ENZYMES, GROWTH FACTORS, PROTEINS, AND RECEPTORS

Collagenases

What enzymes are secreted by leukocytes to pierce the basement membrane, allowing them to enter extravascular tissue?

Elastases

What enzymes are secreted by leukocytes to pierce the basement membrane, allowing them to enter extravascular tissue?

PECAM-1 (Platelet Endothelial Cell Adhesion Molecule 1)

What adhesion molecule is involved in leukocyte migration through the intercellular junctions between endothelial cells?

Melanin

What pigment imparts a brown or black color to fungal colonies and protects these fungi from host defenses?

Amphids

What sensory organs are present in nematodes?

Phasmids

What sensory organs are present in nematodes?

Cyclooxygenase (COX)

What enzyme activity is increased by pyrogens, leading to the production of prostaglandins that can drive fever?

NADPH oxidase

What enzyme generates reactive oxygen species (ROS) by oxidizing NADPH and reducing oxygen to superoxide anion?

Myeloperoxidase (MPO)

What enzyme, in the presence of a halide, converts hydrogen peroxide (H2O2) to hypochlorite (OCl•), forming the most efficient bactericidal system of neutrophils?

Nitric Oxide Synthase (NOS)

What enzyme produces nitric oxide (NO) from arginine?

Phospholipases (mainly Phospholipase A2)

What enzymes are responsible for releasing arachidonic acid from membrane phospholipids?

Proteases (e.g., plasmin)

What substances activate matrix metalloproteinases (MMPs) from their zymogen forms?

Toll-like receptors (TLRs)

What receptors can detect bacteria, viruses, and fungi, and when engaged, trigger signaling pathways that stimulate the production of chemical mediators of inflammation?

G protein-coupled receptors

What receptors are found on neutrophils and macrophages that recognize short bacterial peptides and various mediators of inflammation like chemokines and C5a?

Fc receptors

What leukocyte receptors bind opsonized particles, such as IgG antibodies, to promote phagocytosis and activate cells?

C3 receptors

What leukocyte receptors bind opsonized particles, such as C3b complement proteins, to promote phagocytosis and activate cells?

Integrins

What adhesion molecules mediate the firm adhesion of leukocytes to the endothelium and are also involved in retaining leukocytes at the site of inflammation by binding to extracellular matrix proteins?

Selectins

What molecules mediate the initial rolling interactions of leukocytes on the endothelium?

VCAM-1 (Vascular Cell Adhesion Molecule 1)

What endothelial adhesion molecule serves as a ligand for the VLA-4/β1 integrin on leukocytes?

ICAM-1 (Intercellular Adhesion Molecule-1)

What endothelial adhesion molecule serves as a ligand for the LFA-1 and Mac-1/β2 integrins on leukocytes?

Antibodies (e.g., IgG)

What plasma proteins act as principal defenders against foreign invaders and can also function as opsonins?

Neutrophils

What predominant inflammatory cells are mainly involved in acute inflammation, acting as phagocytes that are short-lived in tissues?

Monocytes

What circulating white blood cells differentiate into macrophages upon entering tissues?

Macrophages

What tissue phagocytes play an important role in the inflammatory response, derived from monocytes, and become the dominant cell population in chronic inflammation?

Plasma proteins

What fluid component of the blood contains substances like antibodies that can act as chemical mediators of inflammation?

Fibrin

What plasma protein accumulates in fibrinous exudate due to large vascular leaks?

Histamine

What vasoactive amine, produced by mast cells, basophils, and platelets, is the principal mediator of the immediate transient phase of increased vascular permeability and causes dilation of arterioles?

Nitric oxide (NO)

What substance, produced by endothelial cells, macrophages, and some neurons, causes vascular smooth muscle relaxation and vasodilation, and can also reduce leukocyte and platelet adhesion?

Prostaglandins

What arachidonic acid metabolites (e.g., PGI2, PGE1, PGE2, PGD2) cause vasodilation, and specifically, which one (PGE2) induces the hypothalamus to elevate body temperature?

Leukotrienes

What arachidonic acid metabolites (e.g., C4, D4, E4) can cause vasoconstriction, bronchospasm, and increase vascular permeability, and which one (B4) is a chemotactic agent?

Thromboxane A2

What arachidonic acid metabolite causes vasoconstriction and promotes platelet aggregation?

Lipoxins (A4, B4)

What arachidonic acid metabolites are anti-inflammatory, functioning to inhibit neutrophil adhesion and chemotaxis?

VLA-4/β1 integrin

What leukocyte integrin binds to VCAM-1 to mediate firm adhesion to the endothelium?

LFA-1/β2 integrin

What leukocyte integrin binds to ICAM-1 to mediate firm adhesion to the endothelium?

Mac-1/β2 integrin

What leukocyte integrin binds to ICAM-1 to mediate firm adhesion to the endothelium?

Sialyl-Lewis X

What ligand, expressed on neutrophils, mediates initial rolling interactions by binding to E- and P-selectins on endothelial cells?

TNF (Tumor Necrosis Factor)

What cytokine enhances the expression of selectins and integrins on endothelial cells, induces early release of granulocytes from marrow, and acts as a pyrogen to cause fever?

IL-1 (Interleukin-1)

What cytokine enhances the expression of selectins and integrins on endothelial cells, induces early release of granulocytes from marrow, and acts as a pyrogen to cause fever?

Chemokines

What chemical mediators bind to and activate rolling leukocytes, stimulating them to migrate through interendothelial spaces toward the site of injury or infection?

C5a

What complement protein acts as an endogenous chemoattractant for leukocytes?

PAF (Platelet Activating Factor)

What mediator of inflammation activates endothelial cells?

HETE (Hydroxyeicosatetraenoic acid)

What arachidonic acid metabolite is a chemotactic agent?

Opsonins

What substances (e.g., IgG antibodies, C3b complement proteins, Mannan-binding lectin) coat a microbe to target it for ingestion by phagocytes?

C3b complement proteins

What complement protein acts as an opsonin, coating microbes to facilitate phagocytosis?

Mannan-binding lectin

What lectin acts as an opsonin, coating microbes to facilitate phagocytosis?

Interferon-γ (IFN-γ)

What cytokine, secreted by natural killer cells and antigen-activated T lymphocytes, is a major macrophage-activating cytokine?

Reactive Oxygen Species (ROS)

What microbicidal products (e.g., superoxide anion, hydrogen peroxide, hydroxyl radical) are generated primarily by NADPH oxidase and used for killing and degradation?

Superoxide anion (O2-)

What reactive oxygen species is generated by NADPH oxidase oxidizing NADPH and reducing oxygen, and is then converted into hydrogen peroxide?

Hydrogen peroxide (H2O2)

What reactive oxygen species is converted from superoxide anion, and can be further converted to hypochlorite by MPO or to hydroxyl radical?

Hypochlorite (OCl•)

What potent antimicrobial agent is formed when myeloperoxidase (MPO) converts hydrogen peroxide (H2O2) in the presence of a halide?

Hydroxyl radical (•OH)

What powerful destructive agent is formed from hydrogen peroxide (H2O2) during microbial killing?

Peroxynitrite (ONOO•)

What highly reactive free radical is generated when nitric oxide (NO) reacts with superoxide, participating in microbial killing?

P-selectin

What endothelial adhesion molecule is involved in the tethering and margination of neutrophils during acute inflammation?

E-selectin

What endothelial adhesion molecule is involved in the rolling of neutrophils along the endothelium?

Matrix Metalloproteinases (MMPs)

What enzymes degrade the extracellular matrix (ECM) to allow for remodeling and extension of vascular tubes during angiogenesis, and also continuously modify and remodel connective tissue in scars?

Tissue Inhibitors of Metalloproteinases (TIMPs)

What proteins inhibit the activity of matrix metalloproteinases (MMPs)?

Vascular Endothelial Growth Factor (VEGF)

What growth factor promotes vascular leakage by increasing the number and size of channels, stimulates the migration and proliferation of endothelial cells, and induces vasodilation?

Fibroblast Growth Factor 2 (FGF-2)

What growth factor stimulates the proliferation of endothelial cells, promotes the migration of macrophages and fibroblasts to damaged areas, and stimulates epithelial cell migration to cover wounds?

Angiopoietins 1 and 2 (Ang 1 and Ang 2)

What growth factors are involved in the structural maturation of new vessels during tissue repair?

Platelet-Derived Growth Factor (PDGF)

What growth factor recruits smooth muscle cells for larger caliber vessels and is a driver of fibroblast migration and proliferation in connective tissue deposition?

Transforming Growth Factor-Beta (TGF-β)

What cytokine suppresses endothelial proliferation and migration, is the most important cytokine in connective tissue deposition, stimulates fibroblast migration and collagen synthesis, and has anti-inflammatory effects?

Hepatocyte Growth Factor (HGF)

What growth factor, along with TGF-alpha, makes hepatocytes enter the cell cycle during liver regeneration?

Integrins (in tissue repair)

What cell-to-cell adhesion molecules are used by cells to bind to extracellular matrix proteins and communicate?

Macrophages (in chronic inflammation)

What dominant cell type in chronic inflammation, derived from monocytes, phagocytoses microbes and dead tissues, secretes various mediators, and presents antigens to T-cells?

Lymphocytes

What cells play a role in chronic inflammation, amplifying and propagating it due to their activation by microbes and their long-lived memory cells?

Plasma cells

What cells, derived from B-lymphocytes, produce antibodies against pathogens, self-antigens, or altered tissue components, and are seen in chronic inflammation?

Eosinophils

What cells are usually present in reactions mediated by IgE and in parasitic infections, and produce Major Basic Protein?

Major Basic Protein

What protein is produced by eosinophils and is toxic to helminths, but can also cause tissue damage?

Mast cells

What cells are the main drivers of allergic reactions, expressing the FcεRI receptor that binds IgE and degranulating to release histamine and prostaglandins?

Th1 cells

What subtype of CD4+ T-lymphocytes secretes IFN-gamma, leading to the classical pathway activation of macrophages, and is involved in bacterial and viral infections and autoimmune diseases?

Th2 cells

What subtype of CD4+ T-lymphocytes secretes IL-4, IL-5, and IL-13, recruiting eosinophils and activating macrophages via the alternative pathway, and is involved in helminthic infections and allergic reactions?

Th17 cells

What subtype of CD4+ T-lymphocytes secretes IL-17, inducing the secretion of chemokines that recruit neutrophils and macrophages, and is involved in bacterial and viral infections and autoimmune diseases?

B-cells

What lymphocytes can differentiate into plasma cells, which produce antibodies?

IgE

What immunoglobulin is involved in allergic reactions, binding to the FcεRI receptor on mast cells to trigger histamine release?

Pyrogens

What substances, such as Lipopolysaccharide (LPS) from bacteria, Interleukin-1 (IL-1), and Tumor Necrosis Factor (TNF), induce fever?

Lipopolysaccharide (LPS)

What pyrogen from bacteria induces fever by increasing cyclooxygenase activity and prostaglandin production?

Acute Phase Proteins

What proteins are produced by the liver, and their elevation can indicate inflammatory processes?

C-reactive protein (CRP)

What acute phase protein acts as an opsonin and indicates inflammatory processes?

Serum amyloid A (SAA)

What acute phase protein acts as an opsonin, and if its elevation is prolonged, can lead to secondary amyloidosis?

Fibrinogen

What acute phase protein binds to red cells, causing them to stack together in rouleaux formation, which is the basis for the erythrocyte sedimentation rate test?

Hepcidin

What acute phase protein can cause anemia?

Thrombopoietin

What acute phase protein may be the cause of elevated platelets in inflammation?

Colony-Stimulating Factors (CSFs)

What factors cause an increase in the production of various white blood cell types, leading to leukocytosis?

Extracellular Matrix (ECM)

What provides a scaffold for blood vessels to grow, interacts with integrin receptors, and contains proteins that activate cell proliferation during tissue repair?

Collagen

What fibrous tissue is laid down in scar formation, transitioning from Type III to Type I, and contributes to wound strength?

Fibronectin

What protein is synthesized by TGF-β, is part of the provisional matrix that fills large tissue deficits during healing, and can be degraded by metalloproteinases?

Myofibroblasts

What cells are fibroblasts that exhibit smooth muscle properties and are responsible for scar contraction, particularly important in secondary intention healing?

Epithelioid histiocytes

What activated macrophages, seen in granulomas, have abundant cytoplasm with indistinct borders, resembling epithelial cells?

Langhans giant cells

What multinucleated cells are formed by the fusion of epithelioid macrophages and may or may not be present in granulomatous inflammation?

Aspartyl proteinases (SAP)

What enzymes are secreted by Candida species and are able to degrade host cell membranes and destroy immunoglobulins?

Phospholipase (PLB1)

What enzyme is secreted by Candida yeasts and pseudohyphae?

Pattern recognition receptors

What receptors are found on host cell membranes and bind to specific fungal cell wall moieties to stimulate innate immune responses?

Chitins

What is a primary component of the rigid cell wall of fungi?

Glucans

What are components of the rigid fungal cell wall that can activate the complement cascade and provoke an inflammatory reaction?

Ergosterol

What chemical is present in the cell membrane of fungi and is an important target for antifungal pharmacology?

Immunodominant antigens (fungal)

What antigens are released by fungal cell walls and may elicit cellular immune responses and diagnostic antibodies?

Mannans (Candida)

What cell wall component of Candida typically elicits innate host defenses and immune responses during infection?

Glycoproteins (Candida)

What cell wall components of Candida, along with mannans and polysaccharides, elicit innate host defenses and immune responses?

Agglutinin-like sequence (ALS) surface glycoproteins

What family of glycoproteins is produced by Candida species, some of which function as adhesins that bind host cell membrane receptors to mediate attachment to epithelial or endothelial cells?

Lysozymes

What enzymes are found in bacteriophages?