2. • Natural killer (NK) cells:
– Patrol the body and attack virus-infected body
cells and cancer cells (IMMUNGOLOGICAL
SURVEILLANCE)
– Trigger apoptosis in the cells they attack
NK Cells video clip
4. -Small proteins produced in response to viruses or cancer
cells.
-Cytokines
-Stimulate the actvities of macrophages and NK Cells
-Interferon therapy
interferon clip
9. Purposes of Inflammation
• To perform a temporary repair at the injury site
and prevent access of additional pathogens
• To slow the spread of pathogens from the
injury site
• To mobilize a wide range of defenses that can
overcome the pathogens
• To aid in permanent tissue repair
(REGENERATION)
14. Fever = the maintenance of a body temp >37.2ᵒC (99ᵒF)
Hypothalamus
Pyrogens – endogenous vs. exogenous
15. Fever
Pros
• Increases rate of metabolism
• Cells move faster
(phagocytes)
• Enzymatic reactions
proceed more quickly
(lysozymes)
Cons
• High fever can damage
physiological systems
– Nausea
– Disorientation
– Hallucinations
– Convulsions
– Brain damage (@42ᵒC)
Editor's Notes
NK cells are WBCs, but LYMPHOCTYES (not phagocytes)
Distinctively different from T cells & B cells
Part of IMMUNOLOGICAL SURVEILLANCE
Secrete PERFORINS
About 30 proteins make up the complement system, which can cause lysis of invading cells and help trigger inflammation.
Called COMPLEMENT b/c this system complements the actions of antibodies
Complement cascade = complement proteins interacting with one another in chain reactions similar to those of the clotting system.
Classical pathway (QUICK) – complement proteins bind to antibodies
Alternative pathway (SLOW) – triggered by exposure to foreign antigens in the absence of antibodies
Complement cascade:
Complement molecules activated by antibodies form doughnut-shaped complexes in a bacterium’s plasma membrane.
Holes in the complement complex allow sodium ions and then water to diffuse into the bacterium.
After enough water has entered, the swollen bacterium bursts.
Inflammatory response = localized tissue response to injury or infection; can be produced by any stimulus that kills or damages tissue.
Mast cells are present in most tissues characteristically surrounding blood vessels and nerves, and are especially prominent near the boundaries between the outside world and the internal milieu, such as the skin, mucosa of the lungs and digestive tract, as well as in the mouth, conjunctiva and nose.
Mast cells are very close to basophil granulocytes (a class of white blood cells) in blood. Both are granulated cells that contain histamine and heparin, an anticoagulant.
These similarities have led many to speculate that mast cells are basophils that have "homed in" on tissues. However, current evidence suggests that they are generated by different precursor cells in the bone marrow. Nevertheless, both mast cells and basophils are thought to originate from bone marrow precursors expressing the CD34 molecule. Basophils leave the bone marrow already mature, whereas the mast cell circulates in an immature form, only maturing once in a tissue site. The site an immature mast cell settles in probably determines its precise characteristics.[2]
Two types of mast cells are recognized, those from connective tissue and a distinct set of mucosal mast cells. The activities of the latter are dependent on T-cells.
