Lecture 1

Question 1

Extracellular Microbes

Answer 1

Survive in animals by growing extracellularly, being simply immersed in nutrients

Question 2

Intracellular Microbes

Answer 2

Invade and live and replicate intracellularly within animal cells where they utilize host-cell energy sources

Question 3

Immunity

Answer 3

Set of cooperative defense mechanisms which provide protection from various infectious diseases

Question 4

Tissue Injury

Answer 4

Immunopathology; immune response against microbes that causes “injury”, “collateral damage”

Question 5

Antigens

Answer 5

Noninfectious foreign substances that elicit an immune response; in some pathological conditions, self antigens (Ags) in the body can elicit an autoimmune response; include proteins, carbohydrates, lipids, and nucleic acids

Question 6

Antibody (Ab)

Answer 6

Protein produced by the immune system when it detects antigens

Question 7

Epitope

Answer 7

Portion of an Ag molecule to which an antibody binds; also called an antigenic determinant; the smallest epitope which an antibody can be made is about 3-6 AA or about 5-6 sugar residues

Question 8

T Cell Receptors

Answer 8

Recognize linear AA sequences

Question 9

Immunogens

Answer 9

Ags which can stimulate an immune response; all immunogens are Ags, but not all Ags are immunogens

Question 10

Haptens

Answer 10

Very small Ags that can bind to Abs but they CAN’T initiate an immune response

Question 11

Innate Immunity

Answer 11

First line of defense against infection that works rapidly, gives rise to acute inflammation, some specificity for Ag, and has no memory; also called the “decision-making stage” of immune response

Question 12

Adaptive Immunity

Answer 12

Takes longer to develop, highly specific, and shows memory (remembers Ag it has encountered previously)

Question 13

Primary Fixed Elements of Immune System

Answer 13

Bone marrow, thymus

Question 14

Secondary Fixed Elements of Immune System

Answer 14

Spleen/lymph nodes, mucosal immune tissues

Question 15

Mobile Elements of Immune System

Answer 15

Immune cells, soluble (humoral) components (Abs, complements, acute phase proteins)

Question 16

Antimicrobial Peptides

Answer 16

Small peptides which target pathogenic microorganisms ranging from viruses to parasites

Question 17

Complement

Answer 17

System of plasma proteins that enhances (complements) the ability of Abs and phagocytic cells to clear pathogens from an organism

Question 18

Acute Phase Proteins (APPs)

Answer 18

Large group of blood proteins whose plasma concentrations change in response to tissue injury, acute infections, burns, or inflammation

Question 19

Cytokines

Answer 19

Cell signaling molecules that aid cell-to-cell communication in immune responses; large group of small secreted proteins with diverse structures and functions, which regulate and coordinate many activities of the cells of innate and adaptive immunity

Question 20

Chemokines

Answer 20

Subfamily of cytokines secreted by immune cells to induce chemotaxis (movement) in nearby cells; large subset of structurally related cytokines that regulate cell migration and movement

Question 21

Phagocytes

Answer 21

Immune cells that have the ability to ingest and digest microbes; include neutrophils and macrophages; secrete cytokines

Question 22

Cellular and Chemical Barriers of Innate Immunity

Answer 22

Skin, mucosal epithelia, antimicrobial peptides

Question 23

Blood Proteins of Innate Immunity

Answer 23

Complement, acute phase proteins, cytokines, chemokines, and others

Question 24

Cells of Innate Immunity

Answer 24

Phagocytes (macrophages, neutrophils), dendritic cells, natural killer cells, innate lymphoid cells

Question 25

Cellular and Chemical Barriers of Adaptive Immunity

Answer 25

Lymphocytes in epithelia; Abs secreted at epithelial surfaces

Question 26

Blood Proteins of Adaptive Immunity

Answer 26

Abs, cytokines

Question 27

Cells of Adaptive Immunity

Answer 27

B and T Lymphocytes

Question 28

Functions of Cytokines

Answer 28

Regulate growth and differentiation of all immune cells, activate the effector functions of lymphocytes and phagocytes; acts via a specific signaling receptor expressed on target cells

Question 29

Steps in Functional Responses of Phagocytes

Answer 29

Recruitment of the cells to the sites of infection; Recognition of and activation by microbes; Ingestion of the microbes by the process of phagocytosis; Destruction of ingested microbes

Question 30

Neutrophils

Answer 30

Also called polymorphonuclear leukocytes because their nucleus is segmented into 3-5 connected lobules; most abundant population of circulating spherical white blood cells; mediate the earliest phases of inflammatory reactions; produced in the bone marrow and arise from precursors that also give rise to mononuclear phagocytes; last in blood for hours or a few days, but only 1-2 days in tissues

Question 31

Mononuclear Phagocyte System

Answer 31

Includes circulating monocytes and resident tissue macrophages which play a central roles in innate and adaptive immunity; resident tissue macrophages populate many tissues and have phenotypes depending on the organ and these cells arise from committed precursor cells in the bone marrow, driven by monocyte/macrophage colony stimulating factor (M-CSF)

Question 32

Monocytes

Answer 32

Mature monocytes enter the blood circulation and then migrate into tissues, where they further mature into macrophages, especially during inflammation

Question 33

Macrophages

Answer 33

Tissue resident macrophages are a heterogenous population of immune cells that fulfill tissue-specific and niche-specific functions; these range from homeostatic functions, immune surveillance, response to infection, and resolution of inflammation

Question 34

Dendritic Cells

Answer 34

Cells of innate immunity that comprise a diverse group of professional antigen presenting cells (APCs); share a particular morphology (long surface membrane extensions called dendrites); potent stimulators of T cells to induce the adaptive immunity; can be broadly divided to myeloid (mDCs) and plasmacytoid (pDCs); other DC subpopulations include Langerhan’s cells residing in epidermis of the skin

Question 35

mDCs

Answer 35

Derived from monocytes and differentiated from peripheral blood mononuclear cells (PBMCs)

Question 36

Mast Cells, Basophils, and Eosinophils

Answer 36

Play roles in innate and adaptive immune responses, protect against helminthes and reactions that cause allergic diseases; share the common feature of having cytoplasmic granules filled with various inflammatory and antimicrobial mediators

Question 37

Location of Mast Cells

Answer 37

Common at sites in the body that are exposed to the external environment, such as the skin; found in close proximity to blood vessels, where they can regulate vascular permeability and effector-cell recruitment; although they don’t have direct cell-to-cell contact with local cell populations, mast cells can modulate the behavior of these and other neighboring effector cells through the release of mediators