Chapter 17: Adaptive Specific Host Defenses

Question 1

Specificity

Answer 1

Refers to the adaptive immune system’s ability to target pathogens.

Question 1

Memory

Answer 1

Refers to its ability to quickly respond to pathogens to which it has previously been exposed.

Question 2

Primary Response

Answer 2

The immune system’s first time responding to a bacteria/virus; where programming for memory and specificity occur.

Question 3

Secondary Response

Answer 3

Is faster and stronger as a result of the body’s memory of the first exposure; also is specific to the pathogen itself.

Question 4

B Cells

Answer 4

Mature in the bone marrow and are responsible for the production of glycoproteins called antibodies, or immunoglobins.

Question 5

Antibodies

Answer 5

Involved in the body’s defense against pathogens and toxins in the extracellular environment.

Question 6

Humoral Immunity

Answer 6

Mechanisms of adaptive specific immunity that involve B cells and antibody production.

Question 7

T Cells

Answer 7

Mature in the thymus; function as the central orchestrator of both innate and adaptive immune responses; responsible for destruction of cells infected with intracellular pathogens.

Question 8

Cellular Immunity

Answer 8

The targeting and destruction of intracellular pathogens by T cells.

Question 9

Antigens/Immunogens

Answer 9

Similar to PAMPs, but unique to a specific pathogen.

Question 10

Antigenic

Answer 10

A molecule that stimulates antibody production.

Question 11

Haptens

Answer 11

Free epitopes that are not part of the complex 3-D structure of a larger antigen.

Question 12

Antibodies/Immunoglobulins

Answer 12

Glycoproteins that are present in both the blood and tissue fluids.

Question 13

Disulfide Bonds

Answer 13

A covalent bond between the sulfhydryl R groups found on two cysteine amino acids.

Question 14

Heavy Chains

Answer 14

The two largest chains on an antibody; identical to each other.

Question 15

Light Chains

Answer 15

The two smaller chains on an antibody; identical to each other.

Question 16

Fab Region

Answer 16

The two ‘arms’ of the Y-shaped antibody molecule; stands for ‘fragment of antigen binding’.

Question 17

Variable Region

Answer 17

Serves as the site of antigen binding; the amino acid sequence dictates the 3-D structure, and thus the specific 3-D epitope to which the Fab region is capable of binding.

Question 18

Constant Region

Answer 18

Includes the trunk of the Y lower portion of each arm of the Y.

Question 19

Fc Region

Answer 19

The trunk of the Y; stands for ‘fragment of crystallization’; the site of complement factor binding and binding to phagocytic cells during antibody-mediated opsonization.

Question 20

Isotype/Class

Answer 20

How antibodies are group; determined by the constant region.

Question 21

IgG

Answer 21

Most abundant antibody in human blood; penetrates efficiently into tissue spaces, and is the only antibody class with the ability to cross the placental barrier, providing passive immunity to the developing fetus during pregnancy.

Question 22

IgM

Answer 22

The first antibody produced and secreted by B cells during the primary and secondary immune responses, making pathogen-specific IgM a valuable diagnostic marker during active or recent infections.

Question 23

IgA

Answer 23

The most common and abundant antibody class found in the mucus secretions that protect the mucous membranes; traps pathogens in mucus so that they can later be eliminated form the body.

Question 24

IgD

Answer 24

Not secreted by B cells and only trace amounts are detected in serums; a membrane-bound monomer found in the surface of B cells, where it serves as an antigen-binding receptor.

Question 25

IgE

Answer 25

The least abundant antibody class in serum; its role in adaptive immunity is restricted to anti-parasitic defenses.

Question 26

Neutralization

Answer 26

Involves the binding of certain antibodies (IgG, IgM, or IgA) to epitopes on the surface of pathogens or toxins, preventing their attachment to cells.

Question 27

Opsonization

Answer 27

The coating of a pathogen with molecules, such as complement factors, C-reactive protein, and serum amyloid A, to assist in phagocyte binding to facilitate phagocytosis.

Question 28

Agglutination/Aggregation

Answer 28

Involves the cross-linking of pathogens by antibodies to create large aggregates.

Question 29

Complement System

Answer 29

Promotes the inflammatory response, recruits phagocytes to site of infection, enhances phagocytosis by opsonization, and kills gram-negative bacterial pathogens with the membrane attack complex (MAC).

Question 30

Classical Pathway

Answer 30

Requires the initial binding of IgG or IgM antibodies to the surface of a pathogen cell, allowing for recruitment and activation of the C1 complex.

Question 31

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

Answer 31

Enhances killing of pathogens that are too large to be phagocytosed.

Question 32

Major Histocompatibility Complex (MHC)

Answer 32

A collection of genes encoding for MHC molecules found in the surface of all nucleated cells of the body.

Question 33

Human Leukocyte Antigen (HLA) Genes

Answer 33

The MHC genes in humans.

Question 34

MHC I

Answer 34

Found on all nucleated cells; they present normal self-antigens as well as abnormal or nonself pathogens to the effector T cells involved in cellular immunity.

Question 35

MHC II

Answer 35

Only found on macrophages, dendritic cells, and B cells; they present abnormal or nonself pathogen antigens for the initial activation of T cells.

Question 36

Antigen-Presenting Cells (APCs)

Answer 36

Macrophages, dendritic cells, and B cells that have the ability to present antigens specifically for the purpose of activating T cells.

Question 37

T-Cell Independent Activation

Answer 37

What the activation of B cells without the cooperation of helper T cells is referred to and occurs when BCRs interact with T-independent antigens.

Question 38

T-Cell Independent Activation

Answer 38

What the activation of B cells without the cooperation of helper T cells is referred to and occurs when BCRs interact with T-independent antigens.

Question 39

Plasma Cells

Answer 39

Antibody factories that secrete large quantities of antibodies.