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Transforming growth factor-beta1 (TGF-beta1) exerts potent immunosuppressive effects. In this study, we investigated the potential role of TGF-beta1 produced by hepatocellular carcinoma (HCC) cell lines in immunosuppression mechanisms. Using the Mv1Lu cell-growth inhibition assay and an enzyme-linked immunosorbent assay (ELISA), we detected optimal levels of TGF-beta1 in the culture supernatants conditioned by the HCC cell lines PLC/PRF/5, Hep3B, and HepG2. To determine the biological activity of TGF-beta1 in the supernatants, we examined the effects of the culture supernatants on the production of interferon (IFN)-gamma induced during the culture of peripheral blood mononuclear cells (PBMCs) stimulated with interleukin (IL)-12. IFN-gamma production of IL-12-stimulated PBMCs in the 1:1 dilution of the acid-activated conditioned medium of PLC/PRF/5, Hep3B, and HepG2 reduced to 14.7 +/- 0.8, 17.3 +/- 9.0, and 35.9 +/- 14.6%, respectively, compared with the value in the culture with control medium (complete culture medium). These results suggest that HCC cells producing TGF-beta1 may reduce the generation or activation of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, and thus could enhance their ability to escape immune-mediated surveillance.

Corticoids are well known for their immunosuppressive properties. Interleukin-10 (IL-10) is an intrinsic antiinflammatory peptide in immune diseases, originally identified as cytokine synthesis inhibitory factor. We examined the effect of hydrocortisone sodium succinate (HSS) on the production of IL-10 by human peripheral blood mononuclear cells (PBMCs). PBMCs from healthy volunteers and cancer-burden patients were preincubated separately with or without HSS for 1 h, then stimulated with 5 microg/ml lipopolysaccharide (LPS). Production of IL-10 by human PBMCs was detected with LPS stimulation and its production was higher in cancer-burden patients than in normal volunteers, although this was not statistically significant. HSS suppressed production of IL-10 by LPS-stimulated PBMCs in a dose-dependent manner both in normal volunteers and in cancer-burden patients. These results indicate that, in addition to their antiinflammatory properties, corticoids act to restore the immunosuppressive states even in cancer-burden states

The relationship between endogenous cytokine antagonists and surgical stress is poorly understood. Surgical stress induces immunosuppression, and the reversed therapy of postoperative immunosuppression has been expected. The aim of the present study was to assess the effect of a serine protease inhibitor on postoperative immune reactivity. Twenty patients with colorectal cancer were randomly separated into experimental and control groups of 10 patients each. The experimental group received perioperative administration of a serine protease inhibitor while the control group did not. Plasma levels of cytokine antagonists, which suppress cell-mediated immunity, such as cortisol, interleukin-1 receptor antagonist, soluble interleukin-2 receptor (sIL-2R) and soluble tumor necrosis factors p55, p75 (sTNF-R55, -R75) were simultaneously measured. Significant reductions of plasma concentration of sIL-2R and sTNF-R55 were observed. Perioperative administration of a serine protease inhibitor may contribute to ameliorating immunosuppression after major surgery.

The effects of centrally administered interleukin-1 beta (IL-1) or platelet activating factor (PAF) on adrenocorticotropin (ACTH) and catecholamine secretion, blood pressure and heart rate were examined to determine if these agents stimulate similarly the hypothalamic-pituitary-adrenal (HPA) axis or the sympathetic-adrenomedullary system. Intra-third ventricular administration of IL-1 (50, 200 ng) evoked significant ACTH secretion. Centrally administered IL-1 (50 ng) elevated plasma noradrenaline and adrenaline levels, systolic blood pressure and heart rate. Plasma ACTH, noradrenaline and adrenaline levels were also increased by the higher dose (200 ng) of IL-1 while systolic blood pressure and heart rate were not affected. Intra-third ventricular administration of 9 micrograms of PAF elevated the plasma ACTH level while 3 micrograms of PAF did not stimulate ACTH secretion. Neither dose of centrally administered PAF affected any plasma catecholamine level or systolic blood pressure. These results suggest that central IL-1 stimulates both the HPA axis and the sympathetic-adrenomedullary system, that a higher dose of IL-1 stimulates a mechanism to antagonize the elevation of blood pressure and heart rate and that central PAF is not involved in the control of the sympathetic-adrenomedullary system. Thus, IL-1 and PAF do not interact in the brain, although they interact peripherally.

Lymphokine activated killer (LAK) cells can destroy not only tumor cells but also syngeneic liver cells. In this study, the effects of passive transfer of LAK cells on liver regeneration were examined by the 3H-thymidine uptake and bromodeoxyuridine (BrdU) labeling methods after resection of 70% of the volume of the liver. LAK cells were infused 12h after hepatectomy and the effects on regeneration of liver cells were examined 36 h later. The transfusion of LAK cells induced significant inhibition of liver regeneration at a dose of 5-10 x 10(7) cells. Neuraminidase treatment of lymphocytes is desirable to enhance the selective entrapment of LAK cells into the liver. When LAK cells were treated with neuraminidase (0.5 units/ml), and transfused into hepatectomized mice, more potent suppression of liver regeneration was induced in comparison with the same dose of LAK cells. The intraperitoneal injection of recombinant interleukin 2 (rIL-2) after partial hepatectomy also inhibited the regeneration of remnant liver. From these results, lymphocytes such as LAK cells appear to regulate liver regeneration.

To assess the usefulness of flowcytometric monitoring in the early detection of acute allograft rejection, we studied surface markers of graft infiltrating lymphocytes, coronary sinus blood lymphocytes and peripheral blood lymphocytes after rat heart transplantation. Fisher rats served as donors and Lewis rats as recipients. Among recipients that received no immunosuppression, grafts were removed 2 days after transplantation (Ongoing Rejection Group: n = 7) and on the day of terminal rejection (Rejection Group: n = 7). The Immunosuppression Group (n = 7) was treated with cyclosporine A at a dose of 3 mg/kg/day intramuscularly for 14 days. The following two color analyses were studied: OX8 (anti-CD8) with OX39 (anti-interleukin 2 receptor; IL2R), W3/25 (anti-CD4) with OX39, W3/25 with OX8. Histological grading demonstrated no significant difference between the Ongoing Rejection Group and the Immunosuppression Group, which showed mild rejection (1.29 +/- 0.27 versus 1.14 +/- 0.24). The proportion of CD8(+)IL2R(+) graft infiltrating lymphocytes showed a more significant increase in the Ongoing Rejection Group than in the Immunosuppression Group (32.1 +/- 3.05 versus 20.6 +/- 9.02; p < 0.01). The proportion of CD8(+) IL2R(+) coronary sinus blood lymphocytes also showed significant increase in the Ongoing Rejection Group compared with the Immunosuppression Group (4.63 +/- 1.91 versus 2.52 +/- 1.60; p < 0.05). These results suggest that this technique can detect acute allograft rejection earlier than endomyocardial biopsy, before the phase in which histological findings become evident.

A sustained release system for interleukin-2 (IL-2), and IL-2 mini-pellet (IL-2 mp), was developed by fusing IL-2 into a needle shaped collagen. Serum concentration of IL-2 after a single subcutaneous injection of the IL-2 mp into C57BL/6 mice remained elevated longer than after an injection of aqueous IL-2. IL-2 in the serum became undetectable by 6h after a subcutaneous injection of 1 x 10(6) unit of IL-2 in phosphate-buffered saline (PBS). In contrast, after a single subcutaneous injection of IL-2 mp containing the same amount of IL-2, the concentration of IL-2 increased to its maximum at 6h after injection, then began to decrease gradually. IL-2 was detected even on the third day after a single subcutaneous injection of one IL-2 mp. Augmentation of NK activity and generation of IL-2 activated killer cells were observed in the spleen from day 1--day 3 after a single subcutaneous injection of IL-2 mp into C57BL/6 mice. This activation was not observed following a single subcutaneous injection of the same amount of IL-2 in PBS. Adoptive immunotherapy by a single subcutaneous injection of IL-2 mp followed by intravenous injections of in vitro cultured IL-2 activated killer cells showed better results in decreasing the number of metastases of Lewis lung carcinoma in C57BL/6 mice than immunotherapy using IL-2 solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Early diagnosis of rejection and timely immunosuppression are absolutely important in clinical lung transplantation. We studied surface markers of peripheral blood lymphocytes (PBL), graft infiltrating lymphocytes (GIF) and bronchoalveolar lavage fluid (BALF) in a rat using flow cytometric monitoring to diagnose rejection. Left lung transplantation was performed on Brown Norway (BN) rats and Lewis (LEW) rats in the following groups; Group 1: LEW-LEW (isograft), Group 2: BN-LEW (allograft; no immunosuppression), Group 3: BN-LEW (allograft; treated with Cyclosporine A at a dose of 15 mg/kg/day i.m.). In each group, rats were killed 3, 5, 7 days postoperatively (n = 6 on each day). Monoclonal antibodies investigated in this study were W3/25 (anti-helper T lymphocyte), OX8 (anti-suppressor/cytotoxic T lymphocyte), and OX39 (anti-interleukin 2 receptor). Histological classification of rejection in Group 2 showed vascular phase at 3 days, alveolar phase at 5 days, and destructive phase at 7 days, respectively. No evidence of rejection was found in Group 1 or 3. In Group 2, W3/25 positive cell proportion in GIL and BALF significantly decreased as the rejection progressed, but OX8 positive and OX39 positive cell proportion increases were significantly greater than in Groups 1 and 3 as the rejection progressed. These results lead us to speculate that the studies of T cell subsets in GIL and BALF lymphocytes are useful for diagnosis of rejection in lung transplantation.

To determine how interleukin-7 (IL-7) affects the proliferation of T cells in patients with rheumatoid arthritis (RA), we evaluated the response of mononuclear cells (MNC) obtained from their peripheral blood (PB), synovial fluid (SF) and synovial tissue (ST) to stimulation by recombinant IL-7 and interleukin-2 (IL-2). Each cytokine was administered alone or combined with phytohemagglutinin (PHA). Cellular DNA synthesis was assayed by the [3H]-thymidine incorporation method. The stimulatory effect of 500 u/ml IL-7 on PBMNC obtained from 19 patients with RA was significantly lower than on PBMNC from 19 healthy controls. However, the same degree of stimulatory activity of 500 u/ml IL-2 was observed on the PBMNC from both RA patients and control subjects. The response of PBMNC to a suboptimal dose of PHA (0.2 micrograms/ml) was enhanced by adding either IL-7 or IL-2 (100 or 500 u/ml) to the cultures. The enhanced synthesis of DNA by both RA and control PBMNC on exposure to IL-7 following stimulation by a suboptimal dose of PHA was higher than that of IL-2. The effect of IL-7 on RA PBMNC was significantly greater than that of IL-2 at the concentration of 100 u/ml on PBMNC from the same RA patients. The stimulatory activity of IL-2 at the concentrations of 100 and 500 u/ml on SF MNC and ST MNC exceeded that of IL-7. In particular, an IL-2 dose of 500 u/ml had a marked effect on SF MNC. The PHA response of SF MNC was the lowest seen among the MNC from three different compartments.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular immunocompetence was investigated in 17 cases of aortitis syndrome (3 active, 14 inactive stage). Both the active and inactive groups demonstrated significantly lower interleukin-2 (IL-2) production than healthy volunteers. The active aortitis syndrome group produced significantly more interleukin-1 beta (IL-1 beta) than the inactive group. The proportion of CD11b+ CD8+ cells was significantly lower in the active aortitis syndrome group. Further, the proportions of CD11b- CD8+ cells and CD57+ CD16- cells in the aortitis syndrome patients were significantly higher than the healthy volunteers. These results suggest that there are intrinsic qualitative abnormalities in the T cells that produce IL-2 in aortitis syndrome. Pathogenesis of aortitis syndrome is considered as follows: during the active stage, diminished IL-2 production impairs differentiation and proliferation of suppressor T cells, thus creating abnormalities in the inhibitory functions of immunoregulation and promoting the proliferation of cytotoxic T and natural killer (NK) cells. This presumably initiates inflammation of the aorta and/or artery.

The anti-tumor effect of immunization with heat-killed Mycobacterium tuberculosis (Tbc) and Tuberculin (PPD)-coupled syngeneic tumor cells was examined in vivo. Three tumor cell lines were employed. Immunization of Tbc-primed BALB/c mice with PPD-coupled syngeneic Meth-A tumor cells displayed a potent anti-tumor effect on viable Meth-A cells inoculated subcutaneously. Neither PPD-coupled LLC (Lewis Lung Carcinoma) cells nor sonicated PPD-coupled Meth-A cells were capable of immunizing these mice. PPD-coupled syngeneic whole tumor cells were indispensable for induction of this tumor-specific resistance. Immunization of Tbc-primed C3H/He mice with PPD-coupled syngeneic MH134 tumor cells did not elicit anti-tumor activity against MH134, but additional pretreatment of mice with cyclophosphamide brought on an anti-tumor effect. Antimetastatic reactivity was investigated in C57BL/6 mice bearing LLC, with a reduction in metastases noted. This antimetastatic effect was observed even when the mice were immunized with PPD-coupled LLC cells three days after removal of the initial tumor. Immunization with Tbc and PPD-coupled Meth-A cells together with intraperitoneal administration of murine or rat interleukin 2 (IL 2) further augmented anti-Meth-A resistance. Murine IL 2 further inhibited tumor growth during the early stage, while rat IL 2 showed an anti-tumor effect throughout the course of tumor growth.

We investigated the effects of lymphokine-activated killer (LAK) cells on epidermal hyperplasia induced by cholera toxin (CT). LAK cells showed cytotoxic activity against both tumor cell lines and proliferating normal cells including skin epidermal cells. When 1 x 10(7) LAK cells were injected intradermally together with 1.0 ng of CT, epidermal hyperplasia was markedly suppressed. The LAK effectors inhibiting epidermal hyperplasia showed surface phenotypes of asialo-GM1+, Thy-1+, Lyt-2- and L3T4-, that were different from those of LAK cells killing tumor cells in vitro. Epidermal hyperplasia induced by CT was not suppressed by topical administration of cytokines such as interleukin-2, interferon and tumor necrosis factor. Therefore, the antiproliferative effect of LAK cells might be attributed to their direct action on the epidermal cells.

The antidonor immune response was examined in a one haplotype-mismatched renal transplant recipient with an allograft that had been well-functioning for more than 10 years. Although the relative response of the mixed lymphocyte reaction (MLR) was (45.8)% and the MLR responder cells stimulated by donor cells produced measurable amounts of interleukin-2 (IL-2) (11.6 U/ml), the cytotoxic T lymphocytes (CTL) could not be generated against donor cells, even with exogenous IL-2. These results indicate that antidonor CTL precursors were either deleted or inactivated in this recipient.

Previously, we reported that interleukin-2 (IL-2)-stimulated helper T cells produced an unknown soluble factor which induced dendritic cell-like differentiation in primary cultures of monocytic leukemia cells and we referred to this factor as dendritic cell differentiation factor (DCDF). In this study, we attempted to purify and characterize DCDF and investigated its biological effect on normal human monocytes. Gel filtration chromatography indicated that the molecular weight of DCDF is approximately 30-35 kDa. Chromatofocusing indicated that the isoelectric point of DCDF is approximately 5.0. DCDF, partially purified by subsequent gel filtration, chromatofocusing, and hydrophobic chromatography, significantly enhanced the HLA-DR expression of normal human monocytes and a human monocytic leukemia cell line, THP-1. This biological activity was not neutralized by any known antibodies to human cytokines. DCDF significantly amplified the T-cell stimulatory activity of monocytes in the allogeneic mixed leukocyte reaction (MLR). Moreover, DCDF significantly enhanced IL-1 beta and IL-6 production by monocytes in a dose-dependent manner. These results suggest that DCDF is a novel human cytokine which stimulates the accessory cell function of monocytes.

In this study, we investigated serum-soluble interleukin-2 receptor (sIL-2r) and neopterin (NPT) levels in five patients with severe postoperative infections. A total of 25 synchronous determinations of sIL-2r and NPT were performed. A marked increase in sIL-2r and NPT levels was observed, and the increase in sIL-2r was significantly correlated to that of NPT which is a marker of macrophage activity. These results suggest that macrophages are involved in the stimulation of sIL-2r release, representing a potentially negative biological effect. The results indicate that sIL-2r may be a useful indicator of the efficacy of antibiotics and of prognosis.

The accumulation of polymorphonuclear leukocytes (PMN) in synovial fluid is a common feature of rheumatoid arthritis (RA). We studied the chemotactic response of PMN obtained from the synovial fluid and from the peripheral blood of patients with RA using a modified Boyden's method, in which interleukin-8 (IL-8) or N-formyl-methionyl-leucyl-phenylalanine (FMLP) was used as a chemotactic agent. The IL-8-induced response of peripheral blood PMN from 15 patients with RA did not differ from that of 15 healthy controls. A decreased chemotactic response to IL-8 was, however, observed in PMN from the synovial fluid of 12 patients with RA compared with peripheral blood cells of the same individual. This defective chemotactic ability of PMN was inversely correlated with the number of infiltrating cells in the synovial fluid. We also obtained similar results with FMLP. These results indicate that the chemotactic ability of PMN may be reduced after migrating to the synovial fluid.

Interleukin-2 (IL2) is the obligatory signal for both T cell mitogenesis and in vitro generation of alloreactive cytotoxic T lymphocytes (CTL). An investigation was made to determine whether an antibody directed against IL2 would suppress the rejection reaction of rat cardiac allografts. Rabbit anti-interleukin 2 (anti-IL2) antiserum was obtained by immunizing at 2 week intervals over a period of 8 weeks with 10(6) U of recombinant human IL2 along with complete Freund's adjuvant. The bioassay for inhibition of IL2 activity by anti-IL2 antiserum was carried out in conjunction with the IL2-dependent cytotoxic T cell (CTLL cell) assay. Cardiac allografts of F344 rats were heterotopically transplanted into ACI rats. Seven daily doses of 1 ml of anti-IL2 antiserum were administered intravenously following transplantation. IL2-driven [3H]thymidine incorporation in CTLL cells was significantly inhibited by rabbit anti-IL2 antiserum. Graft survival in the anti-IL2 serum-treated group was significantly prolonged in a dose-dependent fashion compared to control groups. In conclusion, these results indicate that rabbit anti-IL2 antiserum may prove to be of significant value as an immunosuppressive agent in clinical organ transplantation.

Mechanical stress plays a key role in the pathogenesis of cartilage destruction seen in osteoarthritis (OA). We investigated the effect of cyclic tensile stress (CTS) on the anabolic and catabolic gene expression of rat cultured normal chondrocytes using the Flexercell strain unit. The effects of interleukin (IL)-4, a chondroprotective cytokine, on the changes in gene expression induced by CTS were also investigated. CTS (7% elongation at 0.5 Hz) for 24 h did not affect the expression of aggrecan and type II collagen, whereas CTS significantly upregulated matrix metalloproteinase (MMP)-13 and cathepsin B mRNA expression by chondrocytes. IL-1beta expression was also signifi cantly upregulated by CTS up to 12 h. The upregulation of MMP-13 was observed at 3 h, which was earlier than that of IL-1beta. Furthermore, pre-treatment with IL-4 (10 ng/ml) suppressed both MMP-13 and cathepsin B induction by mechanical stress, as well as CTS-induced IL-1beta expression. Our results suggest that IL-4 might have a therapeutic value in the treatment of OA by downregulation of mechanical stress-induced MMP-13 and cathepsin B expression by chondrocytes.

Co-cultivation of thymus and spleen cells of Fisher and Lewis rats with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, FIRT-1, FIRS-1, LERT-1, and LERS-1, respectively. Cells of these cell lines had rat T-cell characters as demonstrated by the positive reaction to monoclonal antibodies (MAbs) to rat T cell antigens (Thy 1 and pan T). They lacked surface immunoglobulins and strongly expressed rat interleukin-2 receptor antigen (Tac) and Ia antigen. Karyotypic analysis revealed that they had the normal rat karyotype in early cultures, but showed marked aneuploidy after long cultivation. None of them expressed HTLV gag proteins (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally and weakly expressed pX gene products (p40x). They were not transplantable into syngeneic newborn rats.