Tuberc Respir Dis.  1971 Mar;18(1):12-20. 10.4046/trd.1971.18.1.12.

A Study on the Macrophage-Mycobacterium Interactions in Vitro

• KMID: 2529111
• DOI: http://doi.org/10.4046/trd.1971.18.1.12

Abstract

Numerous studies on the interactions between phagocytes and pathogens were reported; however, informations on the biology of the phathogen in the host, or the biochemical alterations occurring in the tissue of the host due to infection is incomplete or missing. It would be worthwhile to learn more about the mechanisms involved in the maintenance or destruction of function and life as a consequence of the relationship between phagocytes and pathogens. Thus, an experiment was planned and performed to study the mode of interactions between rabbit macrophages and mycobacteria which are facultative intracellular parasites, at different temperatures which might influence the metabolic activities at various cells. Normal rabbit macrophages were collected from the peritoneal cavity, suspended in the CMF medium and mixed with suspensions of mycobacteria. The macrophage-bacteria suspensions were maintained for 24 hours at 37 ℃. and 33 ℃., and the rate of appearance of the macrophages containing the organisms, and the extracellular and intracellular viable population of the organisms were studied. The results of the observation were summerazied as follow: 1) At 37 ℃. and 33 ℃. percentages of the intracellular units to the total viable units of Mycobacterium tuberculosis (H₃₇Rv) reached 63% after 1 hour and after 6 hours above 65%. Percentages of macrophages containing H₃₇Rv strains began to show above 40% after 2 hours at 37 ℃. and 33 ℃. 2) Percentages of the intracellular units to the total viable units of Mycobacterium bovis (Ravenel) reached 61% at 37 ℃. , or 54% at 33 ℃. after 1 hour, but after 3 hours 70% were phagocytized at both temperatures. After 2-3 hours 40% of macrophages contained Ravenel strains in the cytoplasm at 37 ℃. and 33 ℃. 3) Percentages of the intracellular units to the total units of Mycobacterium bovis( BCG) showed 45% after 1 hour, and 60% after 3 hours at 37 ℃. and 33 ℃. After 3-6 hours 40% of macrophages contained BCG strains intracellularly at 37 ℃. and 33 ℃. 4) Percentages of the intracellular units to the total units of Mycobacterium ulcerans showed 42 % at 37 ℃., or 47% at 33 ℃. after 1 hour, and after 3 hours 56% at 37 ℃. , or 60% at 33 ℃. Percentages of macrophages containing Myco. ulcerans were appeared 32% at 37 ℃. , or 42% at 33 ℃. after 3-6 hours. 5) 40% of the total viable units of Mycobacterium fortuitum were phagocytizied after 1 hour, and only about 50% after 6 hours at 37 ℃. and 33 ℃. At both temperatures 48% of macrophages contained Myco. fortuitum within cytoplasm after 3-6 hours.