Unit 4.1 Day 2

Opener Talk to your table group, summarize the effects of cholera toxin on your body

Agenda Lecture: The Innate Immune Response Review for Cell membrane assessment Assessment is on Thursday All work for this unit is due then

The Immune System Two types of immune response Innate (all animals, plants) Adaptive or acquired (only vertebrates) Innate Response Components Physical barriers Cells Complement system (humoral, or molecular) Inflammation Innate Response: immediate and non-specific

Self vs. Non-Self Key to innate immune response: Examples: Different pathogen groups contain “molecular signatures” Pathogens= bacteria, fungi and viruses Signatures recognized by immune system cell protein receptors Cell membrane receptors Cytoplasmic receptors Nuclear Receptors Examples: Double stranded RNA (viral) Peptidoglycan (part of bacterial cell wall)

Barriers First line of defense: Physical: skin, exoskeleton, cuticle Prevent entry of pathogen Destroy it as it tries to enter Physical: skin, exoskeleton, cuticle Mechanical: coughing, sneezing, crying, peeing, mucus Chemical: enzymes in tears, saliva and mucus secretions; breast milk; gastric acid in stomach Biological: symbiotic “good” bacteria

Human Skin Bacteria

Cells Leukocytes: white blood cells Phagocytes: “eat” invading pathogens Macrophages (tissues) Neutrophils (blood) Dendritic cells (tissues in contact with outside environment)

Phagocytosis

Dendritic Cell Phagocytosis

Other key leukocytes and cell roles. . . Natural Killer (NK) Cells attack body cells that have been compromised: Tumor cells Cells infected by viruses Mast Cells: carry histamine and to trigger inflammation response Other Key Roles: Chemical signaling Activating Adaptive Immune Response (dendritic cells and macrophages)

Complement System Number of small proteins circulating in blood Initial binding of one or more complement proteins to pathogen initiates a “catalytic cascade” Result: complement proteins converted into a number of “active” forms What do they do? Identify pathogens for phagocytosis (opsonization) Recruit leukocytes to site of infection (inflammation) Directly attack pathogen cell membrane (membrane attack complex) Interactive (slide 9)

Inflammation

Repetition #1 Go back through your notes Highlight each NEW WORD or PHRASE you need to know to understand the INNATE IMMUNE SYSTEM You have 5 minutes

Kahoot. it