L14 - Adaptive Immunity

Vocabulary flashcards about adaptive immune system lecture.

Tolerance

The ability of the adaptive immune system to not react to self.

Central Tolerance

Tolerance that occurs during lymphocyte development in the thymus and bone marrow, where highly self-reactive cells are deleted.

Peripheral Tolerance

Tolerance that occurs in the periphery (outside of the thymus and bone marrow), where regulatory cells suppress the activation of self-reactive lymphocytes.

Specific or Acquired Immunity

Another term for adaptive immunity, highlighting its specific targeting and development in response to microbial invaders.

Lymphocytes

Immune cells, including B cells, T cells, and natural killer cells; B and T cells are central to adaptive immunity.

B Cells/B Lymphocytes

Main adaptive immune cells which develop in the bone marrow (in humans) and produce antibodies.

T Cells/T Lymphocytes

Adaptive immune cells that develop in the thymus and mediate cell-mediated immunity.

B Cell Receptor (BCR)

Receptors on B cells that bind to antigens; nearly identical to antibodies.

T Cell Receptor (TCR)

Receptors on T cells that bind to antigens presented on MHC molecules.

Antigen

A substance that generates an immune response and binds to B and T cell receptors.

Clonal Expansion

The proliferation and expansion of activated lymphocytes, creating a large population of cells specific to the recognized antigen.

Humoral Immunity

Immunity mediated by molecules in the body fluids, primarily antibodies, to target extracellular microbes and toxins.

Plasma Cell

Term for a more differentiated form of a B cell; the effector cell of the B cell which functions as an antibody-producing factory.

Isotypes

Also known as classes, these are different types of antibodies (IgM, IgD, IgG, IgE, IgA) each involved in different types of immune responses.

IgM

A type of antibody that is the first antibody produced during an immune response, and expressed on the surface of naive B cells.

IgG

Antibody abundant in blood and effective against bacteria and viruses; can cross the placenta to provide initial immune defense to babies.

IgE

Antibody important for defence against worms and parasites and is involved in allergic responses.

IgA

Antibody abundant at mucosal sites, where it neutralizes pathogens before they penetrate the gut wall.

MADGE

Isotype	Function (Quick)
IgM	First responder, great at activating complement
IgA	Mucosal immunity (gut, saliva, tears)
IgD	Role unclear, involved in B cell activation
IgG	Most abundant in blood, long-term immunity
IgE	Allergies and parasite defense

Class Switching/Isotype Switching

The process where B cells switch from producing IgM to producing other antibody isotypes (IgG, IgE, IgA) with the help of T cells

MHC (Major Histocompatibility Complex)

Molecules on antigen-presenting cells (like dendritic cells) that present processed antigens to T cells for activation.

Helper T Cells

T cells that help other immune cells (B cells, macrophages, neutrophils) through cell-to-cell interactions and cytokine release.

Killer T Cells/Cytotoxic T Cells

T cells that directly kill infected cells by recognizing pathogen-derived antigens on the cell surface.

Memory Response

The ability of the immune system to mount a quicker and more potent response upon subsequent encounters with the same antigen.

Autoimmune Disease

Immunity against self, resulting from an immune malfunction that targets specific cells or molecules; includes diseases like type 1 diabetes and multiple sclerosis.

Tolerance Mechanisms

Mechanisms that prevent immunity against self, either by deleting self-reactive cells or suppressing their activation.

Antibody Therapy

A type of immunotherapy that blocks molecules from putting the brakes on T cells allowing them to stay activated.