Immunology Flashcards
Significance of low oxygen tension on skin
Good against aerobic microbes
Main immunoglobin found in mucous
sIgA, prevent attachment and penetration of epithelial cells
Enzymes in mucous
Lysozyme, defensins, antimicrobial particles directly kill pathogens. Lactoferrin starve invading bacteria
What are bactericidins
Produced by commensal bacteria which can cause lysis of other bacteria
What is humoral immunity
Immunity mediated by soluble macro-molecules found in extracellular secretions and fluids such as antibodies, complement system proteins, cytokines
What are cytokines
Small proteins and peptides that modulate behaviour of cells and co-ordinate the immune system
Different long lived tissue macrophage
Kupffer cell - Liver
Alveolar macrophage - Lung
Mesangial cell - Kidney
Microglial cell - Nervous system
What are polymorphonuclear cells
Neutrophils
Main role of natural killer cells
Detect and kill tumour cells and virally infected cells
Also kill antibody-bound cells/pathogens
Main function dendritic cells
Phagocytose, process and present antigen on surface
What are primary lymphoid tissues
Sites of leukocyte development - Thymus and Bone Marrow
What cells do immune cells derive from
Hematopoietic stem cells
What are secondary lymphoid organs
Sites where T and B cell become activated by antigen
Adenoid, tonsil, lymph node, spleen, peyer’s patch in small intestine, large intestine
What comprises the adaptive immunity
B cells, T cells, antibodies
What cells acts as a link from innate to adaptive
Dendritic cells
Example of anti-viral cytokines
Interferon alpha, beta released by virally infected cells
How does recognition occur in innate immunity
Pathogen Associated Molecular Pattern on pathogens are recognised by Pattern Recognition Receptors on innate immune cells
PRR for lipopolysaccharide found on gram negative bacteria
Toll-like receptor 4
PRR for beta-glucans (Fungi)
Dectin - 1
PRR for ssRNA (Virus)
Toll-like receptor 7
Which cells are best at phagocytosis
Macrophage, Neutrophils and Dendritic cells
What cell release pro-inflammatory mediators
Natural killer cells release Interferon Gamma that activate macrophage
How is Natural Killer Cell response mediated
NK cells contain inhibitory receptor that doesn’t affect cells with normal MHC Class-1. Also activated by interferon alpha/gamma
How is phagocytic capacity of macrophage increased
By natural killer cells releasing Interferon gamma