Immune regulatory effect of hepatic factor associated with thymus alteration

ArticleinResearch in Experimental Medicine 185(3):245-52 · February 1985with1 Read
DOI: 10.1007/BF01852039 · Source: PubMed

    Abstract

    This study was carried out to clarify the mechanism of the immune regulatory effect of factors which were liberated from the ischemic damaged liver.
    By occlusion of the hepatic vessels (hepatic artery and portal vein) for 40min daily during 5 days to induce the ischemic damage of the liver, reduced thymus weight (50 ± 5 mg; control, 274 ± 23 mg) and cell count (0.7 ± 0.3 × 107; control, 3.5 ± 0.3 × 108) and complete differentiation of thymocytes were observed, i.e., helper cells reacting to monoclonal antibody W3/25 were 34 ± 8% and suppressor/cytotoxic cells to OX-8, 49 ± 5% (in control W3/25:89 ± 1%, OX-8:89 ± 1%). These quantitative and qualitative changes of thymocytes were correspondent to those of animals treated with 40mg CsA/kg per day for 5 days; however, medication with 10mg prednisolone/day 5 times could not induce any alteration of thymocyte subpopulation (W3/25:89 ± 1%, OX-8:87 ± 1%) although the weight and cell count decreased to 92 ± 8mg and 4.1 ± 0.6 × 107, respectively.
    Furthermore, 5 days after liver allotransplantation (BDE to LEW), the weight and cell count of the thymus were extremely reduced (58 ± 6 mg, 2.7 ± 0.2 × 107), and thymocyte differentiation was observed (W3/25:56.6%, OX-8:61 ± 11%). On the other hand, in heart transplantation the atrophy of the thymus was not so strong (105 ± 28mg, 1.3 ± 0.6 × 108), and there was no change in the subpopulation (W3/25:89 ± 2%, OX-8:88 ± 1%).
    We conclude from these results that the liver should have an immune regulatory factor similar to CsA, which could stimulate formation of suppressor cells in the thymus, but different from prednisolone. This factor might be liberated from the damaged liver and responsible for immunologic benefit of hepatic grafts.