innate immune responses

innate

nonspecific “prepared” immune response that animal was born with; response occurs in similar way no matter which agent is encountered

• each type of response has a unique cell product or cell responder leading to a unique name when observed in body tissues

serous

watery fluid production by membranes

catarrhal

mucus production

• flushing mechanism

neutrophils

• suppurative

• purulent

• abscess

*make puss

macrophages

• histiocytic

• granulomatous

miscellaneous innate immune response types

• eosinophils

• basophilis

• mast cells

• natural killer (NK) cells

transudate

clear to red watery fluid

• occurs due to fluid leakage from vessels

• only the fluid component leaks

exudate

inflammatory cells, fibrin & fluid

• occurs due to inflammation

• whole cells exit vessels

serous transudate

• occurs in early viral infection & in response to environmental irritants

• increased fluid production by vascular leakage or lining glandular cells

• creates flushing effect for microorganisms

• ex. runny eyes & nose

catarrhal response

increased mucus production

• can become excessive in some disease conditions

• slimy, clear gel/colloid-like feel

how is mucus produced

produced by goblet cells

• embedded in epithelial surfaces, coats over surface

fibrinous inflammation

clotting protein (fibrin) leakage from vessels coats tissue surfaces

suppurative/purulent inflammation

• respond to bacteria, fungi, foreign matter, etc

• attracted by chemical mediators to damaged tissue

• travel to site via blood stream

• leave vessels by extravasation

suppurative/purulent inflammation: in tissues

• enzymes either target internal digestive chambers (phagosomes) or can dump into environment (degranulation) → liquefy agents & innocent cells

main enzyme for neutrophils

myeloperoxidase

• liquifies/rips materials apart to create pus

“bystander” effect that occurs with neutrophils

normal body cells can also become liquified

role of neutrophils

create pus

• “suicide bomber” of the white blood cell family

• destroy self & adjacent cells for the singular purpose of removing agents

inspissate

drying out of pus → creates solid lesions

• this material may be difficult to remove & protect agents from clearance

abscess

localized collection of puss (mass lesion of suppuration or degenerative neutrophils)

• etiologic agents are often found at the center of the “target”

histiocytic/granulomatous: cell types

• monocytes (in blood)

• macrophages/histiocytes in tissue

*cells are phagocytic

phagocytic

able to “eat’ material around them

granulomatous

formation of mass lesion comprised of responding macrophages

• etiologic agents are usually found neat the center of “target” lesion

  • may also be visible within macrophages or giant cells

granulomatous: multinucleated giant cell (MNGC) formation

fusion of multiple macrophages into one large multinucleated cell

• occurs in response to foreign body or chronic infection

misc. innate responses

only differentiated microscopically, even if some may cause gross lesions

eosinophils, basophils, & mast cells

• respond to allergic & parasite disease

• cells release histamine & heparin → tissue swelling

• not typically named grossly; only discernible by microcopy based on unique cell granules

natural killer cells

response to virally infected cells, cancer cells

• not observed grossly

• specialized lymphocytes that kill through formation of perforin pore through cell membranes

Karloff cell

natural killer cells (direct cytotoxic function)

• unique cell only found in Capybara & Guinea pig

• has a large nucleus and 1 giant granule

summary

1. innate immune response have a limited & set way of reacting each time an agent is encountered

2. innate responses are named for the type of cell product or cell responder involved in the tissue

3. innate responses can have unintended consequences on body tissues (bystander effect, mass effect from abscess or granuloma, etc)