Questions Flashcards
B cells become memory cells under the influence of…
CD40
The T cell ligand which binds to CD80 on a professional antigen-presenting cell is:
CD28
For vaccination against mycobacterial diseases such as tuberculosis the most important facet of the immune response to be stimulated is:
cytotoxic Tcells
IgE mainly binds to receptors on:
Mast cells
The vaccine to human papilloma virus (HPV) is an example of which type?
- subunit
- recombinant
main functions of neutrophils
bacterial killing
IgM antibodies can lyse
bacteria (in the presence of complement)
IgD antibodies are found on
the surface of B cells
NK cells lack receptors with
Specificity for MHC class II molecules
The uptake of antigen into the processing pathway for class II MHC restricted T cells can be initiated by
Surface immunoglobulin
Expression of MHC genes is
Codominant
what is An epitope
the area on an antigen which contacts antibody
The T-cell receptor for antigen is
a heterodimer
Examples of integrins are
LFA-1, VLA-4
Naïve lymphocytes enter the lymph nodes via
High endothelial venules
Eosinophils do not
stain with basic dyes
only acidic
Natural killer cells
a Contain serine proteases
b Respond to interferon
c Contain TNF
do not:Kill by only damaging the target cell outer membrane
Th2 CD4+ T cells
- are responsible for the symptoms of asthma
- help B cells by producing IL-4
- Protective immunity against intestinal worm infections require Th2 cells
IL-5 is critical for the development of
eosinophils
A major source of IL-12 is
dendritic cells
Lysozyme:
splits peptidoglycan (hydrolyses)
Complement component C3 is cleaved by
C3bBb
Th2 cells produce:
IL-4
Development of follicular helper T cells requires:
- IL6 and IL21
- Require the transcriptional repressor Bcl-6
IgA in mucus secretions
can coat potential pathogens
T cells have been harnessed as therapies specifically targeting tumours and metastatic disease.
TILs
c Chimeric antigen receptor T cells
d EBV-specific CTL
How do you create “passive immunity” in a host
Transfer serum from an immunised donor
what can distinguish between influenza viruses of different strains?
CD4+ T lymphocytes
MHC Class I molecules
They are polymorphic in their α1- and α2-domains
MHC Class II molecules present
antigens processed through the lysosome
CD28
controls the production of IL-2 by CD4+ T cells
functions associated with antibodies
- opsonisation
- Complement activation
- Virus neutralization
naïve B cells express
IgM
Natural Treg
CD4+CD25+; develop in thymus under control of specific transcription factor FoxP3; recognise self antigens; prevent autoimmunity by producing transforming growth factor β (TGFβ) and by inhibiting APC – CTLA4 on surface of Treg removes CD80/CD86 from APC
Inducible Treg
recognise self or foreign antigens; differentiate from naïve CD4+ T cells after recognition of antigen in peripheral immune system; several subsets; some produce IL10 selectively (Tr1), but most are FoxP3+ and function in same way as natural Treg.
γδ T LYMPHOCYTES
- Recognise conserved, non-peptide antigens from pathogens (eg components of bacterial cell walls) and on damaged cells
- Do not express CD4 or CD8; not MHC restricted
NK T LYMPHOCYTES
-Express natural killer molecule NK1.1 – mostly CD4+ T cells
• Recognise lipids on pathogens
• Not MHC restricted
• Produce large amounts of cytokines early in immune response (IL4, γIFN)
• Link innate and adaptive immune responses
class switching
whereby cells initially producing IgM class antibody, alter their heavy chain to produce IgG (or IgA) instead
Th17 cells
-produce IL17, IL22
-differentiation requires TGFβ, IL6 and IL23
- inhibited by γIFN
IL17 recruits and activates cells of innate immune response such as neutrophils; IL22
induces anti-microbial peptides + tight junctions in intestine
• Th17 cells involved in protection vs extracellular bacteria, fungi
• Inappropriate activation of Th17 cells causes marked tissue inflammation
Th2 cells
-produce IL4, IL5, IL6, IL9, IL10, IL13
• Differentiation dependent on the cytokine IL4
• IL4 production favoured by products of helminth worms and other parasites
• Th2 differentiation determined by transcription factor GATA-3 in T cells
• IL4 is “switch factor” which induces B lymphocytes to produce IgE and IgG1 classes of antibodies
Inappropriate activation of Th2 cells causes
IgE mediated diseases - asthma, hay fever
• IL4, IL5, IL6 and IL13 needed for
B lymphocyte proliferation and differentiation during Ab production
Th1 cells
- produce γIFN
- differentiation depends on IL12 (produced by DC or macrophages)
- CD40 involved
- Th1 cells important for protection vs intracellular pathogens
Inappropriate activation of Th1 cells leads to:
⇒ tissue inflammation and disease – eg arthritis,
inflammatory bowel disease
CD4+ Helper T Lymphocytes
60-70%
-Class II MHC restricted – recognise antigens taken up from outside APC
• Activation dependent on expression of costimulatory molecules such as
CD28
CD8+ Cytotoxic T Lymphocytes
30-40%
Class I MHC restricted – recognise antigens synthesised in cytoplasm or nucleus of infected cell
• Priming of naïve CD8+ T cell usually needs activated CD4+ T cells to provide IL2 for the CD8+ T
perforin
Perforin forms pores in cell membrane and intracellular vesicles of target cell
granzymes
Granzymes induce target cell death by apoptosis
