NOVEL USE OF WATER SOLUBLE GLUCAN

OLIGOMER ISOLATED FROM SACCHAROMYCES CEREVISIAE IS2 FOR PREVENTION AND TREATMENT

OF AVIAN FLU

Technical Field [1] The present invention relates to novel use of water soluble glucan oligomer isolated from Saccharomyces cerevisiae IS2 for the preparation of pharmaceutical composition to treat and prevent avian flu, specifically H1N2 type avian influenza in a mammal including human in need thereof.

Background Art[2] Various kinds of avian flu including nonpathogenic and highly pathogenic flu are caused by avian viral infection mediated by poultries such as chick, duck, turkey, wild avian and the like on farms and in live markets. Among them, highly pathogenic avian influenza has been designated as the 1 group of legal communicable disease in Korea and List A infectious disease in OIE (Office International desEpizooties). The pathogen, i. e. , avian influenza virus, a sort of zoonotic virus is classified into highly pathogenic, weakly pathogenic and non-pathogenic virus according to their pathogenecity and there are 135 kinds of viruses according to their serotypes including 15 HA proteins and 9 NA proteins. Among those serotypes, virulent avian virus transmitted to human such as H5Nland H9N2 subtype has been reported recently.

[3] Avian influenza virus is frequently transmitted to human through intermediate host such as swine, chicken, etc, modified by genetic mutation in the host and the mutated virus is transmitted to human through respiratory tract and other pathway resulting in pathogenic avian flu.

[4] However, there have not yet developed effective agents to prevent or treat avian flu till now since avian influenza virus has lots of serotypes and shows frequent mutation.

Accordingly, most of affected countries by pandemic avian flu have used to adopt mass culling or slaughter policy and it has been reported that barrier quarantine such as strict off limits and disinfection is the best way to protect avian flu.

[5] Recently, it has been found that the subtype of swine influenza virus isolated from Korean pig is H1N2 and the PA and PB gene isolated from 8 gene fragment of H1N2 isolated strain are derived from avian influenza virus (K. Jung and C. Chae., Archives of Virology, in press, 2004). Accordingly, it is confirmed that the H1N2 isolated strain has the part of avian influenza virus.

[6] Beta-glucan can be isolated from various resources such as yeast, microorganism, mushroom, grain and algae. It has been studied and applied as various types of product till now. In particular, beta-glucan derived from yeast cell wall has been studied and known well.

[7] Yeast, a microorganism classified into GRAS (Generally Recognized As Safe) in FDA, has been used in various field including food field and the inner cell membrane of yeast comprises beta 1,3-and 1,6-gluccano as a main ingredients, and a small amount of chitin and mannoprotein, however, outer cell membrane thereof comprises mannoprotein, a protein linked to mannan.

[8] Beta-glucan, a major component of yeast cell wall has been reported to stimulate immune system and reinforce the preventing mechanism of infected host by virus.

TNF-a secreted from macrophage and monocytes during inflammation and NO(inducible nitric oxide) induced therefrom are reported to be effective in preventing RNA virus including avian influenza virus (Akaike T et al, Immunology, 101,pp3DG308, 200Q Seo S. H. et al, Journal of Virology, 76, pp l071-1076, 20(2).

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