I. The Innate Immune System

A. The Innate Immune System: An Overview

B. Cells Involved in Body Defense

1. Defense Cells in the Blood: The Leukocytes

2. Defense Cells in the Tissue: Dendritic Cells, Macrophages, and Mast Cells

C. Immediate Innate Immunity

1. Antimicrobial enzymes and Antimicrobial Peptides

2. The Complement System

a. The Classical Complement Pathway

b. The Lectin Pathway

c. The Alternative Complement Pathway

3. Anatomical Barriers to Infection, Mechanical Removal of Microbes, and Bacterial Antagonism by Normal Body Microbiota

D. Early Induced Innate Immunity

1. Pathogen-Associated Molecular Patterns (PAMPs) and Danger-Associated Molecular Patterns (DAMPs)

2. Pattern-Recognition Receptors (PRRs)

3. Cytokines Important in Innate Immunity

4. Harmful Effects Associated with Abnormal Pattern-Recognition Receptor Responses, Variations in Innate Immune Signaling Pathways, and/or Levels of Cytokine Production

5. Phagocytosis

a. An Overview of Phagocytic Defense

b. The Steps Involved in Phagocytosis

6. Natural Killer Cells (NK Cells) and Invariant Natural Killer T-Lymphocytes (iNKT Cells)

7. Inflammation

8. Nutritional Immunity

9. Fever

10. The Acute Phase Response

11. Intraepithelial T-lymphocytes and B-1 cells