21.2.10 complement system (innate immunity)

complement

refers to a family of over 30 soluble and cell-bound proteins

• most components are produced in the liver in inactive forms

• 3 separate pathways all converge to produce C3 and C5 convertase activities (C3 AND C5 TAKE C6-C8 )

membrane attack complex

• comprises of the C3 and C5 to get C6-C8 and they join together

• they open the pores of the target cell, LYSES THEM, leaves the pore so the cell can be killed from the inside out

inflammation

a stereotypic innate immune response

complement activators

• a response to an injury

• it upregulates complement destruction of foreign threats

histamine kinins

• a response due to an injury

• causes arteriole vasodilation

• upregulates arteriole blood flow

• upregulates capillary permeability

  • too much can cause edema (built up of lymph/fluids int he intersitial area)

• clean-up and repair of damaged area (due to upregulation)

prostaglandin kinins

brings pain to the injured area

it lets the body know that the healing process is starting

leukocytosis factors

• a response to an injury

• causes the attraction of leukocytes

• upregulates phagocytic activity

• release of cytokines

• upregulates leukocyte proliferation

• ultimate goal is to clean-up and repair damaged area

  • ex. if there’s a paracytic infection, the cytokine releases to make more WBC pertaining to the infection