摘要:

Although proliferation of oval cells is often observed during the early stages of chemical hepatocarcinogenesis, the role of these putative hepatic stem cells during the neoplastic process is unknown. In earlier studies our laboratory showed that feeding a choline-deficient (CD) diet containing 0.05% 2-acetylaminofluorene (CD-AAF) to rats produced three subpopulations of oval cells that antigenically resemble biliary duct cells, fetal liver cells, and transitional cells. In the present investigation we have employed a semiallogeneic transplantation protocol in order to study the fate of these nonparenchymal epithelial cells (NPEC) beyond the 4-week endpoint imposed by the lethality of CD-AAF diet. An enriched NPEC suspension containing γ-glutamyl-transpeptidase (GGT)-positive oval cells (>75%) was isolated from ACI rats maintained on CD-AAF diet for 3 weeks. The donor cells were transplanted via the portal vein into livers of male F1progeny (LE×ACI) that had been fed a CD diet for 7 days prior to receiving a partial hepatectomy and the cell suspension. Host rats were then fed either a CD or choline-supplemented (CS) diet for 12 weeks and killed. Colonies of donor-derived cells identified in frozen sections by their lack of reactivity with ACI anti-LE alloantiserum in indirect immunofluorescence (IF) assays were only observed in rats continuously fed the CD diet. Histochemical analysis indicated that the donor-derived colonies expressed GGT, a preneoplastic marker for liver cancer.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

T cell mediated responses play a role in xenograft as well as allograft rejection. In vitro T cell responses to xenogeneic antigens are characterized by T cell recognition of polymorphic determinants of gene products encoded by the major histocompatibility complex of the stimulating cells, but little is known of the fine specificity of this recognition of xenogeneic antigens and its comparability to allogeneic antigen recognition. In order to study the fine specificity of human CTL in the recognition of xenogeneic antigens, long-term lines or clones were established from a secondary mixed lymphocyte response in which the stimulator cells wereH-2bmurine splenocytes. By comparing the ability of a series of target cells derived from congenic recombinant mouse strains to be lysed by these CTL, it was demonstrated that all isolated lines specifically lysed target cells expressingH-2bor T1a/Qa-1bproducts. Of the effector populations specific forH-2bcell surface molecules, all recognized class I products withKbspecificity predominating when evaluated for their ability to lyse in vivo-derived class I mutants or cells transfected with class I genes. These human xenoreactive CTL were able to distinguish wild typeKbmolecules from those altered by amino acid changes confined to a single molecular domain ofKb. These findings demonstrate that xenogeneic antigen recognition by human T cells is characterized by a fine specificity of antigen recognition comparable to the specificity of recognition of major histocompatibility complex-encoded molecules by murine CTL across allogeneic differences.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

As previously reported, acute cyclosporine-induced nephrotoxicity is characterized by a decline in glomerular filtration rate and a selective intrarenal production of the vasoconstrictor thromboxane (TxA2), but not vasodilator prostaglandin E2(PGE2), or prostacyclin (PGI2), cyclooxygenase metabolites. Fish oils (FO), that are rich in n-3 polyunsaturated fatty acids have a high affinity for cyclooxygenase but serve as poor substrate inhibit TxA2 synthesis. We have shown that when FO replaces olive oil (OO) as the vehicle for CsA, CsA-induced nephrotoxicity and increased TxA2 synthesis are obviated in rodent models. In this study, we demonstrate that the FO vehicle for CsA does not compromise CsA's immunosuppressive properties as deduced from studies of a delayed-type hypersensitivity (DTH) model in BALB/c mice and in a rat heart transplant model. In fact, concurrent FO administration with CsA actually enhances immunosuppression. A dose of CsA incapable of blunting DTH when injected in OO was suppressive when given in FO. Administration of as little as 0.05 ml of FO vehicle potentiated the suppressive action of CsA. In addition, nonconcurrent dietary supplementation of FO in animals receiving CsA caused an increase in the immunosuppressive action of CsA in DTH. FO alone reduced DTH as compared with OO, but was far less effective than CsA plus FO. Furthermore, doses of CsA (5 mg/kg/day or 1.5 mg/kg/day), which are subtherapeutic when administered with OO, prolonged engraftment of Lewis recipients of Lewis × Brown-Norway F1hearts when CsA was solubilized with FO. These studies indicate that concurrent administration of CsA and FO potentiates the activity of CsA and thus increases its therapeutic index. Thus, CsA plus FO is potentially a safe, potent antirejection therapy worthy of clinical testing, especially insofar as FO prevents CsA-induced acute nephrotoxicity in the rodent.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The function of renal cortical mitochondria isolated from rats with cyclosporine nephrotoxicity was studied. Renal cortical mitochondria were isolated from 5 male Fischer rats after 14 days of daily intraperitoneal administration of CsA, 25 mg/kg body wt. Compared with the mitochondrial function of 5 pair-fed control rats receiving vehicle alone, state 3 respiration (ADP-dependent) using several substrates was mildly depressed only with pyruvate-malate supported respiration (27±3 vs. 36±2 nmol O2/min/mg protein; P<0.05). The Ca2+accumulation rate was slightly reduced (354±14 vs. 416±18 nmol/min/mg protein; P<0.025) while the cytochrome enzyme concentrations were not different from controls. Respiratory control ratios were not affected (CsA group: 9.5±2.8, control group: 8.9±2.3; glutamate-malate as substrates). These minor alterations in mitochondrial function occurred in the presence of severe depression in the glomerular filtration rate and renal morphologic changes commonly seen with CsA administration. Moreover, there was no increase in en-zymuria. These results indicate that CsA has minor effects on the respiratory function of renal cortical mitochondria. The severe depression in the glomerular filtration rate is out of proportion to these minor alterations in mitochondrial function. These findings argue against a prominent role for a direct toxic action of CsA on tubular cells in the pathogenesis of acute cyclosporine-induced renal dysfunction.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Natural suppressor (NS) cell lines were derived from the spleen and thymus of adult mice using procedures previously used to derive NS cells from neonatal spleen. Adult spleen-derived NS cells showed slightly greater suppression of the MLR than neonatal spleen-derived NS cells, and thymus-derived NS cells showed the least suppression. Adult spleen-derived NS cells prevented death from lethal GVHD when administered to suble-thally irradiated weanling mice that received an otherwise lethal GVHD provoking inoculum. The stable cell surface phenotype of adult tissue-derived NS cells was similar to that previously described for neonatal and TLI spleen-derived NS cells: strongly positive for Thy 1.2, Ly-5, and asialo-GM1 antigens while negative for Ly-1, Ly-2, L3T4, MAC-1, and surface immunoglobulin.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

To test the influence of T cell depletion of the marrow in allogeneic bone marrow transplantation on functional T cell recovery, in vitro lymphocyte proliferation tests (LPTs) to microbial antigens were regularly performed in 23 recipients of normal BM and in 25 patients receiving BM with a fixed low number of T cells (1×105T cells/kg body weight; recipients of T-depleted BM).The long-term recovery of positive LPT to at least 1 of the 4 tested microbial antigens—Candida, herpes simplex virus (HSV), varicella-zoster virus (VZV), and cytomegalovirus—was nearly similar in both groups: 16/23 versus 18/25. Recovery of LPT toCandidaand HSV in the first 3 months appeared to be greatly influenced by prophylactic measures; only 2/23 recipients of normal BM, receiving amphotericin B, showed a positive LPT toCandidaversus 13/25 recipients of T-depleted BM (P < 0.01). In contrast, only 1/23 seropositive recipients of T-depleted BM, receiving acyclovir, showed a positive LPT to HSV versus 9/22 recipients of normal BM (P < 0.05). A positive LPT to CMV in the first 3 months was found in 9/9 seropositive recipients of normal BM, versus in 5/11 seropositive recipients of T-depleted BM (P < 0.05). Five of the 6 patients with a negative LPT died of CMV-interstitial pneumonia versus 1/14 with positive LPT (P < 0.01).We conclude that in CMV-seropositive recipients of allogeneic BM, T cell depletion of the graft affects the early recovery of T cell proliferation to CMV, which is associated with a higher risk of fatal CMV-interstitial pneumonia.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Administration of cyclosporine to allograft recipients and patients with immunologically mediated disorders is associated with a high incidence of the development of hypertension. We studied the effect of CsA on blood pressure and on the in vitro tail artery contractile response to transmural nerve stimulation (TNS) and exogenous norepinephrine (NE) in the spontaneously hypertensive rat (SHR). Fourteen days of p.o. administration of CsA 5 mg/kg/day (CsA5) or CsA 20 mg/kg/day (CsA20) resulted in significant increases in blood pressure. The effective level of TNS that resulted in a 50% of maximal response (ED50) was significantly (P < 0.05) decreased in the CsA5 and CsA20 animals compared to controls. The values for controls (n = 7), CsA5 (n = 10), and CsA20 (n = 9) were 4.3±0.3, 3.2±0.3, and 3.1±0.4 pulses/sec, respectively. In the CsA20 group, the doseresponse curve to NE was significantly shifted to the left, and the ED50was significantly (P< 0.01) decreased compared to controls (5.7 ± 0.8×10−5mol/L, n = 11, vs. 8.9±0.6×10−5mol/L, n = 12). We conclude that the in vitro contractile response to nerve stimulation is augmented by CsA. Some of the increase may be related to an enhancement of NE response, but a direct effect on neurovascular function is also suggested. This effect of CsA may be important in the development of hypertension and the changes in neurovascular tone seen with the clinical administration of this immunosuppressant.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We report on the preparation of an antibody-conjugated enzyme consisting of xanthine oxidase, a free-radical-producing enzyme, linked to the 62B1 monoclonal antibody, which recognizes the last steps of differentiation of B cell lineage (plasma cell and hairy cells). The conjugate specifically kills target cells, retaining both enzymic and immunological properties, without any damage to normal myeloid clonogenic efficiency. The model is suitable for ex vivo bone marrow purging in multiple myeloma patients.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In the course of exploring the antibody response in the unsensitized WF (u) female pregnant by a DA (a) male, we prepared a hybridoma that secreted an antibody (mAb 213) that was specific to theahaplotype but identified an antigen different from Pa. This antigen was designated RT11. It is present from the twelfth day of gestation on the collagen fibers of the placenta and of all organs in fetal and adult rats. It is particularly prominent on red blood cells; in the yolk sac epithelium; in the walls of the endodermal sinus, blood vessels and bronchioles; and in capsules and trabeculae. A very small amount is present on DA lymphocytes, since 17–20% of them react with mAb 213 by cytofluorimetery. The RT11 antigen is absent from the basal and labyrinthine trophoblast cells, from the parenchymal cells of all organs, and from T and B cells. This distribution pattern is completely different from that of the Aaand Pa antigens.Inhibition and absorption studies showed that RT11 is not an integral part of the collagen molecule. The SDS-PAGE analysis of the immunoprecipitates of RT11 from radioiodinated whole-membrane extracts of red blood cells and from the glycoprotein fraction thereof showed that it is an unglycosylated protein of molecular weight 29,000. The evidence to date suggests that RT11 is a blood group antigen.Studies on the genetic control of the expression of RT11 were undertaken to determine whether a gene linked to the MHC was involved and whether the control mechanism was unigenic or polygenic. Backcrosses generated using inbred strains—(DA×BN)F1×DA—and using complementary congenic strains—(DA.1N×BN.1A) F1×BN.1A—showed that the expression of RT11 was under polygenic control, and that both an MHC-linked gene (1.2 cM from RT1.Aa) and genes not linked to the MHC are involved. By contrast, the expression of the Pa antigen is under the control of an MHC gene only.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In the 20-year period from March 1968 to March 1988, 860 patients received 1001 renal transplants in the Northwestern Regional Renal Transplant Unit at Manchester Royal Infirmary. Through a continuing policy of avoiding mismatches for HLA antigens and lymphocytotoxic antibody crossmatching, transplant survival rates were found to correlate with the degree of HLA-A and B antigen mismatching from 1968 to 1978 and with HLA-B and DR antigen mismatching from 1979 to 1988. Mismatching for HLA-B and DR antigens was also found to correlate with transplant survival in highly sensitized patients and in patients transplanted since 1981, the “cyclosporine era.” Recipients who were HLA-DR1 positive were found to have the highest graft survival compared to recipients negative for this antigen. In contrast, HLA-DR3 positive recipients had the poorest outcome. Transplants from HLA-DRw6 positive donors showed higher transplant survival rates than donor kidneys positive for any other HLA-DR antigen. A correlation of transplant survival with HLA-B and DR mismatching was seen whether kidneys were collected within our region or received through the UK Transplant Service.We conclude that avoidance of mismatching for HLA-B and DR antigens confers high transplant survival rates (91.1% at 5 years for 0 HLA-B and DR mismatches), and in order to achieve this rate for most recipients exchange of donor kidneys between transplant centers will be essential.

ISSN:0041-1337    

出版商:OVID    

年代:1989

数据来源: OVID