A Study Of The Effect Of Soluble Complement Receptor Ⅰ On Cardiac Xenotransplantation In Hyperacute Rejection

The objective of cardiac xenotransplantation is to solve the shortfall in donor heart,andto achieve long term survival and a high quality of life for the recipient. However, theclinical application of cardiac xenotransplantation has so far been cumbered by hyperacuterejection.Cardiacians have been working on cardiac xenotransplantation for many years, buthyperacute rejection in discordant cardiac xenotransplantation has never been solved. It iswell established that gene therapy, donor organ perfusion, plasma exchange, total lymphoidirradiation,splenectomy, immunoadsorption ,new immunosuppressive drugs, and so on,couldall inhibit HAR to a certain extent. It has been documented that continuous ornon-continuous Ad.sCR1 vein injection could inhibit HAR and prolong donor hearts'survival time.However, Ad.sCR1 injection to the whole body affects the recipients' immunesystem and is very costly as well. It is hypothesized that the recipients' immune systemwould not be seriously affected if sCR1 gene expression is limited to donor's cardiomyocytes.Report has not been on whether Ad.sCR1 fusion protein could be expressed via localtransfection of recombinant adenoviruses containing sCR1 gene to cardiomyocytes byinjecting it into the ventricular free wall directly. Therefore, in the present study, areplication-deficient adenovirus vector coding for the gene sCR1 was conducted toinvestigate its effects on inhibiting inflammation and HAR.Methods:1. The establishment of the cervical heterotopic discordant cardiac xenotransplantationmodel from guinea pigs to rats Eighty healthy guinea pigs and 80 SD rats were used in this study guinea pigs weighted200±30g,and SD rats weighted 250±30g. These animals were anesthesized by abdominalcavity administration with 0.3% Pentobarbital sodium randomly divided into two groups foreach of the two species. In Group I(control group, n=40), cuff technique was adopted, whilein groupII (treatment group, n=40), modified cuff technique was applied. The rebeat and themean survival time(MST) of donor hearts were monitored and compared between the twogroups. This would enable us to search for better cardiac xenotransplantation model forsmall animals.2. Ad.lacZ, Ad.GFP and Ad.sCR1 transfer cardiomyocytes in vivo and the detection of theirprotein expression Forty healthy guinea pigs weighted 200±30g were used in this study. The animals wereanesthesized by abdominal cavity administration with 0.3% Pentobarbital sodium. Thereplication-defective recombinant adenovirus of lacZ, GFP and sCR1 gene constructed in thesame condition was respectively injected into the left ventricular free wall of guinea pigsrespectively, after the hearts were exposed via a left lateral thoractomy. These animals wererandomized into four groups. In detection Group I (control group,n=10), Sodium LactateRinger's Injection(SLRI) was injected in each case. In detection Group II (treatmentgroup,n=10), Ad.lacZ was injected; In detection Group III(treatment group,n=10), Ad.GFPwas injected;and finally in detection Group IV(treatment group,n=10), Ad.sCR1 was 5第二军医大学硕士学位论文 英文摘要 胸心外科专业injected.In each group, fifty microlitre drugs were injected into the left anterior and lateralventricular free wall respectively.For each group the protein expression in guinea pig heartslides was observed with conventional microscope and fluorescence microscope and wastraced by sCRI immunohistological labeling and immunohistochemistry staining at 0.5, 7, 14,21 and 28 days after injection.3. Observation of Ad. lacZ, Ad. GFP and Ad. sCRI protein expression cusp period For the detection groups(group II, III, and IV), one infected animal was randomlyselected for each group at 0.5, 7, 14, 21, and 28 days.One slide was selected randomly foreach animal for cardiac myocyte observation under microscope, and for each slide 10 f...