B cells are an integral part of the humoral immune response due to their ability to produce antibodies against foreign antigens. They originate from hematopoietic stem cells in the bone marrow, where they undergo several phases of antigen-independent development, leading to the generation of immature B cells. Immunoglobulin gene rearrangement during these early stages of B cell development results in the expression of a mature B cell receptor (BCR) that is capable of binding to antigen. This is followed by positive and negative selection processes, which are designed to eliminate non-functional and self-reactive immature B cells. Surviving B cells complete antigen-independent maturation in the spleen, producing immunocompetent naïve mature B cells, which subsequently develop into either follicular or marginal zone B cells. During the antigen-dependent phase of development, follicular B cells participate in germinal center reactions, where they differentiate into memory B cells or long-lived, antibody-secreting plasma cells. Defects in these developmental processes, selection, or B cell function have been linked with immunodeficiencies, autoimmune diseases, and cancer.
Note: Lin– for Mouse CLP, BLP, B1 and B2 Progenitor cells: CD3– CD4– CD8– Gr-1/Ly-6G– Integrin aM/CD11b– TER-119– Lin– for Mouse Pre-Pro B, Pro-B, Pre-B cells: CD3– Gr-1/Ly- 6G– Integrin αM/CD11b– TER-119–