Flashcards in Structure Of The Immune System Deck (19)
What are the two arms of the immune system?
Innate: fast, non-specific, immediate, PAMPs and early induced response
Adaptive: slow but highly specific, antigen driven, mediated by lymphocytes and late response
What are the barriers of the immune system?
Tissue and mucus
What is haematopoeisis?
Differentiation and maturation of haematological cells
Two lineages; erythroid and lymphoid
What are the innate immune cells?
Non toxic ILCs
Natural killer cells
γδ T cells
What are monocytes?
large, horse shoe shaped nucleus, recruited to tissue and differentiate into tissue specific macrophages
What are neutrophils?
multi lobed nucleus and granular cytoplasm, 40-95% of total wbc, migrate into tissue and act as phagocytes, important in bacterial infections, produce anti microbial peptides
What are mast cells?
Precursors differentiate in tissues
Allergic response- cross linking of IgE
Release of granules
What are basophils?
Similar to mast cells (IgE)
Fewer but larger granules
Differentiate and mature in bone marrow
Circulate in periphery but can infiltrate tissue
What are eosinophils?
Bi-lobed nucleus and protein granules
Granules can kill larger pathogens
Important in parasitic infection and allergy
Can do phagocytosis but not main role
What are dendritic cells?
Most potent APC
Concentrated in secondary lymphoid organs
Various non-self receptors
What are non-cytotoxic ILCs?
Classical lymphoid morphology but no cell surface markers
ILC1: involved in immunity to intracellular bacteria and parasites
ILC2: involved in anti-helminth immunity, allergic inflammation and tissue repair
ILC3: can promote antibacterial immunity, chronic inflammation and tissue repair
What are natural killer cells?
Develop in bone marrow
Kill virus infected cells
What are γδ T cells?
Type of T cell with γ and δ sub units
Not restricted to presented peptide and recognise while protein and free Ag
Mostly in gut
What are the cells of the innate immune system?
What are naive lymphocytes?
Small, motile and morphologically indistinguishable
Short life span
Thin rim of cytoplasm around condensed nucleus
What are T cells?
Progenitors from bone marrow migrate to thymus for maturation and expansion
98% die due to positive and negative selections against them
T helper: assist other leukocytes
Cytotoxic: destroy infected cells
NKT: recognise glycolipid Ag on CD1d
γδ Τ cells
What are B cells?
Progenitors arise and mature in bone marrow
Migrate to spleen and lymph nodes
Antigen blinds to B cell receptor
Plasma cell; antibody producer
Memory; dormant ready for secondary infection
Follicular; most common and generate high affinity antibody
Marginal zone; live in spleen and act as first line defence against blood pathogens
What is opsonisation?
Particles targeted for destruction by an immune cells known as a phagocyte