Characterization of macrophages from the bony fish gilthead seabream using an antibody against the macrophage colony-stimulating factor receptor

• Published in: Developmental and comparative immunology 2008, Vol.32 (10), p.1151-1159
• Main Authors: Mulero, Iván, Pilar Sepulcre, M., Roca, Francisco J., Meseguer, José, García-Ayala, Alfonsa, Mulero, Victoriano
• Format: Article
• Language: English
• Subjects: Acidophilic granulocytes; Amino Acid Sequence; Animals; Antibodies - immunology; Cell Separation; Conserved Sequence; Cross Reactions - immunology; Danio rerio; Dicentrarchus labrax; European seabass; Granulocytes - immunology; Infection; Innate immunity; Interleukin-1 β; Interleukin-1beta - biosynthesis; Macrophages - immunology; Macrophages - metabolism; Marine; Molecular Sequence Data; Organ Specificity - immunology; Receptor, Macrophage Colony-Stimulating Factor - chemistry; Receptor, Macrophage Colony-Stimulating Factor - immunology; Receptor, Macrophage Colony-Stimulating Factor - metabolism; Sea Bream - anatomy & histology; Sea Bream - immunology; Sea Bream - metabolism; Sequence Alignment; Teleostei; Teleosts; Vibrio anguillarum
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2008.03.005

Two major professional phagocyte populations have been described in fish, namely granulocytes and monocytes/macrophages. Although the distribution and localization of macrophages have been documented in several teleost species using mainly light and/or electron microscopy, the lack of appropriate markers for these cells has hampered our in-depth knowledge of their biology. We report here the generation of a monospecific rabbit polyclonal antibody against the gilthead seabream macrophage colony-stimulating factor receptor (Mcsfr), which is an excellent marker of macrophages in mammals and the zebrafish. The anti-Mcsfr has been found to be very useful in immunohistochemistry (IHC) to specifically immunostain the purified macrophages (adherent cells) obtained from the head-kidney as well as different cell populations in paraffin-embedded organs, including the head-kidney, spleen, thymus, gills and liver. Unexpectedly, however, no Mcsfr immunoreactive (Mcsfr +) cells were observed in the brain and intestine of the gilthead seabream. We also show that the distribution of Mcsfr + cells in the head-kidney and the spleen is unaltered following infection with the fish pathogenic bacterium Vibrio anguillarum and that the Il1b-producing cells in these two organs after infection are exclusively acidophilic granulocytes. Finally, as the epitope recognized by the anti-Mcsfr is well conserved, we illustrate the potential usefulness of this antibody in other teleost species, such as the European seabass.