Influenza virus infection in seal (Phocidae) : seroepidemiological survey of influenza virus in Caspian seals(Phoca caspica)

In the last a few decades, several viral diseases in marine mammals such as seals and cetaceans were characterized. Influenza virus causes a worldwide zoonosis, influenza, and was shown to be involved in mass mortality in seals. Several influenza virus strains have been isolated from the sick seals. Because interspecies transmission of influenza virus plays a crucial role in the introduction of pandemic influenza disease in humans, it is important to monitor the virus distribution in wild animals including marine mammals. In this article, we review the previous findings on influenza virus infection in seals, and introduce our recent serological surveillance of influenza virus in Caspian seals (Phoca caspica) in 1993-2000. Our recent results suggested that the Caspian seals were infected by human related influenza viruses. The possibility of seals as reservoirs of influenza virus, and the importance of surveillance of the virus infection in marine mammals have been discussed

Immunopathological Characterization of liposome Adjuvant Coated with Mannan

The adjuvant activity of liposomes coated with mannan-cholesterol was studied in mice. Ovalbumin (OVA) was reconstituted into liposomes as a model antigen. The adjuvant activity was assessed by the following two immunological responses: delayed-type hypersensitivity (DTH) footpad swelling responses and in vitro release of interferon-γ and interleukin-4 by regional lymph node cells. First, we studied dose effects on DTH responses of total lipid, mannan-cholesterol and OVA used for liposomes. The minimal doses per mouse required for the induction of optimal responses were as follows; 1μg of OVA, 10μg of mannan-cholesterol and 336μg of total lipid. Second, immunological and histopathological studies showed the following two points: 1) mannan-coated liposomes induced a tuberculintype DTH response while non-coated liposomes elicited a Jones-Mote reaction, and 2) mannan-coated liposomes induced obvious microabscesses but non-coated liposome did not. Third, the inoculation of mannan-coated liposomes rendered the regional lymph node cells to release a large amount of interferon-γ with little IL-4 against OVA while non-coated lipo-some released neither of the lymphokines. These results indicated that mannan-coated lipo-somes are a potent adjuvant to induce type 1 helper T cells but have a disadvantage to form microabscesses at the inoculation sites

Mucus glycoproteins selectively secreted from bacteriocytes in gill filaments of the deep-sea clam Calyptogena okutanii

The deep-sea clam Calyptogena okutanii possesses a large gill containing vertically transmitted symbiotic sul-fur-oxidizing bacteria. It produces large amounts of highly viscoelastic mucus from the gill, which is thought to be a physical and chemical barrier. The mucus collected from the gill was shown to be composed of glycoproteins having the following sugar composition: Man (17.4%), GlcNAc (16.6%), GalNAc (15%), Glc (1.1%), Gal (29.9%), Xyl (3.0%), Fuc (14.4%), and unknown (2.6%), indicating that it contained mucin-like glycoproteins. In a monoclonal antibody li-brary against the gill tissue, we found a monoclonal antibody (mAb), CokG-B3C10, reacting to the mucus. Western blot analysis using the mAb showed that it reacted to several glycoproteins in the mucus from the gill tissue, but not with those of other tissues such as the mantle, foot, and ovary, where mucus production has been reported in bivalves. Fur-ther, immunohistochemical analysis showed the CokG-B3C10 mAb reacting to glycoproteins was detected in the inner area of the gill, which was occupied by many bacteriocytes in the row of gill filaments. Strong mAb signals were found on the outer surface of the bacteriocytes facing the interfilamental space, and in the interfilamental spaces between filaments. Weaker signals were also observed in the bacteriocyte cells. These results indicate that the CokG-B3C10 mAb-binding mucus glycoproteins were produced from cells including bacteriocytes and nonbacteriocyte cells in the inner area of the gill filaments.http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt09-06_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-01/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-08/