SPECIFIC ANTIBODY-FORMING B-LYMPHOCYTE COLONIES .1. DISTRIBUTION AND NATURE OF SRBC ANTIBODY-FORMING B-LYMPHOCYTE COLONIES IN MOUSE LYMPHOMYELOID ORGANS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 35  (2) , 397-406
Abstract
When normal mouse spleen or lymph node cells are cultured for 7 days in agar-medium containing 2-mercaptoethanol and sheep red blood cells (SRBC), approximately 1 B [bone marrow-derived] lymphocyte colony (BLC) develops per 50-100 cells seeded. Incubation of cultures for 3 h with guinea pig complement [C] at day 7 demonstrated that 0.05-0.25% of BLC form specific antibody against SRBC (SRBC-AF-BLC). The SRBC specific colonies appear centrally in lytic plaques of 2-5 mm in diameter and cells recovered from individual SRBC-AF-BLC produced antibodies of the Ig[immunoglobulin]M class against SRBC. Cells forming SRBC-AF-BLC are absent in the newborn and infantile spleen but appear in adult mice with a frequency of 5, 10-25 and 25-70/106 bone marrow, spleen and lymph node cells, respectively. Specific immunization in vivo or in vitro does not greatly affect the number of SRBC-AF-BLC-forming cells. Cytolysis of spleen cells with anti-Ig serum plus C prior to culture reduced the number of total BLC and that of specific SRBC-AF-BLC by 93% and 94%, respectively. The peak sedimentation velocity of SRBC-AF-BLC-forming cells and total BLC-forming cells was 3.5 mm/h. Spleen cells enriched 200-300 times for cells that bind specifically to the hapten NIP [4-hydroxy-3-iodo-5-nitrophenyl acetic acid] were not enriched for cells forming colonies with specific antibody production against NIP. Cells that give rise to specific antibody-forming colonies belong to a mature virgin B cell group of small Ig-positive B lymphocytes.