Adaptive Immunity

What are the two types of immunity?

Innate (non-specific, present at birth) and adaptive (specific, acquired)

What unique feature does adaptive immunity have?

Memory

What do PAMPs bind to?

PRRs

What is an antigen?

A substance that provokes a specific immune response

What is an epitope?

The specific part of an antigen recognized by lymphocytes

Which cells express MHC-I?

All nucleated cells

Which cells express MHC-II?

Immune cells

MHC-I presents what type of antigens?

Intracellular antigens

MHC-II presents what type of antigens?

Extracellular antigens

What are primary lymphoid organs?

Sites of lymphocyte origin and maturation

Name secondary lymphoid organs.

Lymph nodes, spleen, tonsils, Peyer’s patches

What do B-cell receptors bind?

Free antigens

What are antibodies made of?

Immunoglobulins

What do T-cell receptors bind?

Processed antigen + MHC

Are T-cell receptors secreted?

No

What does CD4⁺ T-cell recognize?

Antigen on MHC-II

What is the role of CD4⁺ T cells?

Cytokine release and immune activation

What does CD8⁺ T-cell recognize?

Antigen on MHC-I

What is the role of CD8⁺ T cells?

Kill infected cells

What is the primary immune response?

Slow, first exposure

What causes the secondary immune response to be faster?

Memory B cells

What activates the classic complement pathway?

Antigen-antibody complexes

What does MAC do?

Lysed Gram-negative bacteria