T1 L1 An overview of immunology Flashcards
What is an antigen?
Anything the immune system responds to
Usually a protein
What is an antigen receptor?
Recognises the antigen
What is an effector mechanism?
The action to respond to the antigen
What immune system has gremlin encoded pattern recognition receptors?
Innate
What do common lymphoid progenitors differentiate into?
B cell
T cell
NK cell
What do macrophage (granulocyte) progenitors differentiate into?
Neutrophil Eosinophil Basophil Unknown precursor of mast cell Monocyte
What is the role of a neutrophil?
Phagocytosis
What is the appearance of a neutrophil?
Large cell
Granular cytoplasm
Multilobe nucleus
What is the role of an eosinophil?
Not fully understood but found at sites of allergic inflammation and parasitic infections
What is the appearance of an eosinophil?
Granular cytoplasm
What is the role of a monocyte?
Phagocytosis
Antigen presentation
What is the role of a dendritic cell?
Antigen presentation
What is the role of a basophil?
Allergic reactions
Parasitic infections - role is still slightly unclear
What is the appearance of lymphoid cells?
Similar size to RBC
Little cytoplasm
Few granules
What are the roles of B cells?
Make antibody
Antigen presentation
What are the roles of NK cells?
Direct lysis of infection cells and antibody dependent cellular cytotoxicity
Where is lymphoid tissue?
Adenoid Tonsil Right and left subclavian vein Thymus Heart Thoracic duct Spleen Peyer's patchy in small intestine Large intestine Lymph nodes Kidney Appendix Lymphatics Bone marrow
What is endocrine signalling?
Long distance signalling
What is paracrine signalling?
Acts on adjacent cell
What is autocrine signalling?
Acts on same cell
What is juxtacrine signalling?
Contact dependent mechanism
What are cytokines?
Small proteins released by cells that have an effect on another cell
What are chemokine?
Small proteins similar to cytokines but a different structure, receptors and nomenclature
What do pattern recognition receptors recognise?
Pathogen associated molecular patterns (PAMPS)
What are the key features of innate antigen receptors?
Work quickly so are first line of defence
No memory as they are germline encoded
Where is mannose binding ligand produced?
In the liver then secreted into the bloodstream
What does mannose binding ligand bind to?
Mannose and fucose residues with correct spacing
How are adaptive antigen receptors produced?
Random somatic recombination events
What do B cells recognise?
Intact antigens
What do T cell receptors recognise?
Processed antigens in form of linear peptides
How are the most useful receptors selected after somatic recombination events?
After birth upon exposure to pathogens
What are some effector mechanisms?
Barriers Cytokines Complement Phagocytosis Cytotoxicity Antibody-dependent cellular cytotoxicity Mast cell and eosinophil degradation
What are the cardinal features of inflammation?
Hot
Painful
Red
Swollen
What are the blood vessel changes in acute inflammation?
Vasodilatation
Adhesion molecules
Increased permeability
