Cell-Mediated Response

What makes adaptive immunity different from innate immunity?

Adaptive immunity provides specificity and memory.

What are the two main processes of adaptive immunity?

Antibody-mediated (B cells) and cell-mediated (T cells) immunity.

What is the main difference between antibody-mediated and cell-mediated immunity?

Antibody-mediated immunity targets pathogens in extracellular fluids, while cell-mediated immunity targets pathogens inside cells.

How is a helper T cell activated?

An APC presents an antigen on MHC II, which is recognized by the helper T cell's TCR and CD4 protein.

What is the relationship between MHC I/CD8 and MHC II/CD4?

MHC I → CD8+ cytotoxic T cells; MHC II → CD4+ helper T cells.

What happens during clonal selection of helper T cells?

The activated T cell multiplies and produces effector T cells and memory T cells.

What is the role of helper T cells in activating cytotoxic T cells?

Helper T cells release cytokines that stimulate cytotoxic T cells to become fully activated

What is the purpose of memory T cells?

They remain in the body and allow for a faster and stronger response when the same antigen is encountered again.

How do perforins and granzymes help cytotoxic T cells destroy infected cells?

Perforins create holes in the infected cell, allowing granzymes to enter and trigger apoptosis.

What are the functions of granulysin and lymphotoxin?

Granulysin damages the microbe itself, while lymphotoxin stops the cell's metabolism and prevents viral replication.

What causes autoimmune diseases?

The exact cause is often unknown, but possible causes include molecular mimicry, bypassing helper T-cell involvement, or a deficiency in regulatory T cells.

What are common treatments for autoimmune diseases?

Immunosuppressive drugs, thymus removal, and plasmapheresis.

What does celiac disease attack, and what triggers it?

It attacks the small intestine in response to gluten.

What happens in type 1 diabetes?

The immune system attacks pancreatic cells, causing insufficient insulin production.

What does Graves disease target?

The TSH receptors on the thyroid.

What does multiple sclerosis (MS) attack?

Myelin in the central nervous system.

What are some important examples of immune system involvement in disease/treatment?

HIV targets CD4+ helper T cells, organ transplant rejection involves a cell-mediated response, and cancer immunotherapy can boost T-cell function.

What tissues are targeted in psoriasis and rheumatoid arthritis?

Psoriasis → skin; rheumatoid arthritis → joints.