Glycoconj J (2006) 23: 107–113 DOI 10.1007/s10719-006-5443-y Gangliosides are not essential for influenza virus infection Mikhail Matrosovich · Takashi Suzuki · Yoshio Hirabayashi · Wolfgang Garten · Robert G. Webster · Hans-Dieter Klenk C  Springer Science + Business Media, LLC 2006 Abstract Sialic acid is known to be an essential part of in- fluenza virus receptors, but the specific identity of the recep- tor molecules on target cells is still not defined. In particu- lar, the relative roles played by cellular sialylglycoproteins and gangliosides in virus entry into target cells remain un- clear. To test whether gangliosides are essential for virus infection, we used the GM-95 mutant cell line of mouse B16 melanoma which lacks synthesis of major glycosphin- golipids including gangliosides. We found that GM-95 cells grown in serum-containing medium harboured substantial amounts of ganglioside receptors for influenza virus due to incorporation of serum gangliosides. To obtain ganglioside- free cells, we adapted GM-95 cells to growth in defined M. Matrosovich () Institute of Virology, Philipps University, Robert Koch str. 17, 35037, Marburg, Germany e-mail: Mikhail.Matrosovich@med.uni-marburg.de Tel: +49-(6421)-286-5166 Fax: +49-(6421)-286-8962 M.P. Chumakov Institute of Poliomyelitis and Viral Encephalitides, Moscow, Russia T. Suzuki Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan Y. Hirabayashi Neuronal Circuit Mechanisms Research Group, Brain Science Institute, The Institute of Physical and Chemical Research (RIKEN), Japan W. Garten · H. D. Klenk Institute of Virology, Philipps University, Marburg, Germany R. G. Webster Division of Virology, Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN, USA serum-free (sf) medium. Ganglioside-free GM-95-sf cells could be infected by avian and human influenza A viruses and produced infectious virus progeny demonstrating that gangliosides were neither absolutely necessary for the early nor for the late stages of the infection. However, sensitivity of the GM-95-sf cells to the viruses was 2–4 times lower than that of the ganglioside-containing parent cell line. Further studies are needed to specify whether this effect was due to the lack of gangliosides, neutral glycosphingolipids, or other effects. Keywords Influenza virus . Glycosphingolipid-deficient cells . TLC overlay assay . GM-95 . MEB-4 . Serum-free medium Abbreviations BSA bovine serum albumin Dk/98 A/Mallard duck/Alberta/279/98 (H3N8) DMEM Dulbecco’s modified Eagle medium FCS fetal calf serum GM-95-sf GM-95 cells adapted to serum-free medium GD1a disialoganglioside Neu5Acα2-3Galβ 1-3Gal- NAcβ 1-4(Neu5Acα2-3)Galβ 1-4Glcβ 1-1Cer GM3 monosialoganglioside Neu5Acα2-3Galβ 1-4- Glcβ 1-1Cer GT1b trisialoganglioside Neu5Acα2-3Galβ 1-3Gal- NAcβ 1-4(Neu5Acα2-8Neu5Acα2-3)Galβ 1-4- Glcβ 1-1Cer GalCer galactosylceramide GlcCer glucosylceramide HRP horseradish peroxidase LacCer lactosylceramide NP nucleoprotein of influenza virus MDCK Madine-Darby canine kidney cells Springer