Antibodies against swine influenza virus neutralize the pandemic influenza virus A/H1N1.

The most effective method for the prevention of influenza infection would be prophylaxis with a safe and effective vaccine and anti-viral materials. After vaccination, neutralizing antibodies are generated by plasma cells following various immune responses, thus resulting in protection against an infectious agent expressing the same antigens. However, in the case of novel or unknown pathogens, the onset of immune responses is occasionally delayed, thus resulting in considerable morbidity and mortality. Antibodies are therefore considered to play an important role in preventing infectious diseases. Furthermore, antibodies are used for additional purposes, including diagnosis and immunotherapy. In the beginning of spring 2009, an outbreak of influenza in North America was caused by a novel strain of influenza virus, designated pandemic influenza A/H1N1 2009. Initially, most people had low immunity against this pathogen, resulting in the worldwide spread of the infection to produce a so-called 'pandemic'. We herein report the generation of 'immunoglobulin yolk (IgY)' neutralizing antibodies against the pandemic influenza virus A/H1N1 from ostrich eggs immunized with a swine influenza virus vaccine strain. Using this simple method, a large amount of specific antibody against the influenza virus was produced by one female ostrich. An enzyme-linked immunosorbant assay and immunocytochemistry indicated that the IgY from the immunized ostrich eggs possessed strong cross-reactivity to the pandemic influenza virus A/H1N1 2009, as well as to the swine influenza virus. Moreover, the hemaggregation activities of the erythrocytes induced by pandemic influenza A/H1N1 virus were inhibited by the ostrich antibodies generated by swine virus immunization. In addition, the cytopathological effects on MDCK cells of infection with pandemic virus were clearly inhibited in co-cultures with the antibodies, indicating the neutralizing of viral infectivity in the cells. In conclusion, we have succeeded in the mass production of neutralizing antibodies against pandemic influenza virus A/H1N1 2009 using ostrich eggs immunized with swine influenza virus antigens. This enables the cost-effective production of effective antibodies, which could be applied to facial masks and air-conditioning filters in order to prevent populations from acquiring pandemic influenza virus A/H1N1.

Protection from avian influenza H5N1 virus infection with antibody-impregnated filters.

There is worldwide concern over the possibility of a new influenza pandemic originating from the highly pathogenic avian H5N1 influenza viruses. We herein demonstrate that functional air filters impregnated with ostrich antibodies against the hemagglutinin of the H5N1 virus protect chickens from death by H5N1 transmission. These results suggest that the use of ostrich antibody-impregnated filters might be a powerful way to prevent the transmission of H5N1.

Ostrich produce cross-reactive neutralization antibodies against pandemic influenza virus A/H1N1 following immunization with a seasonal influenza vaccine.

An outbreak of influenza in 2009 was found to be caused by a novel strain of influenza virus designated as pandemic influenza A/H1N1 2009. Vaccination with recent seasonal influenza vaccines induced little or no cross-reactive antibody response to the pandemic influenza virus A/H1N1 2009 in any age group in human populations. Accordingly, most people had low immunity against this pathogen, thus resulting in the worldwide spread of the infection to produce a so-called 'pandemic'. This report presents the important finding that ostrich eggs generate cross-reactive antibodies to the pandemic influenza virus A/H1N1 following immunization of female ostrich with a seasonal influenza vaccine. This simple method produced a large amount of antibodies against influenza viruses by one female ostrich. An enzyme-linked immunosorbent assay (ELISA) and immunocytochemistry indicated that the ostrich antibodies possessed strong cross-reactivity to the pandemic A/H1N1 as well as to the seasonal A/H1N1, A/H3N2 and B viruses. The hemaggregation activities of erythrocytes induced by this pandemic strain were also inhibited by the ostrich antibodies. In addition, the cytopathological effects of infection with a pandemic virus on MDCK cells were clearly inhibited in co-cultures with the ostrich antibodies, thereby indicating the neutralization of viral infectivity in the cells. In conclusion, cross-reactive neutralization antibodies against pandemic influenza virus A/H1N1 2009 were successfully generated in ostrich eggs produced by females immunized with seasonal influenza viral vaccine.

Involvement of gicerin, a cell adhesion molecule, in the portal metastasis of rat colorectal adenocarcinoma cells.

Gicerin, an Ig-superfamily cell adhesion molecule, has homophilic adhesion activity, thus leading to the formation of gicerin aggregates. Gicerin is highly expressed in various embryonic tissues, and it contributes to development through its adhesive activities. In contrast, the expression of the protein is limited to the muscular tissues and endothelial cells in the mature animals. In the liver, gicerin is constitutively expressed in sinusoidal endothelial cells. Interestingly, an overexpression of gicerin is found in a variety of tumors and may play a role in tumorigenesis. Previously, up-regulated expression of the gicerin protein was found in some sporadic cases of chicken colorectal adenocarcinomas and their hepatic metastasized lesions. In the present study, gicerin cDNA was introduced into endogenous gicerin negative ACL-15 cells, a rat colon adenocarcinoma cell line. The cells were subsequently evaluated for changes in their metastatic potentials in order to elucidate the possible role of gicerin in the hepatic metastasis of colorectal adenocarcinomas. The stable overexpression of gicerin in the cells enhanced the self-aggregation and migratory activities on the protein compared with the mock-transfectants. In addition, the gicerin- transfectants had enhanced metastatic potential to the liver compared with mock-transfected cells after implantation into the ileocolic vein of the cognate rats. These results suggest that gicerin might promote the interaction of tumor cells with a hepatic endothelium, thus leading to the hepatic metastasis of colon adenocarcinomas.

Involvement of gicerin, a cell adhesion molecule, in a dermal autograft chicken model.

Gicerin is a cell adhesion molecule in the immunoglobulin superfamily. This molecule has homophilic and heterophilic adhesive activities, binding to the neurite out-growth factor (NOF). We have previously reported that gicerin plays an important role in the development and regeneration as well as in the metastasis of tumors through its adhesive activities, mediating cell-cell and/or cell-extracellular matrix interactions. In this study, we investigated the involvement of gicerin in a dermal autograft chicken model. Gicerin and NOF were transiently present in the regenerating epithelia after the dermal graft transplantation. The treatment with an anti-gicerin polyclonal antibody, by placing drops onto the wounds, inhibited the adhesiveness of the grafts to the marginal skin. The chimeric protein of gicerin-IgG, gicerin-Fc, and NOF proteins promoted the regeneration of the grafts. These findings suggest the potential function of gicerin in dermal autografts, and gicerin and NOF proteins could help clinical improvement after transplantations.