past paper questions Flashcards
what does AIDS stand for
acquired immune deficiency syndrome
effect of HIV-1 on human immune system
infects immune cells
specifically CD4 T cells
mechanism of using host cell receptors for tissue invasion
tissue tropism
importance of epithelial cells in the intestine expressing CCR5 against HIV-1
allows the HIV viral envelope glycoprotein gp120 to bind and for transcytosis of the virus to occur
what is CCR5
chemokine receptor
examples of host cell receptors bound by gp120
CCR5
CXCR4
CD209
what is CXCR4
chemokine receptor
what is CD209
c-type lectin receptor on dendritic cells
which cells express CCR5
M cells
which components of innate immune system maintain viral immunity
complement
natural killer cells
type 1 interferons
which components of the adaptive immune system maintain viral immunity
cellular - CD8 T cells
humoral - antibodies
how do antibodies provide immunity to viral infections
neutralisation
NK cell-mediated ADCC
examples of opportunistic yeast pathogens of AIDS patients
candida
cryptococcus
histoplasma
what is dimorphism
the ability of a yeast pathogen to switch between yeast and filamentous growth
examples of opportunistic mould pathogens of immunocompromised patients
aspergillus
fusarium
mucor
scedosporium
haematological malignancy
cancer that begins in blood-forming tissue cell e.g. bone marrow or in immune cells
haematological malignancy patients typically suffer from what type of infection
pulmonary infection by moulds
which immune cells are crucial for maintaining pulmonary immunity to fungal pathogens
macrophages
neutrophils
how does CpG DNA initiate an immune response
- CpG DNA binds to TLR 9
- NFkB pathway activated via Myd88 adaptor protein
- activation of transcription factors results in the production of cytokines e.g. IL-1, IL-6, TNF
- also chemokines, adhesion molecules and co-stimulatory molecules
examples of bacterial PAMPs
lipopolysaccharide fibrinogen heat shock proteins single/double-stranded RNA flagellin
examples of diseased that have toxoid vaccines
diptheria tetanus anthrax cholera botulism
immune response induced by toxoid vaccine
antibody response
kills toxin by neutralisation
effect of unmethylated CpG DNA motifs
act as immunostimulants
CpG
DNA
PAMP
recognised by PRR - TLR9
what mediates entry of the virus into cells of the respiratory epithelia
haemagglutinin (HA)
which receptors on human respiratory epithelia does the virus bind?
receptors that have the α-2,6 sialic acid linkage to galactose
what mediates viral release from cells of the respiratory epithelia
Neuraminidase (NA)
3 major components of innate immunity to viruses?
Complement, Type 1 interferons, Natural Killer (NK) cells
what is Major adaptive immunity to viruses mediated by
CD8 T cells
antibodies
Which cellular compartments of the cell does MHC II
monitor for foreign antigen?
endosomal and lysosomal compartments
effector functions of complement
Inflammation – C3a C5a
Opsonisation - C3b
Lysis (MAC) – C5-C9
bacterial diseases are associated with C9 deficiency?
Meningitis and sepsis caused by Neisseria
vaccines that induce antitoxin antibodies
Diphtheria, tetanus, anthrax, pertussis
how does formaldehyde detoxification work
formation of inter- and intra-molecular cross-links between amino groups in lysine and glutamine residues
problems associated with formaldehyde detoxification
Reversion
batch-to-batch variability
balance between loss of toxicity and loss of immunogenicity
production difficulties associated with the need to grow the pathogens and purify the toxin
bacterial polysaccharide
LPS O-antigen
processing of the polysaccharide antigen when a glycoconjugate is used
- glycol-conjugate is internalized into an endosome of the B cell
- processed into glycanP saccharides, peptides and glycanP-peptides.
- MHCII presentation of glycanP-peptide to CD4+ T cells
- Activation of the T cell by the carbohydrate/MHCII
- T-cell production of cytokines
- B cell matures to become a memory B cell.
