Agglutination of Bacteria by Lymphoid Cells in Vitro.

Abstract

Antibody production was induced in the popliteal lymph nodes of rabbits through injn. into the footpads of 0.5 ml. of a commercial typhoid H. or Brucella antigen. From 2 to 14 days after injn. the nodes were removed and their cells suspended in physiol. saline soln. The antibody contained in the lymph plasma was washed out by twice repeated centrifugation and resuspension in saline. A drop of the final suspension was placed on a slide and covered with a drop of a similarly washed and suitably diluted portion of the antigen. It was found that certain lymphoid cells agglutinated the bacteria on their surface. The number of cells showing this phenomena was greatest 5-7 days following the injn. of antigen when antibody concn. in the lymph nodes was highest. It occurred only between cells of immunized rabbits and the bacteria with which this immunization was achieved. There was no cross reaction. The agglutinating cells which could be identified belonged to the plasma cell series; typical small lymphocytes, monocytes, macrophages and polymorphonuclear leukocytes failed to show the phenomenon. Apparently it is the plasma cell rather than the lymphocyte which elaborates agglutinins.