Bone marrow stem cells develop into hematopoietic and mesenchymal lineages but have not been known to participate in production of hepatocytes, biliary cells, or oval cells during liver regeneration. Cross-sex or cross-strain bone marrow and whole liver transplantation were used to trace the origin of the repopulating liver cells. Transplanted rats were treated with 2-acetylaminofluorene, to block hepatocyte proliferation, and then hepatic injury, to induce oval cell proliferation. Markers for Y chromosome, dipeptidyl peptidase IV enzyme, and L21-6 antigen were used to identify liver cells of bone marrow origin. From these cells, a proportion of the regenerated hepatic cells were shown to be donor-derived. Thus, a stem cell associated with the bone marrow has epithelial cell lineage capability.

http://science.sciencemag.org/content/sci/284/5417/1168.full.pdf

Bone marrow as a potential source of hepatic oval cells.

The present invention relates to a composition containing novel proteins and methods for the diagnosis and treatment of immune related diseases.

Compositions and methods for the treatment of immune related diseases

http://d-scholarship.pitt.edu/5570/1/31735062120963.pdf

Tolerogenic immunosuppression for organ transplantation.

The morbidity arising from the chronic use of antirejection medications is an incentive to establish the lowest possible level of immunosuppression necessary to maintain stable graft function. The finding that complete freedom from immunosuppression was sporadically possible in long-surviving recipients of liver (1) and kidney allografts (2) prompted a prospective trial of drug weaning (3). Although it was shown that significant reductions in medication or their discontinuance could be safely accomplished, the danger of consequent rejection has not been completely assessed and guidelines for judicious weaning need to be clarified. We present here further observations on 3 cohorts of liver recipients: 5 who self-weaned many years ago (1), 59 who were in the prospective weaning trial of Ramos et al. (3), and 36 who were subsequently entered.

Weaning of immunosuppression in liver transplant recipients.

It has been only 14 years since the first scattered examples were recorded of extended survival in humans of nutrition-supporting intestinal allografts transplanted under cyclosporine-based immunosuppression. 1–6 Then, with the advent of tacrolimus in 1989 to 1990, 7,8 clinical intestinal transplantation began to emerge as a practical means of treating intestinal failure. 9–15 Multiple factors have sustained and increased these efforts, including technical innovations in surgery and improvements in nonspecific postoperative care.

The most important therapeutic achievement, however, has been the increasingly efficient prevention and/or control of rejection, exemplified by our experience reported here with 155 recipients of 165 intestinal, liver-intestinal, or multivisceral abdominal allografts whose transplantations were performed between May 2, 1990, and February 18, 2001. The emphasis in this analysis will be placed on the long-term outlook of patients who were still alive at the time of previous reports, and on attempts to improve the prognosis with new adjunct immunosuppressants or management strategies that have yielded promising results in laboratory models.

/pdf/clinical-intestinal-transplantation-a-decade-of-experience-xiiwjzxsb6.pdf

Clinical Intestinal Transplantation: A Decade of Experience at a Single Center

The persistence of microchimerism in human whole organ recipients years or decades after transplantation (1, 2) reflects the migration long before of bone marrow-derived donor leukocytes from the allografts (3, 4). We have postulated that these immunocompetent donor cells represent one limb of initially antagonistic but ultimately attenuated or abrogated host-versus-graft (HVG,* rejection) and graft-versus-host (GVH) reactions (1-5) (Fig. 1). We describe here a study in rats of the HVG and GVH components of this two-way immunologic paradigm. The clinical and histopathologic expression of the two arms with and without immunosuppression was correlated with the quantity and quality of recipient tissue chimerism and with the development of donor-specific tolerance following transplantation from Lewis (LEW) donors to Brown Norway (BN) recipients of different organs (intestine, liver, heart, kidney) and of different free leukocyte suspensions (bone marrow, lymph nodes, spleen, thymus, and blood).



Figure 1

Dualistic immune reactions of host-versus-graft (HVG) and graft-versus-host (GVH) in the two-way paradigm of transplantation immunology. Following the acute reaction, the evolution of tolerance of each leukocyte population to the other is seen as a low-grade ...



Although the results leave numerous questions unanswered about basic mechanisms, they cast light on 4 issues that are relevant to planning of clinical tolerance induction protocols: (1) The relative risk of producing clinical GVHD with the tranplantation of different organs and with infusion of a standardized dose of leukocytes obtained from various lymphoid organs, (2) the relative tolerogenicity of the parenchymal organs and the leukocyte suspensions, (3) correlation of 1 and 2 with the density and lineage profile of the chimerism in recipient tissues and, (4) the relation to the quantity and lineage composition of chimerism to chronic rejection.

/pdf/variable-chimerism-graft-versus-host-disease-and-tolerance-85m5qtmhpx.pdf

Variable chimerism, graft-versus-host disease, and tolerance after different kinds of cell and whole organ transplantation from Lewis to brown Norway rats.

Following rat heterotopic heart allotransplantation, low to lethal doses of the antimetabolites mizoribine (MIZ), RS-61443 (RS), and AZA were given alone or in combination with subtherapeutic doses of FK506 (0.04 mg/kg/day) for 14 days after transplantation. With the median effect analysis of Chou and Kahan for quantitative drug interactions, substantial therapeutic synergism was demonstrated between FK506 and non-toxic doses of MIZ (2.5, 5, and 10 mg/kg/day) or AZA (5, 30, and 45 mg/kg/day), which was particularly evident with the lowest dose MIZ (2.5 mg/kg/day). When FK506 was used in combination with MIZ or AZA but not with RS, the maximum effect (peak median graft survival) was enhanced significantly from 15 days (MIZ alone) to 26 days (P < 0.05), and from 19 days (AZA alone) to 32 days (P < 0.01). In contrast, RS interacted with FK506 no more than additively. Although RS was the most powerful single antimetabolite, the best overall survival was obtained by combining AZA and FK506. The addition of FK506 did not significantly increase the percent mortality and LD50 of the antimetabolites.

/pdf/combined-immunosuppressive-therapy-with-low-dose-fk506-and-21dt1g775c.pdf

Combined immunosuppressive therapy with low dose FK506 and antimetabolites in rat allogeneic heart transplantation.

Hamster to rat renal xenotransplantation was performed with recipient nephrectomies. Recipients were treated beginning on day 0 with continuous FK 506 monotherapy, a 7-day or open-ended monotherapeutic course of cyclophosphamide (CP), * and the two drug regimens combined. CP alone (10 mg/kg/day) prevented a xenospecific antibody response and tripled median survival of the kidney (defined as recipient death) from 6 (control) to 18.5 days whereas FK 506 alone had no effect. The drugs in combination were no better than CP alone (15 days) unless the 5-day course of CP was given at a higher dose (15 mg/kg) and started 3 days preoperatively (79 days). In further experiments, adjuvant measures were added to the minimally effective FK 506/7-day CP regimen which gave a median survival of only 15 days. In the moat successful modification, intraoperative antibody depletion by the temporary transplantation of third party hamster liver or en bloc kidneys increased median survival from 15 to 34 and 48 days, respectively. An intraoperative i.v. dose administration of the anticomplement drug K76 instead of antibody depletion increased survival to 26 days. Although the events of Kidney rejection were similar to those of heart xenografts and partially forestalled by the antibody inhibiting CP treatment, or by antibody depletion, survival for >100 days was accomplished in only 5 of 86 treated animals. The poorer survival previously reported with cardiac xenotransplantation is largely explained by the life support requirement of the kidneys. Renal failure was responsible for almost all deaths before 60 days, and subnormal renal failure was a pervasive adverse factor thereafter, frequently caused by pyelonephritis which is suspected to have had an immunologic etiology

/pdf/hamster-to-rat-kidney-xenotransplantation-effects-of-fk-506-u2tjj05q9l.pdf

Hamster to rat kidney xenotransplantation effects of fk 506, cyclophosphamide, organ perfusion, and complement inhibition

In normal rats, the xenobiotic K76 inhibited the C5 and probably the C2 and C3 steps of complement and effectively depressed classical complement pathway activity, alternative complement pathway activity, and the C3 complement component during and well beyond the drug's 3-hr half-life. It was tested alone and with intramuscular tacrolimus (TAC) and/or intragastric cyclophosphamide (CP) in rat recipients of heterotopic hearts from guinea pig (discordant) and hamster (concordant) donors. Single prevascularization doses of 100 and 200 mg/kg increased the median survival time of guinea pig hearts from 0.17 hr in untreated controls to 1.7 hr and 10.2 hr, respectively; with repeated injections of the 200-mg dose every 9-12 hr, graft survival time was increased to 18.1 hr. Pretreatment of guinea pig heart recipients for 10 days with TAC and CP, with or without perioperative splenectomy or infusion of donor bone marrow, further increased median graft survival time to 24 hr. Among the guinea pig recipients, the majority of treated animals died with a beating heart from respiratory failure that was ascribed to anaphylatoxins. Hamster heart survival also was increased with monotherapy using 200 mg/kg b.i.d. i.v. K76 (limited by protocol to 6 days), but only from 3 to 4 days. Survival was prolonged to 7 days with the addition of K76 of intragastric CP at 5 mg/kg per day begun 1 day before operation (to a limit of 9 days); it was prolonged to 4.5 days with the addition of intramuscular TAC at 2 mg/kg per day beginning on the day of transplantation and continued indefinitely. In contrast to the limited efficacy of the single drugs, or any two drugs in combination, the three drugs together (K76, CP, and TAC) in the same dose schedules increased median graft survival time to 61 days. Antihamster antibodies rapidly increased during the first 5 days after transplantation, and plateaued at an abnormal level in animals with long graft survival times without immediate humoral rejection. However, rejection could not be reliably prevented, and was present even in most of the xenografts recovered from most of the animals dying (usually from infection) with a beating heart. Thus, although effective complement inhibition with K76 was achieved in both guinea pig- and hamster-to-rat heart transplant models, the results suggest that effective interruption of the complement cascade will have a limited role, if any, in the induction of xenograft acceptance.

/pdf/effect-of-anticomplement-agent-k76-cooh-on-hamster-to-rat-45dgfxf3cm.pdf

Effect of anticomplement agent k76 cooh on hamster-to-rat and guinea pig-to-rat heart xenotransplantation

Fk 506 has had a major beneficial effect on the survival of transplanted organs However, the use of FK 506 is limited by its toxicity To circumvent this problem, we attempted to amplify the therapeutic efficacy of low-dose FK 506 by the combined use of various antimetabolites, including RS-61443 (RS),1 mizoribine (MIZ),2 and azathioprine (AZA) Therapeutic interaction was evaluated with rat allogeneic heart transplantation

/pdf/therapeutic-synergism-between-low-dose-fk-506-and-4uqc2z6f0q.pdf

H. Miyazawa

Papers

Variable chimerism, graft-versus-host disease, and tolerance after different kinds of cell and whole organ transplantation from Lewis to brown Norway rats.

Combined immunosuppressive therapy with low dose FK506 and antimetabolites in rat allogeneic heart transplantation.

Hamster to rat kidney xenotransplantation effects of fk 506, cyclophosphamide, organ perfusion, and complement inhibition

Effect of anticomplement agent k76 cooh on hamster-to-rat and guinea pig-to-rat heart xenotransplantation

Therapeutic synergism between low-dose FK 506 and antimetabolites in rat allogeneic heart transplantation.