Immunology 2 Flashcards
What are the main receptors in the immune system and what arm do they belong to?
Innate:
PRRs (Pattern Recognition Receptors) = bind PAMPs and DAMPs / Fc receptors = bind antibody
Adaptive:
T and B cell receptors = bind antigen epitopes presented on MHC on surface of antigen-presenting cells.
What is a Pattern Recognition Receptor (PRR)?
Receptor which binds general bits or building blocks of cells called PAMPs and DAMPs.
Define PAMPs.
PAMPs = Pathogen Associated Molecular Patterns.
Fragments of pathogen capable of ligating PRRs on innate immune cells.
Define DAMPs.
DAMPs = Damage Associated Molecular Patterns.
Fragments of damaged self-cells capable of ligating PRRs on innate immune cells
Define antibody.
Antibody = protein secreted by B cells of the adaptive immune system, which bind antigen to mediate pathogen destruction and to enhance innate immune response.
Define antigen.
Antigen = a protein which is capable of initiating an immune response.
Define epitope.
Epitope = A short peptide sequence which is part of an antigenic protein.
What are the non-cellular components of the innate immune system and give examples?
Physical barriers - epithelial cells joined by tight junctions / mucous and fluid flow.
Chemical protection - low pH and acids / enzymes / antimicrobial peptides
Microbiological - commensal bacteria
Protein cascades - the complement cascade
Define opsonisation.
Opsonisation = the process by which molecules called opsonins stick to a pathogen and mark it out for degradation.
What are the four functions of innate immune cells?
- Phagocytosis
- Degranulation
- Antigen presentation
- Antibody Dependent Cellular Cytotoxicity (ADCC)
Define phagocytosis.
Phagocytosis = the process of internalisation of large particles by phagocytic cells.
Define degranulation.
Degranulation = the release of toxic granules to destroy a pathogen.
Define allergen.
Allergen = a non-pathogenic molecule which should be ignored by the body, but initiates an allergic immune response instead.
Define antigen presentation.
Antigen presentation = processing and presentation of antigens to activate adaptive immune cells.
Define antibody dependent cellular cytotoxicity (ADCC).
ADCC = specialised killing of virally infected or cancerous self-cells by NK cells.
