PAS 505 Immunology

What does the immune system do?

destroys and neutralizes pathogens

What does the immune system distinguish between?

self and non self

What is immunity?

protection from infectious disease

What is an immune response?

the collective, coordinated response of the cells and molecules of the immune system

What are the branches of immunity?

innate and adaptive

Is innate immunity immediate or long term?

immediate

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Is adaptive immunity immediate or long term?

long term

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Is innate immunity specific or nonspecific?

nonspecific

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Is adaptive immunity specific or nonspecific?

specific

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Innate immunity has a ______ immunological memory.

limited

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Adaptive immunity has a ______ immunological memory.

long term

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What are the two cells groups of the immune system?

regulatory and effector cells

Which cells assist in controlling immune response?

regulatory cells

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Which cells are involved in the final stages of immune responses that eliminate the antigen?

effector cells

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What kind of cell are helper t-lymphocytes?

regulatory cell

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What kind of cell are cytotoxic t-lymphocytes?

effector cell

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Which immune system cannot distinguish between pathogens?

innate

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What are the two lines of defense in the innate immune system?

external and internal defenses

What does the innate immune system recognize?

PAMPs and DAMPs

What receptor recognizes PAMPS?

PPR (pattern recognition receptors)

What is the first line of defense in the innate immune system?

physical and chemical barriers

What kind of barrier is skin?

physical

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What kind of barrier is mucous membrane?

physical

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What kind of barrier is hair?

physical

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What kind of barrier is cilia?

physical

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What kind of barrier is urine?

physical

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What kind of barrier is dermicidin?

chemical

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What kind of barrier is acid mantle?

chemical

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What kind of barrier is lysozyme?

chemical

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What kind of barrier is lactoferrin and transferrin?

chemical

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What kind of barrier is gastric juice?

chemical

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What is dermicidin?

an antibiotic in sweat to protect against bacterial growth

What is the acid mantle?

low pH layer created by thick lactic acid

What are lysozymes?

enzymes that act as an antibiotic produced in tears, perspiration, saliva

What do lactoferrin and transferrin do?

inhibit microbial growth by binding (withholding) iron

What does gastric juice do?

kills bacteria in stomach due to high acidity

What is the second line of innate immunity?

internal/cellular defenses

What are the phagocytic leukocytes?

monocytes, macrophages, natural killer cells (NK)

What kind of response is inflammation?

cellular innate

What kind of response is fever?

cellular innate

What type of granulocyte is the first responder to infection?

neutrophil

What type of granulocyte participates in phagocytosis?

neutrophil

What type of granulocyte has a chemical killing zone?

neutrophil

What is the chemical killing zone in neutrophils?

production of reactive O2 and lysosomal enzymes

What granulocytes are involved in the inflammatory response?

basophils

What type of granulocyte has heparin and histamine?

basophils

What type of granulocyte contains toxic anti parasitic proteins?

eosinophils

What granulocyte helps to regulate the inflammatory response?

eosinophils

What are the types of mononuclear phagocytes?

macrophages and dendritic cells

What is the main function of macrophages?

phagocytosis

What is a secondary function of macrophages?

antigen presentation

What do macrophages release to signal inflammation?

cytokines

What is the main function of dendritic cells?

antigen presentation to T cells

What do dendritic cells release to attract T and B cells?

chemokines

What are the types of antigen presenting cells?

dendritic cells, macrophages, B lymphocytes

What lymphoid cell does not express T or B cell receptors?

natural killer cells

What is the function of natural killer cells?

immune surveillance

What is the only lymphoid cell involved in innate immunity?

natural killer cells

What do natural killer cells release to cause apoptosis?

perforins and granzymes

What do the preforins released from natural killer cells do?

create holes in pathogen membrane

What do the granzymes released from natural killer cells do?

destroy organelles

Natural killer cells require activation

False

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Natural killer cells are automatic and do not require activation

True

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What is the major effector of innate immunity?

inflammation

What does the inflammation response do?

limit pathogen spread, removes debris, initiates tissue repair

What is the initial event of inflammation?

release of vasoactive chemicals

What does the release of vasoactive chemicals do in inflammation?

vasodilation occurs leading to hyperemia which directs blood flow to the injured area

increase in vascular permeability

What signs does inflammation contribute to?

4 cardinal signs: redness, edema, heat, and pain

What are the stages of inflammation?

margination, diapedesis, chemotaxis

During what stage of inflammation are cell-adhesion molecules (CAMs) produced?

margination

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What are CAMs?

adhesive molecules on endothelial surface (cellular velcro)

During what stage of inflammation do leukocytes attach to the endothelium of the vascular wall?

margination

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During what stage of inflammation do cells squeeze and crawl between vascular endothelial cells to travel to the site of infection?

diapedesis

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During what stage of inflammation do cells migrate along chemical gradients created by pathogens?

chemotaxis

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What are cytokines?

small proteins that serve as cell signaling molecules to assist in activation of immune mechanisms

What are the characteristics of cytokines?

pleiotropism, redundancy, and multifunctional

What is pleiotropism in cytokines?

ability to act on all cell types

What is redundancy in cytokines?

ability of cytokines to stimulate the same or overlapping functions

What is multifunctionality in cytokines?

same cytokine can regulate multiple different functions

What does the activation of cytokines cause?

activation of more cytokines

What kind of response are cytokines?

innate

What are the types of antimicrobial proteins?

interferons, interleukins, chemokines

What are antimicrobial proteins?

cytokines

What are interferons?

cytokines secreted by cells invaded by viruses that stimulate other cells to help defend against viruses

What do interferons IFN-a and IFN-B do?

bind receptors of neighboring cells to promote macrophage function, induce apoptosis, and triggers release of enzymes that denature viral DNA/RNA

What are interleukins?

cytokines that are secreted by leukocytes and act on other leukocytes

What are the types of interleukins?

IL-4 and IL-2

What does IL-2 do?

produced by Th cells to stimulate Th & Tc cells

What does IL-4 do?

secreted by Th cells to stimulate growth of B cells

What are chemokines?

cytokines that stimulate migration and activation of cells

What controls chemotaxis?

chemokines

What is the complement system?

group of inactive precursor plasma proteins with three activation pathways that leads to pathogen destruction

What is the end result of the complement system?

four mechanisms for pathogen destruction

What are the four mechanisms for pathogen destruction?

inflammation, immune clearance, phagocytosis, cytolysis

What are the three pathways of the complement system?

classical, alternative, lectin

Which complement system pathway is antibody-dependent?

classical

What happens in the classical pathway of activation?

Ag-Ab complex forms on microbe which exposes complement binding sites

complement fixation

What is complement fixation in the classical pathway?

chain of complement proteins attach to antibody enabling a cascade

What kind of immune response is the classical pathway?

adaptive

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What kind of immune response is the alternative pathway?

innate

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