Generation, Characterization and Application of Antibodies Directed against HERV-H Gag Protein in Colorectal Samples.
A substantial part of the human genome originates from transposable elements, remnants of ancient retroviral infections. Roughly 8% of the human genome consists of about 400,000 LTR elements including human endogenous retrovirus (HERV) sequences. Mainly, the interplay between epigenetic and post-transcriptional mechanisms is thought to silence HERV expression in most physiological contexts. Interestingly, aberrant reactivation of several HERV-H loci appears specific to colorectal carcinoma (CRC).



The expression of HERV-H Gag proteins (Gag-H) was assessed using novel monoclonal mouse anti Gag-H antibodies. In a flow cytometry screen four antibody clones were tested on a panel of primary CRC cell lines and the most well performing ones were subsequently validated in western blot analysis. Finally, Gag-H protein expression was analyzed by immune histology on cell line cytospins and on clinical samples. There, we found a heterogeneous staining pattern with no background staining of endothelial, stromal and infiltrating immune cells but diffuse staining of the cytoplasm for positive tumor and normal crypt cells of the colonic epithelium.



Taken together, the Gag-H antibody clone(s) present a valuable tool for staining of cells with colonic origin and thus form the basis for future more detailed investigations. The observed Gag-H protein staining in colonic epithelium crypt cells demands profound analyses of a potential role for Gag-H in the normal physiology of the human gut.
University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany.
Christina S
CS
Mullins
University Medicine Rostock, Institute of Pathology, Strempelstraße 14, 18055 Rostock, Germany.
Maja
M
Hühns
University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany.
Mathias
M
Krohn
University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany.
Sven
S
Peters
Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France.
Valérie
V
Cheynet
Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France.
Guy
G
Oriol
Global R&D Immunoassay, bioMérieux, Marcy l'Etoile, France.
Michèle
M
Guillotte
R&D Immunoassay, bioMérieux, Raw Material Department, Marcy l'Etoile, France.
Sandrine
S
Ducrot
Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France.|EA Pathophysiology of injury-induced immunosuppression, University of Lyon1-Hospices Civils de Lyon-bioMérieux,Hôpital Edouard Herriot, 5, Place d'Arsonval, 69437 LYON Cedex 3, Lyon, France.
François
F
Mallet
University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany.
Michael
M
Linnebacher
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002460:Cell Line; D003106:Colon / Q000276:immunology* / Q000821:virology*; D015179:Colorectal Neoplasms / Q000276:immunology / Q000821:virology; D003593:Cytoplasm / Q000276:immunology / Q000821:virology; D020077:Endogenous Retroviruses / Q000276:immunology*; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D015894:Genome, Human / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D015683:Gene Products, gag; D011994:Recombinant Proteins