Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock

Invasion and intracellular growth of Mycobacterium tuberculosis and Mycobacterium avium complex adapted to intramacrophagic environment within macrophages and type II alveolar epithelial cells

Abstract

Profiles of the invasion and intracellular growth of M. tuberculosis (MTB) and M. avium complex (MAC), which had been adapted to intramacrophagic environment, within Mono Mac 6 human macrophages (MM6-M phi s) and A-549 human type II alveolar epithelial cells (A-549 cells) were studied. In this study, we used the organisms grown in MM6-M phi s (intracellularly-adapted: I-type) and those passaged in 7H9 liquid medium (extracellularly-adapted: E-type). First, I-type MTB was less efficient than E-type MTB in invading into MM6-M phi s, while I-type MTB invasion into A-549 cells was greater than of E-type MTB. On the other hand, I-type MAC was more efficient than E-type MAC in entering both into MM6-M phi s and A-549 cells. Second, the ability of MTB and MAC to replicate within MM6-M phi s was increased by intracellular passage of these organisms through MM6-M phi s. In contrast, the ability of these organisms to grow within A-549 cells was decreased to some extent by intramacrophagic passage. These findings suggest that growth within M phi s changes the efficiency of MTB and MAC in invading and replicating in M phi s and type II alveolar epithelial cells.