4 Innate Immunity

Question 1

Which type of immunity is:
Natural/inborn
NO lag period
Targets MICROBES
NO memory (same response every time)
Has TOLL-LIKE RECEPTORS

Which type of immunity is:
Acquired/adaptive
Has lag period
Targets ANTIGENS
Develops memory (response improves w/time)

Both are self-tolerant

Answer 1

Innate immunity

Adaptive immunity

Question 2

___________ function by phagocytosis and intracellular killing. Inflammation and debridement.

____________ function by phagocytosis and intracellular killing. PLUS antigen presentation for specific immune response

___________ function by killing certain parasites and involved in allergies

Answer 2

Neutrophils

Macrophages or monocytes

Eosinophils

Question 3

(LO) Identify which TLR binds bacterial
lipopolysaccharides (LPS/endotoxin)??

Identify the TWO mechanisms whereby TLRs kill phagocytized microbes.

Answer 3

TLR-4 binds to LPS

Reactive oxygen species and nitric oxide kill the microbes!

Question 4

(LO) Recall that activated macrophages produce pro-inflammatory cytokines IL-1, IL-8, TNFa, and IL-6; describe the local and systemic effects of TNFa and IL-6.

Answer 4

Local:
TNFa–activates vascular endothelium; increases vascular permeability…leads to increased entry of IgG, complement, and cells
IL-6– lymphocyte activation, increased antibody production

Systemic:
TNFa–Fever, mobilization of metabolites of shock

IL-6-Fever, induces acute-phase proteins from liver

Question 5

(LO) Identify the source and recognize the significance of elevated levels of C-reactive protein (CRP) and fibrinogen in the blood, as identified in lecture

Answer 5

IL 6 goes into the liver and makes fibrinogen and mannan binding lectin.

The increased levels cause clotting to increase. ESR (erythrocyte sedimentation rate) is influenced heavily by fibrinogen. Which means they have inflammation.

HIGH LEVELS=INFLAMMATION

CRP= VERY sensitive marker of inflammation. Blood biomarker!

Question 6

(LO) Explain the role of Toll-like receptors (TLRs) in differentiating self from non-self.

Answer 6

TLR are a class of pattern recognition receptors (PRR), which are phagocytic-associated.
Overall mechanism for innate recognition of foreign invaders:
-recruitment of adapter proteins
-recruitment and activiation of protein kinases
-activation of transcription factors
-gene transcription
-expression of inflammatory cytokines, antiviral cytokines, etc.

Question 7

Macrophages are activated when they _________. They then secrete ________ cytokines.

Answer 7

Ingest bacteria

Question 8

Macrophages are activated when they _________.

They then secrete ________ cytokines, like TNF-a and IL-6.

Answer 8

ingest bacteria

proinflammatory

Question 9

Pathogen-associated molecular patterns (PAMPs) are ________-associated, whereas pattern recognition receptors (PRRs) are ________-associated and can be thought of as TLRs (toll-like receptors)

Answer 9

microbe

phagocyte

Question 10

______ are the first at the site of infection or injury and comprise around _____% of white blood cells. They self-destruct after bacterial mechanisms are activated.

Answer 10

Neutrophils, ~60%

-aka PMNs or SEGs
polymorphonuclear neutrophils and segmented neutrophils

Question 11

• Macrophages exist in blood as ________ and only become macrophages once they are in _______.
• After microbial antigens are phagocytized and digested, the macrophage presents microbial ______ to other immune cells.
• They produce _____/_____, which initiate inflammation.

Answer 11

monocytes, tissue

antigens

cytokines or chemokines

Question 12

Identify the leukocytes (wbcs) that express pattern recognition receptors (PRRs)- more than one apply

T-lymphocytes
B-lymphocytes
Monocytes
Neutrophils

Answer 12

Monocytes and neutrophils

Question 13

Which of the following contain molecular patterns recognized by macrophages?

1. Most microbes.
2. Restricted to bacteria
3. Restricted to viruses

Answer 13

1. Most microbes! Bacteria and viruses