B Lymphocytes — Antibody-Mediated

B-cell receptors

Y-shaped antibodies located on the B cell membrane.

Antibody structure

An antibody consists of two heavy chains and two light chains arranged in a Y shape.

Heavy chains

The two longer polypeptide chains of an antibody.

Light chains

The two shorter polypeptide chains of an antibody.

Hinge region

The flexible region of an antibody that allows movement of its arms.

Binding sites

The regions at the ends of the antibody that bind specific antigens.

Stem region

The lower portion of the Y-shaped antibody.

Immunoglobulin

Another name for an antibody.

B cell activation

Requires the correct B cell to bind its antigen, present the antigen on MHC II, and receive co-stimulation from a Helper T cell.

B cell co-stimulation

Helper T cells release interleukins that provide the second signal required for full B cell activation.

B cell clonal selection

Proliferation and differentiation of an activated B cell into plasma cells and memory B cells.

Plasma cells

Activated B cells that produce and secrete antibodies specific to a pathogen.

Memory B cells

B cells stored after an immune response that allow a faster response during future exposure to the same pathogen.

Plasma cell antibody production

Plasma cells can produce approximately 2,000 antibodies per second according to the slides.

Plasma cell lifespan

Plasma cells produce large amounts of antibodies for approximately 2–3 weeks before dying.