In situ studies of the primary immune response to (4-hydroxy-3-nitrophenyl)acetyl. II. A common clonal origin for periarteriolar lymphoid sheath-associated foci and germinal centers.

• DOI: 10.1084/jem.176.3.679
• Publication Date: 2004-06-24T07:56:10Z
• Authors: J Jacob; G Kelsoe
• Keywords: 0301 basic medicine; B-Lymphocytes; Nucleic Acid; Base Sequence; Lymphoid Tissue; Molecular Sequence Data; Sequence Homology; DNA; Inbred C57BL; Clone Cells; 3. Good health; Immunoenzyme Techniques; Mice, Inbred C57BL; Nitrophenols; Mice; 03 medical and health sciences; Sequence Homology, Nucleic Acid; Animals; Female; Immunoglobulin Heavy Chains; Haptens; Phenylacetates

In the genetically restricted response that follows immunization with (4-hydroxy-3-nitrophenyl)acetyl coupled to protein carriers, two distinct populations of B cells are observed in the spleens of C57BL/6 mice. By 48 h postimmunization, foci of antigen-binding B cells appear along the periphery of the periarteriolar lymphoid sheaths. These foci expand to contain large numbers of antibody-forming cells that neither bind the lectin, peanut agglutinin, nor mutate the rearranged immunoglobulin variable region loci. Germinal centers containing peanut agglutinin-positive B cells can be observed by 96-120 h after immunization. Although specific for the immunizing hapten, these B cells do not produce substantial amounts of antibody, but are the population that undergoes somatic hypermutation and affinity-driven selection. Both focus and germinal center populations are pauciclonal, founded, on average, by three or fewer B lymphocytes. Despite the highly specialized roles of the focus (early antibody production) and germinal center (higher affinity memory cells) B cell populations, analysis of VH to D to JH joins in neighboring foci and germinal centers demonstrate that these B cell populations have a common clonal origin.