Open AccessIncorporation of 3H-thymidine in Mycobacterium leprae within differentiated human macrophages
Author(s) -
H. K. Prasad,
Indira Nath
Publication year - 1981
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/00222615-14-3-279
Subject(s) - mycobacterium leprae , thymidine , leprosy , lepromatous leprosy , microbiology and biotechnology , macrophage , biology , immunology , chemistry , dna , in vitro , biochemistry
The factors influencing the incorporation of 3H-thymidine (3H-Tdr) in the DNA of Mycobacterium leprae within macrophages derived from human blood have been evaluated. Fifty strains of M. leprae derived from skin nodules of patients with lepromatous leprosy were studied for their ability to incorporate 3H-Tdr. Control macrophages of the same donor maintained alone, or with autoclaved M. leprae, showed low levels of baseline 3H-Tdr incorporation. During a 15-day period of pulsing, 27 of the M. leprae strains incorporated 3H-Tdr at levels of 216-2834% of the incorporation by control cultures. Significant incorporation was observable by the second week of culture and cumulative increases occurred by the third week. A 24-h pulse with 3H-Tdr was inadequate for a detectable increase. A minimal duration of 4-5 days of continuous pulsing was required to obtain a significant increase in the incorporation of 3H-Tdr. Of the 50 M. leprae strains, 23 (46%) failed to incorporate the radiolabel. This failure was apparently not related to differences in the disease status of patients, to the transport conditions for the biopsies, to morphological indices of the extracted M. leprae or to the origin of the host macrophages.