Cytokines and Cell Motility

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Cytokines and Cell Motility
2015-11-26 07:49:16

Cytokines and Cell Motility
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  1. What are the three major components of acute inflammation in sequence
    • Vasodilation
    • Increased permeability of vessels to proteins and Leukocytes (including tight junctions)
    • Emigrations of Leukocytes to injury
  2. What are the five classic signs of inflammation
    • Dolor (Pain)
    • Calor (Heat)
    • Rubor (Redness)
    • Turgor (swelling)
    • Fuctio laesa (Loss of function)
  3. Why might not all of the five classic signs be manifest in deep tissue
    Pain only happens where there is receptors
  4. What is an exudative component
    The movement of plasma fluid containing important proteins such as fibrin and immunoglobulins to the inflamed tissue
  5. Where does the fluid from an inflammation go once it is cleared of the infection and swelling
    Into the lymph nodes
  6. What is the difference between an exogenous mediator and an endogenous mediator
    • Exogenous are from bacterial products and toxins
    • Endogenous are from the immune system of the infected cells
  7. Define a cytokine
    Small signaling proteins, peptides, or glycoprotein molecules that communicate with specific receptors of target cells,which then signal second messengers
  8. Cytokines help in the mediation with what important cellular functions
    • Immunity
    • Inflammation
    • Hematopoiesis
  9. Cytokines can both trigger an inflammatory response as well as
    Shut off or stop an inflammatory response
  10. What is the difference between a Cytokine and a hormone
    • A cytokine acts on different cell populations and tissues (most of the time) while a hormone acts on just one organ
    • Additionally, a single cell can produce many cytokines but not different hormones
  11. Cytokines usually act in what proximity
    Local, however some act on distant cells
  12. In an adult, what are the few cell types that have the ability to be motile
    • Fibroblasts
    • WBC
    • Macrophages
    • Sperm
  13. Why is it important that fibroblasts can be motile
    They need to migrate through connective tissue for remodeling, rebuilding sites of injury
  14. What are the most important elements used by motile cells
    • Actin (movement)
    • Integrins (attachment to substratum)
    • Lamellipodium (thin plate foot)
    • Myosin II
  15. What is the difference between stratum and substratum
    Stratum is a horizontal layer of a material and substratum is the underlying layer
  16. What are some examples of attachment ligands for the integrins on motile cells
    • Fibronectin
    • Lamin
    • Collagens
    • ICAM
    • Intermediate filaments
  17. Integrins are heterodimers made up of what subunits
    Alpha and Beta each subtype attaches to a specific ligand (many possibilities and arrangements)
  18. As a cell migrates through focal contacts, it must regulate the activity of the integrins how
    Intracelluar signal pathways via binding of ligands to their intigrins
  19. What makes a cell crawl in a specific direction
    • Insoluble molecules in the substratum or cellular signals like chemotaxis
    • These can move the cell either towards or away from the signal
  20. Chemotaxis can be mediators in what important actions
    • Immune responses
    • Inflammation
    • Wound healing
    • Embryogenesis
  21. What are some of the cells that can be attracted by chemokines
    • Monocytes
    • Basophils
    • Eosinophils
    • Neutrophils
    • Lymphocytes
  22. Leukocytes cross walls of veins and capillaries but not
  23. How does a leukocyte cross the blood vessel wall
    It sticks to the wall first by selectins, and then migrates in to the site of infection or damage through integrins
  24. What are CAMs and their job
    Cell Adhesion Molecules, they are essentially selectins that assist in moving leukocytes into the tissue that has damage
  25. Selectins are classified as what kind of binding agent
    They are cell surface carbohydrate binding proteins (lectins)
  26. Selectins are dependent on what for adhesion interactions
  27. What are the three types of selectins
    • L - Selectins (white blood cells)
    • P - Selectins (Platelets and endothelial cells)
    • E - Selectins (Endothelial cells)
  28. Diapedesis is
    Passage of blood cells especially white blood cells through intact capillary walls into surrounding tissue
  29. L selectins recognize carbohydrates that are expressed exclusively in what portion of the lymph nodes
    High endothelial venules
  30. Why do all of the lymphocytes have a draw to the lymph nodes
    Because of the lymphocytes expression of L selectins that are strongly attracted to the carbohydrates on the lymph nodes
  31. Beyond cell crawling and sperms flagella, what is another mode of cell motility
    Neuronal growth cone extension
  32. What is Neuronal growth cone extension
    When the cell body doesn't move, but the axon extends to form synapses with other neurons or muscles
  33. What is the universal mechanism for cell motility (except sperm)
    • Actin Polymerization at the leading end of the lamellipodium
    • Integrins attachment
    • Insoluble and soluble signals
    • Movement
  34. What are corticosteroids
    Any of the steroid hormones produced by the adrenal cortex or their synthetic equivalents such as cortisol or aldosterone
  35. What effect do corticosteroids have on inflammatory responses
    They inhibit the production of numerous molecules that are critical to an inflammatory response
  36. As a result of corticosteroids in the blood stream, what would you see happen in inflammation
    • Decreased capillary permeability and dilation
    • Diminished secretion of lipolytic and proteolytic enzymes which increase inflammatory responses
    • Decrease movement of leukocytes to injury
    • Ultimately decreased damage to tissue by inflammation
  37. When is inflammation terminated
    When the offending agent is eliminated
  38. Sepsis, arthritis, asthma, and influenza are examples of
    Excessive inflammation causing damage to the cells
  39. What is sepsis
    • The presence of various pus forming and other pathogenic organisms, or their toxins, in the blood or tissue
    • Large, damaging inflammatory responses causing shock to the body
  40. What is a cytokine storm
    A large over zealous immune response as a result of elevated levels of various cytokines.
  41. What can chronic inflammation cause
    It leads to the progressive shift of the type of cells at the site of inflammation, and is characterized by the simultaneous destruction and healing of the tissue
  42. Chronic inflammation is characterized by the dominant presence of
    Macrophages in the injured tissue, the toxins they release are the most harmful
  43. What are considered the weak attachments for WBC rolling and the strong adhesion
    • Weak, L-Selectins
    • Strong, Integrin dependent