Immunopathology (week 3) Flashcards
What are pattern recognition receptors? Give some examples
Antigen recognition receptors in innate immune system. Recognise 2 classes of molecules:
1) Pathogen associated - from microbial pathogens,
2) Damage associated - from cell components released in cell damage
Examples:
TLRs (toll-like), CLRs (C-type lectin), Scavenger receptors
What is the effect of IL-1 cytokine release?
Stimulation of coagulation and inflammation
What is the effect of TNF cytokine release?
Coagulation
Inflammation
Neutrophil activation
What is the effect of IL-6 cytokine release?
B Cell Proliferation
What is the role of macrophages?
Phagocytose bacteria
Produce antimicrobial peptides
Bind LPS
Produce cytokines
What is the role of dendritic cells?
antigen presenting cells - process antigen material and present it to T cells
What is the role of NK cells?
Kill cells that are missing MHC-1 (self-marker)
Natural killer T cell
Kill infected cells
Produce interferon gamma, IL-4, TNF
Neutophils
Phagocytes
Produce antimicrobial peptides
Eosinophils
Kill invading parasites
Basophils
Can cause allergic reactions - produce histamine
Phagocytosis
Which type of cell recongnises MHC-I
cytotoxic T
Which type of cell recognises MHC-II
helper T
What is the role of B lymphocytes?
Secrete antibodies, form memory cells
What is the role of helper T cells?
Secrete cytokines, help B cells
What mediates a type I hypersensitivity reaction?
IgE
What diseases are associated with type I hypersensitivity?
Asthma
Hayfever
What is the role of histamine?
Stimulates irritant nerve receptors
Causes smooth muscle contraction
Increases vascular permeability
What is the role of kallikrein?
Activates bradykinin
What mediates type II hypersensitivity reactions?
Antibodies produced by immune response bind own cells. Can be self or extrinsic antigens.
What type of cells do type II hypersensitivity reactions usually affect? Give some examples of reactions.
Haematopoietic cells
blood group incompatibility
autoimmune haemolytic anaemia
What mediates type III hypersensitivity reactions?
Accumulation of antigen-antibody complexes that have not been adequately cleared by immune system. Involves soluble antigens that are not bound to cell surfaces. Complexes insert into small blood vessels, joints, glomeruli etc.
What mediates type IV hypersensitivity reactions?
Delayed, cell-mediated response. CD4+ helper T cells recognise antigens with MHC-II on surface of antigen presenting cells. These can be macrophages which then stimulate further helper T cells. Examples: allergic contact dermatitis, type 1 diabetes
