Understanding B and T Lymphocytes in Immune Response

These flashcards cover key vocabulary related to B and T lymphocytes and their roles in the immune response, as discussed in the lecture.

Antigen

A substance that induces an immune response in the body, especially the production of antibodies.

B Cell Receptor (BCR)

A membrane-bound immunoglobulin on the surface of B lymphocytes that recognizes specific antigens.

T Cell Receptor (TCR)

A molecule on the surface of T lymphocytes that recognizes antigens presented by Major Histocompatibility Complex (MHC) molecules.

MHC Class I

A protein complex found on all nucleated cells that presents endogenous antigens to CD8 cytotoxic T cells.

MHC Class II

A protein complex found on antigen-presenting cells (like B cells) that presents exogenous antigens to CD4 helper T cells.

Clonal Selection

The process by which the specific B or T cell that recognizes an antigen is selected for activation and proliferation.

Clonal Expansion

The rapid proliferation of specific B or T cells after they have been activated by their respective antigens.

Differentiation into Effector Cells

The process where activated B or T cells develop into effector cells that perform functions such as producing antibodies or killing infected cells.

Memory B Cells

Long-lived B cells that respond more rapidly upon subsequent exposure to the same antigen.

Plasma B Cells

Effector B cells that produce large amounts of antibodies.

CD4 Helper T Cells

A subtype of T cells that help activate B cells and cytotoxic T cells, primarily by recognizing antigens presented on MHC II.

CD8 Cytotoxic T Cells

A subtype of T cells that directly kill infected cells or cancer cells by recognizing antigens presented on MHC I.

Antibody

A protein produced by B cells in response to an antigen that helps neutralize or destroy pathogens.

T Cell Activation

The process through which T cells become activated upon recognizing their specific antigen presented by MHC molecules.

Antigen-Presenting Cells (APCs)

Cells that process and present antigens to T cells, crucial for initiating an adaptive immune response.

Immunological Memory

The ability of the immune system to respond more rapidly and effectively to pathogens that have been encountered previously.

Cytokines

Signaling molecules released by immune cells that mediate and regulate immunity and inflammation.