Hydroquinone, a reactive metabolite of benzene, enhances interleukin-4 production in CD4+ T cells and increases immunoglobulin E levels in antigen-primed mice

Exposure to cigarette smoke is known to increase the risk of the development of allergic disease. The mechanism is not well understood. In this study, we determined the effect of hydroquinone (HQ), a major metabolite of benzene present in large quantities in cigarette tar, on interleukin-4 (IL-4) production by CD4+ T cells. HQ significantly enhanced IL-4 production by keyhole limpet haemocyanin (KLH)-primed CD4+ T cells in a dose-dependent manner. The enhancing effect of HQ on IL-4 production was maximal at a concentration of 50 micro m. It increased the level of IL-4 production approximately 10-fold. HQ enhanced IL-4 mRNA expression and also IL-4 gene promoter activity, suggesting that the enhancing effect of HQ on IL-4 production may occur at the transcriptional level. Furthermore, the injection of KLH-primed mice with HQ resulted in a significant increase in the levels of IL-4 and immunoglobulin E. These findings provide evidence that HQ, a major component of cigarette tar, may enhance allergic immune responses by inducing the production of IL-4 in CD4+ T cells.

Enhancement of 1 alpha,25-dihydroxyvitamin D(3)-induced differentiation of human leukaemia HL-60 cells into monocytes by parthenolide via inhibition of NF-kappa B activity

1. Transcription factors such as NF-kappa B provide powerful targets for drugs to use in the treatment of cancer. In this report parthenolide (PT), a sesquiterpene lactone of herbal remedies such as feverfew (Tanacetum parthenium) with NF-kappa B inhibitory activity, markedly increased the degree of human leukaemia HL-60 cell differentiation when simultaneously combined with 5 nM 1 alpha,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)). PT by itself did not induce HL-60 cell differentiation. 2. Cytofluorometric analysis indicated that PT stimulated 1,25-(OH)(2)D(3)-induced differentiation of HL-60 cells predominantly into monocytes. 3. Pretreatment of HL-60 cells with PT before the 1,25-(OH)(2)D(3) addition also potentiated the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation in both a dose- and a time-dependent manner, in which the enhanced levels of cell differentiation closely correlated with the inhibitory levels of NF-kappa B binding activity by PT. 4. In contrast, santonin, a sesquiterpene lactone without an inhibitory activity of NF-kappa B binding to the kappa B sites, did not enhance the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation. 5. In transfection experiments, PT enhanced 1,25-(OH)(2)D(3)-induced VDRE-dependent promoter activity. Furthermore, PT restored 1,25-(OH)(2)D(3)-induced VDRE-dependent promoter activity inhibited by TNF-alpha, an activator of NF-kappa B signalling pathway. 6. These results indicate that PT strongly potentiates the 1,25-(OH)(2)D(3)-induced HL-60 cell differentiation into monocytes via the inhibition of NF-kappa B activity and provide evidence that inhibition of NF-kappa B activation can be a pre-requisite to the efficient entry of promyelocytic leukaemia cells into a differentiation pathway.

The involvement of Ran GTPase in lipopolysaccharide endotoxin-induced responses

By functional cloning, we have established that Ran GTPase is involved in LPS-induced signal transduction. This has been accomplished by several functional comparisons of the two cDNAs, Lps(n)/Ran (or RanT/n) and Lps(d)/Ran (or RanC/d), which were isolated from cDNA libraries of LPS responder and hyporesponder mice, respectively. The letter n refers to the "normal" phenotype and the letter d refers to the "deficient" phenotype. Consistent with our previous results, more animal studies indicated that adenoviral transduction of RanC/d cDNA, but not RanT/n cDNA, into sensitive mice conferred significant resistance against endotoxin challenge. Thus the incorporation of RanC/d cDNA into gene therapy protocols as a therapeutic sequence remains very attractive. At steady state, hematopoietic cells transduced with RanC/d cDNA led to about a 10-fold increase in exogenous Ran protein compared with RanT/n cDNA. Furthermore, our cumulative data suggest that a slight elevation of Ran protein in B cells enhances LPS responsiveness, but the same elevation of Ran in macrophages does not. On the other hand, a high level of overexpression of Ran in both macrophages and B cells down-regulates LPS signal transduction. Thus LPS-induced signal transduction in macrophages and B cells is likely to occur via different signaling pathways.

Establishment of Porphyromonas gingivalis-specific T-cell lines from atherosclerosis patients

Porphyromonas gingivalis-specific T-cell lines were established from atherosclerotic lesions from two patients. T-cell lines were found to be a mixture of CD4+ and CD8+ T-cells producing variable amount of interferon-gamma, interleukin-4 and interleukin-10. The two patients have had a periodontal disease whose anti-P. gingivalis immunoglobulin G titers were significantly elevated, and P. gingivalis was the one of the predominantly cultivable microorganisms. This is the first report of the successful establishment of P. gingivalis-specific T-cell lines from atherosclerotic patients.

A single point mutation at the 3'-untranslated region of Ran mRNA leads to profound changes in lipopolysaccharide endotoxin-mediated responses

By functional cDNA expression cloning, we have previously established that Ran is important in lipopolysaccharide (LPS) signaling. This was achieved by functional comparison between two cDNAs, differing by a single base substitution within the 3'-untranslated region of the cDNA. This point mutation results in a striking RNA conformational change. No dramatic difference in total RNA at steady state could be found between the two molecules. However, at the protein level, RanC/d (from 870C mRNA) was 5-10-fold higher than RanT/n (from 870T mRNA) and this difference was not observed in non-hematopoietic cells transduced with the same vectors. This tissue-specific difference correlated with a difference in LPS endotoxin responses in corresponding hematopoietic cells. Importantly, the amounts of Ran- C/d and RanT/n proteins were similar initially but the difference became obvious with time. Both Ran proteins migrated from the cytoplasm to the nucleus, but Ran from RanC/d migrated faster than that of RanT/n. RanT/n protein preferentially remained in the cytoplasm and its overall amount was reduced at steady state, consistent with its degradation by intracellular proteases known to be involved in LPS-mediated signal transduction. As the two proteins are identical, the faster RanC/d nuclear localization and a preferred initial cytoplasmic RanT/n distribution suggest a difference in mRNA intracellular localization between the two molecules, as dictated by their RNA structural difference. By pulse-chase experiments, RanC/d proteins are more resistant to degradation than RanT/n protein; there also appear to have two populations of RanT/n proteins, one may reside in the cytoplasm and the other, in the nucleus. More RanC/d GTPase accumulated in the nuclei would conceivably alter the potency of signal transduction and therefore down-modulate LPS-mediated biological responses.

Inhibition of interleukin-12 production in lipopolysaccharide-activated mouse macrophages by parthenolide, a predominant sesquiterpene lactone in Tanacetum parthenium: involvement of nuclear factor-kappaB

Pharmacological control of interleukin-12 (IL-12) production may be a key therapeutic strategy for modulating immunological diseases dominated by type-1 cytokine responses. In this study, we investigated the effects of parthenolide, an anti-inflammatory sesquiterpene, on the production of IL-12 from mouse macrophages stimulated with lipopolysaccharide (LPS). Parthenolide potently inhibited the LPS-induced IL-12 production in a dose-dependent manner. The effect of parthenolide on IL-12 p40 promoter activation was analyzed by transfecting RAW264.7 monocytic cells with p40 promoter/luciferase constructs. The repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor-kappaB (p40-kappaB). Furthermore, activation of macrophages by LPS resulted in markedly enhanced binding activity to the kappaB site, which significantly decreased upon addition of parthenolide. These results suggest that parthenolide-induced inhibition of IL-12 production in macrophages may explain some of the biological effects of parthenolide including its anti-inflammatory activity.

Inhibition of interleukin-12 production in lipopolysaccharide-activated mouse macrophages by hpyericin, an active component of Hypericum perforatum

Hypericin, an active component of Hypericum perforatum, was evaluated for the regulation of interleukin-12 (IL-12) production in mouse macrophages. Hypericin significantly inhibited IL-12 production in lipopolysaccharide-activated macrophages in a dose-dependent manner (IC50 = 1.45 micrograms/ml). Furthermore, hypericin potently inhibited the activation of IL-12 gene promoter, suggesting that hypericin negatively regulated IL-12 production at the transcription level. These results may explain some known biological activities of hypericin including its anti-rheumatic effect.

Capsaicin potentiates 1,25-dihydoxyvitamin D3- and all-trans retinoic acid-induced differentiation of human promyelocytic leukemia HL-60 cells

Human promyelocytic leukemia HL-60 cells are differentiated into monocytic or granulocytic lineage when treated with 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] or all-trans retinoic acid, respectively. In this study, the effect of capsaicin, an active component of the red pepper of the genus Capsocum, on cell differentiation was investigated in a HL-60 cell culture system. Treatment of HL-60 cells with 5-30 microg/ml capsaicin for 72 h inhibited cell proliferation and induced a small increase in cell differentiation. Interestingly, synergistic induction of HL-60 cell differentiation was observed when capsaicin was combined with either 5 nM 1,25-(OH)2D3 or 50 nM all-trans retinoic acid. Flow cytometric analysis indicated that combinations of 1,25-(OH)2D3 and capsaicin stimulated differentiation predominantly to monocytes whereas combinations of all-trans retinoic acid and capsaicin stimulated differentiation predominantly to granulocytes. Capsaicin enhanced protein kinase C activity in 1,25-(OH)2D3- and all-trans retinoic acid-treated HL-60 cells. In addition, inhibitors for protein kinase C [bisindolylmaleimide (GF-109203X), chelerythrine, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7)] and an inhibitor for extracellular signal-regulated kinase [2-(2'-amino-3'-methoxyphenyl)-oxanaphthalen-4-one (PD-098059)] significantly inhibited HL-60 cell differentiation induced by capsaicin in combination with either 1,25-(OH)2D3 or all-trans retinoic acid. These results indicate that capsaicin potentiates 1,25-(OH)2D3- or all-trans retinoic acid-induced HL-60 cell differentiation and that both protein kinase C and extracellular signal-regulated kinase are involved in the cell differentiation synergistically enhanced by capsaicin.

Specific association of Type I c-Abl with Ran GTPase in lipopolysaccharide-mediated differentiation

Each of several isoforms of c-Abl may be involved in different biological functions. Type I c-Abl has been shown to be involved in LPS-induced differentiation and Type IV c-Abl, apoptosis. Ran has recently been shown to be involved in LPS endotoxin signal transduction. Here we show that Type I c-Abl associates with Ran. Formation of this complex is specific, as Ran did not associate with the highly homologous Type IV c-Abl isoform. In non-stimulated lymphoid B cells, Type I c-Abl tyrosine kinase is inactive, whereas Type IV kinase is active. Formation of Type I c-Abl/Ran complex and activation of Type I c-Abl kinase activity are LPS dose-dependent. This complex is detectable in B cells of endotoxin-sensitive inbred mice but absent in B cells of endotoxin-resistant mice. These findings therefore suggest that Type I c-Abl and Ran are important targets in lipopolysaccharide-induced biological responses of hematopoietic cells.

EPIC tile flow and nitrate loss predictions for three Minnesota cropping systems

Subsurface tile drains are a key source of nitrate N (NO3-N) losses to streams in parts of the north central USA. In this study, the Erosion Productivity Impact Calculator (EPIC) model was evaluated by comparing measured vs. predicted tile flow, tile NO3-N loss, soil profile residual NO3-N, crop N uptake, and yield, using 4 yr of data collected at a site near Lamberton, MN, for three crop rotations: continuous corn (Zea mays L.) or CC, corn-soybean [Glycine max (L.) Merr.] or CS, and continuous alfalfa (Medicago sativa L.) or CA. Initially, EPIC was run using standard Soil Conservation Service (SCS) runoff curve numbers (CN2) for CC and CS; monthly variations were accurately tracked for tile flow (r2 = 0.86 and 0.90) and NO3-N loss (r2 = 0.69 and 0.52). However, average annual CC and CS tile flows were underpredicted by -32 and -34%, and corresponding annual NO3-N losses were underpredicted by -11 and -52%. Predicted average annual tile flows and NO3-N losses generally improved following calibration of the CN2; tile flow underpredictions were -9 and - 12%, whereas NO3-N losses were 0.6 and -54%. Adjusting a N parameter further improved predicted CS NO3-N losses. Predicted monthly tile flows and NO3-N losses for the CA simulation compared poorly with observed values (r2 values of 0.27 and 0.19); the annual drainage volumes and N losses were of similar magnitude to those measured. Overall, EPIC replicated the relative impacts of the three cropping systems on N fate.

Induction of immune hyporesponsiveness after portal vein immunization with ovalbumin

BACKGROUND

Previous work has demonstrated prolonged allograft survival after donor-specific portal vein immunization before the transplantation. The purpose of this study was to examine the potential mechanism of portal vein-induced hyporesponsiveness after portal vein immunization with the soluble protein ovalbumin.

METHODS

Balb/c mice were immunized with a portal vein injection of ovalbumin. After the immunization, in vivo delayed-type hypersensitivity response and in vitro proliferative response of ovalbumin-specific T cells were assessed to determine host immune response. Type 1 (IL-2, IL-12, IFN-gamma) and type 2 (IL-4, TGF-beta) regulatory cytokines were assessed by semiquantitative reverse transcriptase polymerase chain reaction. Sera anti-ovalbumin IgG, IgG1, and IgG2a were measured by enzyme-linked immunosorbent assay, and the antigen-presenting ability of liver nonparenchymal cells (NPCs) was assessed by T-cell proliferation to ovalbumin in vitro.

RESULTS

There was significant inhibition of ovalbumin-specific delayed-type hypersensitivity and T-cell proliferation in portal vein-immunized mice compared with intraperitoneal-immunized or control mice. Reverse transcriptase polymerase chain reaction analysis results showed that lymphocytes from portal vein-immunized mice exhibited decreased type 1 and increased type 2 cytokine messenger RNA expression compared with intraperitoneal-immunized or control animals. The type 2 cytokine response of lymphocytes from ovalbumin portal vein-immunized mice correlated with increased sera ovalbumin-IgG1 and decreased IgG2a. The results of an antigen-presenting assay revealed that liver NPCs were deficient antigen-presenting cells compared with adherent cells from heart or spleen.

CONCLUSIONS

Processing of ovalbumin by hepatic NPCs results in hyporesponsiveness to ovalbumin by an impaired type 1 cytokine response and a preferential shift toward a type 2 cytokine response, possibly because of defective antigen presentation by hepatic NPCs. Intrahepatic processing of antigen may play an important role in the development of strategies to reduce host immunoreactivity against transplanted allografts.

Expression of a truncated retroviral envelope gene enhances expression of normal cellular phenotypes

The envelope gene of Moloney murine leukemia virus (Mo-MLV) and its various functional domains have been studied extensively but not as much in terms of their biological effects on cell growth. In this study, we report the biological characterization of a truncated Mo-MLV envelope gene, LN11, which is devoid of a signal peptide. Its expression in various cell types, as compared to the control, enabled the transduced cells to assume a more normal phenotype, which is defined by an increase in contact inhibition and factor dependence, as well as reduced tumorigenicity. LN11-transduced fibroblasts exhibited a higher degree of contact inhibition, assumed a more flattened morphology and were more adherent compared to the control. In v-abl transformed hematopoietic cells, expression of LN11 resulted in slower cell growth, which was due to an enhanced dependence on exogenous growth factors. Enforced expression of LN11 also resulted in a slower rate of tumor development and a reduced tumor load. Thus, modification of a retroviral genome could have a significant impact on cell growth and development. This is one example where we need to consider the safety issue carefully when constructing retrovirus vectors for gene therapy.

Oxidized low density lipoprotein inhibits interleukin-12 production in lipopolysaccharide-activated mouse macrophages via direct interactions between peroxisome proliferator-activated receptor-gamma and nuclear factor-kappa B

Lipopolysaccharide (LPS) increases the production of interleukin-12 (IL-12) from mouse macrophages via a kappaB site within the IL-12 p40 promoter. In this study, we found that oxidized low density lipoprotein (oxLDL) inhibited this LPS-stimulated production of IL-12 in a dose-dependent manner while native LDL did not. OxLDL inhibited p40 promoter activation in monocytic RAW264.7 cells transiently transfected with p40 promoter/reporter constructs, and the repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor-kappaB (NF-kappaB) (p40-kappaB). Activation of macrophages by LPS in the presence of oxLDL resulted in markedly reduced binding to the kappaB site, as demonstrated by the electrophoretic mobility shift assays. In contrast, native LDL did not inhibit the IL-12 p40 promoter activation and NF-kappaB binding to the kappaB sites, suggesting that oxidative modification of LDL was crucial for the inhibition of NF-kappaB-mediated IL-12 production. 9-Hydroxyoctadecadienoic acid, a major oxidized lipid component of oxLDL, significantly inhibited IL-12 production in LPS-stimulated mouse macrophages and also suppressed NF-kappaB-mediated activation in IL-12 p40 promoter. The NF-kappaB components p50 and p65 directly bound peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in vitro. In cotransfections of CV-1 and HeLa cells, PPAR-gamma inhibited the NF-kappaB transactivation in an oxLDL-dependent manner. From these results, we propose that oxLDL-mediated suppression of the IL-12 production from LPS-activated mouse macrophages may, at least in part, involve both inhibition of the NF-kappaB-DNA interactions and physical interactions between NF-kappaB and PPAR-gamma.

De novo acute hepatitis B infection in a previously vaccinated liver transplant recipient due to a strain of HBV with a Met 133 Thr mutation in the "a" determinant

De novo HBV infection post-liver transplantation (LT) from an anti-HBc seropositive donor rarely presents as acute failure. We report a 42-year-old Caucasian female, HBsAg and anti-HBc seronegative, with primary biliary cirrhosis who received an allograft from a HBsAg negative, anti-HBc seropositive donor. The patient, previously vaccinated years pre-LT, was re-vaccinated against HBV and 1 year post-LT had an anti-HBs titre of 256 IU/l. Two years post-LT, elevated serum aminotransferases and worsening liver function with an INR of 2.0 developed. The HBsAg became positive, anti-HBs undetectable and serum HBV-DNA >2000 pg/ml by hybridisation assay. Liver biopsy revealed significant ballooning degeneration, piecemeal necrosis and positive immunostaining for HBsAg. Progressive liver failure developed followed by sepsis and terminal multi-organ failure. Subsequent analysis of the predominant HBV strain revealed mutations in the "a" determinant: Met 133 Thr (codon change ATG to ACG) and Asn 131 Thr.

CONCLUSION

' Acute de novo HBV infection from an anti-HBc sero-positive donor may occur long after LT despite protective anti-HBs titres post-vaccination secondary to the emergence of "a" determinant mutated strains of HBV.

Indications for liver transplantation in British Columbia's Aboriginal population: a 10-year retrospective analysis

OBJECTIVES

To study the indications for liver transplantation among British Columbia's First Nation population.

MATERIALS AND METHODS

A retrospective analysis of the British Columbia Transplant Society's database of Aboriginal and non-Aboriginal liver transplant recipients from 1989 to 1998 was undertaken. For primary biliary cirrhosis (PBC), the transplant assessment database (patients with and without transplants) was analyzed using a binomial distribution and compared with published census data regarding British Columbia's proportion of Aboriginal people.

RESULTS

Between 1989 and 1998, 203 transplantations were performed in 189 recipients. Fifteen recipients were Aboriginal (n=15; 7.9%). Among all recipients, the four most frequent indications for liver transplantation were hepatitis C virus (HCV) infection (n=57; 30.2%), PBC (n=34; 18.0%), alcohol (n=22; 11.6%) and autoimmune hepatitis (n=14; 7.4%). Indications for liver transplantation among Aboriginal people were PBC (n=8; 53.3%; P<0.001 compared with non-Aboriginal people), autoimmune hepatitis (n=4; 26.67%; P=0.017), acute failure (n=2; 13.3%) and HCV (n=1). Among all patients referred for liver transplantation with PBC (n=43), 29 (67.44%) were white and 11 (25.6%) were Aboriginal. A significant difference was found between the proportion of Aboriginal people referred for liver transplantation and the proportion of Aboriginal people in British Columbia (139,655 of 3,698,755 [3.8%]; 1996 Census, Statistics Canada) (P<0.001).

CONCLUSIONS

Aboriginal people in British Columbia are more likely to be referred for liver transplantation with a diagnosis of PBC but are less likely to receive a liver transplant because of HCV or alcohol than are non-Aboriginal people.

Inhibition of interleukin-12 and interferon-gamma production in immune cells by tanshinones from Salvia miltiorrhiza

Pharmacological control of interleukin-12 (IL-12) and interferon-gamma (IFN-gamma) production may be a key therapeutic strategy for modulating immunological diseases dominated by Th1-derived cytokine responses. In this study, we investigated the effects of three different tanshinone pigments from Salvia miltiorrhiza (tanshinone I, dihydrotanshinone, and cryptotanshinone) on IL-12 production in mouse macrophages and on IFN-gamma production in lymph node cells. All tested tanshinones significantly inhibited IL-12 production in lipopolysaccharide (LPS)-activated macrophages and also IFN-gamma production in keyhole limpet hemocyanin (KLH)-primed lymph node cells in a dose-dependent manner. Dihydrotanshinone was more effective than tanshinone I or cryptotanshinone. Tanshinones significantly inhibited the expression of IL-12 p40 gene at the mRNA level. Furthermore, tanshinones potently inhibited the promoter activation of IL-12 p40 gene and nuclear factor (NF)-kappaB binding to the kappaB site, suggesting that tanshinones may negatively regulate IL-12 production at the transcription level. These results may explain some known biological activities of tanshinones including their anti-inflammatory effect, and suggest a possible use of tanshinones in the treatment of immunological diseases dominated by Th1-derived cytokine responses.

Prolongation of heterotopic heart allograft survival by portal venous injection of alloantigen: the role of hepatic nonparenchymal cells

The induction of immune hyporesponsiveness in transplantation is a complex interaction between the immune system and the alloantigen. The route by which an antigen is introduced to the immune system plays an important role in the immune response. Antigen delivered via the portal circulation has the ability to induce T-cell hyporesponsiveness. In this study we examined the mechanism responsible for the induction of hyporesponsiveness by assessing immune response following portal vein (pv) injection of donor alloantigen. C57B1/6 mice were immunized via pv with splenic mononuclear cells (SMNC) from BALB/c mice. The recipient immune response was assessed in vivo by murine heterotopic heart transplant survival. SMNC and hepatic nonparenchymal cells (NPC) were isolated from pv immunized animals and used as regulatory cells in a one-way mixed lymphocyte culture (MLC) as a measure of in vitro recipient responder SMNC proliferation. Survival of murine heterotopic heart transplants was prolonged following pv injection of alloantigen (p < .04 compared to nonimmunized or systemically immunized mice). Stimulation of responder SMNCs isolated from pv immunized mice resulted in an antigen-specific hyporesponsiveness (p < .05 compared with nonimmunized or systemically immunized mice). Cocultures of responder SMNCs from nonimmunized (naive) mice with hepatic NPC from previously pv immunized mice resulted in attenuation of T-cell proliferation in MLR following stimulation with donor alloantigen (p < .05 compared to coculture with NPC from nonimmunized mice or SMNC from pv immunized mice). These data would suggest that the hepatic NPC plays an important role in the regulation of the immune response. With further identification of cell subtypes responsible for induction of hyporesponsiveness, future therapies may be directed at these specific targets, thereby minimizing the harmful side effects of current immunosuppressive therapies.

Increased levels of interleukin-6 are associated with lymphocytosis in bronchoalveolar lavage fluids of idiopathic nonspecific interstitial pneumonia

Local overexpression of interleukin-6 (IL-6) experimentally induces lymphocytic infiltration in the bronchial tree of rat. Among idiopathic interstitial pneumonia (IIP), nonspecific interstitial pneumonia/fibrosis (NSIP) has an increased number of lymphocytes in bronchoalveolar lavage (BAL) fluid when compared with usual interstitial pneumonia (UIP). To reveal a relation of IL-6 with the lymphocyte infiltration of NSIP, IL-6 was measured in BAL fluids of idiopathic NSIP (n = 7), idiopathic UIP (n = 16), and normal control subjects (n = 45). IL-6-producing sites were assessed by IL-6 protein stain on biopsy specimens of NSIP, UIP, and normal lung of mediastinal tumors. Lymphocyte numbers and IL-6 levels in BAL fluids were higher in NSIP than those in UIP (p < 0.01, respectively), which were also higher when compared with those of normal control subjects (p < 0.01, respectively). In NSIP, the levels of IL-6 correlated with the number of lymphocytes (r = 0.93, p < 0.01). UIP cases were divided into two groups: high-UIP (n = 7) or low-UIP (n = 9) according to IL-6 levels greater than or within the 95 percentile of normal control subjects, respectively. The high-UIP group had BAL lymphocytosis when compared with the low-UIP group (p < 0.05). IL-6 stained on epithelial cells of the bronchial tree and on alveolar macrophages of NSIP and UIP. In conclusion, the lymphocytosis in BAL fluid of patients with NSIP and a subgroup of UIP is associated with the high levels of IL-6 and its sources are the epithelial cells of the small airway and the alveolar macrophages.

Therapeutic anti-tumor response induced with epitope-pulsed fibroblasts genetically engineered for B7.1 expression and IFN-gamma secretion

Mouse fibroblasts (H-2(b)) were genetically engineered to express a co-stimulatory B7.1 and an IFN-gamma (Fb/IFN-gamma/B7.1). The Fb/IFN-gamma/B7.1 cells were then pulsed with an ovalbumin epitope (amino acids 257-264, SIINFEKL, H-2K(b)-restricted) as a model antigen (Fb/IFN-gamma/B7.1/OVA) and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2(b)). Genetically engineered fibroblasts lacking either IFN-gamma or B7.1 were constructed and used as controls. Immunization with the Fb/IFN-gamma/B7.1/OVA cells induced strong cytotoxic activity against OVA-expressing EL4 (EG7) tumor cells but not against other H-2(b) tumor cells, such as EL4, C1498, and B16F1. The magnitude of the cytotoxic response in mice with the Fb/IFN-gamma/B7.1/OVA cells was significantly higher than that in mice immunized with any other cell construct. CD8(+) T cells with OVA-specific cytotoxic activity were predominant in mice immunized with Fb/IFN-gamma/B7.1/OVA cells. Furthermore, treatment with Fb/IFN-gamma/B7.1/OVA cells significantly prolonged the survival period of EG7 tumor-bearing mice. Anti-tumor CTL immunity by the Fb/IFN-gamma/B7.1/OVA cells could be induced without the help of host antigen-presenting cells, CD4(+) T cells, or NK1.1(+) cells. Our results suggest that fibroblasts can be genetically modified into efficient antigen-presenting cells for the induction of antigen-specific CTL response in cancer immunotherapy.

Augmentation of antitumor immunity by genetically engineered fibroblast cells to express both B7.1 and interleukin-7

Mouse fibroblasts (H-2(b)) were genetically engineered to express a costimulatory B7.1 and an interleukin-7 (IL-7; Fb/B7.1/IL7). The Fb/B7.1/IL7 cells were then pulsed with an ovalbumin (OVA) epitope (amino acids 257-264, SIINFEKL, H-2 K(b) restricted; Fb/B7. 1/IL7/OVA) and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2(b)). The genetically engineered fibroblasts lacking either B7.1 or IL-7 were constructed and used as controls. Immunization with the Fb/B7.1/IL7/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells. The magnitude of the cytotoxic response in mice with the Fb/B7.1/IL7/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8(+) T cells were a major effector cell-type of antitumor response in the immunized mice with the Fb/B7.1/IL7/OVA cells. Furthermore, immunization with the Fb/B7.1/IL7/OVA cells significantly prolonged the survival period of mice when the mice were injected with EG7 tumor cells one week after the immunization. These results suggest that fibroblasts can be genetically modified to an efficient cell vaccine for the induction of antitumor response.

Genetically engineered fibroblasts with antigen-presenting capability: efficient induction of an antigen-specific cytotoxic T-lymphocyte response and protection against tumor development in vivo

BLK mouse fibroblasts (H-2b) were genetically engineered to express costimulatory B7.1 and interleukin-2 (BLK/IL2/B7.1). The BLK/IL2/B7.1 cells were then pulsed with an ovalbumin (OVA) epitope as a model antigen (Ag) (BLK/IL2/B7.1/OVA), and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2b). The genetically engineered fibroblasts lacking one or two of three factors (interleukin-2, B7.1, and OVA) were constructed and used as controls. Immunization with the BLK/IL2/B7.1/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells, but not against other H-2b tumor cells, such as EL4, C1498 and B16F1 cells. The magnitude of the cytotoxic response in mice with the BLK/IL2/B7.1/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8+ T cells with OVA-specific cytotoxic activities were predominant in mice immunized with the BLK/IL2/B7.1/OVA cells. Furthermore, immunization with the BLK/IL2/B7.1/OVA cells significantly prolonged the survival of mice, compared with any other cell constructs, when the mice were challenged with EG7 tumor cells at 2 weeks postimmunization. Induction of antitumoral CTL immunity by the BLK/IL2/B7.1/OVA cells was independent of host Ag-presenting cells and of CD4+ T-cell and natural killer 1.1+ cell help. These results suggest that fibroblasts can be genetically modified to efficient Ag-presenting cells for the induction of an Ag-specific CTL response.