Napajen Pharma, Inc.

Hironori Ando

Sadaharu Higuchi

Kazuo Sakurai

Ko Rii

Masakazu Kobayashi

Shiro Takahara

Atsushi Uno

An objective of the present invention is to provide a chemically-modified siRNA that has polydeoxyadenylic acid added to the 5' end of the sense strand, and, when complexed with schizophyllan, is high in resistance against RNase and moreover effectively exhibits RNAi activity. To achieve the objective, in the chemically-modified siRNA with polydeoxyadenylic acid added to the 5&#x2032; end of the sense strand, specific chemical modification is performed for dinucleotide sequences of CA, UA, and UG in the base sequence of the sense strand and dinucleotide sequences of CA, UA, and UG in the base sequence at and after the eighth base from the 5&#x2032; end of the antisense strand.

Chemically-modified siRNA

An object of the present invention is to provide a drug and a method for effectively inducing donor-specific immune tolerance in a recipient in transplantation therapy. A complex of an siRNA for a costimulatory factor and schizophyllan is delivered to a Dectin-1 expressing cell which specifically recognizes schizophyllan to regulate the function of the Dectin-1 expressing cell, and therefore can induce immunosuppression effect as well as induce immune tolerance effectively.

Immune tolerance inducer

A highly stable nucleic acid-polysaccharide complex of an siRNA and schizophyllan is formed by adding polydeoxyadenine in which at least part of the phosphodiester link portion is phosphorothioated to an siRNA and allowing the siRNA and schizophyllan to form a complex.

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Nishitokyo, Japan

Hironori Ando