Innate Immunity: Barriers, Organs, and Cells Flashcards
When does the body acquire the innate immune system, specificity, and time of response?
In place at birth
Non-specific
Responds immediately
What are the 3 main components of the innate immune system?
- Physical/physiological barriers
- Antimicrobial molecules
- Sentinel/phagocytic cells
What are the components of the epithelium that aid in its immune barrier?
Tight junctions
Cell turnover
What are the components of the mucus/tears/sebum that aid in its immune barrier?
pH
lysozyme- breaks down outer cell wall
bile
pancreatic enzymes
What are the components of the flushing/peristalsis that aid in its immune barrier?
mucociliary apparatus
Four physical/physiological barriers?
- Epithelium
- Mucus/tears/sebum
- Flushing/peristalsis
- Commensal flora
What are antimicrobial molecules produced by?
Epithelial cells and leukocytes
Functions of antimicrobial molecules?
- Direct toxicity to bacteria, fungi, protozoa, enveloped viruses, tumor cells
- Activate/recruit leukocytes
- Bind/neutralize lipopolysaccharide
- Stimulates wound healing, vascularization
4 examples of antimicrobial molecules?
- Defensins
- Cathelicidins
- Lysozyme
- Lactoferrin
Example of an opsonin?
C3b
What are the mucosal antibodies of opsonins?
IgM, IgA, IgG
What type of protein is the intersection between adaptive and innate immunity?
Opsonins
What are opsonins more susceptible to and why?
More susceptible to phagocytosis because they are extracellular molecules that bind to microbes
Three examples of sentinel cells?
Mast cells
Macrophages
Dendritic cells
Function of mast cells?
Initiate inflammation
Function of macrophages?
Inflammation and phagocytosis
Function of dendritic cells?
Process antigen to start adaptive response
Where are sentinel cell mainly located?
Bone marrow
Where are sentinel cells produced?
Hematopoiesis
What cells are myeloid?
Granulocytes, mast cells, monocytes/macrophages, myeloid dendritic cells
What are the primary lymphoid organs?
Bone marrow/Bursa of Fabricus
Thymus
What cells are lymphoid?
T and B cells, natural killer cells
What are secondary lymphoid organs?
Spleen
Lymph nodes
Tonsils
MALT/GALT (peyer’s patches)/BALT
Stem cells are self what?
renewing
What cells comprise the majority of innate immune cells?
Basophils, neutrophils, eosinophil, monocyte, macrophage, myeloid dendritic cell, NKC, Lymphoid DC
Write out the pathway of hematopoiesis.
Two adaptive immune cells?
T and B lymphocytes
Where do lymphocytes mature?
generative lymphoid organs
Draw out the maturation of mononuclear phagocytes and dendritic cells.
Development of lymphocytes in birds and marrow? T cells?
Bird- bursa of fabricius
Mammal- Bone marrow
T cells- thymus
Where do lymphocytes develop?
Bone marrow
Where do mature naive B cells and T cells circulate to?
secondary lymphoid organs
What are myeloid cells defined by?
Cell shape, nucleus shape, granule staining
Describe pathway of naive B and T cells?
respond to antigens in secondary lymphoid tissues or return by lymphatic drainage to the blood and recirculate through other secondary lymphoid organs
Two cell shape types?
Round vs. irregular
Two shapes of nucleus?
Round vs. multilobulated
Granule staining eosin?
Eosinophils
Hematoxylin granule staining?
Basophil/mast cell
Little dye uptake?
Neutrophil
What type cell is the majority of circulating leukocytes?
Neutrophils
Appearance of neutrophils?
Multilobular nucleus
Pale-staining granules
Role of neutrophils?
First responders that aren’t in the tissue
Primary function of neutrophils?
Primary function to kill infecting microbes
Draw out what granule contents do?
What are heterophils?
In rabbits, hamsters, and guinea pigs they act like neutrophils
Birds heterophils lack significant ________.
myeloperoxidase
What do neutrophil extracellular traps do?
Nuclear contents extruded
NETosis type of process?
Active
What are DNA coated with in NETosis?
histones and granule components
What does NETosis capture?
microbes, kills them, destroys virulence factors
Where are NET traps abundant?
At sites of acute inflammation
Where do eosinophils live (type of tissue)?
connective tissue
Eosinophil shape and nuclei shape?
Round; round to multilobular
Eosinophil granules are _____________ (color)
brightly eosinophilic
When do basophils migrate into tissues?
multicellular parasite infections, late phase allergic reactions
Primary function of eosinophils? Plays a role in?
Multicellular parasites; allergic responses
Basophil cell shape, nuclei shape, and color?
Round, multilobulated, deeply basophilic
Monocytes are the circulating precursors of what two cells?
DCs and macrophages
Macrophage shape, nucleus shape, color, and cytoplasm appearance?
large amoeboid, round, pale basophilic, vacuolated cytoplasm
Basophil function?
Th2 response
Monocyte function?
Respond to inflamed tissues
Monocytes shape, nucleus shape, cytoplasm appearance?
Irregular, round to bean-shaped, pale basophilic with vacuoles
Functions of macrophages?
Sentinel cells- produce cytokines
phagocytosis
antigen presentation
Where do dendritic cells live?
connective tissue
Dendritic cells type of process?
Dendrite-like
The most effective function of dendritic cells?
Antigen presentation
Where do mast cells reside?
Connective tissue near blood vessels and nerves
Mast cell granule appearance?
Fine, basophilic granules
4 functions of mast cells?
Vasodilation, Vascular permeability, Recruit other leukocytes, allergic responses
Why do NKC not need prior sensitization and doesn’t express T or B cell receptors?
Have lymphoid lineage
Size of NKC? Granule appearance?
Larger than other lymphocytes; fine, azurophilic (burgundy)
Functions (2) of NKC?
1st line of defense against viruses
Secrete cytotoxic granules that drive apoptosis
Neutrophil acute or chronic problem?
Acute
Macrophage acute or chronic problem?
Chronic
Lymphocyte acute or chronic problem?
Chronic
Plasma cell acute or chronic problem?
Chronic
Neutrophils cause?
Extracellular bacteria
Macrophages cause?
intracellular bacteria/parasites, fungi, foreign bidy
Eosinophil cause?
extracellular parasites, allergy
Mast cell cause?
allergy
Basophil cause?
allergy
Eosinophil cause?
allergy