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243 Cards in this Set

  • Front
  • Back
What cells differentiate from the lymphoid progenitor
T progenitors and B progenitors give rise to thymocytes and B lymphocytes. These differentiate into helper and cytotoxic T lymphocytes and plasma cells. Lymphoid progenitor turns into NK cell.
What cells differentiate from the myeloid progenitor
Granulocyte progenitor into monocytes and neutrophils. Monocytes differentiate into macrophages and dendritic cells. Eosinophils. Basophil progenitor turns into basophils and mast cells. Megakaryocytes give rise to platelets and the erythroid progenitor turns into erythrocytes
Characteristics of monocytes
Are found in the bloodstream, have horseshoe-shaped nucleus
Characteristics of macrophages
Found in tissues and have ruffled membrane with cytoplasm, vacuoles and vesicles
Chatacteristics of neutrophils
Found in the bloodstream, multilobed nucleus and small pink granules
Characteristics of eosinophils
Found in the bloodstream, have bilobed nucleus with large pink granules
Characteristics of basophils
Found in the bloodstream, have bilobed nucleus with large blue granules
Characteristics of mast cells
Found in tissues, mucosa and epithelia. Have small nucleus and cytoplasm with large blue granules. Release histamine
Characteristics of lymphocytes
Found in the bloodstream and lymphoid tissue. Have large, dark nucleus with a small cytoplasm
Naïve B cell receptors
Membrane-bound IgM and IgD
Describe the structure of immunoglobulins
2 heavy chains and 2 light chains united by disulfide bonds and a flexible hinge region. Th carboxy terminal of the heavy chains for the FC fragment and anchor IgM and IgG to the membrane and are the constant isotype. The N-terminal of all four molecules face the extracellular space and form the FAB fragment with an idiotype that uniquely bninds a single antigen.
What are the molecules of the B cell transduction complex
Ig-α, Ig-β, CD19, CD20
Describe the T cell receptor
Has two chains - α and β. The carboxy terminals anchor the molecules to the membrane while the N-terminals form the idiotype which binds a small peptide sequence presented by antigen-presenting cells
What are the molecules of the T cell transduction complex
CD3
Define VDJ recombination
It’s the process by which B cell Ig heavy chain gene's (and T cell β chain gene's) V, D and J segments are randomly recombined and spliced to form the unique N terminal sequence or idiotype of the B and T receptors
What is VJ recombination
It’s the process by which the B cell light chain gene's (and T cell α chain gene's) V and J segments are randomly recombined and spliced to form a unique N terminal sequence or idiotype on the B and T cell receptors
terminal deoxyribonucleotidyl transferase (Tdt)
Inserts random bases (N-nucleotide addition without a DNA template) at the junctions of the V, D and J segments of Ig heavy chain and T cell receptor β chain. It is only active duting the formation of the Ig heavy chain in the B cell or the formation of both α and β chains of the T cell receptor, therefore it can be used as a marker for B and T cell maturation
Does VDJ recombination always produce a functional protein?
No. If it does not produce a functional protein from recombination of one of the gene alleles, it can try to make a functional protein from the complimnentary allele. If both attempts fail, apoptosis is induced. If a good protein is achieved, the other allele will shut down by allelic exclusion
At what stage of gene expression are the variable and constant domains merged?
They are spliced together at the RNA level
What are the rag enzymes
These are the enzymes that catalyze VDJ recombination. Recombination activating gene (rag).
What are MHC antigens
A collection of polymorphic genes on the short arm of chromosome 6 that are expressed by nucleated cells (MHC-I) and antigen presenting cells (MHC-II). These genes are expressed codomiantly therefore each individual has a unique combination of MHC antigens (one from the mother, one from the father). Lymphocytes are exposed to these antigens during maturation in the marrow and thymus. If they react to them, they are induced to apoptosis.
MHC I gene products
HLA-A, HLA-B, HLA-C. Expressed on all nucleated cells of the body
MHC II gene products
HLA-DP, HLA-DQ, HLA-DR. Expressed on antigen-presenting cells
Structure of the MHC-I molecule
Has an α chain anchored to the cell at the carboxy-terminus and three extracellular domains with a peptide-binding groove to accommodate peptides for presentation to lymphocytes. A β2-microglobulin chain that is involved in transport of the class I antigen to the membrane
Structure of the MHC II molecule
Has an α and β chain with membrane bound carboxy-terminus and extracellular domains that have a peptide-binding groove on the N-terminal end. Are expressend only by macrophages, B-lympphocytes, dendritic and Langherhans cells
What is negative and possitive selection
Lymphocytes with high affinity for self antigens undergo negative selection and apoptosis. Lymphocytes with low affinity for self-antigens are allowed to survive through positive selection
CD4 molecules
On the surface of T lymphocytes that interact with MHC-II, and will become helper T cells
CD8 molecules
On the surface of T lymphocytes that interact with MHC-I, and will become cytotoxic T cells
Cell markers: μ+
pre-B cells in bone marrow with heavy chains
Cell markers: Tdt+
Progenitor B cells in bone marrow without heavy chains or pre-thymic/thymic cortex T cells
Where are Tdt+ T cells found
bone marrow and thymic pre-cortex
B cell markers
CD19, CD20, IgM, B7, CD40, CD20, MHC-II
T cell markers
CD4, CD8, CD3, TCR
B-cell rich areas of the lymph node
The cortex. Contains primary follicles.
T-cell rich area of the lymph node
The paracortex.
Define: antigen
Substance that is foregin, complex and with molecular weight over 5,000Kd that can induce an immune response
Define: epitope
The portion of the antigen to which the Ig idiotype binds. Antigen should have two epitopes to induce a response.
Define: hapten
Single antigenic determinants. An antigen with a single epitope. Needs to form an hapten-carrier complex to induce an immune response
Leukocyte adhesion deficiency
Absense of CD18 (β chain of LFA-1 integrin). No adhesion of leukocytes. Omphalitis, no abscess or pus formation.
Chemoattractants for neutrophils
IL-8, C5a, LTB4, formyl methionyl peptides from microorganisms
Opsonins
Fc portion of IgG, C3b. Macrophages and eosinophils have recptors
NADPH oxidase
Synthesizes superoxide radicals for respiratory burst
Myeloperoxidase
Lysosomal enzyme converts H2O2 + Cl- --> hypochlorite (bleach) which is microbicidal
Pathophysiology of CGD
Deficiency of NADPH oxidase with no production of superoxide radical and H2O2 which is the substrate for myeloperoxidase to produce bleach. In catalase(-) infections myeloperoxidase uses H2O2 produced by the bacteria. If it's catalase(+), H2O2 is degraded by the bacterial catalase and theres insuficient respiratory burst response to kill Staph, pseudomona, serratia, aspergillus. Dx.: with negative nitroblue tetrazolium test
MHC-I and MHC-II coreceptors on T cells
MHC-I --> CD8; MHC-II --> CD4
LFA-1
On T cells binds ICAM-1 on macrophages to increase cell-cell adherence during antigen presentation
CD2
On T cells binds LFA-3 on macrophages to increase cell-cell adherence
CD28
On T cells binds B7 on macrophages to trigger transcription of cytokines
IL-2
Secreted by T cells promote their on proliferation after activation.
Superantigens
Crosslink TCR with MHC-II in the absense of specific antigen producing policlonal activation and excess production of IFN-γ which activates macrophages with release of IL-1, IL-6 and TNF-α and systemic shock. Staph enterotoxin, TSST-1 and strep exotoxin are superantigens.
Cytokines produced by TH1 cells
IFN-γ, TNF-β, IL-2
Cytokines produced by TH2 cells
IL-2, IL-4, IL-5, IL-6, IL-10
Cytokines that stimulate TH1 differentiation
IL-12, IFN-γ produced by macrophages
Cytokines that stimulate TH2 differentiation
IL-4 self-produced by TH2 cells
Cytokines that inhibit TH1 cells
IL-4 and IL-10 produced by TH2 cells
Cytokines that inhibit TH2 cells
IFN-γ
Cytokines that stimulate B cell differentiation
IL-4 and IL-5 produced by TH2 cells
Pathophysiology of tuberculoid leprosy
Strong TH1 response with production of IFN-γ and TNF-β that activates cell-mediated immunity with granuloma formation and erradication of the infection. Mild damage to tissue.
Pathophysiology of lepromatous leprosy
Strong TH2 response inhibits TH1 cell-mediated immunity. IL-4 and IL-5 activate B cells with production of humoral antibodies that are insuficient to erradicate the infection. Severe tissue damage and disfiguration.
B7
On antigen presenting cells such as macrophages and B lymphocytes. It binds CD28 on T lymphocytes to activate production of cytokines
CD40L
On TH2 cells. Binds CD40 on B lymphocyte to induce proliferation and isotype swtching. Deficient in X-linked hyper IgM syndrome.
Costimulatory molecules on B cells
CD40 and B7, bind CD40L and CD28 on TH2 cells
Costimulatory molecules on T cells
LFA-1, CD2, CD28. Bind ICAM-1, LFA-3 and B7 on macrophages respectively
Thymus-independent antigens
Gram(-) LPS and capsular antigens directly stimulate B cells to produce IgM antibodies. Weaker response with no immunologic memory.
Papain Ig digestion
Produces 2 Fab plus 1 Fc. Fab fragments are capable of binding
Pepsin Ig digestion
Produces 1 Fab2 plus 1 Fc. Fab2 is capable of binding and bridging
Characteristics of IgM
Pentamer has low affinity, highest avidity; most effective activator of the complement; incapable of binding Fc receptors and thus induce ADCC; It's the first to be released (before isotype switching).
Define: affinitty maturation
Random somatic hypermutations of the idiotype increase its affinity for antigen. Therefore as the response evolves, the avidity decreases but the affinity increases.
Define: isotype switching
TH2 cells direct the activated B cell to start expressing the isotypes directly downstream from the IgM isotype
X-linked hyperIgM syndrome
Defective CD40L on TH cells. No stimulation of isotype switching by B cells with high levels of IgM (>1.5 mg/mL) and low levels of IgG, IgA, IgE. Recurrent respiratory infections, specially P. jirovenci.
Characteristics of IgG
Produced after IgM; activates the complement, opsonizes and mediates ADCC; its transported across the placenta.
Characteristics of IgA
Inhibits binding of antigens to mucosal surfaces; exists as a dimer; secreted in breast milk; does not activate complement or act as opsonin
Characteristics of IgE
Binds Fc receptors on mast cells and basophils (releasing histamine) to mediate type I allergic reactions. Protects against parasites
Antibodies that can activate the classic complement
IgG, IgM
Cell-mediated immunity
Response against intracellular pathogens. Macrophages, CD8 T cells and NK cells are activated by TH1 cells after activation by MHC-I/TCR interaction
IFN-γ
Secreted by TH1, CD8 and NK cells. Stimulates TH1 proliferation, inhibits TH2 proliferation, enhances macrophage phagocytosis, upregulate MHC molecules.
CTL costimulatory molecules
CD28 on CTLs bind B7 on APCs. IL-2 produced by TH1 cells stimulate CTL differentiation
Mechanism of CTL and NK mediated killing
Release of perforins create membrane pores; granzymes induce caspases and apoptosis; IFN-γ, TNF-α and TNF-β induce apoptosis; Fas ligand expressed by CTLs binf Fas receptor on target cell activating caspases and apoptosis; Fc receptors for ADCC; NK cells kill their target when theres no MHC-I present on their surface
NK cell markers
CD16 and CD56
Macrophage cell markers
CD14
Evasion of immune response by CMV
Down regulates MHC-I molecules on host cell to evade cytotoxic killing; synthesizes a decoy MHC-I to fool NK cells; cannot escape ADCC
Risks of passive immunotherapy
Anaphylaxis; anti-isotype antibodies and type III reactions; persons with selective IgA deficiency can develop reactions against infused IgA (a molecule they have not seen before)
Antibody to diagnose infections in neonates
IgM because IgG and IgA are maternal
Vaccines given at birth
HBV
Vaccines given at 2, 4 and 6 months
DTP, Hib, inactive polio, PCV, HBV
Vaccines given at 1 year
MMR
Bruton's agammaglobulinemia
X-linked recessive. No B cells, No Igs. Recurrent staph, haemophilus and strep infections after 6 months. Increased pre-B cells. Mutation of B-cell Bruton tyrosine kinase (btK).
Common variable immunodeficiency
B-cell maturation defect. Hypogammaglobulinemia, recurrent bacterial infections, giardia lamblia.
DiGeorge syndrome
Failure to develop 3rd and 4th pharyngeal pouches results in absence of parathyroid and thymus glands, hypocalcemia, tetany, T-cell deficiency, recurrent viral infections, heart defects, chronic candidiasis
SCID
B and T cell deficiency due to mutation of IL-2 receptor (x-linked), adenosine deaminase deficiency (AR) or failure to make MHC II. Recurrent infections and susceptibility to candida, CMV and p. carinii
Wiskot-Aldrich syndrome
X-linked recessive. "WIPE": recurrent infections, thrombocytopenic purpura, eczema, risk of lymphomas, low IgM
Ataxia-Telangiectasia
Ataxia, spider angiomas, low IgA, defect of DNA repair enzyme
Chronic granulomatous disease
Low NADPH oxidase. Recurrent catalase+ infections, negative nitroblue tetrazolium test.
Leukocyte adhesion deficiency
Defect of CD-18 (LFA-1 beta chain), no pus formation, failure of umbilical cord to detach
Chediak-Higashi
Defect in microtubules with no phagocytosis by lysosome. Partial albinism, peripheral neuropahty, recurrent infections
Hereditary angioedema
Edema at mucosal surfaces. Defect of C1-INH (esterase inhibitor). Decreased C1, C2, C4
Hyper IgM
Defect of CD-40L on T-lymphocytes. No isotope switching, increased IgM
MHC-I deficiency
Normal CD4, no CD8. Failure of TAP-1 to transport peptides to MHC-I groove
Hemolytic disease of the newborn
Rh- mother develops antiRh+ IgG that injures fetus. Rx. RhoGAM.
Examples of autografts
Same individual transplant. Skin grafting in burns, coronary artery replacement with saphenous veins, hair transplant
Syngeneic grafts
Between genetically identical twins
Alogeneic grafts
Between members of the same species
Xenogeneic grafts
Between members of different species
Mechanism of graft rejection
CD8 and CD4 host cells enter in contact with the graft tissue and fail to recognize MHC on its surface. TH1 start to produce IFN-γ and TNF-β that activate macrophages and upregulate MHC-I and II molecules on the graft.
Hyperacute graft rejection
Minutes to hours. Mediated by preformed antibodies and complement. Anaphylactic reaction
Accelerated graft rejection
Days. Reactivation of sensitized T cells
Acute graft rejection
Days to weeks. Primary activation of T cells
Chronic graft rejection
Months to years.
Graft Vs. host disease
Occur after bone marrow transplant if mature donor T cells are present. Donor T cells react against recipient causing rash, jaundince, diarrhea, and GI hemorrhage
Tissue compatibility tests
ABO blood typing, HLA matching (tissue typing), screening for preformed antibodies and crossmatching
Universal blood donor
Type O. These individuals will have anti-A and anti-B IgM antibodies and therefore can only accept O blood.
Universal blood acceptor
Type AB. These individuals have no antibodies against A or B blood and can accept any blood type
Direct coombs test
Detects antibodies bound to RBC. Used to diagnose autoimmune hemolytic anemia or anti-Rh antibodies directly in the fetus
Indirect Coombs test
Detecs production of anti-RBC antibodies. Used to detect anti-Rh antibodies in the mother.
Latex bead agglutination test
Antibodies against the pathogen are conjugated to latex beads. When a drop of infected CSF is placed on the bead, agglutination occurs. Available for meningitis by Haemophilus, pneumococcus, menigococcus, Cryptococcus neoformans
ELISA test
The particular antigen is coated onto microplates and serum from the patient is added followed by addition of enzyme-labeled antihuman Ig. A chromogenic substrate for the enzyme is then added which produces color if positive. Very sensitive. Used for the HIV p24 antigen as well as many hormones, antibiotics, proteins infectious antigens and tumor markers.
Western blot test
HIV antigens are blotted into nitrocellulose paper followed by patient serum and an antihuman Ig conjugated to radioactive labels or enzyme. The resulting radioactivity or color change is detected by microscope.
Flow cytometry test
Analyzes and sorts cell types from a complex mixture. Fluorescent antibodies of different colors agasint cell surface markers bind to different cell types and are detected by a machine that plots a histogram with the x-axis for one dye and the y-axis for the other. Therefore cells that are CD3+ and CD8+ will be plotted on the top right quadrant.
CD2 (LFA-2)
Adhesion molecule expressed by T-cells, thymocytes, NK cells. Binds LFA-3 on lymphocytes and APCs
CD3
Signal transduction complex of T cells
CD4
Co-receptor for TCR-MHC-II interaction on TH cells. Receptor for HIV.
CD8 molecules
Co-receptor for MHC-I/TCR interaction on CTLs.
CD14
LPS receptor binds LPS expressed by monocytes, macrophages, granulocytes
CD16
Fc receptor on NK cells, macrophages, neutrophils. IgG-mediated opsonization and ADCC
CD18
β chain of LFA-1 integrin on leukocytes. Cell adhesion molecule missing in LAD
CD19
Coreceptor with CD21 for B-cell activation and signal transuction
CD20
B-cell activation
CD21
Receptor for C3d and B cell coreceptor complex eith CD19. EBV receptor.
CD28
T cell receptor for costimulatory molecule B7 on APCs
CD34
Mediates adhesion to leukocyte L-selectin. Expressed by hematopoietic precurssors and HEVs
CD40
Expressed by APCs and endothelium. Binds CD40L on TH cells for activation
CD10
CALLA. Expressed by acute lymphlobastic leukemia cells (ALL)
CD46
Expressed by NK cells
IL-1
Secreted by APCs and endothelium. TH cell activation; B-cell maturation; Enhances NK cells; Increases ICAM expression on endothelium; Chemotactic for macrophages and neutrophils; Acute phase reactant synthesis by hepatocytes; Induces fever in hypothalamus
IL-2
Secreted by TH cells. Induces proliferation and enhances activity of TH and CTLs
IL-3
Secreted by TH and NK cells. Growth and differentiation of myeloid cells
IL-4
Secreted by TH2 cells. Costimulates activation of antigen-primed B cells; Stimulates proliferation and differentiation of activated B cells; Isotype switching from IgG1 to IgE; Suppresses TH1 cells; Stimulates TH2 cells.
IL-5
Secreted by TH2 cells. Stimulates proliferation and differentiation of activated B cells and induces isotype switch to IgA
IL-6
Secreted by macrophages and TH2 cells. Promotes terminal differentiation into plasma cells; Stimulates Ab secretion; Promotes differentiation of myeloid stem cells; Induces acute-phase reactant synthesis by hepatocytes.
IL-7
Secreted by bone marrow and thymic stromal cells. Induces differentiation of lymphoid stem cells into progenitor B and T cells.
IL-8
Secreted by macrophages and endothelium. Chemotactic for neutrophils.
IL-10
Secreted by TH2 cells. Suppresses TH1 cells; Stimulates TH2 cells.
IL-12
Secreted by macrophages and B-cells. Differentiation of TH1 cells; Differentiation and proliferation of CD8 cells; Proliferation of NK and TH1 cells
IFN-α
Secreted by leukocytes. Inhibits viral replication
IFN-β
Secreted by fibroblasts. Inhibits viral replication
TGF-β
Secreted by platelets, macrophages, lymphocytes, mast cells. Induces IgA isotype switching on B cells
TNF-α
Secreted by macrophages and NK cells. Cytotoxic to tumor cells; Cytokine secretion by inflammatory cells; cachexia of chronic inflammation
TNF-β
Secreted by TH1 and CTLs. Cytotoxic to tumor cells; Enhances phagocytosis by macrophages and neutrophils
Granulocyte colony-stimulating factor (G-CSF)
Secreted by macrophages and TH cells. Proliferation of bone marrow granulocyte precursors; Used as Rx.: for neutropenia.
Granulocyte macrophage colony stimulating factor (GM-CSF)
Secreted by macrophages and TH cells. Proliferation of granulocyte and macrophage precursors. Used as Rx. For neutropenia.
P-selectin
Selectin on endothelium and platelets.
E-selectin
Selectin on activated endothelium
L-selectin
Selectin on leukocytes binds CD34 (endothelial venules), GlyCam-1 (HEVs) and MadCAM-1 (mucosal lymhpoid tissue venules)
LFA-1
Integrin expressed by monocytes, T cells, macrophages, neutrophils, dendritic cells. Binds ICAMs
CR3
On neutrophils and macrophages. Binds ICAM-1, C3b, fibrinogen
CR4
On dendritic cells, macrophages, neutrophils. Binds C3b
VCAM-1
Adhesion molecule xpressed by active endothelium. Binds VLA-4 on leukocytes
ICAMs
On vessels and lymphocytes. Bind LFA-1 on leukocytes.
TH cell surface molecules
CD4, CD3, TCR, CD28, CD40L
CTL cell surface molecules
CD8, TCR, CD3
Macrophage cell surface molecules
MHC-II, B7, CD40, CD14, Fc and C3b receptors
NK cell surface molecules
Receptors for MHC-I, CD16, CD56
Type of hypersensitivity: Anaphylaxis
Type I
Type of hypersensitivity: Allergic rhinitis
Type I
Type of hypersensitivity: hemolytic anemia
Type II
Type of hypersensitivity: ITP
Type II
Type of hypersensitivity: eythroblastosis fetalis
Type II
Type of hypersensitivity: rheumatic fever
Type II
Type of hypersensitivity: Goodpasture syndrome
Type II
Type of hypersensitivity: Bullous pemphigoid
Type II
Type of hypersensitivity: Graves
Type II
Type of hypersensitivity: Myasthenia gravis
Type II
Type of hypersensitivity: SLE
Type III
Type of hypersensitivity: Rheumatoid arthritis
Type III
Type of hypersensitivity: PAN
Type III
Type of hypersensitivity: Poststrep glomerulonephritis
Type III
Type of hypersensitivity: Serum sickness
Type III
Type of hypersensitivity: Arthus reaction
Type III
Type of hypersensitivity: Hypersensitivity pneumonitis
Type III
Type of hypersensitivity: Type 1 DM
Type IV
Type of hypersensitivity: Multiple sclerosis
Type IV
Type of hypersensitivity: Guillain-Barre
Type IV
Type of hypersensitivity: Hashimoto's
Type IV
Type of hypersensitivity: Graft Vs. Host
Type IV
Type of hypersensitivity: PPD test for tuberculosis
Type IV
Type of hypersensitivity: Contact dermititis
Type IV
ANA
SLE
Anti-dsDNA
Specific for SLE
Anti-Smith
Specific for SLE
Antihistone
Drug-induced lupus
Anti-IgG
Rheumatoid factor/rheumatoid arthritis
Anticentromere
CREST
Anti-Scl-70
Diffuse scleroderma
Antimitochondrial
Primary billiary cirrhosis
Antigliadin
Celiac disease
Anti-GBM
Goosdpasture
Anti-epithelial cell (anti-desmosome)
Pemphigus vulgaris
Antimicrosomal
Hashimoto's
Antithyroglobulin
Hashimoto's
Anti-Jo-1
Polymyositis, dermatomyositis
Anti-SS-A (anti-Ro)
Sjogren
Anti-SS-B (anti-La)
Sjogren
Anti-U1 RNP
Mixed connective tissue disease
Anti-smooth muscle
Autoimmune hepatitis
Anti-glutamate decarboxylase
Type 1 DM
c-ANCA
Wegener's
p-ANCA
PAN
HLA-B27
Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter's (PAIR)
HLA-B8
Grave's disease, celiac sprue
HLA-DR2
Multiple sclerosis, hay fever, SLE, Goodpasture
HLA-DR3
DM type 1
HLA-DR4
Rheumatoid arthritis, type 1 DM
HLA-DR5
Pernicius anemia, Hashimoto's
HLA-DR7
Steroid-responsive nephrotic syndrome
processes responsible for idiotype diversity
1) gene rearrangements at the DNA level; 2) alternative splicing to isotype at RNA level
heavy chain gene structure
DVJ segments, delta, gamma3, gamma1, alpha1, gamma2, gamma4, epsilon, alpha2
site of immature thymocytes in the thymus
cortex; CD3+, CD4+, CD8+
mu+
heavy chains are formed in cytoplasm, but light chain rearrangement is in process --> pre-B-cell
tdt+
heavy chains are in the process of being formed --> pro-B-cell
markers of T cells as they leave bone marrow to thymus
CD4-, CD8-, TCR-; they are in the process of gene rearrangement as they leave marrow; in thymic cortex they are CD4+, CD8+, TCR+
origin of C5a
endothelial damage --> activates Hageman --> plasmin actiavation
origin of fibrinopeptides
endothelial damage --> Hageman --> thrombin --> fibrin clot degradation
antigen presentation on MHC-II molecules
1) antigen is endocytosed; 2) newly formed MHC-II in the endoplasmic reticulum have invariant chains that block the idiotype, so that it wont react with cytoplasm antigens; 3) MHC-II with invariant chains are transferred to antigen-containning vesicles; 4) MHC-II vesicles fuse with antigen-containning vesicles and the invariant chain is degraded; 5) the MHC-II molecule reacts with antigen and is transported to the membrane
invariant chain
it's a protein that blocks MHC-II idiotype so that it doesn’t react with cytoplasm antigens until in reaches foreign antigen-containning vesicles
TAP complex
transports cytoplasm degradation peptides into endoplasmic reticulum so that MHC-I molecules react with them
beta2 microglobulin
not encoded within MHC; helps transport antigen-loaded MHC-I to membrane
binding sites of superantigens
variable beta domain of TCR and alpha chain of MHC-II; does not bind idiotypes --> polyclonal activation
interleukin for IgE isotype switch
IL-4
interleukin for IgA isotype switch
IL-5
interleukin for differentiation of myeloid progenitors
IL-3
interleukin for differentiation of lymphoid progenitors
IL-7
B-cell mitogen
thymus independent antigens that directly and polyclonally activate B cells to secrete IgM; lipopolysacchride and polysacchride capsules are mitogens
pepsin cleavage site of immunoglobulins
just below the hinge region to produce 1 Fab2 and 1 Fc fragments
papain cleavage site of immunoglobulins
just above the hinge region to produce 2 Fab and 1 Fc fragments
isotype region of immunoglobulins
Fc fragment
constant heavy chain region of immunoglobulins
just above hinge region and below idiotype region
variable heavy chain region of immunoglobulins
at the N-terminal end, above the hinge and constant regions
C3b binding region of IgG and IgM
below the hinge region
order of isotype switching
IgM, IgG, IgA (IL-5), IgE (IL-4)
Ig's that can opsonize
IgG
Ig's that can activate the complement
IgG, IgM
Ig's that activate ADCC
IgG
NK cell stimulant molecules
IFN-α, IFN-β and IL-12 produced by macrophages