Unit 4.1 Day 2

Opener If you were here on Monday: tell someone who wasn’t THREE THINGS about viruses or Ebola If you were not here: listen You have three minutes. I will be asking the “not here on Monday” group what they learned

Agenda Check in: Ebola Ebola Reading Lecture: The Innate Immune Response Managing the Vocabulary: Concept Cards

Ebola Caused by a virus Viruses invade host cells Once in the cell, the virus hijacks the molecular machinery of the cell to copy, transcribe and/or translate its genes Result: production of new virus particles (virions) Ebola is an RNA virus; it has only 7 genes

Reading Read the text Mark the text: Margin notes: QUESTIONS Highlight/underline information about how the virus attacks the immune system Highlight/underline information about the effects of Ebola on the body Margin notes: QUESTIONS Things you are curious about Things you don’t understand (especially about how Ebola interacts with the immune system) TWELVE MINUTES

Info and Questions 2 minutes: Share Ebola/Immune system info and margin note questions at your table Share with class

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” Signatures recognized by immune system cell protein receptors Cell membrane receptors Cytoplasmic 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, 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: roll in inflammation 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 Recruit leukocytes to site of infection Directly attack pathogen cell membrane

Inflammation Protective response involving cells, blood vessels and molecules Cytokines Histamine Enzymes Injury or Infection Leukocytes release chemical signals Complement System Activated Blood vessels become “leaky” More complement proteins move to infected area More leukocytes recruited to infected area Plasma flows to tissues

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

Concept Cards: Repetition #1, part 2 Front: Term Back: Description: what is it? Role: what is its job or role in the innate immune response? Interaction: how does it interact with other parts of the innate immune response? Do 1 and 2 first. Then go back and do 3. If you finish early, start your homework.

Concept Cards Physical Barriers Mechanical Barriers Chemical Barriers Biological Barriers Innate Immune Response Leukocytes Phagocytes Macrophages Neutrophils Dendritic Cells Natural Killer Cells Mast Cells Complement System Inflammation