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

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

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’

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

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

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

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

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

Antibodies Variable Region Constant Region

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

Antibodies

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

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