A Correlate of Human Delayed Hypersensitivity: Specific Inhibition of Capillary Tube Migration of Sensitized Human Lymph Node Cells by Tuberculin and Histoplasmin

Summary The migration of human monocytic-phagocytic sensitive cells from lymph node tissue culture suspensions was consistently and specifically inhibited by 10 µg/ml of PPD or 30 µg/ml of histoplasmin. Complete correlation of the inhibition of cell migration with the delayed hypersensitivity skin test was obtained in 27 patients sensitive to PPD, histoplasmin, or to neither or both of these antigens. For migration of these cells to occur, prior maintenance as tissue culture suspensions for 72 hr was necessary before placement in the capillary tubes for 36 hr. During tissue culture, a large proportion of the lymphocytes developed the ability to phagocytize microsized iron particles and this transformation is probably relevant to the development of the migrating cell population. The application of the capillary tube cell migration method to man will facilitate the elucidation of factors important in human delayed hypersensitivity reactions and has implications for evaluating the role of delayed hypersensitivity in autoimmunity, contact sensitivity, infectious diseases and transplantation immunity.