An evolutionarily-conserved role for murine Ly-1 B cells in protection against bacterial infections.
The murine Ly-1 B cell lineage, although comprising only a minority of peripheral IgM+ B cells, secretes a major proportion of the IgM antibodies occurring naturally in serum. Ly-1 B cells also seed a large number of IgA+ plasma cells to the gut walls, thereby contributing significantly to production of natural IgA antibodies in response to chronic stimulation by the normal gut flora. Apart from these naturally-produced antibodies, Ly-1 B cells also produce specific antibodies following deliberate immunisation with the bacterial cell wall antigens, phosphorylcholine and dextran. The inability of the X-linked immunodeficient CBA/N mice to produce antibody responses to these two antigens is overcome by reconstitution with normal Ly-1 B cells from the parental CBA strain. Ly-1 B cells therefore appear to play a dominant role in natural immunity and protection against bacterial infections. The compartmentalisation of development and function within murine B cells is suggestive of an evolutionary structuring of the murine immune system, with Ly-1 B cells representing a conserved, primitive B cell lineage and retaining key, associated functions.
Lalor
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Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Victoria, Australia.
D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial; D000950:Antigens, Ly; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001424:Bacterial Infections / Q000276:immunology / Q000517:prevention & control*; D005075:Biological Evolution; D007113:Immunity, Innate; D051379:Mice
D000942:Antigens, Bacterial; D000950:Antigens, Ly