Adaptive - Cellular

What are the 3 common cells in an adaptive immune response

T Lymphocytes, B Lymphocytes and APCs (Antigen Presenting Cells)

Where do lymphocytes originate from?

Red Bone Marrow

Where are T Cells matured or “educated” to become full grown Naive cells?

The Thymus

Where do T and B cells get exposed to an antigen for the first time?

Lymph nodes

T Cells must recognize what 2 things to be matured?

Self-MHC proteins (destroy) and self-antigens (spare)

What threats do B Cells usually address?

Extracellular pathogens - bacteria, parasites, fungi, certain viruses

What threats do T Cells usually address?

Intracellular threats - virus or cancer infected cells

What kind of immunocompetent cell do CD4s become?

Helper T Cells (and regulatory T Cells)

What kind of immunocompetent cell do CD8s become?

Cytotoxic T Cells

What protein is found on every nucleated cell?

Class I MHC

What does an abnormal MHC Class I indicate?

An endogenous, or intracellular, problem such as cancer or an invading pathogen. APCs can also present it to T Cells

What protein is only found on APCs?

Class II MHC

What is the purpose of Class II MHC?

To carry a fragment of a phagocytized invader to present to T Cells

Full activation of T Cells requires antigen binding and _______

Co-Stimulation

Chemical messengers involved in cellular immunity are called what?

Cytokines (including interferons and interleukins)

What 3 roles can helper T Cells perform?

Activation of B Cells, Activation of CD8 cells, and amplification of innate defenses

How do cytotoxic T cells kill?

Perforins (puts a hole in the membrane) and granzymes. They can also bind to cells and induce apoptosis (cell suicide)