p.32
Cytokines and Their Functions
What defines the actions exerted by cytokines?
The target of the cytokines.
p.36
Cytokines and Their Functions
What is a Cytokine Storm?
A phenomenon where white blood cells release too many cytokines into the blood too quickly, causing harm to the host.
p.33
Cytokines and Their Functions
How do cytokines affect cell activity?
They stimulate or inhibit activation, proliferation, and differentiation of various cells.
p.31
Cytokines and Their Functions
What typically mediates the signal-transduction pathways triggered by cytokines?
Secondary messengers, typically tyrosine kinases.
p.31
Cytokines and Their Functions
What does it mean for target cells to have high affinity receptors?
Picomolar concentrations of cytokines can produce physiological responses.
p.37
Cytokines and Their Functions
What is the role of chemokines?
They direct the movement of leukocytes around the body and affect leukocyte behavior.
p.14
Alternative Pathway of Complement Activation
What is the significance of the amplification stage in the Alternative Pathway?
It enhances the production of C3b, leading to a stronger immune response.
p.44
Cytokines and Their Functions
What is the function of the migration inhibitory factor?
Keeps macrophages localized at the site of high antigen concentration.
p.36
Cytokines and Their Functions
What happens to blood vessels during a Cytokine Storm?
They become leaky, filling the lungs with fluid.
p.3
Functions of Complement
What is one function of the complement system related to cells and pathogens?
Lysis of cells, bacteria, and viruses, with or without antibody.
p.12
Alternative Pathway of Complement Activation
What happens to C3 in the plasma?
It is continuously and spontaneously cleaved into C3a and C3b.
p.32
Cytokines and Their Functions
What is a paracrine cytokine?
A cytokine that affects cells that are near the secretor.
p.31
Cytokines and Their Functions
What is the effect of cytokine signaling on target cells?
It alters the behavior of the cell, including gene expression.
p.6
Complement Protein Components
What role do proteases play in the activation of complement proteins?
They cleave proenzymes to activate them.
p.6
Complement Protein Components
What is a potential outcome of complement activation?
Signaling molecules for inflammation.
p.22
Cytokines and Their Functions
Which cells are attracted by C5a?
Neutrophils, basophils, eosinophils, and monocytes.
p.22
Cytokines and Their Functions
What effect does C5a binding to monocytes have?
It leads to oxidative burst and increases production of hydrolytic enzymes.
p.28
Excess Activation of Complement
What can trigger complement activation in autoimmune diseases?
Immune complexes formed in the diseases.
p.28
Excess Activation of Complement
What do hydrolytic and lysosomal enzymes released from phagocytic cells do?
They damage nearby host cells.
p.10
Biological Functions of Complement Activation
What type of pathogens does the Membrane Attack Complex primarily target?
Bacteria and some viruses.
p.2
Biological Functions of Complement Activation
What types of reactions does the complement system mediate?
Cytotoxic reactions towards cells and microorganisms.
p.45
Cytokines and Their Functions
What technique is used for real-time quantitative PCR in cytokine testing?
mRNA real-time quantitative PCR.
p.37
Cytokines and Their Functions
What is chemotaxis?
The process by which chemokines affect the movement of leukocytes.
p.14
Alternative Pathway of Complement Activation
What role does properdin play in relation to C3 convertase?
Properdin binds and stabilizes C3 convertase, extending its half-life to 30 minutes.
p.44
Cytokines and Their Functions
What are chemokines?
Cytokines with chemotactic activities.
p.27
Functions of Complement
Why are increased complement levels of limited use?
Because they are common and nonspecific.
p.44
Cytokines and Their Functions
What does macrophage chemotaxin do?
Attracts monocytes and macrophages to the site of antigen concentration.
p.26
Regulation of Complement Activation
What role does the C1 inhibitor play in complement regulation?
It forms a complex with C1r2s2, causing it to dissociate from C1q.
p.42
Cytokines and Their Functions
What is Macrophage/Monocyte Colony-stimulating Factor (M-CSF)?
A cytokine produced mainly by fibroblasts and epithelial cells that induces growth of hematopoietic cells destined to become macrophages and monocytes.
p.22
Cytokines and Their Functions
What do platelet activating factors do?
They promote platelet aggregation and activation.
p.45
Cytokines and Their Functions
What type of assay is the ELISA multiplex kit?
A serological assay for quantitative detection.
p.30
Cytokines and Their Functions
How do cytokines affect immune responses?
They influence the behavior of immune cells and coordinate the immune response.
p.14
Alternative Pathway of Complement Activation
How does C3 convertase (C3bBb) contribute to the complement system?
It cleaves C3 and amplifies the production of more C3b.
p.13
Alternative Pathway of Complement Activation
What happens to soluble C3 in the plasma during the Alternative Pathway?
It is spontaneously hydrolyzed to form C3a and C3b.
p.34
Cytokines and Their Functions
What is pleiotropy in the context of cytokines?
Pleiotropy refers to a cytokine having different biological effects on different target cells.
p.21
Biological Functions of Complement Activation
Which anaphylatoxin is the most potent?
C5a, which is 100 times more potent than C3a.
p.12
Alternative Pathway of Complement Activation
What is the first step in the Alternative Pathway?
Proteolytic cleavage of C3.
p.24
Regulation of Complement Activation
What potential damage can complement components cause?
They can cause lysis of 'bystander' cells, damaging host tissues.
p.17
Lectin Pathway of Complement Activation
What are lectins?
Circulating proteins that bind to carbohydrates.
p.17
Lectin Pathway of Complement Activation
What does Mannose-binding lectin (MBL) bind to?
Mannose residues on glycoproteins or carbohydrates on microbial membranes.
p.17
Lectin Pathway of Complement Activation
What happens after MBL binds to mannose?
A serine protease binds to MBL, which can activate either the C1r2s2 enzyme complex or MBL-associated serine protease (MASP).
p.1
Alternative Pathway of Complement Activation
What initiates the alternative pathway of complement activation?
The spontaneous hydrolysis of complement component C3.
p.31
Cytokines and Their Functions
What is a cytokine?
A large group of molecules involved in signaling between cells during immune responses.
p.27
Functions of Complement
What are common causes for increases in complement levels?
Inflammation, trauma, and acute illness such as myocardial infarction.
p.23
Functions of Complement
What is the primary function of opsonization?
To facilitate phagocytosis and clearance of foreign substances.
p.2
Introduction to the Complement System
What is the complement system?
Soluble mediators (effectors) of the Innate (Natural) Immune System.
p.2
Functions of Complement
What role does the complement system play in host defense mechanisms?
It is an essential part of normal host defense mechanisms.
p.5
Complement Protein Components
What is the complement system composed of?
A heat labile series of 18 plasma proteins, mainly proteolytic enzymes or Serine Proteinases.
p.34
Cytokines and Their Functions
What is synergy in cytokine interactions?
Synergy occurs when the combined effect of two cytokines on cellular activity is greater than the sum of their individual effects.
p.30
Cytokines and Their Functions
What role do cytokines play in the immune system?
They act as signaling molecules that mediate and regulate immunity, inflammation, and hematopoiesis.
p.12
Alternative Pathway of Complement Activation
What initiates the Alternative Pathway of complement activation?
C3b covalently binding to the membrane of a foreign microorganism.
p.3
Functions of Complement
What is immune clearance in relation to the complement system?
The removal of immune complexes from circulation and their deposition in the spleen and liver.
p.25
Regulation of Complement Activation
How do Complement Receptor Type 1 (CR1) and Membrane Cofactor Protein contribute to complement regulation?
They block the formation of C3 convertase.
p.28
Excess Activation of Complement
What can result from neutrophil aggregation in the lungs due to complement activation?
Emboli and damage to tiny pulmonary capillaries.
p.42
Cytokines and Their Functions
What link do colony-stimulating factors provide?
A link between the lymphoid and the hematopoietic system.
p.38
Cytokines and Their Functions
What are lymphokines?
Cytokines secreted by lymphocytes that regulate the function of other cells and tissues.
p.7
Complement Activation Pathways
What role does one of the peptides play after proteolytic cleavage?
One peptide binds to the immune complex and becomes a functional part of it (e.g., peptide b).
p.37
Cytokines and Their Functions
What are the main classes of cytokines?
Interleukins, Interferons (IFNs), Tumor necrosis factors, and Chemokines.
p.8
Lectin Pathway of Complement Activation
How is the lectin pathway of complement activation initiated?
By the recognition of pathogens with terminal mannose groups.
p.13
Alternative Pathway of Complement Activation
What is the role of Factor D in the Alternative Pathway?
Factor D cleaves Factor B after it binds to C3b to form Bb.
p.10
Biological Functions of Complement Activation
What is the Membrane Attack Complex (MAC)?
A structure formed by complement proteins that creates pores in the membranes of target cells.
p.12
Alternative Pathway of Complement Activation
What is the Alternative Pathway in the complement system?
An antibody-independent means of generating C3 convertase and activating the MAC.
p.21
Biological Functions of Complement Activation
What are anaphylatoxins?
Small peptides that cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils and mast cells.
p.12
Alternative Pathway of Complement Activation
What occurs if C3b remains in the fluid phase?
It is quickly hydrolyzed and becomes inactivated, stopping complement activation.
p.2
Biological Functions of Complement Activation
What is one of the potent functions of the complement system?
It acts as a mediator of inflammation.
p.26
Regulation of Complement Activation
What is the function of Factor H in the alternative pathway?
It blocks the association between C3b and Bb, preventing the formation of C3 convertase (C3bBb).
p.28
Excess Activation of Complement
What activates the alternative pathway in cases of bacteremia with gram-negative bacteria?
LPS (lipopolysaccharides).
p.21
Biological Functions of Complement Activation
What are leukotrienes associated with in the context of anaphylaxis?
They are substances that cause prolonged contraction of smooth muscle, sometimes referred to as slow-reacting substances of anaphylaxis (SRS-A).
p.24
Regulation of Complement Activation
Why is it important to prevent the consumption of complement components?
If all components are used up, the body cannot continue to fight infection.
p.43
Cytokines and Their Functions
What role does Stem Cell Factor play in hematopoietic progenitor cells?
It helps them acquire characteristics of specific cell lineages (e.g., Myeloid or Lymphoid).
p.18
Biological Functions of Complement Activation
What is the primary function of complement activation?
To amplify the inflammatory response to destroy and clear foreign antigens.
p.1
Complement Protein Components
What are the main components of the complement system?
Complement proteins, which are mainly produced by the liver.
p.41
Cytokines and Their Functions
How does TNF-γ affect macrophages?
Activates them to express HLA-DR molecules and produce active oxygen intermediates.
p.32
Cytokines and Their Functions
What is an endocrine cytokine?
A cytokine that affects cells in distant parts of the body.
p.8
Classical Pathway of Complement Activation
What is the classical pathway of complement activation initiated by?
Antibodies bound to the surface of the target.
p.23
Functions of Complement
Which types of cells have specific receptors for opsonins like C3b?
Erythrocytes, neutrophils, and monocytes/macrophages.
p.2
Functions of Complement
How does the complement system relate to humoral immunity?
It is an important effector of humoral immunity, acting as the 2nd or 3rd line of defense in reference to antibody interaction.
p.3
Functions of Complement
How does the complement system activate the inflammatory response?
By binding to specific complement receptors on immune system cells, triggering immune responses.
p.25
Regulation of Complement Activation
What is Factor I and its function in the complement system?
A serine protease that cleaves C4b or C3b, preventing C3 or C5 convertase from forming.
p.5
Complement Protein Components
What are proteinases?
Enzymes that break down proteins into shorter fragments by hydrolysis of peptide bonds.
p.38
Cytokines and Their Functions
What are interleukins?
Cytokines produced by leukocytes that affect the inflammatory process.
p.7
Complement Activation Pathways
What does the term 'cascade' refer to in enzymatic processes?
One event must occur before another takes place.
p.41
Cytokines and Their Functions
What is the principal mediator of the acute inflammatory response to gram-negative bacteria?
Tumor Necrosis Factor (TNF).
p.17
Lectin Pathway of Complement Activation
How does the mechanism of the Lectin Pathway compare to the Classical Pathway?
It is almost exactly like the Classical Pathway but is antibody independent.
p.7
Complement Activation Pathways
What happens to the other peptide after proteolytic cleavage?
It diffuses away and can become an inflammatory mediator by binding to a receptor (e.g., peptide a).
p.20
Complement Protein Components
What is the role of C3 convertase in the complement system?
To cleave C3 into C3a and C3b, which are crucial for opsonization and inflammation.
p.41
Cytokines and Their Functions
What is the relationship between TNF-γ and IL-4?
TNF-γ is antagonistic to IL-4.
p.9
Classical Pathway of Complement Activation
What does C4b do after being cleaved?
It binds to the cell surface.
p.33
Cytokines and Their Functions
What is one function of cytokines in the immune response?
Regulate the intensity and duration of the immune response.
p.33
Cytokines and Their Functions
What do cytokines stimulate the secretion of?
Antibodies and other cytokines.
p.6
Complement Protein Components
What is required for proenzymes to become enzymatically active?
Proteolytic cleavage by other proteases.
p.16
Alternative Pathway of Complement Activation
What happens to C3 in the alternative pathway?
C3 is spontaneously hydrolyzed and C3b binds to microbial surface.
p.44
Cytokines and Their Functions
What is the role of soluble immune response suppressor (SIRS)?
Turns off or inhibits antibody production.
p.10
Biological Functions of Complement Activation
How does the Membrane Attack Complex contribute to the immune response?
By directly killing pathogens and infected cells.
p.21
Biological Functions of Complement Activation
What effect does C5a have on neutrophils?
It causes neutrophils to release leukotrienes, which lead to prolonged contraction of smooth muscle.
p.34
Cytokines and Their Functions
What is cascade induction in cytokine signaling?
Cascade induction is when the action of one cytokine on a target cell induces that cell to produce other cytokines, which may then induce additional target cells to produce more cytokines.
p.25
Regulation of Complement Activation
What is the function of S protein in the terminal end of the complement pathway?
It binds soluble C5b67, preventing membrane insertion.
p.25
Regulation of Complement Activation
What do Homologous Restriction Factor and Membrane Inhibitor of Reactive Lysis do?
They bind C5b678 on autologous cells, preventing the binding of C9.
p.24
Regulation of Complement Activation
What happens to some complement components if not stabilized?
They spontaneously inactivate.
p.41
Cytokines and Their Functions
What role does TNF-α play in the immune response?
It plays a role in inflammatory responses.
p.18
Biological Functions of Complement Activation
Does the complement activation cycle always lead to cell lysis?
No, it does not always have to proceed to lysis to accomplish its goal.
p.1
Complement Activation Pathways
How is the complement system activated?
Through three main pathways: classical, alternative, and lectin pathways.
p.40
Cytokines and Their Functions
What is the source and function of IFN α?
Source: leukocytes; Function: inhibits viral replication.
p.29
Regulation of Complement Activation
What can cause secondary decreases in complement levels?
Diseases that give rise to immune complexes.
p.39
Cytokines and Their Functions
What are the source cells for Interleukin-1 (IL-1)?
Macrophages, monocytes, B & T Cells.
p.32
Cytokines and Their Functions
What is an autocrine cytokine?
A cytokine that affects the cell that is secreting it.
p.31
Cytokines and Their Functions
How do cytokines affect target cells?
By binding to specific receptors on their membranes, triggering signal-transduction pathways.
p.15
Alternative Pathway of Complement Activation
What complex is formed by the binding of additional C3b to the microbial surface?
C3bBb3b, which is the C5 convertase for the Alternative Pathway.
p.36
Cytokines and Their Functions
What can excessive immune response during a Cytokine Storm lead to?
Acute respiratory distress syndrome and multiorgan failure.
p.13
Alternative Pathway of Complement Activation
What complex is formed after Factor B is cleaved by Factor D?
The C3bBb complex, which is the C3 convertase for the Alternative Pathway.
p.10
Biological Functions of Complement Activation
What is the primary function of the Membrane Attack Complex?
To lyse target cells by disrupting their membrane integrity.
p.34
Cytokines and Their Functions
What does antagonism refer to in cytokine activity?
Antagonism refers to the effect of one cytokine inhibiting or offsetting the effects of another cytokine.
p.22
Cytokines and Their Functions
What is interleukin-1?
A cytokine that enhances T cell activation, produces fever, and increases acute phase reactants.
p.11
Complement Protein Components
Which complement proteins are involved in the Classical Pathway?
C1, C4, C2, C3, C5, C6, C7, C8, C9 (with C4 being out of order).
p.28
Excess Activation of Complement
What condition can damaged blood vessels in the lungs cause?
Interstitial pulmonary edema.
p.43
Cytokines and Their Functions
What type of receptor does Stem Cell Factor interact with?
A tyrosine kinase membrane receptor (c-kit).
p.38
Cytokines and Their Functions
What are monokines?
Small peptides secreted by monocytes that regulate the function of other cells and tissues.
p.1
Functions of Complement
What role does the complement system play in the immune response?
It helps to opsonize pathogens, recruit inflammatory cells, and lyse pathogens.
p.18
Biological Functions of Complement Activation
What is one mechanism by which complement causes cell lysis?
Through the membrane attack complex (MAC).
p.18
Biological Functions of Complement Activation
What are anaphylatoxins and their role in complement activation?
They stimulate inflammation and activate PMNs (neutrophils) to release granules.
p.1
Lectin Pathway of Complement Activation
What is the lectin pathway of complement activation?
A pathway activated by the binding of lectins to specific carbohydrates on pathogens.
p.29
Regulation of Complement Activation
What is the relationship between circulating immune complexes and complement levels after infection?
Increased circulating immune complexes (IgM or IgG) after infection are associated with decreased complement levels.
p.39
Cytokines and Their Functions
What is the primary biological function of IL-1?
Mediator of host inflammatory response to infections and other inflammatory stimuli.
p.15
Alternative Pathway of Complement Activation
What does the C5 convertase (C3bBb3b) cleave C5 into?
C5b (large) and C5a (small).
p.15
Membrane Attack Complex
What role does C5b play in the Membrane Attack Complex (MAC)?
C5b becomes bound to the Convertase and initiates the assembly of the MAC (C5 - C9).
p.15
Membrane Attack Complex
How is the assembly of the Membrane Attack Complex (MAC) similar to the Classical Pathway?
The initiation of MAC assembly by C5b is similar in both pathways.
p.34
Cytokines and Their Functions
What does redundancy mean regarding cytokines?
Redundancy means that two or more cytokines can mediate similar functions, making it difficult to attribute a specific activity to a single cytokine.
p.30
Cytokines and Their Functions
What are cytokines?
Messengers of the immune system.
p.22
Cytokines and Their Functions
What is the role of neutrophil chemotactic factor?
It attracts neutrophils to sites of infection or inflammation.
p.5
Complement Protein Components
What role do enzymes play in biological processes?
They catalyze metabolic processes.
p.11
Classical Pathway of Complement Activation
What is the recognition unit of the Classical Pathway?
C1qr2s2, which binds the Fc portion of two IgG antibody molecules or one IgM.
p.26
Regulation of Complement Activation
How does Factor H assist in the regulation of C3b?
It binds C3b for cleavage by Factor I.
p.43
Cytokines and Their Functions
What is one function of Stem Cell Factor?
To make bone marrow stem cells responsive to CSFs without causing colony formation.
p.43
Cytokines and Their Functions
How does Stem Cell Factor affect T Cells and mast cells?
It may sustain their viability and proliferative capacity.
p.1
Introduction to the Complement System
What is the complement system?
A part of the immune system that enhances the ability to clear microbes and damaged cells.
p.20
Complement Activation Pathways
What are the three main pathways of complement activation?
Classical pathway, alternative pathway, and lectin pathway.
p.40
Cytokines and Their Functions
What are interferons (IFNs) originally thought to do?
Interfere with viral replication in an infected cell.
p.40
Cytokines and Their Functions
Which cells produce interferons?
T cells and other cell lines.
p.20
Regulation of Complement Activation
What role do regulatory proteins play in the complement system?
They prevent excessive complement activation and protect host cells.
p.29
Regulation of Complement Activation
What does chronic consumption of complement components indicate?
It indicates ongoing activation and depletion of complement levels.
p.39
Cytokines and Their Functions
Which diseases are associated with IL-1?
Inflammatory bone resorption, gout, and promotes Helper T Cell response.
p.39
Cytokines and Their Functions
What diseases are associated with IL-6?
Deficient innate immunity and acute-phase responses, lymphopenia.
p.22
Cytokines and Their Functions
What is a chemotaxin?
A chemical messenger that causes migration of cells in a particular direction.
p.26
Regulation of Complement Activation
What regulates the classical and lectin pathways of complement activation?
C4b-binding protein and C1 inhibitor.
p.26
Regulation of Complement Activation
How does C4b-binding protein affect C3 convertase formation?
It blocks the formation of C3 convertase (C4b2a) by binding C4b for cleavage by Factor I.
p.3
Functions of Complement
What is opsonization in the context of the complement system?
Deposition of opsonins on antigens, promoting stable adhesive contact with phagocytic cells.
p.25
Regulation of Complement Activation
What is the role of Decay Accelerating Factor (DAF) in complement regulation?
It speeds the dissociation of C3 convertase.
p.42
Cytokines and Their Functions
What is Granulocyte Colony-stimulating Factor (G-CSF)?
A cytokine produced by fibroblasts and epithelial cells that induces growth of hematopoietic stem cells destined to become granulocytes.
p.42
Cytokines and Their Functions
What ability do colony-stimulating factors have?
They can stimulate the growth and development/expansion of various leukocytes or erythroid colonies from bone marrow cells.
p.20
Functions of Complement
What is the primary function of the complement system?
To enhance the ability of antibodies and phagocytic cells to clear pathogens.
p.41
Cytokines and Their Functions
What is the function of TNF-β?
Acts against virally infected cells and tumor cells.
p.18
Biological Functions of Complement Activation
How does complement promote phagocytosis?
By opsonization of microbes.
p.18
Biological Functions of Complement Activation
What is immune clearance in the context of complement activation?
It removes immune complexes from circulation and deposits them in the spleen and liver.
p.40
Cytokines and Their Functions
What is the source and function of IFN β?
Source: fibroblasts; Function: inhibits viral replication.
p.9
Membrane Attack Complex
What role does C9 play in the MAC?
Helps stabilize the MAC for full lysis capability.
p.39
Cytokines and Their Functions
What is the biological function of IL-2?
T Cell growth factor, enhances cytotoxicity of T cell and NK cells.
p.39
Cytokines and Their Functions
What is the primary function of IL-10?
Immune suppression; decreases antigen presentation and MHC class II expression.
p.45
Cytokines and Their Functions
What does the ELISA multiplex kit detect?
Multiple (~8) cytokines simultaneously in a single sample.
p.42
Cytokines and Their Functions
What is Granulocyte-Macrophage Colony-stimulating Factor (GM-CSF)?
A cytokine produced by activated T cells and other cell lines that stimulates an increased supply of granulocytic cells and macrophages.
p.43
Cytokines and Their Functions
Where is Stem Cell Factor synthesized?
By stromal cells of the bone marrow.
p.24
Regulation of Complement Activation
What does regulation of the complement system prevent?
Consumption of components through unregulated amplification.
p.38
Cytokines and Their Functions
What is the primary function of interleukins?
Communication between white blood cells.
p.25
Regulation of Complement Activation
Can complement activation be regulated specifically for one pathway or multiple pathways?
Yes, it can be regulated specifically for one particular pathway or multiple pathways.
p.24
Regulation of Complement Activation
What occurs to C3b when it is 40 nm away from convertase?
C3b undergoes hydrolysis.
p.17
Lectin Pathway of Complement Activation
What initiates the Lectin Pathway?
Circulating lectins binding to microbial polysaccharides.
p.20
Classical Pathway of Complement Activation
What initiates the classical pathway of complement activation?
The binding of antibodies to antigens.
p.20
Alternative Pathway of Complement Activation
How does the alternative pathway of complement activation differ from the classical pathway?
It is initiated by the spontaneous hydrolysis of C3 and does not require antibodies.
p.29
Regulation of Complement Activation
Which autoimmune disorder is commonly associated with depression of complement levels?
Systemic Lupus Erythematosus (SLE).
p.39
Cytokines and Their Functions
What diseases are associated with IL-4?
Susceptibility to extracellular pathogens and allergic asthma.
p.5
Complement Protein Components
In which serum protein electrophoresis fractions are complement proteinases found?
In the beta 1 and beta 2 globulin fractions.
p.7
Complement Activation Pathways
What is the significance of each activated enzyme in a cascade?
Each activated enzyme can generate multiple activated enzymes at the next step, leading to amplification of enzymatic events.
p.17
Lectin Pathway of Complement Activation
What is structurally similar to C1q?
Mannose-binding lectin (MBL).
p.1
Classical Pathway of Complement Activation
What is the classical pathway of complement activation?
A pathway that is triggered by the binding of antibodies to pathogens.
p.20
Biological Functions of Complement Activation
What is the end result of complement activation?
Formation of the membrane attack complex (MAC) that can lyse pathogens.
p.40
Cytokines and Their Functions
What is the source and function of IFN γ?
Source: T-helper (CD4), T cytotoxic (CD8), and NK cells; Function: has antiviral effects, activates macrophages, NK cells, and stimulates B-cells to make antibodies.
p.9
Classical Pathway of Complement Activation
What initiates the Classical Pathway of complement activation?
Binding of C1q to IgM or IgG antigen-antibody complexes.
p.9
Classical Pathway of Complement Activation
What complex is formed when C2a binds to C4b?
The C3 convertase complex.
p.39
Cytokines and Their Functions
What are the source cells for Interleukin-6 (IL-6)?
Macrophages, T Cells, fibroblasts, and others.
p.39
Cytokines and Their Functions
What diseases are associated with IL-12?
Impaired Helper T Cell responses and increased susceptibility to intracellular pathogens.
p.28
Excess Activation of Complement
What happens if complement attaches to red blood cells?
They may lyse, producing anemic conditions.
p.7
Complement Activation Pathways
What happens during proteolytic cleavage of an enzyme?
It results in two peptides.
p.38
Cytokines and Their Functions
Which cells primarily produce interleukins?
Leukocytes, specifically T cells and macrophages.
p.18
Biological Functions of Complement Activation
What role do effector molecules play in complement activation?
They are generated early in the cascade and play a major role in destroying foreign antigens.
p.41
Cytokines and Their Functions
What effect does TNF-γ have on Fc receptors?
Increases their expression.
p.1
Regulation of Complement Activation
How is the complement system regulated?
Through various regulatory proteins that prevent damage to host cells.
p.9
Classical Pathway of Complement Activation
What happens when C1s binds in the Classical Pathway?
It attracts and cleaves C4 into C4a and C4b.
p.39
Cytokines and Their Functions
What is the primary function of IL-4?
Proliferation and differentiation of Helper T Cells; promotes IgG and IgE isotype switching.
p.39
Cytokines and Their Functions
What is the biological function of IL-12?
Differentiation and proliferation; promotes Helper T Cells and cytotoxicity.
p.38
Cytokines and Their Functions
How do interleukins affect other cells?
By increasing soluble factors or cells involved in the inflammatory process.
p.41
Cytokines and Their Functions
What is the role of TNF-γ?
Augments the activity of many cytokines.
p.20
Lectin Pathway of Complement Activation
What triggers the lectin pathway of complement activation?
The binding of mannose-binding lectin (MBL) to specific carbohydrates on pathogens.
p.1
Biological Functions of Complement Activation
What are the biological functions of complement activation?
Enhancing phagocytosis, promoting inflammation, and directly lysing pathogens.
p.9
Classical Pathway of Complement Activation
What complex is formed when C3b binds to the C3 convertase?
The C5 convertase complex.
p.39
Cytokines and Their Functions
What diseases are associated with IL-2?
Lymphoproliferative disease and susceptibility to autoimmune disease.
p.39
Cytokines and Their Functions
What diseases are associated with IL-10?
Immune pathology due to uncontrolled inflammation.
p.17
Lectin Pathway of Complement Activation
How does the rest of the Lectin Pathway compare to the Classical Pathway?
It is identical, differing only in the initiation and activation steps.
p.29
Regulation of Complement Activation
What does a decrease in complement levels suggest?
It suggests that complement has been excessively activated, is currently being consumed, or a single component is absent due to a genetic defect.
p.39
Cytokines and Their Functions
What are the source cells for Interleukin-12 (IL-12)?
Macrophages, B cells, neutrophils, dendritic cells.
p.39
Cytokines and Their Functions
What are the target cells for Interleukin-2 (IL-2)?
T, B, NK cells, and macrophages.
p.39
Cytokines and Their Functions
What are the source cells for Interleukin-10 (IL-10)?
Differentiated T helper cells, Tregs, B cells, dendritic cells, others.
p.39
Cytokines and Their Functions
What is the biological function of IL-6?
Inflammatory and co-stimulatory action; induces proliferation and differentiation.
