module 2- chapter 2- immunology Flashcards
what is nonclonal, has identical receptors on all cells of the same lineage?
innate immunity
what are the two principal types of reaction of the innate immune system
stimulate acute inflammation and anti-viral defenses
accumulation of leukocytes, phagocytic cells, plasma proteins, and fluid derived from blood at extravascular tissue site of infection or injury
stimulate acute inflammation in innate
NK cell mediated killing of virus-infected cells.
interferon (type I) which are secreted by virus-infected cells, bind to receptors on surrounding cells and induce antiviral state in those cells
anti-viral defenses of innate
what are the prominent cell associated pattern recognition receptors and sensors of innate immunity
toll-like receptors TLRs
NOD like receptors NLRs
RIG like receptors RLR
where are TLR found?
NOD found?
RIG found?
TLR- extracellular surface and endosomal
NOD- cytosol
RIG- cytosol
these receptors are a family of cytosolic proteins that recognize pamps and damps and recruite other proteins to form signaling complexes that promote inflammation
nod like receptors
cytosolic sensors of viral RNA that respond to viral nucleic acids by inducing production of the antiviral type I interferons
RIG like receptors
physical barrier to infection and aids in killing of microbes by local antibiotics or by intrapeithelial lymphocytes
epithelial barrier
(component of innate response)
circulating phagocytic cells and most abundant
first cell to respond to infection
neutrophils
secrete cytokines that induce inflammation and ingest/destroy microbes
survives for long time
macrophages (type of phagocyte)
secretes cytokines and present antigenic peptides to t cells
dendritic cells
(sentinel cells)
abundant cytoplasmic granules
present in skin and mucosal epithelium
contain vasoactive amines (histamines)
cause vasodilation and capillary permeability
mast cells
lymphocyte-like cells
produce cytokines but lack t cells antigens receptors TCRs
innate lymphoid cells
this induces inflammation, opsonize microbes enhancing their phagocytosis, cause osmotic lysis or microbes
complement
the inflammatory response:
delivery of cells to the site of inflammation is to due reversible changes in blood vessels in the infected/damage tissue to:
- increase blood flow into tissue
- increase adhesiveness of circulating leukocytes
- increase permeability of capillaries and venules to plasma proteins and fluids
all the inflammatory response changes are induced by cytokines and small molecule mediator intially derived from sentinel cells in tissue, in response to stimulate
Pamps and Damps
what are the sequences of events in migration of blood leukocytes to the site of infection in the innate immune response?
- selectin-mediated rolling(leukocyte)
- integrin activation by chemokine to promote adhesion
- migration of blood leukocytes to extravascular site of infection
these cells kill virus-infected cells
secrete interferon y which activates macrophages
natural killer cells
when NK cell has inhibitory receptor engaged=
NK cell is not active so not killing cell
when NK cell has inhibitory receptor not engaged=
NK is active and killing infected cell
secreted by virus infected cells, induce anti-viral state in surrounding cells
IFN (type I interferons)
-prevent from multiplying
-make local response
this is requirement for lymphocyte activation for the role of innate immunity in stimulating adaptive immune response
two-signals (to cause lymphocyte proliferation and differentation
these microbes are combated by acute inflammatory response, in which neutrophils and monocytes are recruited to the site of infection and by complement system
extracellular bacteria and fungi
these microbes can survive inside phagocytes, and eliminated when microbial killing functions of phagocytes are activated by Toll-like receptors and other sensors as well as cytokines
intracellular bacteria
defense against _____ is provided by type I interferons and by nk cells
viruses
