Vocabulary for Week One/Chapters 1 & 2

Question 1

What is Innate Immunity?

Answer 1

1) The cellular and biochemical defense mechanisms that are in place even before infection
2) Characterized by rapid response to initial infection
3) Consists of physical and chemical barriers located in the skin, epithelial membranes and blood

Question 2

What is Adaptive Immunity

Answer 2

1) “adaBT” Also called specific/acquired immunity 2) develops as response to infection

Question 3

What are the three characteristics of the AdaBTive Immunity?

Answer 3

Specificity; Memory ;Diversity

Question 4

What is a cytokine?

Answer 4

Cytokines are a large group of secreted proteins that regulate and coordinate activities of both the innate and adab

Question 5

Name some of the functions of Cytokines (3)

Answer 5

1) Growth and differentiation of immune cells
2) Activation of effector molecules, phagocytes and lymphocytes
3) Directed movement of immune cells from blood to tissues

Question 6

Passive Immunity

Answer 6

Individuals become immune to exposure to disease by the transfer of serum or lymphocytes from a specifically immunized individual

Question 7

What is the process by which a person obtains passive immunity?

Answer 7

Adoptive transfer

Question 8

Opsonization

Answer 8

The process by which molecules coat antigens and make them easier to be phagocytosed

Question 9

Epitopes

Answer 9

The part of an antigen that lymphocyes respond to. Determinants

Question 10

What is Diversity? Which type of immunity is it associated with?

Answer 10

1) Variability in the strucutres of the antigen binding sites of lymphocytes.
2) Associated with Adaptive Immunity

Question 11

Immunological Memory

Answer 11

Each exposure to an antigen generates long-lived memory cells specific for the antigen, which are more numerous than the naive lymphocytes.

Question 12

Clonal Expansion

Answer 12

The process by which lymphocytes bind to an antigen and proliferate

Question 13

Tolerance

Answer 13

Immunological unresponsiveness

Self tolerance the ability for the immune system to NOT attack cells marked self

Question 14

Lymphocytes

Answer 14

The cells that specifically recognize and respond to foreign antigens. (Mediators of humoral and cell mediated immunity)

Question 15

B-Lymphocytes

Answer 15

The only cells capable of producing antiBodies

Recognize extracellular soluble and cell surface antigens

Differentiate into anti-body secreting plasma cells.

Question 16

T-Lymphocytes

Answer 16

The cells of cell mediated immunity

Recognize the antigens of intracellular microbes

Also help Phagocytes to destroy microbes or infected cells

Recognize peptides derived from foreign proteins that are bound to host proteins (MHC)

Question 17

Helper T-Cells

Answer 17

Call for help “messenger” molecules

Secrete cytokines that stimulate the differentiation of T cells, activate B cells, macrophages, and other leukocytes.

Question 18

CTLs

Answer 18

Cytolytic T Lymphocytes

Kill Cells that produce foreign antigens

Question 19

Regulatory T Cells

Answer 19

Function mainly to inhibit immune responses

Question 20

APCs

Answer 20

Antigen presenting cells. Capture antigens and present them to lymphocytes.

Question 21

DC

Answer 21

Dendritic Cells. Capture microbial agents (antigens) that enter from the external environment, transport them to lymphoid organs, and present the antigens to naive T lymphocytes to intiate immune responses; most important APC; link innate/adaBTive immune response; phagocytotic; located in lymphoid tissues, mucosal epithelium and organ parenchyma; has a hematopoietic derivation

Question 22

Effector Cells

Answer 22

Mediate the elimination of antigens

Question 23

What are the two main innate immune responses to microbes?

Answer 23

1) Inflammation
2) Antiviral defense

Question 24

Inflammation

Answer 24

1) The process of the recruitment of leukocytes and plasma proteins from the blood, their accumulation in tissues and their activation to destroy microbes
2) Macrophages, cytokines, dendritic cells, monocytes, neutrophils

Question 25

Antiviral Defense

Answer 25

Consists of a cytokine mediated reaction in which cells acquire resistance to a viral infection and killing of virus infected cells by specialized cells of the innate immune system. Natural Killer cells.

Question 26

What are the three main strategies the adaptive immune system uses to combat most microbes?

Answer 26

1) Antigens (Bind to pathogen, block them from binding to cells, mark them for destruction)
2) Phagocytosis (Ingest and kill microbes; antibodies and helper T cells enhance microbidicidal abilities of the phagocytes
3) Cytotoxic T lymphocytes kills cells/antigen that antibodies and phagocytes can’t.

Question 27

Function of Dendritic Cells in the Innate Immune System

Answer 27

1) Phagocytose microbes and present their antigens on the plasma membrane
2) Travel to draining lymph nodes where T lymphocytes circulate
3) Also work in the spleen

Question 28

Functions of Macrophages

Answer 28

1) Ingest and kill microbes, dead and dying host cells
2) Secrete cytokines that act on endothelial cells for recruitment of more monocytes, leukocytes etc.
3) Serve as APCs that displays antigens for T Cell activation
4) Promote repair of damaged tissues via new blood vessel growth (angiogenesis) mediated by cytokines

Question 29

Alternative Activation

Answer 29

The process by which cytokines stimulate macrophages to promote tissues remoldeling and repair.

Question 30

What are some examples or granulocytes? (4)

Answer 30

Basophils

Eosinophils

Monocytes

Question 31

APCs

Answer 31

Capture antigens, present them to lymphocytes and provide signals that stimulate the proliferation and differentiation of lymphocytes

Question 32

Types of APCs

Answer 32

Dendritic cells; Macrophages and B-lymphocytes (APC for CD4+ helper T cells)

Question 33

CTLs

Answer 33

Cytotoxic T-lymphocytes; CD8+ effector cells that recognize antigens on any type of nucleated cell

Question 34

Effector Cells

Answer 34

cells whose function is to eliminate the antigen

Question 35

Memory cells

Answer 35

cell whose function it is to mediate rapid and enhanced responses to subsequent exposure

Question 36

What is the importance of cytokines for B/T cell (naive) Survival?

Answer 36

if B/T cells do not get stimulated, they die; (IL-7) promotes survival and low level cycling of naive T-cells

Question 37

ILCs

Answer 37

Innate Lymphoid Cells; subset of bone marrow derived cells; lymphoid morphology/effector functions like T-cells; lack T-cell antigen receptors; functions: Early defense, recognize stressed/damaged cells, help eliminate cells.

Question 38

NK cells

Answer 38

Natural Killer cells; ILC; secrete IFN gamma; kills infected and damaged cells

Question 39

What are the peripheral, secondary, lymphoid organs of the B-Cells and T-Cells?

Answer 39

B-Cells (Spleen/Lymph nodes)/ T-Cells (Peripheral organs and tissues)

Question 40

Thymus

Answer 40

Site of T-Cell maturation;

Question 41

Medullary Thymic Epithelial Cells

Answer 41

Plays a special role in presenting self-antigens to developing T cells and cause their deletion (important for self tolerance)

Question 42

Active vs. Passive Immunity

Answer 42

1) Encounter with antigen is both specific and confers memory. 2) Passive Immunity, serum antibodies from an immune individual. Is specific, but does not confer memory.

Question 43

What are the three stages of the immune response?

Answer 43

1) Recognition (Activation of innate cells and inflammatory response) 2) Effector (activation of specialized APCs to induce adaptive immunity 3) Regulation (Lymphocytes activated by antigen give rise to clones of Ag specific effector cells.

Question 44

Where is IL-6 produced by? What effects does it have in the body?

Answer 44

Produced by macrophages in response to interaction with pathogens. Stimulate the liver to release MBL, C-reactive proteins, SP-A, SP-D, Serum amyloid proteins, fibrinogen. MBL and C-reactive protein act as opsonins and activate complement.