2. Immune System Antigen – molecule that induces an immune response OR..?
Pathogen – infectious agent that causes disease
Antibody – proteins produced by the immune system to help remove antigens – specificity – “each” antibody recognizes a different antigen
Interferon – chemical signal from infected cell “warning” other cells and (sometimes) telling the immune system to kill the cell

3. Immune System
B-cell – WBC that is part of humoral immunity component of the adaptive immune system. Secrete antibodies
T-cell – WBC that is part of cell-mediated immunity component adaptive immune system. Regulate immune response or directly attack infected cell
Antibody – proteins produced by the immune system to help remove antigens – specificity – “each” antibody recognizes a different antigen
Phagocyte – a cell that ‘eats’ other cells and particles

4. Immune System
Clone – WBC that is copied (mitosis) in response to its interaction with an antigen
MHC – Major Histocompatibility Complex – proteins on a cell surface that display proteins (antigens) from foreign cells for T- cell recognition
APC – cells that have MHCs on their surface for presentation of antigens
Perforin – Released by cytotoxic T-cells, forms pores in foreign-cell membrane – ‘uncontrolled’ diffusion - related to ‘complements’

5. Immune System
Complement Proteins– a family of proteins in the blood that, when activated, can enhance immune response (phagocytosis and attracting immune cells) and can rupture cell membranes
Memory Cells – special clones of B and T cells that remain in the body and allow a quicker and ‘higher’ response to antigen upon further exposure

6. Immune System Neutrophils – small, highly mobile, phagocytes
Eosinophils – variety of functions, but ‘most important’ in defense against parasites

8. Immune System Neutrophils – small, highly mobile, phagocytes
Eosinophils – variety of functions, but ‘most important’ in defense against parasites
Monocytes – Large cells that can turn into macrophages or dendritic cells

9. Antibodies Y-shaped proteins that bind to antigens
Binding to the antigen can ‘flag’ the microbe for attack from other immune system cells
Can also ‘stop’ the invading microbe by blocking part of its function

10. Antibodies They’re proteins, so they’re made of..?
That means they have..?
So how do they ‘bind’ to antigens?

11. Antibodies
Variable Region
Constant Region

12. Antibodies Variable vs Constant Region – just what you think
Fab Region
Fragment antigen-
binding
Fc Region
Fragment
crystallizable

13. Antibodies

14. # antigen binding sites
Antibodies
Type of antibody (Ig)
Structure of Ig
# antigen binding sites
Function
Fc binds to…

15. Homework
Be ready for a quiz