OBJECTIVE: In the guinea pig-to-rat cardiac xenotransplantation model, the effect of complement depletion by using Chinese Cobra Venom Factor(CVF) on hyperacute rejection was evaluated. METHODS: Cardiac xenograft from guinea pig was transplanted into the abdomen of rat after the recipient being given i.p. a dose of CVF 0.20 microgram/g. the recipients were divided into group A (control group), group B (only given CVF), group C (CVF + Cytoxan + Splenectomy), group D (Cytoxan + Splenectomy) Cytoxan was injected into the abdominal cavity with a dose of 60 mg/Kg. The survival time of xenograft was measured and histologic observation was carried out after the cardiac arrest. RESULTS: The survival time of xenograft ranged from 15 to 3,120 minutes. There were significant difference among group A compared with group B and C (P lt; 0.01), and no difference between group A and group D, as well as group B and C (P gt; 0.05). There were significant difference between group B and D, as well as group C and D(P lt; 0.01). The histologic observation proved that the hyperacute rejection in group A and D was milder than group B and C. CONCLUSION: The study reveals that CVF can prolong the xenograft time by depleting complement activities and restricting hyperacute rejection in this model. Further basic and clinical study of effect of CVF in xenograft transplantation is worthwhile.
Objective To investigate the role and mechanism of heat shock protein 60 (HSP60) in induction of murine skin allograft tolerance. Methods At the age of 8-12 weeks, inbred female BALB/C (H-2d) mice (n=45) and CBA/N (H-2k)mice (n=15) were used as transplantation donors and C57BL/6 (H-2b) mice (n=60) as recipients. Recipients C57BL/6 (H-2b) mice were randomized into 4 groups (n=15). In group A, 1 cm × 1 cm Wolfe-Krause skin graft was excised from the back of BALB/C (H-2d) mice and hypoderma was scraped off aseptically, and then transplanted to the back of C57BL/6 (H-2b)mice. The method of skin transplantation in the other 3 groups was the same as to group A. In group B, C57BL/6 (H-2b) mice were treated with imcompleted Freund’s adjuvant (IFA) administration into the back 2 weeks before transplantation of BALB/C (H-2d) mice skin. In group C, C57BL/6 (H-2b) mice were administered HSP60 emulsified in IFA into the back 2 weeks before transplantation of BALB/C (H-2d) mice skin. In group D, C57BL/6 (H-2b) mice were treated with HSP60 emulsified in IFA into the back and followed by skin transplantation of CBA/N (H-2k) mice 2 weeks later. The delayed type hypersensitivity was determined 7 days after transplantation. One-way mixed lymphocyte reaction, the concentration of cytokines in the mixed lymphocyte reaction culture supernatant was determined 7 days and 25 days after transplantation. The survival time of skin allograft was observed. Results The survival time of skin allograft in groups A, B, C and D was 12.4 ± 0.5, 11.6 ± 0.8, 29.3 ± 2.6 and 27.6 ± 2.1 days, respectively. There was significant difference between groups A, B and groups C, D (P﹤0.05), while there was no significant difference between group A and group B as well as between group C and group D (P gt; 0.05). The counts of per minute impulse (cpm) of mixed lymphocyte reaction 7 days after transplantation in groups A, B, C and D was 12 836 ± 1 357, 11 876 ±1 265, 6 581 ± 573 and 6 843 ± 612, respectively. There was significant difference between groups A, B and group C and group D (P lt; 0.05), while there was no significant difference between group A and group B as well as between group C and group D (P gt; 0.05). The cpm of mixed lymphocyte reaction at 25 days after transplantation in group A, B, C and D was 13 286 ±1 498, 12 960 ± 1 376, 11 936 ± 1 265 and 12 374 ± 1269, respectively. There was no significant difference among 4 groups (P gt;0.05).The concentration of IL-10 in the mixed lymphocyte reaction culture supernatant in groups C, D were higher than that in groups A, B, and IL-2 and IFN-γ were lower than that in groups A, B 7 days after transplantation (P lt; 0.05), while there was no significant difference between group A and group B as well as between group C and group D (P gt; 0.05). There was no significant difference in cytokines among the 4 groups 25 days after transplantation (P gt; 0.05). The delayed type hypersensitivity in groups A, B, C and D 7 days after transplantation was 0.84 ± 0.09, 0.81 ± 0.07, 0.43 ± 0.05 and 0.46 ± 0.03 mm, respectively. There was significant differences between groups A, B and groups C, D (P lt; 0.05). While there was no significant difference between group A and group B as well as between group C and group D (P gt; 0.05). Conclusion HSP60 may play a role in induction and maintenance of murine skin allograft tolerance.