The "Ly-1 B" cell subpopulation in normal immunodefective, and autoimmune mice

J Exp Med. 1983 Jan 1;157(1):202-18. doi: 10.1084/jem.157.1.202.


A small subpopulation of normal murine splenic B cells carrying all of the classic B cells markers (IgM, IgD, Ia, and ThB) also carries Ly-1, one of the major T cell surface molecules. This "Ly-1 B" subpopulation (identified and characterized by multiparameter FACS analyses) consists of relatively large, high IgM/low-IgD/low-Ly-1 lymphocytes that represent approximately 2% of the spleen cells in normal animals and, generally, 5-10% of spleen cells in NZB mice. Ly-1 B are clearly detectable in all normal mouse strains tested as well as NZB, CBA/N, other X-id mice and nude (nu/nu) mice. They are found primarily in the spleen; are either absent or very poorly represented in lymph node, bone marrow, and thymus; appear early during ontogeny, and comprise about a third of the small number of lymphocytes present in 5-d-old mice. NZB and (NZB x NZW)F1 mice have more Ly-1 B than all other strains and, furthermore, have a unique Ly-1 B population that secretes IgM when cultured under usual conditions in the absence of added antigen. The IgM secretion by these Ly-1 B cells accounts for the previously reported "spontaneous" IgM secretion by NZB spleen cells in culture. Studies with FACS-sorted cells show that the presence of Ly-1 on these IgM-secreting cells distinguishes them from the (Ly-1 negative) IgM-secreting "direct" plaque-forming cells generated in NZB mice after stimulation with sheep erythrocytes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Animals
  • Antigens, Ly / analysis*
  • Antigens, Surface / analysis
  • Autoimmune Diseases / immunology*
  • B-Lymphocytes / classification
  • B-Lymphocytes / immunology*
  • Cell Separation
  • Flow Cytometry
  • Immunoglobulin M / analysis
  • Immunologic Deficiency Syndromes / immunology*
  • Mice
  • Mice, Inbred NZB / immunology
  • Receptors, Antigen, B-Cell / analysis
  • Spleen / cytology
  • Spleen / embryology


  • Antigens, Ly
  • Antigens, Surface
  • Immunoglobulin M
  • Receptors, Antigen, B-Cell