The Fc portion of an IgG molecule is responsible for binding to Fcg receptors and for complement activation. The World Health Organization has, through a world-wide vaccination program, successfully eradicated smallpox as a disease. Secretory component is a large polypeptide chain produced by epithelial cells that binds to IgD. 5. Allelic exclusion refers to the inactivation of Ig genes in T cells in the thymus. Whether a B cell inserts an Ig molecule in the membrane or secretes it, is determined by switch sequences.
B cells recognize protein, carbohydrate and lipid antigens.
A hapten can stimulate antibody formation but cannot combine with antibody molecules. All isotypes are normally found in each individual of a species. Draw a lymph node. Identify the parts. Indicate what cells are present and where they are found.