1. INNATE HOST DEFENSES
CHAPTER 16

2. Host Defenses
Innate immune systems provide immediate defense against infection, and are found in all classes of plant and animal life.
Adaptive immune systems composed of highly specialized, systemic cells and processes that eliminate or prevent pathogenic challenges. Thought to have arisen in the first jawed vertebrates, the adaptive or "specific" immune system is activated by the innate immune system.

3. Defense Barriers Physical skin/mucous membrane
Chemical antimirobial substances in body fluids. Ex. Lysozyme
Cellular defenses phagocytes
Inflammation swelling, reddening, histamine response
Fever pyrogenic
Molecular defenses interferon, complement

4. Physical Barriers
Skin- keratinized
Mucous membranes

5. Chemical Barriers
Salt pH
Lysozyme
Transferin
Lactoferrin
Defensins

6. Cellular Defenses - Granulocytes
Basophils/Mast cells
Eosinophils
Neutrophils
Dendritic cells
most abundant
migrate toward the site
of inflammation
predominant cells in pus
store histamine,
inflammatory response
1-6% of white blood cells
ROS and ILs
process antigen material and present it on the surface
to other cells of the immune system

7. Cellular Defenses — Agranulocytes
Monocytes
Lymphocytes
natural killer cells (NK cells)
small lymphocytes are the T cells and B cells
(1) replenish resident macrophages and dendritic cells under normal states, and
(2) in response to inflammation signals, monocytes can move quickly (approx hours) to sites of infection
in the tissues and divide/differentiate into macrophages and dendritic cells to elicit an immune response

8. Blood Cells

9. Phagocytosis Cells Involved = macrophages Process Chemotaxis Adherence
Ingestion
Digestion

10. Nucleus Cytoplasmic membrane of phagocyte Phagolysosome
Myeloperoxidase
NADPH
oxidase
Nitric oxide
synthase
Phagolysosome
Phagocytosed bacteria

11. Characteristics of Inflammation
Acute Inflammation
Repair/
Regeneration
Chronic Inflammation

12. Fever Exogenous/Endogenous Pyrogens Benefits/Risks
Leukocyte Endogenous Mediator

13. Interferon
Interferon protein

14. Complement System

15. Complement System

16. Complement — Cytolysis

17. Complement — Cytolysis

18. Non-specific Defenses