STEVES Immunity and the Immune System Overview

Immunity

Condition of being resistant to disease

Eosinophils

Blood cell that has reddish staining granules and is able to kill large parasites

Clusters of differentiation (CD)

Antigenic groups identified by different sets of antibodies reacting in a similar manner to certain standard cell lines

Monocyte

WBC capable of further differentiation in tissues

Effective immunogen

Internal complexity, Large molecular weight, Presence of numerous epitopes

Hapten

Antigenic only when coupled to a carrier

Epitope

Key portion of the immunogen

NK cells

Kill target cells WITHOUT prior exposure to them

Adjuvants

Act by protecting antigen from being degraded

Dendritic cell

Most potent phagocytic cell in the tissue

Heterophile antigen

Exists in unrelated plants or animals

Innate immunity

Ability of an individual to resist infection by means of normally present body functions

Class II MHC (HLA) antigens

Found on B cells and macrophages

CD4+ T cells

Recognize Class II MHC molecules

Neutrophil

Cell characterized by a nucleus with two to five lobes, a diameter of 10 to 15μm, and a large number of neutral staining granules

Primary lymphoid organ

Bone marrow, thymus

TAP

Transport peptides into the lumen of the endoplasmic reticulum

Unstimulated B cells

Cells would be found in a primary follicle

B cells

Distinguishing feature is the presence of surface antibody

Secondary lymphoid organs

Lymphocytes mainly come in contact with antigens

CD4

T cell subset known as helpers

Adaptive immunity

Specificity for each individual pathogen

Cytokines

Produced by T cells to regulate both innate and adaptive immunity

Human microbiota

Presence acts as a defense mechanism

CRP levels

Measurement used for monitoring drug therapy with anti-inflammatory agents and tracking the progress of an organ transplant

Invariant chain

Purpose is to block binding of endogenous peptides

Class I MHC molecules

Binds peptides made within the cell

Acute-phase reactants

Characterized by rapid increase following infection

HLA molecules A, B, and C

Class I

Hypochlorite ions

Most significant agent formed in the phagolysosome for the elimination of microorganisms

Haplotype

Child inherits one set of six HLA genes together from one parent

Haptoglobin

Acute-phase reactant helps to prevent formation of peroxides and free radicals that may damage tissues.

Opsonization

Enhancement of phagocytosis by coating of foreign particles with serum proteins.

Toll-like receptors (TLRs)

Enhance phagocytosis and play an important role as an external defense mechanism.

C-reactive protein (CRP)

Acts before the antibody appears.

Process of inflammation

Characterized by increased blood supply to the area, migration of WBCs, and appearance of APRs.

Skin, lactic acid secretions, stomach acidity, and the motion of cilia

Components of innate immunity.

Phagolysosome

Structure formed by the fusion of engulfed material and enzymatic granules within the phagocytic cell.

Alpha1-antitrypsin deficiency

A condition that can lead to premature emphysema in smokers.

MHC Class II molecule

Necessary for antigen recognition by CD4+ T cells.

Variable domains of immunoglobulins

Occur on both the heavy (H) and light (L) chains.

T-independent antigen

Consists of a limited number of repeating determinants.

IgM

Fixes complement and has a J chain.

Humoral immunity

Production of antibody by plasma cells.

Antigen-independent maturation of B lymphocytes

Takes place in the bone marrow.

Positive selection of immature T cells

Based upon recognition of MHC antigens in the thymus.

IgE

Structure differs from that of IgG by having one more constant region.

Mature B cell

Expresses IgM and IgD.

Cytotoxic T cells

Kill target cells by producing granzymes that stimulate apoptosis.

Bence Jones proteins

Identical to light chains.

Fab fragment

Consists of one light chain and one-half of a heavy chain.

IgA

Best protects mucosal surfaces.

Pre-B cell

Distinguished by having u chains in the cytoplasm.

Typical immunoglobulin structure

Composed of 2 light (L) and 2 heavy (H) chains.

Genetic rearrangement for coding of antibody light chains

Takes place during B-cell development as the cell becomes an immature B cell.

CD4 T-cell subset

Known as helper/inducers.

Major portion of antibody production

Occurs in lymph nodes.

Double-negative thymocyte

Characterized by CD2+CD3+CD4-CD8-.

Immunodeficiency disorder

May result from a lack of IL-4, which also stimulates the production of IgG2a and IgE.

Subclasses of IgG

Differ mainly in the arrangement of disulfide bonds.

Role of the secretory component of IgA

Transport mechanism across endothelial cells

Known as the T-cell growth factor

IL-2

Autocrine effect of IL-2

Increased IL-2 receptor expression by the Th cell producing it

Main function of IgD

Enhancing proliferation of B cells

Best at agglutination and complement fixation

IgM

IFN-a and IFN-β differ in which way from IFN-gamma

IFN-α and IFN-β inhibit cell proliferation, whereas IFN-gamma stimulates antigen presentation by class II MHC molecules

Attributed to the clonal selection hypothesis of

B cells are preprogrammed for specific antibody formation

Patient in septic shock caused by a gram-negative bacterial infection exhibits the following symptoms

High fever, very low blood pressure, and disseminated intravascular coagulation.

True of IgE

Fails to fix complement

Cytokine most likely contributor to these symptoms

A. attaches to tissue mast cells

Found in the serum of allergic persons

IgE

IL-10 acts as an antagonist to

IFN-gamma

True of IgE, EXCEPT

Heat stable

Best assay to measure a specific cytokine

ELISA testing

Purpose of HAT medium in the preparation of monoclonal antibody

Restricting the growth of myeloma cells

Selective destruction of Th cells by the human immunodeficiency virus contributes to immune suppression by

Decrease in IL-2

Papain digestion of an IgG molecule results in

2 Fab and 1 Fc fragment

Antibody provides protection to the growing fetus because it is able to cross the placenta

IgG

Colony stimulating factor be given to a cancer patient

Increase production of certain types of leukocytes

Best characterizes the secondary response

Large increase in IgG but not IgM

Result from a lack of TNF

Decreased ability to fight gram-negative bacterial infections

Ability of a single cytokine to alter the expression of several genes

Pleiotropy

Attributed to IL-1

Mediation of the innate immune response by inducing IL-10

Target cells of IL-3

Myeloid precursors and Lymphoid precursors

Decreased CH50 level and a normal AH50 level indicate which deficiency

Decrease in components of the classical pathway only

Best describes the role of an anaphylatoxin

Increases permeability of blood vessels

Best describes the role of Factor H

Prevents binding of Factor B to C3b

Lack of C1-INH might result in

Hereditary angioedema

Classical complement pathway is activated by

Antigen-antibody complexes

Characteristic of complement components

Normally present in serum

True of the recognition unit

Consists of C1q, C1r, and C1s, subunits require calcium for binding together

In the chain of infection, a contaminated work area would serve as

Reservoir

Referred to as C3 convertase

C4b2a, C3bBb

Role of properdin in the alternative pathway

Stabilization of C3/C5 convertase

Myeloid precursors

Precursor cells that develop into myeloid lineage cells.

Lymphoid precursors

Precursor cells that develop into lymphoid lineage cells.

Decrease in components of the classical pathway only

Indicates a deficiency in the classical complement pathway.

Decreased CH50 level and a normal AH50 level

Indicate a deficiency in the classical complement pathway.

Role of an anaphylatoxin

Increases permeability of blood vessels.

TNF-a and IL-6

Cytokines that play a role in the immune response.