The Identification of Six Mouse Lymphocyte Subpopulations by Their Natural Binding of Bacteria

Abstract

Abstract The natural adherence of eight strains of bacteria to mouse spleen cells is described. The bacteria used were: Arizona hinshawii, Brucella abortus, Brucella melitensis, Corynebacterium xerosis, three strains of Escherichia coli (E. coli-2, E. coli-3 and E. coli-4), and Pasteurella pestis. A strain of E. coli that did not bind naturally to spleen cells was chemically coated with anti-mouse Ig antibodies (anti-Ig Ab-E. coli) and used to identify cells with surface Ig, i.e., Ig+ cells (B cells). Cells that lacked detectable surface Ig (Ig- cells) were considered to be primarily T cells. By mixing anti-Ig Ab-E. coli and another bacteria with the lymphocytes, we found that some of the bacteria bound to either Ig+ or Ig- cell subsets and some bound to both Ig+ and Ig- cell subsets. One strain of bacteria (B. melitensis) bound to essentially all of the Ig+ cells and none of the Ig- cells. By labeling the lymphocytes with various combinations of two bacteria, we identified three Ig+ (B cell) and three Ig- (presumably T cell) lymphocyte subpopulations. B1 cells bound B. melitensis, B. abortus, and C. xerosis; B2 cells bound B. melitensis, A. hinshawii, C. xerosis, E. coli-2, and E. coli-4; B3 cells bound B. melitensis, P. pestis, and E. coli-2, T1 cells bound C. xerosis, E. coli-2, and E. coli-3; T2 cells bound E. coli-3 and E. coli-4. T3 cells did not bind any of the bacteria. Whereas B. melitensis, C. xerosis, E. coli-2, E. coli-3, and E. coli-4 adhered to more than one subset of lymphocytes, B. abortus, A. hinshawii, and P. pestis adhered to only a single subset—B1, B2, and B3 cells, respectively. The use of the natural adherence of bacteria to lymphocytes provides a simple method for identifying lymphocyte subpopulations and may facilitate the elucidation of the roles that lymphocyte subsets play in immune phenomena.