Immunity Flashcards
1
Q
describe how pregnancy test can detect presence of HCG
A
- 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
2
Q
Drug cocktail for HIV
A
- 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
3
Q
WHY ANTIBIOTICS DO NOT WORK AGAINST HIV
A
- virus acellular so no peptidoglycan cell wall/ribosomes
- antibiotics only work against bacteria
- ionised rifampicin for 6-12 months
4
Q
mode of HIV
A
- 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
5
Q
mode of penicillin
A
- 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
6
Q
ANTIBIOTIC RESISTANCE
A
- 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
7
Q
phagocytosis
A
- 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
8
Q
Early making of antibodies
A
- phagocytosis
- macrophage engulf bacteria
- APC made
B lymo speceific reptor/antibody on its CSM bind to APC - clonal selection
9
Q
monoclonal antibodies
A
- 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
10
Q
describe HIV ss
A
- 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
11
Q
AIDS
A
Accquired immunodefiency syndrome
12
Q
explain how infective agent is able to hijack once entered t lymph
A
- 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
13
Q
b + t lmyph produced where
A
- BOTH produced in bone marrow
- B lymp MATURE in spleen
- T lymph MATURE in thymus gland
14
Q
impt of disulphide bonds in protein mol
A
- DB bonds between cysteine/between R groups
- strong bond
- holds polpep chains tgt
- tertiray/quant ss
- maintain shape
15
Q
ACTIVE VS PASSIVE
A
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
16
Q
vaxx protecting unvaxxed?
A
- high perc of ppl in population vaxxed
- herd effect/immunity
- fewer people get infected w diseases in community
- protects unvaxxed as disease cannot be tranmsitted from vaxxed to unvaxxed person
17
Q
why hard to develop vaccine for malaria
A
- plasmodium high antigenic shift
- many diff stages of life cycle
- parasite only vulnerable when free in plasma
- antigenic concealment e.g plasmodium enters RBC/liver cells agaisnt antibodies in plasma
18
Q
why must malaria vaccine use form of parasite by moquito not the form leaving liver?
A
- 1st form in plasma exposed
+ easy to harvest - 2nd form of paraiste concealed in liver/rbc cells
- so more exposure to lymphocytes
- fewest number of paraistes to destroy
- vaxx agaisnt form leaving liver still damages liver
19
Q
whats meant by infectious disease
A
- communicable/transmissable
- passed from host to another person
- caused by pathogen e.g virus, bacterium
20
Q
malaria tranmssion
A
- females Anopheles mozzie (protoctist)
- takes blood meal from infected person + feeds on uninfected person
- PLasmodium transmitted in salivaa
21
Q
explain how plasmodium enters cells + how it effects treatment
A
- plasmodium only exposed in blood plasma for short time to lymphocytes
- next stage of life cycle inside cells
- parasites reproduce inside liver/rbc
- cell lysis + drugs cannot penetrate liver/rbc = antigenic concealment
- no symptoms untill parasite leaves cells
PROPHYLACTIC DRUGS e.g chloroquine inhibiting protein synthesis + prevents parasite spreading in body
22
Q
suggest why fatality higher in some countries than others
A
- overcrowding
- not diagnosed/treated early
- lack of vaxx/vaxx innefective
- antibiotics not available + too $$
- lack of access to healthcare
- poor sanitation
23
Q
discuss problems with eradction TB
A
- problem w vaccine
- doenst work for all ethnic groups
- less effeicnt w age
- too expensive for LEDC’s
24
Q
Treating HIV
A
- incurable - Antigenic shift (viral coat changes)
- Zidovudine = binds to reverse transcriptase (CI) and DNA polymerase, blocks its action - similair ss to thymine
- stops replication of viral DNA
+ increase in Th lymp
25
Outline use of monoclonal antibodies
- some mAbs act directly target cells
- by binding to specific/complimentry antigen//surface receptors
- drugs/radioactive isotopes attatched to mAbs
- drug activated at site of action
- interrupting cell signalling
- stimulating immune system/phagocytes
26
cholera
Cholera enters small intestine
It released choleragen - a toxin
Which enters intestinal epithelial cell by endocytosis
The choleragen increases chloride and sodium ion conc in the intestinal lumen by blocking chloride and sodium ion channels
There is low water potential in lumen
Water enters by osmosis
Causes diarrhea
27
explain using example whats meant by "opportunisyic infection" when related to AIDS
- breakdown/lack of Th lymphocytes leading to further infection
- e.g infected perosn with TB may sneeze around uninfected immunocompromised AId patient and inhale TB bacterium
28
why hybrideoma cells must be formed
- plasma cells cannot grow/divide in culture
- myeloma cells continoly divide by mitosis
- obtain genetic material from both cells
29
ADVT of using mAB comapred w conventional methods in diagnosis of disease
- quick diagnosis than having to CULTURE PATHOGEN
- SO quicker treatment
- More specific to antibody produced using antigen marker
- e.g treating lymphoma
- not all pathogens cultured
- viruses difficult to identify
30
ELISA METHOD: HIV diagnosis
1. Place antigens on glass plate
2. Pour blood from HIV suspected patient onto dish
3. Antibodies from blood complimntry/specific to antigen
4. wash off in case, no antibodies present
5. MAB have enzyme attatched complimntry to HIV antibodies in blood
6. wash off
7. add substrate, produces colored product = HIV++
31
method of extracting DNA from bac cells
++ Penicillin.
- stop cross links forming between peptidoglycan CW
- inhibit glycoprotein peptidase
- place bac in hypotonic solution
- lysis/burst
32
explain why parasites of malaria killed using radioactivity and not high temp for vaccine production
- vaccine contain antigens
- antigens are glycoproteins/proteins
- denatured by heat NOT by radioactivity
- loss of tertiary ss
33
how do antibodies protect against pathogens
- secrete antibodies by B plasma cells
- variable region is specific antigen binding site
- neutralises toxins
- agglutinates- phagocytes engulf more number of pathogens at one time.
- opsonisation enabling recognition
- lysis of pathogens
- coats bacteria for phagocytosis
34
disulphide bonds in antibodies
2 SS in middle and 1 SS on each chain
- holds 2 poplypep chains tgt - heavy chain + light chain
- strong COVELANT bond
- maintaisn 3D shape/tertiary/quant ss
- between R group of 2 cyestines
-
35
explain why diff antibodies produced to give immunity to new strains of virus
- new vaccine contaisn altered antigens
- antibodies specific to antigen
- complimentary shape between variable region of antibody + antigen
- virus high antigenic shift = antigen protein altered requiring antibodies w diff variabel regions
36
explain hwo vaccien program can control + eradictae infectious deisease
- vaxx programs aim to vaccinate whole population
- vaccine allows population to have immune response against antigens of disease
- memory b cells produced
- cannot become infected + transmit disease to others
- high vaxx rates in community protects unvaxxed ppl = herd immunity
37
malaria transmission
- female Anopheles mosquito feed on blood + vector for malaria
- anticogulant in saliva passed when mosquito feeds = prevents blood clotting so organism passed into blood
- gametes fuse + develop in most gut = infective stages
- infective stages pass out into blood w/ anticogulant---> enter liver cells where MATURE + MULTIPLY
- burst out of liver cells + enter RBC = antigenic concealment
- transmitted during blood transfuion + unsertile needles used
- can pass across placenta from m - f
- female mosquito blood meal/bite
38
how does antibiotic resistance spread in bacteria
- Horizontal and Verticl transmission
HORIZONTAL:
- Sexual repro
- Pill adhere to another bacteria
- tube formed between 2 bac
- plasmid containing antibiotic resistant gene transferred
- CONJUGATION
Vertical:
- Asexual repro
- Binary fission
- Loop of circular DNA+ plasmid replicated
- Each bac have identical copy
