Immunological Memory

Antibodies/Ig

Glycoproteins produced by B-lineage cells

Membrane-bound Ig

Serves as B-cell receptor

Secreted Ig (antibody)

Produced by plasma cells

Heavy chains

Determines antibody class

Light chains

Either 2 k or 2 a light chains

Does not determine class

Antibody specificity

Determined by variable regions of both heavy and light chains

IgG

Most abundant in blood

Neutralizes, opsonizes, and activates classical pathway

Important in secondary immune responses

Crosses placenta and provides passive immunity to fetus

IgA

Mucosal immunity

Monomer form in blood

Dimer form joined by J chain found in mucosal secretions

Provides passive immunity to newborns via breast milk

IgM

First antibody in a primary response

Monomer form expressed as BCR with IgD

Pentamer form joined by J chain is secreted

Early IgM has lower affinity, while later pentamer has high avidity

IgE

Allergy and parasite defense, binds mast cells

IgD

Functions as BCR on B cells

Primary response

First exposure

Slower and weaker

Activates naive B cells w/ CD4 helper T cell

IgM produced first, then later class switchingS

Secondary Response

Driven by memory B cells

Faster, stronger, longer-lasting

Usually IgG high-affinity antibodies

RhIG/RhoGAM

Preformed anti-D antibodies

Given to unsensitized Rh- mothers during pregnancy to prevent sensitizationA

Adoptive Cellular Therapy

Transfer of immune cells into patient to enhance immune response

CAR T-cell therapy

patient's T cells are genetically engineered to recognize a tumor antigen

Tumor-Infiltrating Lymphocytes Therapy

T cells are isolated from the patient's tumor, expanded outside the body, reinfused