title: High-Density Lipoprotein Binds to Mycobacterium avium and Affects the Infection of THP-1 Macrophages.
abstract: High-density lipoprotein (HDL) is involved in innate immunity toward various infectious diseases. Concerning bacteria, HDL is known to bind to lipopolysaccharide (LPS) and to neutralize its physiological activity. On the other hand, cholesterol is known to play an important role in mycobacterial entry into host cells and in survival in the intracellular environment. However, the pathogenicity of Mycobacterium avium (M. avium) infection, which tends to increase worldwide, remains poorly studied. Here we report that HDL indicated a stronger interaction with M. avium than that with other Gram-negative bacteria containing abundant LPS. A binding of apolipoprotein (apo) A-I, the main protein component of HDL, with a specific lipid of M. avium might participate in this interaction. HDL did not have a direct bactericidal activity toward M. avium but attenuated the engulfment of M. avium by THP-1 macrophages. HDL also did not affect bacterial killing after ingestion of live M. avium by THP-1 macrophage. Furthermore, HDL strongly promoted the formation of lipid droplets in M. avium-infected THP-1 macrophages. These observations provide new insights into the relationship between M. avium infection and host lipoproteins, especially HDL. Thus, HDL may help M. avium to escape from host innate immunity.
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan; Department of Clinical Laboratory, Medical Hospital of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Naoya
authors: N
authors: Ichimura
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Megumi
authors: M
authors: Sato
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Akira
authors: A
authors: Yoshimoto
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Kouji
authors: K
authors: Yano
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Ryunosuke
authors: R
authors: Ohkawa
authors: Instrumental Analysis Research Division, Research Center for Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Takeshi
authors: T
authors: Kasama
authors: Analytical Laboratory Chemistry, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
authors: Minoru
authors: 0000-0001-7366-1262
authors: M
authors: Tozuka