Juridical Foundation the Chemo-sero-therapeutic Research Institute

Teijin Limited

Km Biologics Co., Ltd.

Hiroshi Yonemura

Chikateru Nozaki

Ken-ichi Yamamura

Junichi Miyazaki

Masatake Araki

Kenji Soejima

Kazuhiko Kimachi

Takayuki Imamura

Kenichi Masuda

Hiroshi Nakatake

Yoichiro Kino

Yoshitaka Tajima

Keishin Sugawara

Makoto Moriyama

Yuki Mihara

Katsuhiko Fukada

Tajayuki Imamura

A method for preparing a PRP conjugate having high storage stability and a method for producing a Hib conjugate vaccine are provided. A method for preparing PRP conjugate in accordance with the embodiments of the present invention is characterized by that the release of PRPs after preparing the PRP conjugate is suppressed by using PRP with a lowered molecular weight than native PRP for a coupling reaction between PRP and a carrier protein. Also, a Hib conjugate vaccine comprising as an antigen the PRP conjugate prepared by said method has excellent storage stability and maintain sufficient immunogenicity.

Method for producing Hib conjugate vaccine using PRP with lowered molecular weight

A genetic recombinant human thrombin is provided. Human thrombin is efficiently prepared by the genetic engineering technique comprising the steps: (1) culturing a transfectant animal cell transfected with an expression vector in which a gene encoding human prethrombin is incorporated to the downstream of a promoter so as to produce and accumulate prethrombin in culture supernatant and recovering the produced human prethrombin; (2) treating a solution containing human prethrombin recovered in step (1) with ecarin so as to convert human prethrombin into human thrombin; and (3) purifying the solution obtained after the above activation process to obtain purified human thrombin. The present invention allows for provision of human thrombin in a large scale in a safe and economical manner due to exclusion of blood-derived components.

Process for producing human thrombin by gene modification technique

An expression vector for the expression of an exogenous gene in an animal cell, which contains a chick .beta.-actin gene promoter and a restriction enzyme site for incorporating an exogenous gene at the downstream of said promoter and a process for expressing an exogenous gene, which comprises incorporating said exogenous gene into the expression vector at the restriction enzyme site for incorporating the exogenous gene, introducing said vector into an animal cell and culturing the obtained transformed animal cell. The expression system of the present invention can be applied to an expression of any exogenous gene and has an extremely high expression efficiency and is applicable to a wide range of host cells, and hence can sufficiently be utilized for industrial-scale production of a useful material.

Exogenous gene expression vector containing chick .beta.-actin gene

A plasmid for expression of human coagulation factor VIII H-chain, a plasmid for expression of human coagulation factor VIII L-chain, an animal cell transformed with either said H-chain expression plasmid or said L-chain expression plasmid or with both thereof, and a process for preparing a human coagulation factor VIII protein complex which comprises forming a transformed animal cell by introducing both said H-chain expression plasmid and said L-chain expression plasmid into said animal cell, culturing said cell to produce the human coagulation factor VIII protein complex in the culture medium and collecting the same. The process of the present invention allows for the production of a safe factor VIII at a high expression level applicable for the production of Factor VIII on an industrial scale.

Process for preparing human coagulation factor VIII protein complex

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Kumamoto, Japan

Hiroshi Yonemura