nm
- reverse transcriptase
- virus enters cell + hijacks nucleus
- host cell DNA broken down by viral enzymes
- viral DNA used for transcription = mRNA
- viral proteins made + replicates
- viruses burst cell lysis
AIDS
Accquired immunodefiency syndrome
explain how infective agent is able to hijack once entered t lymph
- reverse transcriptase in nucleus
- cDNA made
- DNA polymerase doubles up DNA by adding DNA nucleotides
- Adding PDB + viral DNA inserted in host DNA
- viral RNA produced
b + t lmyph produced where
- BOTH produced in bone marrow
- B lymp MATURE in spleen
- T lymph MATURE in thymus gland
impt of disulphide bonds in protein mol
- DB bonds between cysteine/between R groups
- strong bond
- holds polpep chains tgt
- tertiray/quant ss
- maintain shape
ACTIVE VS PASSIVE
ACTIVE artificial and natural
- exposure to antigen
- primary immune response takes time
- long term protection
- MC produced
- e.g vaccinations + infection
PASSIVE artificial and natural
- NO exposure to antigen
- Immediate protection
- Short term protection
- MC NOT produced
- e.g antitoxins + breast milk