HIV and SIV, B-Cell Responses to

Definition

Humoral immunity refers to the component of an immune response that is mediated by circulating antibodies. B cells secrete antibodies following differentiation into either short-lived plasmablasts, which can circulate, or long-lived sessile plasma cells that reside primarily in the bone marrow, but can also be found in mucosal tissues and the spleen. Classic memory B cells refer to cells that have encountered antigen, responded by undergoing somatic hypermutation in the variable regions of their immunoglobulin genes with or without class switching (to IgG, IgA, or IgE) and returned to a resting state (Tarlinton and Good-Jacobson 2013). Upon reencounter with cognate antigen, memory B cells will rapidly respond by differentiating into plasma blasts/cells. HIV infection leads to numerous perturbations of the B-cell compartment that affect several developmental stages of maturation and differentiation. In the absence of antiretroviral therapy (ART), the resting memory B-cell...