Preliminary Study Of The Biology Of MAN2C1 Gene Transgenic Mouse

MAN2C1 was firstly reported as 6A8 alpha-mannosidase byProfessor Zhu's lab. The gene locates at chromosome 15q11-13.MAN2C 1 encod aa human alpha-mannosidase protein with 116 KDa indeglycosylation state. The MAN2C1 transgenic mouse model has beenestablished by Zhu's Lab.So far, there are few reports on the biological fuctions of MAN2C1and most of them focused on the characters of cellular biology ofMAN2C1 in vitro. In present study we investigated the biologicalfunctions of MAN2C1 by using MAN2C1 transgenic mouse in vivo.Firstly, the expression of MAN2C1 was detected in liver and spleen intransgenic mice by western-blot analysis, while, the obviouslymorhpodogical changes were not detectable in tissues from the transgenic mice. The catalytic activity of MAN2C1 in liver and spleenwas determined using p-nitrophenyl-α-D-mannopyranoside as substrate,and the results showed that catalytic activity of MAN2C1 wereremarkably increased in those tissues in transgenic mice. The ConAbinding assay was also showed that the glycosylation of a 170KDprotein from blood cell and a 80 KD protein from spleen were affectedwith mannose trimming. The peripheral white blood cells (PWBC)counting and classification demonstrated that the total number of PWBCand neutrophilic ganulocyte were decreased by 25% and 37%respectively.For the assay of CD4~+, CD8~+ T cells, B cells and NK cells byflowcytometry, no significant difference were detected betweentransgenic and wild type mice before the BSA stimulation, but thenumber of T cells was increased by 28% and the ratio of CD4/CD8 wasdecreased obviously in transgenic mice compared with wild type miceafer BSA stimulation. The serum antibody titer responding the BSAstimulation was also lower by 48-64% compared with the wild typemise.Since CD8~+ T cells play an important role in cellular immune, in lastpart of this thesis, we performed the infection of transgenic and wild typemice with highly pathogenic avian influenza virus (H5N1), we foundunexpectedly that more serious pathological change and more loading levels of H5N 1 were observed in transgenic mice.In summary, the preliminary study presented in this thesisdemonstrated that the MAN2C1 with catalytic activity was expressed inin spleen and liver and blood ceils. The expression of the gene did notaffect the mohporlogy of those tissues. The expression of the generegulated the ration of PWBC and resulted in suspensibility to H5N1virus infection.