Immunity, Inflammation, and ELISA

• cellular

  • mast cells

  • neutrophils

  • macrophages

• humoral

  • complements

  • lysozymes

  • interferon

  • antibodies

What cellular and humoral components are involved in phagocytosis and inflammation?

1. dilation of arterioles and capillaries

   1. plasma proteins escape circulation and into the injury site

2. edema fluid accumulates in injury site

3. fibrin forms a network in lymphatic vessels

4. chemotaxis

5. phagocytes ingest and digest bacteria/foreign invader

6. apoptosis of phagocytes

7. macrophages are activated

   1. ingests the dead phagocytes

8. inflammation resolves

What are the 8 stages of the inflammatory response?

• polymorphonuclear neutrophils

• monocytes

• macrophages

  • histocytes = macrophages in connective tissue

  • kupffer’s cells = macrophages in liver

  • alveolar cells = macrophages in lungs

  • stem cells can differentiate into many different kinds of macrophages

What are the 3 active phagocytic cells?

to remove dead and damaged cells and foreign matter

also presents ingested antigens on its surface for other immune cells to see

includes:

• phagocytes in blood (monocytes and neutrophils)

• lymphoid tissue (liver, spleen, bone marrow)

• lungs

• etc.

What is the purpose of the mononuclear phagocytic system?

the movement of WBCs towards the injury site via chemical signals

• squeezes through dilated, permeable capillaries into tissue

• neutrophils are highly motile

What is chemotaxis?

• when a foreign cell is tagged with opsonin, a chemical that makes the cell stand out to phagocytic cells for destruction

• serum proteins (especially C-reactive protein) help phagocytes attach

What is opsonization?

• Mycobacterium tuberculosis

• N. gonorrhoeae

• some species of Salmonella

Which bacteria can survive phagocytosis?

• E. coli K1

• S. pneumoniae

• S. aureus

• K. pneumoniae

these bacteria are encapsulated

Which bacteria can avoid phagocytosis all together?

1. chemotaxis

   1. cells move to injury site via chemical signals

2. opsonization

   1. foreign matter is tagged for phagocyte destruction

3. engulfment

   1. foreign matter is eaten and becomes a phagosome (a vesicle)

4. digestion

   1. intracellular, enzymes are released, lactic acid increases, and superoxide is produced, foreign matter is destroyed

   2. neutrophils (phagocytes) undergo apoptosis and are phagocytized by macrophages

What are the 4 steps of phagocytosis?

• endotoxins released from Gram negative bacteria

• chemicals from leukocytes

What induces fever?

• increases mobility of WBCs

• enhances phagocytosis

• diminishes endotoxins

• increases T cell proliferation

• enhances interferon activity

What 5 things does fever do for the inflammatory response?

96 well plates

What device is ELISA performed in?

• horseradish peroxidase

• alkaline phosphatase

• G6PD

• beta galactosidase

What 4 common enzymes are used in ELISA?

1, 2

Direct ELISA uses ___ antibodies, and indirect ELISA uses ___ antibodies

• a measure of how much light a substance absorbs or blocks

• used to measure ELISA results (patient results are compared to a known control)

What is optical density?

• negative: OD below 0.9

• equivocal/gray area: OD between 0.91 to 1.1

• positive: OD above 1.1

Describe the 3 possible results of ELISA