STUDIES ON TUBERCLE BACILLUS-HISTIOCYTE RELATIONSHIP

Abstract

Studies of passive transfer of cellular resistance (as manifested by refractoriness of cells to necrotization with virulent tubercle bacilli) showed that the histiocytes of recipient rabbits, which were injected intradermally with either histiocytes of lymphocytes of BCG-immunized rabbits, were resistant to virulent tubercle bacilli; polymorphonuclear leukocytes and serum from immunized rabbits as well as comparable cells of all types from normal animals lacked this capacity. Comparisons of immune histiocytes and immune lymphocytes showed that the former cells were more efficient; this was indicated by the smaller numbers of immune histiocytes needed for passive transfer, the longer duration of cellular resistance in recipients given histiocytes than in those given lymphocytes, the greater capacity of histiocytes to effect serial passive transfer and the ability of histiocytic but not lymphocytic lysates to transfer cellular resistance. Experiments to establish the mechanism of passive transfer of cellular resistance showed that there was no active induction of resistance in recipients through transfer of bacillary antigens contained in immune histiocytes; in fact, the results of serial passive transfers with immune histiocytes suggested an active replication of the "cell resistance factor.".