Analysis of cytokine immune response profile in response to inflammatory stimuli in mice with genetic defects in fetal and adult hemoglobin chain expression.

Injections of a crude fetal sheep liver extract (FSLE) containing fetal hemoglobin, MPLA, and glutathione (GSSH) reversed cytokine changes in aged mice. To investigate the role of fetal hemoglobin we derived mice with homzygous deletions for either of the two major ßchains, HgbßmaKO or HgbßmiKO. Hgbßmi is the most prominent fetal Hgbß chain, with Hgbßma more prominent in adult mice. Mice lacking another fetal Hgb chain, HgbεKO, died in utero. CHO cells transfected with cloned Hgb chains were used to produce proteins for preparation of rabbit heteroantibodes. Splenocytes from HgbßmaKO mice stimulated in vitro with Conconavalin A showed a higher IL-2:IL-4 ratio than cells from HgbßmiKO mice. Following immunization in vivo with ovalbumin in alum, HgbßmaKO mice produced less IgE than HgbßmiKO mice, suggesting that in the absence of HgbßmiKO mice had a predeliction to heightened allergic-type responses. Using CHO cells transfected with cloned Hgb chains, we found that only the fetal Hgb chain, Hgbε, was secreted at high levels. Secretion of Hgbßma or Hgbßmi chains was seen only after genetic mutation to introduce the two N-linked glycosylation sites present in Hgbε, but absent in the Hgbß chains. We speculated that a previously unanticipated biological function of a naturally secreted fetal Hgb chain may be partly responsible for the effects reported following injection of animals with fetal, not adult, Hgb. Mice receiving injections of rabbit anti-Hgbε but not either anti-Hgbßma or anti-Hgbßmi from day 14 gestation also showed a bias towards the higher IL-2:IL-4 ratios seen in HgbßmiKO mice.

An alteration in the levels of populations of CD4+ Treg is in part responsible for altered cytokine production by cells of aged mice which follows injection with a fetal liver extract.

We have shown previously that a fetal sheep liver extract (FSLE) containing significant quantities of fetal ovine gamma globin chain (Hbgamma) and LPS injected into aged (>20 months) mice could reverse the altered polarization (increased IL-4 and IL-10 with decreased IL-2 and IFNgamma) in cytokine production seen from ConA stimulated lymphoid cells of those mice. The mechanism(s) behind this change in cytokine production were not previously investigated. We report below that aged mice show a >60% decline in numbers and suppressive function of both CD4(+)CD25(+)Foxp3(+) Treg and so-called Tr3 (CD4(+)TGFbeta(+)), and that their number/function is restored to levels seen in control (8-week-old) mice by FSLE. In addition, on a per cell basis, CD4(+)CD25(-)Treg from aged mice were >4-fold more effective in suppression of proliferation and IL-2 production from ConA-activated lymphoid cells of a pool of CD4(+)CD25(-)T cells from 8-week-old mice than similar cells from young animals, and this suppression by CD25(-)T cells was also ameliorated following FSLE treatment. Infusion of anti-TGFbeta and anti-IL-10 antibodies in vivo altered Treg development following FSLE treatment, and attenuated FSLE-induced alterations in cytokine production profiles.

Characterization of human liver dendritic cells in liver grafts and perfusates.

It is generally accepted that donor myeloid dendritic cells (MDC) are the main instigators of acute rejection after organ transplantation. The aim of the present study was to characterize MDC in human donor livers using liver grafts and perfusates as a source. Perfusates were collected during ex vivo vascular perfusion of liver grafts pretransplantation. MDC, visualized in wedge biopsies by immunohistochemistry with anti-BDCA-1 monoclonal antibody (mAb), were predominantly observed in the portal fields. Liver MDC, isolated from liver wedge biopsies, had an immature phenotype with a low expression of CD80 and CD83. Perfusates were collected from 20 grafts; perfusate mononuclear cells (MNC) contained 1.5% (range, 0.3-6.6%) MDC with a viability of 97 +/- 2%. Perfusates were a rich source of hepatic MDC since 0.9 x 10(6) (range, 0.11-4.5 x 10(6)) MDC detached from donor livers during vascular perfusion pretransplantation. Perfusate MDC were used to further characterize hepatic MDC. Perfusate MDC expressed less DC-LAMP (P = 0.000), CD80 (P = 0.000), CD86 (P = 0.003), and CCR7 (P = 0.014) than mature hepatic lymph node (LN) MDC, and similar CD86 (P = 0.140) and CCR7 (P = 0.262) as and more DC-LAMP (P = 0.007) and CD80 (P = 0.002) than immature blood MDC. Perfusate MDC differed from blood MDC in producing significantly higher amounts of interleukin (IL)-10 in response to lipopolysaccharide (LPS), and in being able to stimulate allogeneic T-cell proliferation. In conclusion, human donor livers contain exclusively immature MDC that detach in high numbers from the liver graft during pretransplantation perfusion. These viable MDC have the capacity to stimulate allogeneic T-cells, and thus may represent a major player in the induction of acute rejection.

Prophylactic intravenous immunoglobulin treatment influences serum immunoglobulin M repertoire development after allogeneic bone marrow transplantation.

Patients treated with allogeneic bone marrow transplantation (BMT) suffer from a deficient humoral immunity during the post-transplant period. To prevent infections patients may receive prophylactic intravenous immunoglobulin (IVIG) therapy from 1 week before to 3 months after BMT. We have studied the effect of IVIG treatment on reconstitution of immunoglobulin repertoires in transplanted patients. Sera obtained from 13 IVIG-treated and 31 non-IVIG-treated patients before and at different time points after BMT, ranging from 3 days to 3 years, and from 18 healthy controls, were analyzed using a quantitative immunoblot system. The average immunoglobulin (Ig)M and IgG reactivity profiles against antigens derived from human liver, muscle and skin as well as Staphylococcus epidermidis protein extracts were similar in both patient groups and in controls. Both IgG and IgM reactivity profiles are, however, less heterogeneous among the individuals in the IVIG-treated patient group. Around 1 year after BMT the heterogeneity of the IgM reactivity profiles against allogeneic protein extracts is much lower in the IVIG-treated group compared to the non-IVIG-treated group and the healthy controls. This effect remains months to years after the IVIG treatment has been completed. Our results suggest that IVIG influences selection of the natural antibody repertoire mediated by the variable (V)-region during reconstitution after BMT.

Reducing environment protects sinusoidal lymphocytes isolated from normal human liver from apoptosis.

BACKGROUND/AIMS: We previously reported that the populations of lymphocytes and the expression of activated antigens in human sinusoidal mononuclear cells were different from those in peripheral blood mononuclear cells. Attempts to culture these cells for further study failed because they died rapidly under standard culture conditions in vitro after isolation from the liver. In this study, we evaluated the characteristics of cell death and the effects of various culture conditions on the viability of these cells. METHODS: Sinusoidal mononuclear cells were isolated from University of Wisconsin solution that had been perfused through the portal veins of normal healthy human livers harvested for transplantation into living related recipients. RESULTS: 70% of sinusoidal mononuclear cells cultured in vitro were nonviable within 48 h after isolation, while only 10% of peripheral blood mononuclear cells died under the same conditions. Sinusoidal mononuclear cells showed DNA ladder formation of DNA on electrophoresis and characteristic morphological pattern on electron microscopic examination that suggested they had died in an apoptotic manner. The addition of human liver extracts or 2-mercaptoethanol and reduced glutathione to the cultures rescued the sinusoidal mononuclear cells from apoptosis. Furthermore, diamide, a sulfhydryl group specific oxidant, negated the effect of the liver extract. CONCLUSION: In comparison with peripheral blood mononuclear cells, human sinusoidal mononuclear cells were more subject to death by apoptosis ex vivo, which was reversed by exogenous agents producing reducing conditions. These results suggested that hepatic sinusoidal mononuclear cells might express a different sensitivity to redox environment than peripheral blood mononuclear cells.

Serological analysis of experimental autoimmune thyroiditis in the buffalo strain rat.

Previous experiments have indicated that experimental autoimmune thyroiditis (EAT) induced in the Buffalo strain of rat by neonatal thymectomy closely resembles Hashimoto's thyroiditis. In these experiments we have analysed the serology of this type of EAT. Anti-thyroglobulin (Tg) antibodies were the only thyroid autoantibodies detected by immunoblotting. The IgG subclass distribution, analysed by a monoclonal anti-rat IgG subclass ELISA, altered during the course of disease. The proportion of IgG1 subclass Tg antibodies rose and the proportion of IgG2b subclass antibodies fell as disease progressed and the relative functional affinities of the anti-Tg IgG subclasses increased as disease progressed. The sera from animals with EAT were not cytotoxic in the presence of complement to a cultured rat thyroid cell line. In conclusion, EAT does not result in the production of antibodies against heterologous autoantigens as in Hashimoto's thyroiditis. Tg antibodies are produced which have similar properties to human Tg autoantibodies, including lack of cytotoxicity, and subclass restriction; these appear to have little pathogenic role in the disease.

Antigen-specific modulation of graft-versus-host reactions by two distinct placental factors.

We have previously shown that two distinct mouse placental fractions (PF) are potent immunomodulators in vivo. A 40 kDa PF induces a marked decrease of plaque forming cell (PFC) responses, while a 60 kDa PF increases them. Both effects are specific for the priming antigen. In the present study, these two PF are assayed on a cell-mediated response to allogeneic cells, i.e. in a local graft-versus-host reaction (LGVHR). Mice were primed with allogeneic cells in the presence of various amounts of the 40 kDa or 60 kDa PF, or liver extract (LE) as control. Six days later, their spleen cells were injected into the footpads of F1 recipients. Precise dose-response curves were established and the kinetics of the GVH response were carefully followed. Parallel with the modulation of PFC responses, the 40 kDa PF caused a potent inhibition of the LGVHR, while the 60 kDa PF greatly enhanced it. Both effects were specific for the alloantigens injected with the PF. Furthermore, we showed that these modulations were observed whatever the intensity of the GVH reaction, which varied according to the number of primed spleen cells transferred. This report also demonstrates that these PF can be greatly enriched by passage over affinity columns made of insolubilized lectins. The 40 kDa PF is retained on and can be eluted from columns of insolubilized concanavalin A (Con A) or wheat germ agglutinin (WGA), which indicates that it is a glycoprotein. Conversely, the 60 kDa PF does not bind to any of the above lectins and is probably not a glycoprotein. This biochemical purification step is also a good procedure for obtaining an even cleaner separation of the two fractions from each other. Thus, this paper demonstrates that both PF have important regulatory properties on specific cellular immune responses.

Alteration of thymus and of immune regulatory-antifibroblast factors in acute and chronic hepatic damage.

We studied in this paper the behavior of immunosuppressive and fibroblast proliferation inhibitory factors in the acute, chronic damage and cirrhotic alteration of the liver. We induced in LEW-rats acute hepatic necrosis by i.v. application of dimethylnitrosamine (DMNA: 35 mg/kg b.wt.) and by i.m. injection of CCl4 (1 ml/kg b.wt., twice a week). After 2-4 weeks we found chronic hepatic damage and after 8-10 weeks liver cirrhosis. As a control, untreated animals were used. Sera and liver factors were prepared from the animals and used for inhibition tests of fibroblast proliferation and MLC reaction. Furthermore, cell count and cell subpopulation of the thymus were determined by monoclonal antibodies (W3/25, OX-8). LF of untreated and DMNA-treated animals exhibited very strong unspecific inhibition effects of fibroblast proliferation and allogenic stimulation. However, with progression of hepatic damage (chronic hepatitis and cirrhosis) both suppressive abilities were gradually reduced. Normal sera showed very slight inhibition of allogenic stimulation but sera of animals with acute hepatic damage showed very strong inhibition. In the 2 weeks of CCl4 treatment, their inhibitory abilities were more than 40%, and with progression of hepatic damage they were gradually reduced. Normal sera or sera of animals with chronic hepatic damage could not suppress the fibroblast proliferation; however, sera of acute hepatic damage inhibited it very strongly. With chronic hepatic damage, the thymus gradually atrophied and, after 10 weeks of CCl4 treatment, it had atrophied completely. Thymocyte differentiation was found only in animals with acute hepatic damage. This suggests that factors which were liberated from the damaged hepatocytes caused differentiation of the thymocytes.

Fractionation and immunologic assessment of KCl-extracted cardiac antigens in coxsackievirus B3 virus-induced myocarditis.

Hypertonic salt extracts prepared from the heart tissues of adolescent CD-1 mice were fractionated on Sephadex G-100 columns. Two separate fractions were obtained. Fraction I, containing the antigenic immunoreactive activity, was able to inhibit the migration of CVB3-PPD immune mouse peritoneal exudate cells (IMPEC) as well as PEC from mice infected with CVB3 virus alone. Fraction II did not have antigenic activity as assessed by the agarose droplet cell migration inhibition assay. As controls, Fraction I prepared from the livers of spleens of CVB3-infected CD-1 mice was unable to inhibit the migration of CVB3 IMPEC. Unimmunized or "normal" mouse peritoneal exudate cells (NMPEC) were not inhibited by Fraction I. Antibodies prepared against Fractions I and II were unable to neutralize CVB3m virus in the plaque reduction test, and polyacrylamide gel analysis revealed multiple bands in 10% SDS gels.

Regulation of human lymphocyte function by a soluble extract from normal human liver.

The blastogenic and DNA synthetic response of human peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and allogeneic cells can be inhibited by a nontoxic aqueous extract (LEx) of normal human liver. LEx reversibly inhibits the activation of PBL by PHA, arrests ongoing DNA synthesis, and limits the duration of the DNA synthetic response to PHA at concentrations as low as 0.7 to 1.5 microgram LEx protein/culture. In contrast, human T lymphocyte E rosette formation is unaffected by LEx concentrations in excess of 900 microgram/culture. LEx has been partially purified by ultracentrifugation, ammonium sulfate precipitation, and molecular exclusion chromatography and appears to be a heat labile protein with a m.w. of approximately 65,000 and an isoelectric point of approximately 4.08. LEx is distinct from other previously described human immunoregulatory molecules and is potentially releasable in vivo from injured or necrotic liver cells. Because of its potency and anatomic distribution LEx may potentially modulate immunopathogenetic events responsible for assorted inflammatory and neoplastic liver diseases.

Sensitisation to halothane-altered liver components in severe hepatic necrosis after halothane anaesthesia.

In-vitro sensitisation (inhibiton or stimulation of leucocyte migration) in response to a liver homogenate obtained from rabbits pretreated with halothane was found in eight of twelve patients with halothane-associated hepatitis. Sensitisation was not observed when the homogenates were obtained from animals pretreated with ether. Furthermore, leucocyte migration in response to "halothane homogenate" was normal in eleven patients who had shown no abnormality in liver function after halothane anaesthesia and in thirty patients with other liver diseases. These studies provide direct evidence that sensitisation to halothane-altered liver-cell components is present in those occasional patients in whom severe liver damage develops after halothane anaesthesia.

Effect of mercurascan and tetracycline on ischaemia-altered immunogenicity of liver extract alloantigens in mice.

The action of Mercurascan and Tetracycline on ischaemic liver in mice was investigated. The effect was reflected in different immunogenicity (in allotrasplantation reaction) of liver extracts 1 mg. membrane fraction) derived from treated and normal organs in the donor--recipient strain combination B10--B10.LP. In the recipients treated with a single administration of extract from ischaemic liver the survival time of skin grafts was shortened as compared to the untreated control group and the control group given normal liver extract. Immunogenicity of the liver extracts from Mercurascan- or Tetracycline-treated mice was diminished.

Attempts to serologically classify feline caliciviruses on a national and an international basis.

A serological classification of five feline calicivirus (FCV) strains of Swiss origin and 13 isolates of Austrian origin was attempted. The antisera used had been prepared in rabbits against the five Swiss strains and in goats against six American strains. Homologous and heterologous neutralization tests were made in tube cultures using sera at dilutions that contained 20 antibody units, in unabsorbed sera at low dilution, and in sera after subjection to three consecutive absorptions with lyophilized feline liver powder. None of these procedures resulted in the delineation of serotypes. A study using 20 antibody units yeilded FCV strains with broad-spectrum antigenicity, which seem promising for vaccination trials and for covering global needs. In addition, readily neutralized strains suitable for epidemiological work on cat sera, and possibly also for measuring humoral response to vaccines, could be recognized. The extent of serum titer variance, after 10-fold variance of virus input, was established as being only two- to threefold. Five Swiss FCV strains have been shown to remain antigenically stable over 10 years of laboratory passage. FCV strains and the procedure using 20 antibody units offered a suitable approach for international comparative work. FCV strains with little cross-neutralization should be subjected to higher antibody concentrations of existing antisera before attempting to create serotypes. Liver powder absorptions, which reduced homologous and heterologous neutralization titers to similar extents, subsequently proved to be unsuitable for use in FCV classification.

Endodermally-derived and neural crest-derived differentiation antigens expressed by a human lung tumor.

The plasma membrane antigens of an undifferentiated small cell (oat cell) carcinoma of the lung were studied by the indirect immunofluorescence method on frozen section substrates with a rabbit antiserum prepared to the tumor plasma membrane fraction. After appropriate absorption of the antiserum, at least two differentiation antigens present on the tumor cells but undetectable on normal lung surface or glandular epithelial cells were identified. One antigen(s) was characteristic of certain normal, endodermally-derived epithelial cells of the digestive system, including those of colonic mucosa, hepatic ducts, pancreatic ducts and acini, and islets of Langerhans. The other antigen(s) was characteristic of certain normal, neural crest-derived cells in the peripheral nervous system, including cells in peripheral nerve, dorsal root ganglion, and anterior roots of the spinal cord; parasympathetic ganglion cells in the colon; and small nerves and nerve processes in the lung, colon, and skin. It was concluded that the presence of these differentiation antigens on the tumor cells resulted from the expression of gene products repressed in the normal cell of origin of the tumor.

Immunoblastic lymphadenopathy with mixed cryoglobulinemia. A detailed case study.

The premise that chronic antigenic stimulation may be involved in lymphoproliferative disorders was considered in a patient with immunoblastic lymphadenopathy who had received liver extract by injection and by mouth for many years. The salient features were lymphadenopathy and hepatosplenomegaly, a predominance of lymphocytes and plasmacytoid cells with mitotic figures in lymph-node imprints, a cryoglobulin containing IgG, IgA, IgM and bound complement components, depressed serum complement levels, and Coombs-test-positive erythrocytes. Immunoglobulin concentrations per 100 ml of serum were IgG, 5900 mg, IgA, 1480 mg, and IgM, 5640 mg, with normal ranges of 710 to 1540, 60 to 490, and 37 to 204 mg, respectively. Serum precipitins to an antigen (or antigens) in the liver extract resided in the IgA and IgM classes. Complete remission followed one course of cyclophosphamide, vincristine, and prednisone. We propose that the syndrome was caused by chronic antigenic stimulation with liver extract.