Infectious Diseases Unit 5 Lesson 2 plan

Infectious DiseasesUnit 5 Lesson 2 plan

Do now

• What is Innate Immunity?

Do now

• What is innate immunity?

– Non-specific mechanisms of immune defense that do not change.

Review of immune structures

• Physical

• Chemical

• CellularA neutrophil ingesting a cell

Neutrophil

Cancer Cell

Physical

• Skin

• Mucus

• Tears

Chemical

• Defensins

• Complement

• Stomach Acid

CellularInnate cells:

• Macrophages• Dendritic cells• Neutrophils

Adaptive cells:• B cells• T cells

Innate cells Adaptive cells

All immune cells are made in bone marrow

They all come from a parent cell (stem cell)

Innate cells patrol the body using receptors to identify

invaders

MacrophageNeutrophil

Do you think PAMP patterns will be found in host cells?

• Innate immune receptors ‘see’ foreign molecules called PAMPs

• PAMPs may be:• Bacteria or fungal cell

wall parts, like PS• Flagellin (flagellum

protein)• Bacterial DNA• Viral RNA

PAMPs (Pathogen Associated Molecular

Patterns)

Innate cells respond to invaders in two ways

1. Phagocytosis: Eating the invader

2. Chemotaxis: Recruiting help

• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__phagocytosis.html

Eating the invader:Phagocytosis

Eating the invader:Phagocytosis

Recruiting help:Chemotaxis

Innate cells also activate adaptive cells

1. After digesting the pathogen some innate cells stick its parts (antigens) on their cell membrane:• They are called Antigen Presenting Cells (APCs)

2. By presenting the antigens like this they can activate T cells.

Wrap up1. Physical and chemical barriers are part of the innate immune system

on the outside of the body.

2. Innate cells are in the sterile interior.

3. Innate cells have receptors that see pathogen associated patterns (PAMPs) not found in the host (non-self vs. self).

4. After recognizing a PAMP innate cells phagocytose the invader and present its antigens on their surface.

5. Then they secrete chemokines to call for help from more innate cells.

6. Innate receptors cannot adapt to mutating PAMPs, so they may also call for help from the adaptive immune system.