title: Can 29kDa rhGM-CSF expressed by silkworm pupae bioreactor bring into effect as active cytokine through orally administration?
abstract: In order to study the effect of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) as active cytokine through orally administration, we expressed hGM-CSF within silkworm pupae bioreactor. The purified rhGM-CSF named as BmrhGM-CSF is characterized as 29kDa glycoprotein, and its biological activity was measured both in vitro and in vivo. We found out BmrhGM-CSF could stimulate the colony formation of human bone marrow cells in a dose-dependent manner whether which were treated with or without gamma-ray 24h before. The ability of colony formation induced by BmrhGM-CSF is negatively correlated with gamma-ray intensity. As soon as 15min post oral administration with BmrhGM-CSF labeled with (125)I, an approximately 20kDa protein fragment was detected within mice blood by SDS-PAGE followed by autoradiography. In blood sample of test mice, a protein was also recognized by anti-hGM-CSF antibody using ELISA. The immunohistochemical analysis showed that BmrhGM-CSF was detected within intestinal histiocyte. This indicated it might be absorbed into blood via intestinal microvillus. Pharmacokinetics analysis after orally administered BmrhGM-CSF in animal model of leucopenia including mice, Beagle dogs and macaques showed that: (1) BmrhGM-CSF promoted the CFU-S formation in mice spleen and the synthesis of DNA in bone marrow cells of mice; (2) BmrhGM-CSF induced bone marrow karyocyta granulocyte growth significantly in both macaques and Beagle dogs compared to the negative control group. On the 9th day of orally administration, the animal WBC significantly increased in a dose-dependant manner, in which neutrophilic granulocyte was predominant. The WBC level of dogs in high dose group was about 1.5x10(9)cells/L more than that in the negative control. And the bone marrow smear revealed that the percents of both myloblast and progranulocyte in WBC in the hGM-CSF group were obviously higher than those in the negative control. These results proved that BmrhGM-CSF, a 29kDa glycoprotein expressed by Silkworm pupae bioreactor, could bring into the effect as active cytokine through oral administration.
authors.affiliation: Institute of Biochemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China. yaozhou@chinagene.com
authors.forename: Yaozhou
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Zhengbing
authors.initials: Z
authors.lastname: Lv
authors.forename: Zuoming
authors.initials: Z
authors.lastname: Nie
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiangfu
authors.initials: X
authors.lastname: Wu
mesh_terms: D000284:Administration, Oral; D000595:Amino Acid Sequence; D000818:Animals; D019149:Bioreactors; D012831:Bombyx / Q000235:genetics / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000187:drug effects; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004195:Disease Models, Animal; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006644:Histiocytes / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007958:Leukocyte Count; D007970:Leukopenia / Q000097:blood / Q000188:drug therapy*; D008251:Macaca; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011679:Pupa / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins
chemical_list: D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor