We evaluated the potential ability of germanium biotite (GB) to stimulate the production of antibodies specific for foot-and-mouth disease virus (FMDV). To this aim, we measured the total FMDV-specific antibody responses and IgM production after vaccination against FMD both experimentally and in the field. GB supplementation with FMDV vaccination stimulated the production of anti-FMDV antibodies, and effectively increased IFN-gamma and TNF-alpha levels. These results suggest that GB may be a novel alternative feed supplement that can serve as a boosting agent and an immunostimulator for increasing the efficacy of FMDV vaccination in pigs.
Adjuvants, Immunologic/therapeutic use ; Aluminum Silicates/*therapeutic use ; Animals ; Antibodies, Viral/*immunology ; Antibody Formation/drug effects ; *Dietary Supplements ; Ferrous Compounds/*therapeutic use ; Foot-and-Mouth Disease/*immunology/prevention & control ; Foot-and-Mouth Disease Virus/immunology ; Germanium/*therapeutic use ; Swine ; Swine Diseases/immunology/prevention & control/*virology

Germanium biotite (GB) is an aluminosilicate mineral containing 36 ppm germanium. The present study was conducted to better understand the effects of GB on immune responses in a mouse model, and to demonstrate the clearance effects of this mineral against Porcine reproductive and respiratory syndrome virus (PRRSV) in experimentally infected pigs as an initial step towards the development of a feed supplement that would promote immune activity and help prevent diseases. In the mouse model, dietary supplementation with GB enhanced concanavalin A (ConA)-induced lymphocyte proliferation and increased the percentage of CD3+CD8+ T lymphocytes. In pigs experimentally infected with PRRSV, viral titers in lungs and lymphoid tissues from the GB-fed group were significantly decreased compared to those of the control group 12 days post-infection. Corresponding histopathological analyses demonstrated that GB-fed pigs displayed less severe pathological changes associated with PRRSV infection compared to the control group, indicating that GB promotes PRRSV clearance. These antiviral effects in pigs may be related to the ability of GB to increase CD3+CD8+ T lymphocyte production observed in the mice. Hence, this mineral may be an effective feed supplement for increasing immune activity and preventing disease.
Aluminum Silicates/administration & dosage/*therapeutic use ; Animal Feed/analysis ; Animals ; Antigens, CD3/metabolism ; Antigens, CD8/metabolism ; Antiviral Agents/administration & dosage/*therapeutic use ; Concanavalin A/metabolism ; Dietary Supplements/analysis ; Disease Models, Animal ; Ferrous Compounds/administration & dosage/*therapeutic use ; Germanium/administration & dosage/*therapeutic use ; Lung/immunology/virology ; Lymphocyte Activation/drug effects ; Lymphocytes/cytology/drug effects ; Lymphoid Tissue/immunology/virology ; Mice ; Mitogens/metabolism ; Porcine Reproductive and Respiratory Syndrome/*drug therapy/pathology/virology ; Porcine respiratory and reproductive syndrome virus/*drug effects ; Swine