ENZYMES, GROWTH FACTORS, PROTEINS, AND RECEPTORS

Chemoreceptors

What sensory receptor type provides afferent feedback to the sensory cortex in dyspnea production, contributing to the sensation of air hunger?

Mechanoreceptors

What sensory receptor type provides afferent feedback to the sensory cortex in dyspnea production?

Metaboreceptors

What sensory receptor type provides afferent feedback to the sensory cortex in dyspnea production?

Vagal irritants/receptors

What type of receptors generate signals of chest tightness that are transmitted directly to the brainstem and sensory cortex?

Type I pneumocytes

What alveolar epithelial cell type facilitates gas exchange between the alveoli and blood, and is injured in ARDS, causing the release of TGF-β1?

Type II pneumocytes

What alveolar epithelial cell type is responsible for synthesizing alveolar surfactants, proliferates during the organizing stage of DAD, and undergoes necrosis during ALI/ARDS?

Endothelial cells

What cell type lining the septal capillaries is injured in ALI/ARDS, contributing to increased vascular permeability and allowing the binding of activated neutrophils?

Neutrophils

What inflammatory cell type, characterized as a granular leukocyte, is activated by cytokines like IL-8 and TNF, leading to the release of proteases and oxidants that damage alveolar epithelium in ARDS?

Fibrin

What protein component is deposited alongside edema, inflammation, and cellular debris during the acute stage of Diffuse Alveolar Damage (DAD)?

Procollagen

What precursor protein's deposition is signaled by macrophage-derived fibrogenic cytokines, contributing to fibrosis during the healing phase of ALI?

Cytokines

What chemical mediators are released by macrophages (like TNF, IL-1, and IL-8) that activate neutrophils and signal fibrogenic responses in lung injury?

Proteases

What type of enzymes are released by activated neutrophils and macrophages in ARDS and emphysema, causing damage to the alveolar epithelium and lung structures?

Tumor Necrosis Factor (TNF or TNF-α)

What cytokine, along with IL-1 and IL-8, activates neutrophils in ARDS and is also released due to cord factor stimulation in TB, explaining cachexia?

Interleukin-8 (IL-8)

What pro-inflammatory cytokine is released by macrophages and stimulates neutrophils to upregulate adhesion molecules and extravasate into the alveolar space in ARDS?

Interleukin-1 (IL-1)

What pro-inflammatory cytokine is released in ARDS and causes endothelial activation and neutrophil sequestration?

Nuclear Factor κB (NF-κB)

What transcription factor's activation, often induced by tobacco or ROS, shifts the balance in favor of a pro-inflammatory state, contributing to lung injury in ARDS and emphysema?

Adhesion molecules

What proteins are expressed on activated neutrophils, allowing them to bind to their ligands on activated endothelial cells in the pulmonary capillaries, leading to sequestration?

Platelet activating factor (PAF)

What chemical mediator is released from neutrophil granules, contributing to local tissue damage and fueling the inflammatory cascade in ARDS?

Antioxidants

What protective molecules, including glutathione and superoxide dismutase, counteract the toxic effects produced by the release of granular contents from neutrophils?

Antiproteases

What molecules counteract the damaging effects of proteases, helping to maintain lung integrity (e.g., α1-antitrypsin)?

Transforming Growth Factor-β (TGF-β or TGF-β1)

What cytokine/growth factor, released from injured Type I alveolar epithelial cells and macrophages, drives aberrant epithelial repair, favors fibroblast transformation into myofibroblasts, and is known to be fibrogenic?

Platelet-derived growth factor

What macrophage-derived fibrogenic cytokine signals cytoplasmic growth and collagen deposition associated with the healing phase of ALI/ARDS?

Bone Morphogenetic Protein Receptor Type 2 (BMPR2)

What cell surface protein binds cytokines like TGF-β, BMP, activin, and inhibin, and whose inactivating mutations are found in familial and sporadic cases of pulmonary arterial hypertension?

Bone Morphogenetic Protein (BMP)

What cytokine/protein binds to BMPR2, and whose signaling pathway is involved in embryogenesis, apoptosis, cell proliferation, and differentiation?

Activin

What cytokine/protein binds to BMPR2?

Inhibin

What cytokine/protein binds to BMPR2?

Collagen IV

What protein is the primary component of the glomerular and alveolar basement membranes, and is the target of circulating antibodies in Goodpasture Syndrome?

Antibodies

What circulating proteins cause inflammatory destruction of the glomerular and alveolar basement membranes in Goodpasture Syndrome, leading to linear deposits in immunofluorescence studies?

Immunoglobulins

What protein complex is deposited linearly along the basement membranes of the alveolar septal walls and glomerulus in Goodpasture Syndrome, appearing green upon immunofluorescence staining?

Procalcitonin

What acute-phase reactant is more significantly elevated in bacterial infections than in viral infections, serving as a marker of inflammation with some predictive value?

Elastase

What protease is secreted by neutrophils and macrophages, is the major inhibitor of α1-antitrypsin, and causes destruction of the basement membrane to facilitate neutrophil migration?

Macrophage elastase

What protease, released by alveolar macrophages, is not inhibited by α1-antitrypsin and contributes significantly to alveolar wall damage, especially in smokers?

Proteinase 3

What protease is released from the granules of activated neutrophils in emphysema, contributing to tissue damage?

Cathepsin G

What protease is released from activated neutrophil granules, contributing to tissue damage in emphysema and stimulating mucus hypersecretion in chronic bronchitis?

α1-antitrypsin (α1-AT)

What antiprotease, found in serum, tissue fluids, and macrophages, acts as the major inhibitor of proteases (like elastase) secreted by neutrophils, and whose deficiency leads to panacinar emphysema?

Neutrophil elastase

What specific protease released by activated neutrophils is inhibited by α1-antitrypsin, and whose increased activity due to functional deficiency causes tissue damage in emphysema?

Matrix metalloproteinase (MMP)

What enzyme, released from macrophages in chronic bronchitis, is one of the factors stimulating the hypersecretion of mucus?

Leukotriene B4 (LTB4)

What inflammatory mediator is released by activated inflammatory cells in COPD, capable of sustaining neutrophilic inflammation and damaging lung structures?

Histamine

What chemical is released by sensitized mast cells in asthma, causing an almost immediate increased vascular permeability and vasodilation?

Lipoxygenase pathway

What metabolic route for arachidonic acid produces Leukotrienes C4, D4, and E4, the key mediators of asthmatic bronchoconstriction and increased vascular permeability?

Leukotrienes C4, D4, and E4

What specific lipid mediators are regarded as the slow reacting substances of anaphylaxis, and cause the bronchoconstriction, increased vascular permeability, and vasodilation characteristic of an acute asthmatic attack?

Cyclooxygenase pathway

What metabolic route for arachidonic acid is inhibited by aspirin and NSAIDs, leading to the shunting of metabolism toward the lipoxygenase pathway in drug-induced asthma?

Prostacyclin

What lipid product is generated by the cyclooxygenase pathway of arachidonic acid metabolism?

Thromboxane

What lipid product is generated by the cyclooxygenase pathway of arachidonic acid metabolism?

TH2 cells

What T-lymphocyte subset drives the allergic response in Atopic Asthma by secreting cytokines IL-4, IL-5, and IL-13?

Interleukin-4 (IL-4)

What cytokine, secreted by TH2 cells in asthma and present in IPF inflammation, stimulates B cells to produce IgE?

Interleukin-5 (IL-5)

What cytokine, secreted by TH2 cells in asthma and responsible for recruiting eosinophils, is also elevated in alveolar levels in pulmonary eosinophilia?

Interleukin-13 (IL-13)

What cytokine, secreted by TH2 cells in asthma and present in IPF inflammation, promotes allergic inflammation?

IgE

What antibody coats mast cells in asthma, leading to the release of mediators upon repeat exposure to the allergen?

Mast cells

What immune cells, coated with IgE, release granule contents and mediators like histamine, leukotrienes, and chemokines upon allergen exposure in asthma?

Eosinophil lysophospholipase binding protein: galectin-10

What specific protein forms the microscopic Charcot-Leyden crystals seen in the mucus plugs and sputum of asthmatic patients?

Chemokines

What signaling molecules are produced by mast cells, epithelial cells, and T cells, stimulating the recruitment of leukocytes (eosinophils, neutrophils, T cells) during the late phase reaction of asthma?

Myofibroblasts

What cell type, derived from fibroblasts by TGF-β1 signaling, proliferates in fibroblastic foci and deposits collagen in the pathogenesis of Idiopathic Pulmonary Fibrosis?

Caveolin-1

What predominant structural protein of caveolae acts as an inhibitor of pulmonary fibrosis by limiting TGF-β1-induced extracellular matrix production, and is notably decreased in IPF patients?

Extracellular matrix

What material, including collagen and proteoglycans, is deposited in the pulmonary interstitium by fibroblasts and myofibroblasts under the influence of TGF-β1, leading to fibrosis?

Proteoglycans

What extracellular matrix component is deposited during fibrosis in IPF, and whose increased deposition is also associated with Mitral Valve Prolapse?

Collagen

What protein is deposited by myofibroblasts, forming the core component of fibrosis and contributing to the thickening of the alveolar septa?

CD4+ helper T cells

What T-lymphocyte subset drives the cell-mediated response to an unidentified antigen in the pathogenesis of Sarcoidosis?

M protein

What virulence factor of Group A Streptococcus facilitates resistance to phagocytosis?

Streptococcal pyrogenic exotoxin A

What toxin is produced by Group A Streptococcus?

Sialoglycoconjugates and sulfated glycolipids

What host molecules in the respiratory tract do the P1 molecules of M. pneumoniae adhere to?

Peroxidases and superoxide radicals

What two substances produced by M. pneumoniae cause direct injury to host cells?

Penicillin binding proteins

What proteins are present in the rigid cell wall of Chlamydia pneumoniae, making it susceptible to Penicillin and other β-lactams?

T3SS injector

What drill-like protein is used by C. pneumoniae to inject effector proteins into the host cell to start the infectious process?

Effector proteins

What are the substances injected by the T3SS injector into the host cell by C. pneumoniae to initiate the infectious process?

Host heparin sulfate

What host molecule is used by C. pneumoniae adhesins for binding and invasion?

Adhesins

What C. pneumoniae proteins, including MOMP and OmCB, facilitate binding to host cells?

Major outer membrane protein (MOMP)

What specific protein acts as an adhesin for C. pneumoniae binding and invasion?

OmCB

What specific protein acts as an adhesin for C. pneumoniae binding and invasion?

Filamentous hemagglutinin

What large surface protein is used by Bordetella pertussis for adhesion and tracheal colonization, leading to ciliary stasis?

Fimbriae

What structural proteins of Bordetella pertussis assist filamentous hemagglutinin in attaching to the cilia of the respiratory tract?

Pertussis toxin

What B. pertussis toxin, composed of A/B units, causes lymphocytosis, sensitization to histamine, enhances insulin secretion, and disrupts signal transduction leading to ciliary stasis?

Tracheal cytotoxin

What B. pertussis toxin kills ciliated cells and inhibits DNA synthesis, contributing to cell loss rather than just stasis?

Endotoxin (LPS)

What component of the B. pertussis cell wall causes damage to the host?

Dermonecrotic toxin

What is one of the virulent structures of B. pertussis?

Adenylate cyclase toxin

What is one of the virulent structures of B. pertussis?

Hemolysin

What is one of the virulent structures of B. pertussis?

Teichoic acid

What antigenic structure of S. pneumoniae causes fever and the attraction of inflammatory mediators?

Capsular polysaccharide

What virulence factor of S. pneumoniae, categorized into 91 types, prevents opsonization and is the basis for vaccines?

DNA gyrase

What enzyme's mutation in bacteria causes resistance to Fluoroquinolones?

Ribosomes and RNA

What intracellular components are the target of Macrolides, whose modification or involvement in efflux mechanism leads to drug resistance?

Beta-lactamase

What enzyme is produced by Moraxella catarrhalis and some Legionella species, causing resistance to penicillin?

DNAse

What enzyme is produced by Moraxella catarrhalis and Legionella pneumophila?

RNAse

What enzyme is one of the products produced by Legionella pneumophila?

Protease

What enzyme is one of the products produced by Legionella pneumophila?

Phosphatase

What enzyme is one of the products produced by Legionella pneumophila?

Lipase

What enzyme is one of the products produced by Legionella pneumophila?

Metalloprotease

What enzyme produced by Legionella pneumophila is an important virulence factor causing hemolytic and cytotoxic effects?

Mip protein

What virulence factor of Legionella pneumophila is important for adherence and phagocytosis, facilitating invasion of macrophages?

Type 4 Secretion System (T4SS) or Dot/LCM

What drill-like protein system is used by Legionella to inject effector enzymes into the macrophage, aiding phagosome survival and intracellular multiplication?

Effector enzymes

What substances are injected by the T4SS system in Legionella to ensure phagosome survival and intracellular multiplication within macrophages?

Viral Hemagglutinin

What Influenza virus envelope protein is responsible for antigenic variation, aggregates RBCs, and attaches to the sialic acid receptor on host cells?

Viral Neuraminidase (NA)

What Influenza virus envelope protein is responsible for antigenic variation, acts as a sialic acid enzyme, and cleaves the HA-receptor contact to allow viral release?

Viral hemagglutinin and neuraminidase

What two surface proteins of the Influenza virus are responsible for antigenic variation, determining the virus subtype, and targeted by host antibodies?

Fiber

What projection of the Adenovirus is associated with hemagglutination activity and reacts with the host Coxsackie Adenovirus Receptor (CAR)?

Penton base

What Adenovirus structure is involved in antigen-antibody interactions?

Hexon capsomeres

What Adenovirus structure makes up the capsomeres and is involved in antigen-antibody interactions?

Coxsackie Adenovirus Receptor (CAR)

What host receptor is bound by the Adenovirus fiber to initiate viral entry into the nasal epithelium?

VA RNAs

What substance is produced by Adenovirus to counteract host interferons?

E3 (early 3) protein

What Adenovirus protein inhibits host cell cytolysis and blocks MHC expression to the cell surface?