Review Cards - Immunology Flashcards
Proteins that increase due to infection, injury, trauma (e.g., C-reactive protein, alpha-1 antitrypsin, haptoglobin, fibrinogen, ceruloplasmin, alpha-1 acid glycoprotein, complement)
Acute phase reactants
Antibody formed in response to antigen from individuals of same species
Alloantibody
Foreign substance that can stimulate antibody production; most often a large, complex molecule (MW = >10,000), usually protein or polysaccharide
Antigen
Immunoglobulin produced by plasma cells in response to an antigen
Antibody
Antibody against self
Autoantibody
Strength of bond between antigen & antibody
Avidity
Cytokines that attract cells to a particular site; important in the inflammatory response
Chemokines
Migration of cells toward chemokine
Chemotaxis
Antigenic features of leukocytes
Clusters of differentiation (CD)
Chemicals produced by activated immune cells that affect function of other cells; includes interferons, chemokines, tumor necrosis factors, transforming growth factors, colony stimulating factors, interleukins
Cytokines
Determinant site on antigen
Epitope
Low molecular weight substance that can bind to antibody once it’s formed, but is incapable of stimulating antibody production unless bound to a larger carrier molecule
Hapten
Heightened state of immune responsiveness that can cause tissue damage in host
Hypersensitivity
Resistance to infection
Immunity
Any substance capable of inducing an immune response
Immunogen
Antibody
Immunoglobulin
Cellular & humoral mechanisms involved in reaction to injury or infection
Inflammation
Cytokines with antiviral properties; also active against certain tumors & inflammatory processes
Interferons
Cytokines produced by leukocytes that affect inflammatory response through increase in soluble factors or cells
Interleukins
Molecule that binds to another molecule of complementary configuration; the substance being measured in an immunoassay
Ligand
Enzyme found in tears & saliva that attacks cell walls of microorganisms
Lysozyme
System of genes that control expression of MHC molecules found on all nucleated cells; originally referred to as human leukocyte antigens (HLA)
Major histocompatibility complex (MHC)
Antibody derived from single B-cell clone, frequently used in clinical laboratory assays such as enzyme-linked immunosorbent assay (ELISA)
Monoclonal antibody
Serum proteins that attach to a foreign substance & enhance phagocytosis; most often complement or antibody
Opsonin
Step-wise engulfment of cells or particulate matter by neutrophils & macrophages
Phagocytosis
Transformed B cells that secret antibody
Plasma cells
Antibody produced by many B-cell clones
Polyclonal antibody
Reduced ag/ab complexes due to antigen excess; can cause false negative in serological test for antibodies; repeat test in 1-2 weeks
Postzone
Reduced ag/ab complexes due to antibody excess; can cause false negative in serological tests for antibodies; dilute serum & retest
Prozone
Change of serological test from negative to positive due to development of detectable antibodies
Seroconversion
Small, flat bilobed organ found in thorax; site of T-lymphocyte development; one of two primary lymphoid organs (bone marrow is the other primary lymphoid organ)
Thymus
Means of expressing antibody concentration; reciprocal of highest dilution with positive reaction
Titer
Injection of immunogenic material to induce immunity
Vaccination
When the number of multivalent sites of antigen & antibody are approximately equal; results in optimal reactions
Zone of equivalence
Branches of the immune system - Cellular - definition
cell-mediated
Branches of the immune system - Cellular - defense against
-viruses
-fungi
-mycobacteria
-other intracellular pathogens
-tumor cells
Branches of the immune system - Cellular - cells involved
-T-cells
-macrophages
Branches of the immune system - Cellular - examples
-graft rejection
-hypersensitivity reactions
-elimination of tumor cells
Branches of the immune system - Humoral - definition
antibody mediated
Branches of the immune system - Humoral - defense against
bacteria (extracellular)
Branches of the immune system - Humoral - cells involved
-B cells
-plasma cells
Branches of the immune system - Humoral - examples
antibody production
Types of immunity - innate - explanation
defense mechanisms present at birth; not antigen specific
Types of immunity - innate - components
External defense system:
-intact skin
-mucous membranes
-cilia & mucus in RT
-stomach acid
-flushing of urine
-lactic acid in vagina
-lysozyme in tears & saliva
-normal flora
Internal defense system:
-neutrophils
-macrophages
-acute phase reactants
-complement
-chemokines
Types of immunity - innate - memory?
NO
Types of immunity - acquired or adaptive - explanation
defense mechanisms that are antigen specific
Types of immunity - acquired or adaptive - components
-T-cells
-B-cells
-plasma cells
-antibodies
-cytokines
Types of immunity - acquired or adaptive - memory?
YES
Adaptive immunity - naturally acquired active immunity - explanation
individual infected with microorganism produces antibodies
Adaptive immunity - naturally acquired active immunity - example
clinical or subclinical infection
Adaptive immunity - naturally acquired active immunity - specific?
yes
Adaptive immunity - naturally acquired active immunity - immediate?
no
Adaptive immunity - naturally acquired active immunity - long-term?
yes
Adaptive immunity - artificially acquired active immunity - explanation
individual exposed to antigen through vaccine develops immunity without having the infection
Adaptive immunity - artificially acquired active immunity - explanation
individual exposed to antigen through vaccine develops immunity without having the infection
Adaptive immunity - artificially acquired active immunity - example
-Diphtheria, tetanus, pertussis vaccine (DTap)
-measles, mumps, rubella vaccine (MMR)
-polio vaccine
-tetanus vaccine
-Haemophilus influenzae type b (Hib) vaccine
Adaptive immunity - artificially acquired active immunity - specific?
yes
Adaptive immunity - artificially acquired active immunity - immediate?
no
Adaptive immunity - artificially acquired active immunity - long-term?
yes
Adaptive immunity - naturally acquired passive immunity - explanation
individual protected by antibodies produced by another person
Adaptive immunity - naturally acquired passive immunity - example
maternal antibodies that cross the placenta and are present in breast milk
Adaptive immunity - naturally acquired passive immunity - specific?
yes
Adaptive immunity - naturally acquired passive immunity - immediate?
yes
Adaptive immunity - naturally acquired passive immunity - long-term?
no
Adaptive immunity - artificially acquired passive immunity - explanation
individual receives immune globulin containing antibodies produced by another person
Adaptive immunity - artificially acquired passive immunity - example
-Rh immune globulin
-convalescent plasma
-antitoxins
Adaptive immunity - artificially acquired passive immunity - specific?
yes
Adaptive immunity - artificially acquired passive immunity - immediate?
yes
Adaptive immunity - artificially acquired passive immunity - long-term?
no
Cells of the innate immune system - granulocytes - neutrophils - function
-phagocytosis
-inflammatory response
Cells of the innate immune system - granulocytes - neutrophils - respond to?
Chemotaxins
Cells of the innate immune system - granulocytes - neutrophils - granules contain?
Bactericidal enzymes
Cells of the innate immune system - granulocytes - eosinophils - function
-neutralization of basophil & mast cell products
-destruction of some helminths
-hypersensitivity reactions
Cells of the innate immune system - granulocytes - eosinophils - phagocytic ability?
Some
Cells of the innate immune system - granulocytes - basophils - function
Hypersensitivity reactions
Cells of the innate immune system - granulocytes - basophils - granules contain?
Histamine, heparin, eosinophil chemotactic factor A
Cells of the innate immune system - granulocytes - basophils - bind to what in an allergic reaction?
IgE
Cells of the innate immune system - granulocytes - basophils - when do granules release contents?
In presence of antigen
Cells of the innate immune system - mononuclears - monocytes - function
Phagocytosis
Cells of the innate immune system - Tissue cells - mast cells - function
Hypersensitivity reactions
Cells of the innate immune system - Tissue cells - mast cells - what type of cells?
Connective tissue cells
Cells of the innate immune system - Tissue cells - mast cells - similar to basophils
Yes, but they are larger and have more granules
Cells of the innate immune system - Tissue cells - mast cells - what do they bind to?
IgE
Cells of the innate immune system - mononuclears - monocytes - migration
Migrate to the tissues and become macrophages
Cells of the innate immune system - Tissue cells - mast cells - respond to?
Chemotaxins
Cells of the innate immune system - Tissue cells - macrophages - function
-phagocytosis
-elimination of bacteria, intracellular parasites, & tumor cells
-secretion of cell mediators
-antigen presentation
Cells of the innate immune system - Tissue cells - macrophages - activated by?
Contact with microorganisms or cytokines from T cells
Cells of the innate immune system - Tissue cells - dendritic cells - function
-phagocytosis
-presentation of antigens to T cells
Cells of the innate immune system - Tissue cells - dendritic cells - initiate?
Adaptive immune response
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - function
1st line of defense against tumor cells & cells infected with viruses
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - lymphocytes without?
T or B markers
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - surface antigens?
no unique surface antigens, but CD16+ and CD56+
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - bridge between?
innate and acquired immunity
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - specificity?
no
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - stimulated by?
cytokines
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - released?
early infection - provides time for T & B cells to be activated
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - % of lymphs?
<20%
Cells of the innate immune system - Lymphocytes - Natural Killer (NK) cells - key cell in what?
antibody-dependent cellular cytotoxicity (ADCC)
Cells of the acquired immune system - T-lymphocytes (T cells) - function
cell-mediated immunity
Cells of the acquired immune system - T-lymphocytes (T cells) - derived from?
cells in bone marrow
Cells of the acquired immune system - T-lymphocytes (T cells) - where do they develop T-cell-specific surface antigens?
thymus
Cells of the acquired immune system - T-lymphocytes (T cells) - % of lymphs?
60-80%
Cells of the acquired immune system - Helper T cells - function
-orchestrate cell-mediated immunity
-activate B cells, cytotoxic cells, & NK cells
Cells of the acquired immune system - Helper T cells - surface antigen
CD4+
Cells of the acquired immune system - Helper T cells - constitutes how much of peripheral T cells?
2/3
Cells of the acquired immune system - Helper T cells - normal CD4 concentration
1,000/uL
Cells of the acquired immune system - Helper T cells - CD4 concentration in AIDS
<200/uL
Cells of the acquired immune system - Cytotoxic T cells - function
-suppressor cells inhibit helper T cells
-cytotoxic cells kill other cells
Cells of the acquired immune system - Cytotoxic T cells - surface antigen
CD8+
Cells of the acquired immune system - Cytotoxic T cells - constitutes how much of peripheral T cells?
1/3
Cells of the acquired immune system - Cytotoxic T cells - normal CD4/CD8 ratio?
2:1
Cells of the acquired immune system - Cytotoxic T cells - CD4/CD8 ratio in AIDS?
<0.5:1
Cells of the acquired immune system - T regulatory cells - function
suppress immune response to self
Cells of the acquired immune system - T regulatory cells - surface antigens
CD4+ and CD25+
Cells of the acquired immune system - B lymphocytes (B cells) - function
after antigenic challenge, transform into blasts that give rise to plasma cells & memory cells
Cells of the acquired immune system - B lymphocytes (B cells) - develop where?
bone marrow
Cells of the acquired immune system - B lymphocytes (B cells) - mature cells have what on their surface?
immunoglobulins (IgM, IgD) that act as receptors for antigens
Cells of the acquired immune system - B lymphocytes (B cells) - constitute what percentage of lymphs in peripheral blood?
10-20%
Cells of the acquired immune system - plasma cells - function
antibody production
Cells of the acquired immune system - plasma cells - where are they located?
in peripheral lymphoid organs
Cells of the acquired immune system - plasma cells - do they divide?
no
Cells of the acquired immune system - memory cells - function
respond to antigens when encountered again with increased speed & intensity
Cells of the acquired immune system - memory cells - located?
in peripheral organs
Cells of the acquired immune system - memory cells - live span?
months to years
Cells of the acquired immune system - memory cells - what type of cells?
can be B or T cells
List the primary lymphoid organs.
-bone marrow
-thymus
List the secondary lymphoid organs.
-spleen
-lymph nodes
-tonsils
-appendix
-cutaneous-associated lymphoid tissue
-mucosal-associated lymphoid tissue (MALT), including Peyer patches in the lower ileum
Isolation & identification of lymphocytes - isolation
-density gradient centrifugation with separation media (e.g., Ficoll-Hypaque)
-layers from top to bottom:
–plasma
–mononuclear cells
–separation media
–RBCs
–granulocytes
Isolation & identification of lymphocytes - identification
-flow cytometry
-fluorescent-labeled monoclonal antibodies against specific surface antigens
-each antibody has different fluorescent tag
-light scattering measured as cells flow through laser beam
-common T-cell antigens tested: CD2, CD3, CD4, CD7, CD8
-common B-cell antigens tested: CD19, CD20, CD22, surface Ig
Immunoglobulin (Ig) structure - basic structure
2 heavy (H) chains + 2 light (L) chains held together by disulfide (S-S) bonds
Immunoglobulin (Ig) structure - heavy (H) chains
-determine Ig class (IgG, IgA, IgM, IgD, IgE)
-gamma, alpha, delta, mu, epsilon
Immunoglobulin (Ig) structure - light (L) chains
-kappa or lambda
-both found in all classes of Igs, but only 1 type per molecule
-free L chains = Bence Jones proteins
Immunoglobulin (Ig) structure - Fab fragment
-fragment antigen binding
-consists of 1 L chain & 1/2 H chain held together by S-S bonds
-2 per Ig
-each can bind antigen
Immunoglobulin (Ig) structure - Fc fragment
-fragment crystallizable
-carboxy-terminal halves of 2 H chains held together by S-S bonds
-site of antibody biological activity such as opsonization & complement fixation
Immunoglobulin (Ig) structure - Constant region
carboxy-terminal ends of H & L chains where amino acid sequence is same for all chains of that type
Immunoglobulin (Ig) structure - variable region
-amino-terminal ends of H & L chains where amino acid sequence varies
-also known as antigen-recognition unit
-responsible for Ig specificity
Immunoglobulin (Ig) structure - Hinge region
-flexible portion of H chain between 1st & 2nd constant regions
-allows molecule to bend so that 2 antigen-binding sites can operate independently
Immunoglobulin (Ig) structure - Joining chain
glycoprotein that links Ig monomers in IgM & secretory IgA
Immunoglobulins - IgG - form in serum
monomer
Immunoglobulins - IgG - molecular weight (daltons)
150,000
Immunoglobulins - IgG - H chain
gamma
Immunoglobulins - IgG - L chain
Kappa or lambda
Immunoglobulins - IgG - % of total Ig
70-75%
Immunoglobulins - IgG - % of total Ig
70-75%
Immunoglobulins - IgG - serum concentration (mg/dL)
800-1,600 mg/dL
Immunoglobulins - IgG - antigen binding sites
2
Immunoglobulins - IgG - complement fixation
yes
Immunoglobulins - IgM - form in serum
pentamer
Immunoglobulins - IgM - molecular weight (daltons)
900,000
Immunoglobulins - IgM - H chain
Mu
Immunoglobulins - IgM - L chain
kappa or lambda
Immunoglobulins - IgM - % of total Ig
10%
Immunoglobulins - IgM - serum concentration (mg/dL)
120-150 mg/dL
Immunoglobulins - IgM - antigen binding sites
10
Immunoglobulins - IgM - complement fixation
yes
Immunoglobulins - IgA - form in serum
monomer & dimer
Immunoglobulins - IgA - molecular weight (daltons)
160,000 or 400,000
Immunoglobulins - IgA - H chain
alpha
Immunoglobulins - IgA - L chain
kappa or lambda
Immunoglobulins - IgA - % of total Ig
10-15%
Immunoglobulins - IgA - serum concentration (mg/dL)
70-350 mg/dL
Immunoglobulins - IgA - antigen binding sites
2 or 4
Immunoglobulins - IgA - antigen binding sites
2 or 4
Immunoglobulins - IgA - complement fixation
no
Immunoglobulins - IgD - form in serum
monomer
Immunoglobulins - IgD - molecular weight (daltons)
180,000
Immunoglobulins - IgD - H chain
delta
Immunoglobulins - IgD - L chain
kappa or lambda
Immunoglobulins - IgD - % of total Ig
<1%
Immunoglobulins - IgD - serum concentration (mg/dL)
1-3 mg/dL
Immunoglobulins - IgD - antigen binding sites
2
Immunoglobulins - IgD - complement fixation
no
Immunoglobulins - IgE - form in serum
monomer
Immunoglobulins - IgE - molecular weight (daltons)
190,000
Immunoglobulins - IgE - H chain
epsilon
Immunoglobulins - IgE - L chain
kappa or lambda
Immunoglobulins - IgE - % of total Ig
0.002%
Immunoglobulins - IgE - serum concentration (mg/dL)
0.005 mg/dL
Immunoglobulins - IgE - antigen binding sites
2
Immunoglobulins - IgE - complement fixation
no
Immunoglobulins - IgG - crosses placenta?
Yes
Immunoglobulins - IgG - role(s)
-defense against bacteria & viruses
-neutralizes toxins
-opsonin
-passive immunity in newborns
Immunoglobulins - IgG - precipitation/agglutination
more efficient at precipitation than agglutination
Which immunoglobulin is the main Ig produced during memory (recall) response to antigens?
IgG
Immunoglobulins - IgM - crosses placenta?
no
Immunoglobulins - IgM - role(s)
-neutralizes toxins
-opsonin
Immunoglobulins - IgM - more efficient at what than IgG?
agglutination
Immunoglobulins - IgM - destroyed by?
sulfhydryl compounds
Which immunoglobulin is the first Ig produced in the immune response?
IgM
Which immunoglobulin is the only Ig produced by newborns?
IgM
Which immunoglobulin is the only Ig produced by newborns?
IgM
Which immunoglobulin is the most efficient Ig at initiating the complement cascade?
IgM
Immunoglobulins - IgA - crosses placenta?
no
Immunoglobulins - IgA - role(s)
-1st line of defense
-patrols mucosal surfaces
-prevents adherence of bacteria and neutralizes toxins
Immunoglobulins - IgA - located?
-tears
-sweat
-respiratory mucosa
-GI mucosa
-breast milk
Immunoglobulins - IgD - crosses placenta?
no
Immunoglobulins - IgD - role(s)
may play a role in B-cell maturation
Immunoglobulins - IgD - on surface of what cells?
B cells
Immunoglobulins - IgE - crosses placenta?
no
Immunoglobulins - IgE - role(s)
-role in allergic reactions
-binds to basophils & mast cells
-when 2 adjacent molecules on mast cells bind antigens, degranulation of cell with release of histamine & heparin
Immunoglobulins - IgE - type of hypersensitivity reaction
Type I immediate hypersensitivity reaction
Complement - definition
-group of >30 proteins involved in phagocytosis & clearance of foreign antigen
-most are inactive enzyme precursors that are converted to active enzymes in precise order (cascade)
Complement - functions
-inflammation
-opsonization
-chemotaxis
-cell lysis
Complement - classical pathway
-triggered by ag/ab reaction
-IgM is most efficient activator
-single molecule attached to 2 adjacent antigens can initiate cascade
-IgG1, 2, & 3 can activate complement but at least 2 molecules required
-recognition unit: C1 (first to bind)
-activation unit: C4, C2, C3
-membrane attack complex: C5, C6, C7, C8, C9 (cell lysis)
Complement - alternative pathway
-antibody dependent
-activated by bacteria, fungi, viruses, tumor cells, some parasites
Complement - lectin pathway
-antibody independent
-initiated by mannose-binding lectin (MBL)
-nonspecific recognition of sugars on microorganisms
-important defense mechanism in infancy
Complement - present in highest concentration in plasma
C3 (key component of all 3 pathways)
Complement - deficiencies
-increased susceptibility to infection
-accumulation of immune complexes, which can lead to glomerulonephritis
Complement - ions required
calcium and magnesium
Complement - inactivation
56*C for 30 minutes
Hypersensitivity reactions - Type I: Anaphylactic - key reactant(s)
IgE
Hypersensitivity reactions - Type I: Anaphylactic - mechanism
release of mediators from eosinophils, mast cells, & basophils
Hypersensitivity reactions - Type I: Anaphylactic - onset of symptoms
immediate
Hypersensitivity reactions - anaphylaxis - type of hypersensitivity reaction?
Type I: Anaphylactic
Hypersensitivity reactions - hay fever - type of hypersensitivity reaction?
Type I: Anaphylactic
Hypersensitivity reactions - asthma - type of hypersensitivity reaction?
Type I: Anaphylactic
Hypersensitivity reactions - food allergies - type of hypersensitivity reaction?
Type I: Anaphylactic
Hypersensitivity reactions - transfusion reactions - type of hypersensitivity reaction?
Type II: Cytotoxic
Hypersensitivity reactions - HDN - type of hypersensitivity reaction?
Type II: Cytotoxic