Tuberculin-sensitized lymphocytes detected by altered electrophorectic mobility distributions after incubation with the antigen PPD.

Lymphocytes from donors who had had tuberculosis (a disease known to provoke a cell-mediated immunity) were incubated with the tuberculin antigen, purified protein derivative (PPD), and their distribution of electrophoretic mobility was determined by laser Doppler spectroscopy. In 75% of the cases, the distribution showed a new, high mobility cell subpopulation that was not present before exposure to the PPD. Control lymphocytes from individuals with negative skin tests or no record of tuberculosis showed no mobility changes after incubation with PPD. These observations indicate that the new mobility subpopulation arose from a specific interaction between the antigen and sensitized cells of the donors.