In vivo induction of interferon-alpha in pig by non-infectious coronavirus: tissue localization and in situ phenotypic characterization of interferon-alpha-producing cells.
A low frequency peripheral blood mononuclear cell (PBMC) subpopulation, referred to as natural interferon-producing (NIP) cells, is described as producing interferon-alpha (IFN-alpha) following contact with non-infectious viral structures, namely viral glycoproteins. These cells are characterized in vitro as non-T, non-B, MHC class II+ and CD4+ cells. In this study, NIP cells were analysed in vivo after an intravenous injection of UV-inactivated transmissible gastroenteritis virus in newborn piglets, which resulted in strong serum IFN-alpha production. Splenocytes, but not PBMC, were the IFN-alpha producers in vivo. Using double immunohistochemical labelling for both IFN-alpha and leukocyte markers, we established that splenic NIP cells were not T or B cells. The majority were MHC class II+ and only a minority expressed a macrophage marker. NIP cells were localized in contact with MHC class II-expressing cells and T cells, which suggested that NIP cells might modulate the antiviral immune response.
Riffault
S
S
Unité de Virologie et Immunologie Moléculaires, INRA, Jouy-en-Josas, France. Riffault@biotec.jouy.inra.fr
Carrat
C
C
Besnardeau
L
L
La Bonnardière
C
C
Charley
B
B
D000818:Animals; D000911:Antibodies, Monoclonal; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018352:Coronavirus Infections / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D016898:Interferon-alpha / Q000096:biosynthesis*; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D013552:Swine; D013997:Time Factors; D005760:Transmissible gastroenteritis virus / Q000276:immunology* / Q000472:pathogenicity
D000911:Antibodies, Monoclonal; D015214:Antigens, Differentiation, Myelomonocytic; D000949:Histocompatibility Antigens Class II; D016898:Interferon-alpha