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METHODS article

Front. Immunol.
Sec. Comparative Immunology
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1465952
This article is part of the Research Topic Basic and Applied Research Toward the Development of Vaccines Against African Swine Fever Virus View all 4 articles

Establishment and characterization of an immortalized red river hog blood-derived macrophage cell line

Provisionally accepted
Takato Takenouchi Takato Takenouchi 1*Kentaro Masujin Kentaro Masujin 2Rina Ikeda Rina Ikeda 3Seiki Haraguchi Seiki Haraguchi 1Shunichi Suzuki Shunichi Suzuki 1Hirohide Uenishi Hirohide Uenishi 1Eiji Onda Eiji Onda 4Takehiro Kokuho Takehiro Kokuho 2
  • 1 Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
  • 2 Division of Transboundary Animal Disease Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Kodaira, Tokyo, Japan
  • 3 Kyusyu Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, Kagoshima, Japan
  • 4 Yokohama Zoological Gardens, Yokohama, Kanagawa, Japan

The final, formatted version of the article will be published soon.

    Red river hogs (RRHs) (Potamochoerus porcus), a wild species of Suidae living in Africa with a major distribution in the Guinean and Congolian forests, are natural reservoirs of African swine fever virus (ASFV) and typically are asymptomatic. Since blood and tissue macrophages of suid animals are target cell lineages of ASFV, RRH-derived macrophages are expected to play an important role in suppressing disease development in infected individuals. In the present study, we successfully isolated RRH-derived blood macrophages using co-culture techniques of RRH blood cells with porcine kidneyderived feeder cells and immortalized them by transferring SV40 large T antigen and porcine telomerase reverse transcriptase genes. The newly established macrophage cell line of the RRH-derived blood cell origin (RZJ/IBM) exhibited an Iba1-, CD172a-, and CD203a-positive typical macrophage-like phenotype and up-regulated the phosphorylation of nuclear factor-kB p65 subunit and p38 mitogen-activated protein kinase in response to the bacterial cell wall components, lipopolysaccharide (LPS) and muramyl dipeptide. In addition, RZJ/IBM cells produced the precursor form of interleukin (IL)-1b and IL-18 upon a stimulation with LPS, leading to the conversion of IL-18, but not IL-1b, into the mature form. Time-lapse live cell imaging with pHrodo dye-conjugated Escherichia coli BioParticles demonstrated the phagocytotic activity of RZJ/IBM cells. It is important to note that RZJ/IBM cells are clearly susceptible to ASFV infection and support viral replication in vitro. Therefore, the RZJ/IBM cell line provides a unique model for investigating the pathogenesis of ASFV.

    Keywords: African Swine Fever Virus, Immortalization, in vitro model, Macrophages, red river hog

    Received: 17 Jul 2024; Accepted: 26 Aug 2024.

    Copyright: © 2024 Takenouchi, Masujin, Ikeda, Haraguchi, Suzuki, Uenishi, Onda and Kokuho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Takato Takenouchi, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan

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