In vivo biosynthesis of endogenous and of human C1 inhibitor in transgenic mice: tissue distribution and colocalization of their expression.
We have produced transgenic mice expressing human C1 inhibitor mRNA and protein under the control of the human promoter and regulatory elements. The transgene was generated using a minigene construct in which most of the human C1 inhibitor gene (C1NH) was replaced by C1 inhibitor cDNA. The construct retained the promoter region extending 1.18 kb upstream of the transcription start site, introns 1 and 2 as well as a stretch of 2.5 kb downstream of the polyadenylation site, and therefore carried all known elements involved in transcriptional regulation of the C1NH gene. Mice with high serum levels of human C1 inhibitor, resulting from multiple tandem integrations of the C1 inhibitor transgene, were selected. Immunohistochemistry in combination with in situ hybridization was applied to localize the sites of C1 inhibitor biosynthesis and to demonstrate its local production in brain, spleen, liver, heart, kidney, and lung. The distribution of human C1 inhibitor-expressing cells was qualitatively indistinguishable from that of its mouse counterpart, but expression levels of the transgene were significantly higher. In the spleen, production of C1 inhibitor was colocalized with that of a specific marker for white pulp follicular dendritic cells. This study demonstrates a stringently regulated expression of both the endogenous and the transgenic human C1 inhibitor gene and reveals local biosynthesis of C1 inhibitor at multiple sites in which the components of the macromolecular C1 complex are also produced.
Vinci
Giovanna
G
Institut National de la Santé et de la Recherche Médicale E0021, Département d'Immunologie, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France. vinci@pasteur.fr
Lynch
Nicholas J
NJ
Duponchel
Christiane
C
Lebastard
Thi-May
TM
Milon
Geneviève
G
Stover
Cordula
C
Schwaeble
Wilhelm
W
Tosi
Mario
M
D000818:Animals; D001923:Brain Chemistry / Q000235:genetics / Q000276:immunology; D003174:Complement C1 Inactivator Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D050718:Complement C1 Inhibitor Protein; D003433:Crosses, Genetic; D020566:Dendritic Cells, Follicular / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D005260:Female; D005819:Genetic Markers / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008099:Liver / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic; D009928:Organ Specificity / Q000235:genetics* / Q000276:immunology*; D012333:RNA, Messenger / Q000378:metabolism; D013154:Spleen / Q000737:chemistry / Q000276:immunology / Q000378:metabolism
D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; D005819:Genetic Markers; D012333:RNA, Messenger