Intracellular multiplication of Legionella pneumophila in HL-60 cells functionally differentiated in response to 22-oxacalcitriol

• Published in: Journal of leukocyte biology Vol. 57; no. 4; pp. 574 - 580
• Main Authors: Matsuzaki, Miwako, Shimamoto, Yoshinori, Watanabe, Masayuki, Kukita, Akiko, Yoshida, Shin‐ichi, Tadano, Jutaro
• Format: Journal Article
• Language: English
• Published: United States Society for Leukocyte Biology 01.04.1995
• Subjects: 1,25‐dihydroxyvitamin D3; Animals; Antineoplastic Agents - pharmacology; Bone Marrow - drug effects; Bone Marrow Cells; Calcitriol - analogs & derivatives; Calcitriol - pharmacology; Cell Differentiation - drug effects; human leukemia cell; Humans; Interferon-gamma - pharmacology; interferon‐γ; Intracellular Fluid - microbiology; Legionella pneumophila; Legionella pneumophila - growth & development; Leukemia, Myeloid - drug therapy; Leukemia, Myeloid - microbiology; Leukemia, Myeloid - pathology; Mice; monocyte; Monocytes - cytology; Monocytes - drug effects; osteoclast; Osteoclasts - cytology; Osteoclasts - drug effects; Osteoclasts - ultrastructure; Recombinant Proteins; superoxide anion; Superoxides - metabolism; Tumor Cells, Cultured - drug effects
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.57.4.574

The agent 1,25‐dihydroxy vitamin D3 (D3) induces the differentiation of HL‐60 human leukemia cells into functional monocyte‐like cells that can support the intracellular multiplication of Legionella pneumophila. 22‐Oxacalcitriol (OCT), a synthetic analogue of D3, ex hibits greater differentiation‐inducing activity than D3 in WEHI‐3 mouse leukemia cells and has been suggested to be clinically more useful because of its lower hypercalcemic activity. The abilities of OCT and D3 to induce the functional differentiation of human leukemia HL‐60 cells have now been investigated. OCT induced the differentiation of HL‐60 cells into monocyte‐like cells to a similar extent as D3. Thus, both OCT and D3 increased (1) the surface expression of CD11b, CD11c, CD14, and CD35; (2) nonspecific esterase staining; and (3) phagocytic ac tivity toward fluorescent beads. HL‐60 cells differentiated in response to OCT also supported the intracellular mul tiplication of L. pneumophila. Activation of both OCT‐and D3‐treated HL‐60 cells with human recombinant interferon‐γ (IFN‐γ) for 24 h before infection markedly inhibited L. pneumophila multiplication. IFN‐γ activation enhanced superoxide anion generation by D3‐treated HL‐60 cells but not by OCT‐treated HL‐60 cells, suggesting that the inhibition of L. pneumophila multiplication in IFN‐γ‐activated cells is independent of superoxide generation. Finally, D3, but not OCT, markedly stimu lated the formation of osteoclast‐like multinudeated cells from mouse bone marrow cells, consistent with the lower hypercalcemic activity of OCT. J. Leukoc. Biol. 57: 574–580; 1995.