Chapter 16 Nonspecific immunity Flashcards
Know the basic differences between innate and adaptive immunity.
innate immunity – what we are born with/ always working/ is non-specific
adaptive immunity – what we gain as we encounter pathogens/ specific immunity / more powerful/ not always working – takes several days to initiate
Does first line innate immunity involve the activation of immune cells or immune proteins?
no
Know many examples of first line innate immunity and be able to classify as chemical or physical.
- physical barriers: (skin, urine, nose hairs, saliva, ciliary escalator, vomiting/diarrhea)
- chemical barriers: lysozyme, HCL, histatin, sebum, protease pepsin
Know which immune cells are derived from the myeloid stem cell.
RBC, megakaryocyte, mast cell, eosinophil, basophils, neutrophil, platelets
what 3 innate immune cells that are the common phagocytes.
Neutrophils
macrophages
dendritic cells
Which of these immune cells is known as the ‘best’ phagocyte?
macrophages
What are TLRs? How do TLRs assist with immune defenses?
Toll-like receptors found on surface of neutrophils
- recognize pathogen-associated molecular patterns, which are found only on pathogens. Makes neutrophils able to recognize non-self from self
What type of microorganism is specifically targeted by eosinophils?
Large target organisms
How are basophils and mast cells similar? Conversely, how are basophils and mast cells different?
Both contain granules that contain signaling molecules that promote immune response
Basophils are found floating in blood while mast cells are found stationary within tissue
Which cell type found in the blood can become a macrophage?
monocytes
How is a fixed macrophage different from a free macrophage?
Fixed macrophage (embedded within tissue – brain, skin, lungs)
Free macrophage (roam tissue and gather at infection sites
What is a natural killer cell? How is it different than the other innate cells?
Granulocyte aimed at killing abnormal host cells (virus-infected and cancerous)
other innate immune cells are aimed at causing bacterial death
How do perforin and granzymes kill target cells?
Perforin – creates holes in host cell (causing lysis)
Granzymes – causes apoptosis (programmed cell death)
What is the basic function of a dendritic cell?
Primary antigen presenting cell - after phagocytosis it migrates towards immune organs in order to present antigen to immune cells there
How are inactive complement proteins activated?
in response to foreign cells by means of antibodies or lectin cause activation of C3 protein in complement which then activates cascade
Which organ produces complement proteins?
liver
What are the shorthand terms for the two activated complement fragments?
C3a and C3b
Which specific complement protein is at the end of the activation cascade?
C9
What are the 3 immune responses that occur after the complement activation?
opsonization
inflammation
cytolysis
How does opsonization work?
C3b attaches to foreign cell which improves phagocytosis
how does inflammation work?
caused by C3a signaling mast cells to activate inflammation
how does cytolysis work?
caused by membrane attack complex forming giant holes in foreign cell
What is the end result when the complement cascade from C3 to C9 is completed?
Cytolysis caused by membrane attack complex
Which cell releases interferon alpha?
virus infected host cell
What cells are interferons signaling to?
NK cells
neighboring cells
what do interferons cause neighboring cells to produce/release? Why?
proteases
nucleases
antiviral proteins
(to inhibit virus from infecting the neighboring cells)
Why are antimicrobial proteins a good defense against pathogens?
Attacks microbes in many ways, and there is no known resistance by microbes
What are the five cardinal signs of inflammation?
Pain,
redness,
heat,
swelling,
immobility
What is the result of histamine release at the site of injury?
Increased membrane permeability causing increased fluid delivery
What is the purpose of forming a blood clot as part of inflammation?
Decreases blood flow and allows fluid to accumulate at site
Describe how immune cells leave the bloodstream and travel to sites of infection. What are the three formal terms?
margination
diapedesis
chemotaxis
describe what occurs during margination?
immune cells move to edges of vessel
describe what occurs during diapedesis
immune cells squeeze between endothelial cells
describe what occurs during chemotaxis
immune cells travel to source of histamine
what is a pyrogen?
chemical compound that induces fever
Why is a fever (below 104 F) beneficial?
Fever catalyzes immune cell functions while inhibiting microbial growth
How does a phagocyte destroy an engulfed microorganism?
by means of digestion – lysosome fusing with phagocytic vesicle to break down microbe
Describe the difference between a phagosome and a phagolysosome.
Phagosome is a phagocytic vesicle (vesicle with phagocyte within it)
Phagolysosome is when a vesicle with lysosome fuses with the phagosome (phagocytic vesicle)
What is resistance?
Resistance – is in reference to resistance to a disease
What is susceptible?
Susceptibility – is in reference to the increased likeliness to get a disease
what can cause resistance?
Some genetic traits make someone resistant to specific diseases
what can cause susceptibility?
Age has an effect. The very young (whose immune systems are still developing) and the elderly (whose immune systems are less responsive) are more susceptible to disease
