1. Innate Immune Response (Ch14)

2. Overview of Innate Defense System

3. First lines of Defense Physical Barriers Antimicrobial substances
Skin
Mucous membranes
Antimicrobial substances
Lysozyme
Peroxidase enzyme
Lactoferrin
Defensins
Normal Flora

4. Epithelial Barriers

5. Skin as the first line of defense
Intact skin protects
Epidermis
Dermis

6. Mucous membranes line the interior of the body

7. Ciliated cells are important…where?

8. Antimicrobial Substances

9. Microbial Barriers
Normal flora (biota) play a role in keeping the body protected
Competitive exclusion
E. coli produce bacteriocins which kill Salmonella and Shigella

10. Cells of the Immune System
Cells move from one system to the next
Found in blood, developed from bone marrow
What are some of these cells??
Granulocytes (neutrophils, basophils, eosinophils)
Mononuclear phagocytes
Dendritic cells
Lymphocytes

12. Dendritic cells Branched cells, important in adaptive immunity
Develop from monocytes, engulf material and bring it to other cells for analysis

13. How do cells of the immune system communicate?
Cytokines
Chemokines
Colony-stimulating factors
Interferons
Interleukins
Tumor Necrosis factors

14. Cytokines and their function

15. Interferons Three types of glycoproteins Alpha Beta Gamma
Produced by virus infected host cells, induce mRNA for antiviral proteins
Gamma
Produced by lymphocytes

16. Interferons inhibit viral replication

17. Sensor systems in the blood, tissues and cells
Can detect signs of tissue damage or microbial invasion
Respond by
Detecting parts of bacteria/viruses using pattern recognition receptors (PRRs)
Directly destroy bacteria using complement
Recruit other components of host defense

18. Pattern Recognition Receptors
Toll-Like receptors (TLRs)
Membrane bound receptors which detect bacterial parts
NOD-like receptors (NLRs)
Cytoplasmic proteins detect bacterial parts
RIG-like receptors (RLRs)
Cytoplasmic proteins detect viral RNA

19. Toll-like receptors (TLRs)
A type of PRR
Recognize peptidoglycan, lipopolysaccharide, flagellin, certain nucleotide sequences unique to bacteria

20. Toll-like receptors

21. NOD-like receptors (NLRs)

22. RIG-like receptors
Cytoplasmic proteins which detect viral RNA in a cell
Activate secretion of interferon and inflammatory response chemicals
Overall goal is to inhibit viral replication

23. Complement Proteins are part of the Complement system
Consists of a collection of 9 interacting proteins found in blood and tissues
Activation of these proteins promote
Opsonization
Inflammatory response
Lysis of foreign cell

24. How are the complement proteins activated?

25. Regulation of the complement system

26. What have we covered so far?
The innate immune system is composed of
Cells
Chemicals released by cells to communicate with each other
Receptors to recognize invaders
We need to look at the processes of phagocytosis and inflammation

27. How do phagocytes work?

28. Fever is a nonspecific response
Il-1 increases T lymphocytes
Decreases available iron
Increases cellular reactions

29. Inflammation response
What are the key cells involved?
What are the four key symptoms of inflammation?
What activates the inflammation response?