Induction of interleukin-1alpha production in murine Sertoli cells by interleukin-1

In the present study we examined the involvement of interleukin (IL)-1alpha, -1beta, FSH, and lipopolysaccharide (LPS) in the regulation of IL-1alpha and -1beta production by Sertoli cells under in vitro conditions. Sertoli cell cultures from immature mice produced constitutively basal levels of intracellular IL-1alpha. Stimulation of Sertoli cell cultures with LPS (5 microgram/ml) resulted in a maximal production of intracellular IL-1alpha 2 h after the stimulation. Thereafter, these levels decreased but remained significantly higher within 24 h after stimulation than those in control cultures. The effect of LPS on IL-1alpha production was dose dependent. FSH did not show any effect on intracellular IL-1alpha production by Sertoli cells. IL-1alpha could not be detected in supernatants of unstimulated or stimulated Sertoli cell cultures. Sertoli cell cultures stimulated with recombinant IL-1alpha induced optimal intracellular levels of IL-1alpha within 2 h of stimulation. These levels remained high 24 h after stimulation. However, stimulation of Sertoli cell cultures with IL-1beta induced a peak of IL-1alpha production 8 h after stimulation. These levels decreased 24 h after the stimulation but were still found to be significantly higher than those in control cultures. The addition of IL-1 receptor antagonist (IL-1ra) to Sertoli cell cultures did not significantly alter their capacity to produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cell cultures were reversed by the concomitant addition of recombinant IL-1ra. No immunoreactive IL-1beta could be detected in lysates or conditioned media of immature murine Sertoli cells under any of the stimulatory conditions outlined. Our results may suggest the involvement of physiological (IL-1) and pathophysiological factors (LPS) in the regulation of spermatogenesis and spermiogenesis processes and male fertility.     

Augmentation of pathogenesis of coxsackievirus B3 infections in mice by exogenous administration of interleukin-1 and interleukin-2.

Two variants of coxsackievirus B3 (CVB3) which differ dramatically in the ability to induce myocarditis in BALB/c mice were studied. H3 virus infection of murine monocytes in vitro resulted in release of concentrations of interleukin 1 (IL-1) and alpha/beta interferon that were high compared with those of cells infected with the H310A1 virus variant. In vivo, H3 virus infection caused substantial inflammatory cell infiltration of the myocardium, and lymphocytes from these animals gave predominantly Th1-cell responses to either whole H3 virus or overlapping peptides of the CVB3 vp1 capsid protein, as determined by IL-2 production. In contrast, H310A1 virus infection produced minimal myocarditis and Th1-cell responses, but Th2-cell activation was more pronounced than in H3 virus-infected mice (as determined by IL-4 concentrations). Exogenous treatment of H310A1 virus-infected mice with either IL-1 or IL-2 restored both myocarditis susceptibility and Th1-cell responses to whole virus and vp1 peptides. Furthermore, H310A1 virus-infected mice given exogenous IL-1 showed substantial in situ IL-2 deposition in the myocardium. These results indicate that CVB3-induced myocarditis may depend upon release of specific cytokines during infection and that activation of Th1 cells may be an important factor in pathogenesis.     

Induction of intracellular ceramide by interleukin-1β in oligodendrocytes

The sphingomyelin pathway has been implicated in mediating the effect of several extracellular agents leading to important biochemical and cellular changes. The aim of this investigation is to study interleukin-1β (IL-1β) signaling in oligodendrocytes. For this purpose, the CG4 oligodendrocyte cells were differentiated and incubated with IL-1β. This treatment induced a time- and dose-dependent increase of the endocellular ceramide. To mimic the effect of the elevation of endogenous ceramide, the CG4 cells were treated with the ceramide analogue C2-ceramide. Cell survival, measured with the MTT assay, showed that, by increasing the concentration of ceramide, up to 40% of CG4 cells were dying within 6 h, similar data were obtained with the primary differentiated oligodendrocytes. Condensation of chromatin, nuclear fragmentation, and formation of apoptotic bodies indicated that apoptosis was the cause of death. Surprisingly, long-term exposure (72 h) to increasing concentrations of IL-1β, which increases intracellular ceramide, did not induce oligodendroglial cell death. These results show that an increase of intracellular ceramide is not sufficient to induce apoptosis in oligodendrocytes and that IL-1β signaling through the ceramide pathway in these cells can mediate functions other than programmed cell death. J. Cell Biochem. 66:532–541, 1997. © 1997 Wiley-Liss, Inc.     

Resting human peripheral blood lymphocytes can be activated to cytolytic function by antibodies to CD3 in the absence of exogenous interleukin-2

We investigated the ability of anti-CD3 antibodies to activate resting human peripheral blood lymphocytes (PBL) to a cytolytic function. We found that two anti-CD3 antibodies, but not an anti-CD4, anti-CD8, or anti-CD2 antibody, could activate resting unseparated PBL to become killer cells in the absence of exogenous interleukin-2 (IL-2), although exogenous recombinant IL-2 (rIL-2) synergized with anti-CD3. We also found that these anti-CD3 antibodies were active in the absence of rIL-2 only when linked to a solid surface such as a Sepharose bead or a plastic tissue culture plate. Cytolytic activity was measured in several ways: (i) by the ability of activated PBL to lyse the NK-sensitive line K562, and (ii) by the ability of these cells to lyse a CD10+ (CALLA+), NK-resistant target in the presence of either concanavalin A (lectin-dependent lysis) or an anti-CD10-anti-CD3 heterodimer. At least two different types of cytolytic cells were activated by anti-CD3 antibodies, an NK-like cell, which was CD2+CD3-CD4-CD8-CD16+-NKH1a+, and a CTL-like cell, which was CD2+CD3+CD4-CD8+CD16-NKH1a-. The former cell lysed the K562 line and the latter cell lysed Namalwa in the presence of the anti-CD10-anti-CD3 heterodimer or concanavalin A. The NK-like cell was probably activated by endogenous IL-2 produced by the anti-CD3-activated CD3+ cells and both the NK and CTL-like cells required the presence of adherent cells for maximal activity. The dose response and the kinetics of anti-CD3 activation of PBL to cytolytic activity were also studied. The use of the anti-CD3-activated cytolytic cells as effectors in anti-CD3 heterodimer-mediated lysis of tumor cells may be a novel approach to the therapy of cancer, and a comparison with the well-studied rIL-2/lymphokine-activated killer (LAK) system is discussed.     

Induction of cyclo-oxygenase by interleukin-1 in rheumatoid synovial cells

The ability of interleukin-1 (IL-1) to stimulate prostaglandin E2 (PGE2) production by human rheumatoid adherent synovial cells was found to be time-dependent and sensitive to protein synthesis inhibitors. Cells incubated with exogenous arachidonic acid (10 microM) showed no increase in PGE2 production. However, with IL-1 (2.5 U/ml) and exogenous arachidonic acid there was a marked increase, with levels reaching twice that for cells incubated with IL-1 alone. Aspirin pre-treatment studies and the use of [acetyl-14C]aspirin showed that IL-1 increased PGE2 production through the induction of cyclo-oxygenase.     

Arachidonic acid can induce leukotriene C4 formation by purified human eosinophils in the absence of other stimuli

Stimulation of purified human eosinophils with 50 microM arachidonic acid leads to the production of leukotriene C4, 15-hydroxy-eicosatetraenoic acid and 15-series leukotrienes. The ratio of the amounts of leukotriene C4 and 15-lipoxygenase products was found to be strongly dependent on the arachidonic acid concentration, being relatively large at low arachidonic acid concentrations and very small at high arachidonic acid concentrations. In the presence of 1 microM platelet-activating factor a significant elevation of leukotriene C4 formation is observed, whereas the formation of 15-lipoxygenase products remains unaltered. As arachidonic acid was found to be capable of inducing a fast, transient rise in the cytosolic free Ca2+ concentration, this explains at least partly its ability to induce the Ca2+-dependent formation of leukotriene C4.     

Induction of hepatocyte mitosis in intact adult rat by interleukin-1 alpha and interleukin-6

In the adult rat the liver is normally quiescent, but it proliferates rapidly in response to partial hepatectomy (PH). A hepatectomized rat is subjected to stress by the operation. We have examined the effects of acute phase cytokines. To investigate the mediation of hepatocyte growth, recombinant human interleukin-1 alpha (IL-1) and interleukin-6 (IL-6) were injected into male rats. Administration of IL-1 or IL-6 followed by NH4Cl and glucagon could induce hepatocyte mitosis 30 h after the first injection. This activity was lost when interleukins were exposed to 90 degrees C for 30 minutes. NH4Cl augmented the effects of IL-1 and IL-6. These results suggest that the IL-1 and IL-6 are important mediators of liver regeneration after PH. We present a hypothesis for the triggering mechanism of hepatocyte proliferation.     

Induction of interleukin-1/and interleukin-8 mRNAs and proteins by TGFβ1 in rat lung alveolar epithelial cells

The transforming growth factor-β (TGF-β) has been shown to increase in lung injury and in fibrotic states of the lung. In the current study, we sought to investigate whether TGFβ₁ induced the expression of IL-1α and IL-8 in rat alveolar epithelial cells. We evaluated TGFβ₁, IL-1α, and IL-8 expression by immunofluorescence in silica-injured and saline-treated control rat lungs. Antibodies to IL-1α, IL-8, and TGFβ₁ showed intense staining in silica-injured lungs as compared to saline-instilled lungs. Primary isolated type II cells from silica-injured lungs showed increased expression of IL-1α as compared to saline-instilled lungs. To evaluate the effects of TGFβ₁, we treated an immortalized rat type II cell-derived cell line (LM5) with 100 pg/ml of TGFβ₁ in serum-free medium for 0–24 hours and analyzed the expression of IL-1α and IL-8 mRNAs and proteins using semi-quantitative RT-PCR, Northern blot analysis, Western blot analysis, and immunohistochemistry. Densitometric analysis of Northern blots showed modest constitutive expression of IL-1α gene in untreated control LM5 cells. TGFβ₁ treatment resulted in an increase in IL-1α mRNA, that reached maximum levels (4-fold) by 2 hours and remained elevated for 4–16 hours, with a subsequent decline by 24 hours. Similarly, Northern blot and RT-PCR analysis demonstrated that TGFβ₁ treatment resulted in maximum induction of IL-8 mRNA (6–8.5-fold) within 1–4 hours. The levels remained elevated for up to 24 hours afterwards. Western blot analysis results further confirmed the expression of both IL-1α and IL-8 proteins by LM5 cells. TGFβ₁ treatment resulted in increased expression of both IL-1α and IL-8 proteins. Immunofluorescence studies demonstrated increased staining of IL-1α by TGFβ₁ as compared to untreated cells. These results suggest that TGFβ₁ may regulate IL-1α and IL-8 expression in alveolar epithelial cells and contribute to polymorphonuclear leukocyte recruitment and lung injury in clinical states with increased TGFβ₁. © 1996 Wiley-Liss, Inc.     

Induction of interleukin-1beta by interleukin-4 in lipopolysaccharide-treated mixed glial cultures: microglial-dependent effects

Glial-secreted proinflammatory mediators are dynamically involved in central nervous system responses to exogenous stimuli such as infection, neurotoxins, and nerve injury. The therapeutic use of anti-inflammatory agents may reduce certain central nervous system pathology induced by inflammatory responses. We investigated the role of interleukin (IL)-4 in modulating the production of proinflammatory mediators from lipopolysaccharide-stimulated mixed glia in vitro. Interestingly, IL-4 significantly enhanced IL-1beta secretion and did not affect monocyte chemoattractant protein-1 release, even though IL-4 considerably inhibited IL-6, tumor necrosis factor alpha, and nitric oxide production from rat neonatal mixed glia. Further, IL-4 exhibited inhibitory effects on IL-1beta production in microglial-enriched cultures, while significantly increasing IL-1beta production in microglial-depleted glia. The enhancing effect of IL-4 on IL-1beta production was found to be inversely correlated with the percentage of microglia present in the mixed glial population. In summary, IL-4 did not act as a global anti-inflammatory cytokine and in fact, under certain situations enhanced IL-1beta secretion. We conclude that IL-4 exerts its anti-inflammatory effects in a limited and target-specific manner, which is delicately regulated by the cellular microenvironment. Therefore, precaution should be taken when clinically using IL-4 to treat diseases manifested by overt inflammatory responses.     

Induction of macrophage interleukin-1 production by Listeria monocytogenes hemolysin.

Listeriolysin O produced by a hemolytic strain of Listeria monocytogenes was purified from the ammonium sulfate precipitate of a culture supernatant through the steps of ion-exchange chromatography and gel filtration. The purified hemolysin finally gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular weight of 58,000. When peritoneal exudate macrophages were stimulated with purified hemolysin, we found a high level of IL-1 activity as determined by thymocyte costimulator assay in the culture supernatant. Cell-associated and intracellular IL-1 activity was also detected. The activity in the supernatant or membrane was blocked by polyclonal antibody to murine IL-1 alpha. Moreover, IL-1-specific mRNA expression could be detected in the macrophages stimulated with listeriolysin O by Northern blot analysis. Possible contamination by LPS of the listeriolysin O preparation did not seem to contribute to the induction of macrophage IL-1 production.     

Induction of nociceptive responses by intrathecal injection of interleukin-1 in mice.

Intrathecal (i.t.) injection (between lumbar vertebrae 5 and 6) into mice of a markedly low dose of IL-1alpha (3x10(-4) fmol or 5.4 fg in 5 microl per mouse) induced behaviors involving scratching, biting, and licking of non-stimulated hindpaws. The IL-1-induced behaviors appeared within 10 min of the injection of IL-1alpha, peaked at 20-40 min, and had disappeared 60 min after the injection. The IL-1-induced behaviors were similar to the nociceptive responses induced in mice by i.t. injection of substance P (SP) or subcutaneous (s.c.) injection of formalin into the footpad. The IL-1-induced behaviors were suppressed by intraperitoneal morphine, indicating that they are nociceptive responses. The nociceptive responses induced by 3x10(-4) (5.4 fg) of IL-1alpha were almost completely suppressed by co-injection of 0.3 fmol (7.2 pg) of an IL-1 receptor antagonist (IL-1ra). An antiserum against substance P, but not an antiserum against somatostatin, suppressed the IL-1-induced nociceptive responses. The nociceptive responses induced by s.c. injection of 2% formalin into the footpad were also inhibited by i.t. injection of 30 pmol (720 ng) of IL-1ra. These results suggest that IL-1 may play a role in hyperalgesia in mice by acting as a factor augmenting pain transmission in the spinal cord at least in part by either directly or indirectly releasing substance P.     

Induction of alpha 1-acid glycoprotein by recombinant human interleukin-1 in rat hepatoma cells

The induction of alpha 1-acid glycoprotein mRNA by recombinant murine interleukin-1, recombinant human interleukin-1 alpha, and recombinant human interleukin-1 beta has been studied in the rat hepatoma cell line Fao. Whereas the stimulatory capacities of recombinant human interleukin-1 alpha and recombinant murine interleukin-1 were almost identical, the concentrations of recombinant human interleukin-1 beta needed for half-maximal induction of alpha 1-acid glycoprotein mRNA were lower by three orders of magnitude. A 60-fold increase in alpha 1-acid glycoprotein mRNA levels was observed 18 h after the addition of recombinant interleukin-1 beta. In parallel albumin mRNA levels decreased to about 30%. The alpha 1-acid glycoprotein mRNA induction was strictly dependent on the presence of dexamethasone. For a full stimulation dexamethasone concentrations of greater than 10(-7) M were needed, whereas concentrations of less than 10(-12) M were ineffective. The increase in alpha 1-acid glycoprotein mRNA after recombinant human interleukin-1 beta was followed by a 36-fold stimulation in alpha 1-acid glycoprotein synthesis and secretion. When protein synthesis was blocked by either cycloheximide, puromycin, or emetine, the induction of alpha 1-acid glycoprotein mRNA by recombinant human interleukin-1 beta was impaired suggesting the involvement of a short-lived protein in the induction of alpha 1-acid glycoprotein mRNA.     

Sequence-specific DNA interstrand cross-linking by an aziridinomitosene in the absence of exogenous reductant

The aziridinomitosene derivative (1S,2S)-6-desmethyl(methylaziridino)mitosene (4) was shown to alkylate plasmid DNA at pH 7.4 in the absence of a reducing agent [Vedejs, E., Naidu, B. N., Klapars, A., Warner, D. L., Li, V. -s., Na, Y., and Kohn, H. (2003) J. Am. Chem. Soc. 125, 15796-15806], an activity not found in the parent mitomycins. We sought to evaluate aziridinomitosene 4 for the presence of DNA interstrand cross-linking activity using nonreductive reaction conditions. Radiolabeled DNA treated with 4 was analyzed by denaturing polyacrylamide gel electrophoresis (DPAGE), a technique that readily separates the less mobile cross-linked ds DNA from the more mobile ss DNA products. Nonreduced 4 produced an interstrand cross-link (ICL) in duplex DNA containing 5'-d(CG) sites, and the yield of ICL was comparable to that obtained from reduced MC under similar conditions. A ds DNA having the central tetranucleotide 5'-d(ACGT) provided the greatest ICL yield from both nonreduced 4 and reduced MC. Substitution of 5'-d(CG) with the inverted sequence 5'-d(GC) completely abolished interstrand cross-linking by 4, revealing 5'-d(CG) as its specific site of ICL formation. Replacement of dG at 5'-d(CG) with 2'-deoxyinosine (dI), which lacks the exocyclic C2 amino group present in dG, also prevented DNA ICL formation by 4, revealing an essential role for the dG C2 amino group in the interstrand cross-linking reaction between 4 and duplex DNA. This report directly demonstrates the presence of bifunctional alkylating activity in a nonreduced aziridinomitosene and clearly shows that unreduced 4 alkylates residues in the minor groove of ds DNA, cross-linking with the same 5'-d(CG) sequence specificity displayed by reduced MC.     

Chlorpromazine protects against apoptosis induced by exogenous stimuli in the developing rat brain

Background

Chlorpromazine (CPZ), a commonly used antipsychotic drug, was found to play a neuroprotective role in various models of toxicity. However, whether CPZ has the potential to affect brain apoptosis in vivo is still unknown. The purpose of this study was to investigate the potential effect of CPZ on the apoptosis induced by exogenous stimuli.

Methodology

The ethanol treated infant rat was utilized as a valid apoptotic model, which is commonly used and could trigger robust apoptosis in brain tissue. Prior to the induction of apoptosis by subcutaneous injection of ethanol, 7-day-old rats were treated with CPZ at several doses (5 mg/kg, 10 mg/kg and 20 mg/kg) by intraperitoneal injection. Apoptotic cells in the brain were measured using TUNEL analysis, and the levels of cleaved caspase-3, cytochrome c, the pro-apoptotic factor Bax and the anti-apoptotic factor Bcl-2 were assessed by immunostaining or western blot.

Findings

Compared to the group injected with ethanol only, the brains of the CPZ-pretreated rats had fewer apoptotic cells, lower expression of cleaved caspase-3, cytochrome c and Bax, and higher expression of Bcl-2. These results demonstrate that CPZ could prevent apoptosis in the brain by regulating the mitochondrial pathway.

Conclusions

CPZ exerts an inhibitory effect on apoptosis induced by ethanol in the rat brain, intimating that it may offer a means of protecting nerve cells from apoptosis induced by exogenous stimuli.     

Induction of collagenase mRNA in lapine articular chondrocytes by synovial factors and interleukin-1

The cDNA probe H-9, originally constructed to recognize a portion of the mRNA for lapine synovial collagenase, also hybridized with a RNA of the same size (approximately 2.0 kb) isolated from activated lapine articular chondrocytes. Primary, monolayer cultures of lapine articular chondrocytes did not contain detectable amounts of this RNA, nor did they secrete measurable amounts of collagenase into their culture media. Following exposure to synovial factors, the chondrocytes contained high levels of collagenase mRNA, while their conditioned media had considerable collagenolytic activity. Collagenase mRNA started to appear in chondrocytes 3-5 h after treatment with the synovial material. Maximum levels occurred after 12-24 h. Recombinant human interleukin-1 also induced the appearance of this mRNA. We conclude that chondrocyte collagenase is likely to be the same gene product as synovial collagenase, and that its regulation by lapine articular chondrocytes probably occurs at a pretranslational level.     

Induction of renin release by exogenous prostaglandins in hyporeninemic hypoaldosteronism

A deficiency in renal prostaglandin synthesis has been proposed as the cause of the syndrome of hyporeninemic hypoaldosteronism. To determine if renin release could be stimulated by pharmacologic infusions of PGA₁, we infused PGA₁ 0.075 to 0.60 μg/kg/min to nine patients with the syndrome. Total renal PGE production as measured by urinary PGE excretion was normal (650 ± 169 vs 400 ± 55 ng/24hr in normal subjects). Renin (PRA) was markedly depressed in all patients despite stimulation with upright posture and furosemide (1.0 ± 0.4 vs 9.3 ± 0.7 ng/ml/hr, p<0.001). But in two patients PGA₁ induced an increase in renin similar to that of normal subjects. PRA increased to a lesser degree in two other patients and plasma aldosterone slightly increased. Five showed no response. Infusions of nitroprusside in doses and duration that mimicked the hypotensive effects of PGA₁ failed to increase PRA or aldosterone. The data suggest that total renal PGE production is normal in patients with the syndrome of hyporeninemic hypoaldosteronism. Although orthostasis, furosemide and nitroprusside do not increase renin, prostaglandin A₁ infusion appears to be a potent stimulus to renin release in some of the patients.     

Induction of Mn-superoxide dismutase by tumor necrosis factor, interleukin-1 and interleukin-6 in human hepatoma cells.

Effects of Tumor Necrosis Factor (TNF), Interleukin-1 (IL-1), Interleukin-6 (IL-6) and Interferon-gamma (IFN-gamma) on the expression of Mn-superoxide dismutase (Mn-SOD) protein were investigated in human hepatoma cells, Hu-H1, which revealed resistance to the cytotoxicity of TNF and IL-1. Both TNF and IL-1 enhanced the Mn-SOD production to the level of 30- to 40-fold. IL-6 also increased the enzyme protein to 2- to 3-fold of the basal level without any cell proliferative effect. A specific antibody against IL-6 almost completely inhibited the induction of Mn-SOD. IL-6, as well as TNF and IL-1, appears to play some role in the Mn-SOD protein expression in human hepatoma cells.     

Induction of interleukin-1 receptors on chondrocytes by fibroblast growth factor: a possible mechanism for modulation of interleukin-1 activity

Interleukin-1 is a polypeptide factor with profound effects on several cell types, such as chondrocytes, fibroblasts, and T-cells. The ability of interleukin-1 to induce the synthesis of matrix-degradative enzymes, as well as prostaglandin E2, suggests a pivotal role for this mediator in chronic inflammation. Previous studies have shown that the effect of human monocyte interleukin-1 on the synthesis of collagenase and neutral proteases by chondrocytes was enhanced by basic fibroblast growth factor. Using recombinant human interleukin-1B, we have examined whether the potentiation of interleukin-1 effects by fibroblast growth factor is related to changes in the number or affinity of interleukin-1 receptors. Our studies confirm that rabbit articular chondrocytes in culture contain a single class of high-affinity receptors for interleukin-1 with a Ka of 0.9-1.1 x 10(-13) M-1. While the untreated chondrocytes contain approximately 1,620 receptors per cell, fibroblast growth factor-treated cells exhibit a higher number of receptors (approximately 2,960 per cell) with no apparent change in the affinity. The increase in receptor number can be abolished by inhibitors of lysosomal function, indicating a requirement for intracellular processing of the fibroblast growth factor. Our results suggest that the potentiation of interleukin-1 catabolic effects by fibroblast growth factor may be related to its ability to induce additional interleukin-1 receptors on the chondrocyte cell surface.     

Human BDCA-1-positive blood dendritic cells differentiate into phenotypically distinct immature and mature populations in the absence of exogenous maturational stimuli: differentiation failure in HIV infection

Current immunological opinion holds that myeloid dendritic cell (mDC) precursors migrate from the blood to the tissues, where they differentiate into immature dermal- and Langerhans-type dendritic cells (DC). Tissue DC require appropriate signals from pathogens or inflammatory cytokines to mature and migrate to secondary lymphoid tissue. We show that purified blood mDC cultured in vitro with GM-CSF and IL-4, but in the absence of added exogenous maturation stimuli, rapidly differentiate into two maturational and phenotypically distinct populations. The major population resembles immature dermal DC, being positive for CD11b, CD1a, and DC-specific ICAM-3-grabbing nonintegrin. They express moderate levels of MHC class II and low levels of costimulatory molecules. The second population is CD11b(-/low) and lacks CD1a and DC-specific ICAM-3-grabbing nonintegrin but expresses high levels of MHC class II and costimulatory molecules. Expression of CCR7 on the CD11b(-/low) population and absence on the CD11b(+) cells further supports the view that these cells are mature and immature, respectively. Differentiation into mature and immature populations was not blocked by polymyxin B, an inhibitor of LPS. Neither population labeled for Langerin, E-cadherin, or CCR6 molecules expressed by Langerhans cells. Stimulation of 48-h cultured DC with LPS, CD40L, or poly(I:C) caused little increase in MHC or costimulatory molecule expression in the CD11b(-/low) DC but caused up-regulated expression in the CD11b(+) cells. In HIV-infected individuals, there was a marked decrease in the viability of cultured blood mDC, a failure to differentiate into the two populations described for normal donors, and an impaired ability to stimulate T cell proliferation.     

Accelerated prion disease in the absence of interleukin-10

The identity of pro- and anti-inflammatory cytokines in the neuropathogenesis of prion diseases remains undefined. Here we have investigated the role of anti-inflammatory cytokines on the progression of prion disease through the use of mice that lack interleukin-4 (IL-4), IL-10, IL-13, or both IL-4 and IL-13. Collectively our data show that among these anti-inflammatory cytokines, IL-10 plays a prominent role in the regulation of prion disease. Mice deficient in IL-10 are highly susceptible to the development of prion disease and show a markedly shortened incubation time. In addition, we have correlated cytokine gene expression in prion-inoculated IL-10(-/-) mice to wild-type-inoculated animals. Our experiments show that in the absence of IL-10 there is an early expression of tumor necrosis factor alpha (TNF-alpha). In wild-type prion-inoculated mice, the expression of TNF-alpha mRNA occurs at a later time point that correlates with the extended incubation time for terminal disease development in these animals compared to those that lack IL-10. Elevated levels of IL-13 mRNA are found at early time points in the central nervous system of prion-inoculated IL-10(-/-) mice. At terminal disease, the brains of wild-type mice inoculated with RML or ME7 are characterized by elevated levels of mRNA for the proinflammatory cytokines TNF-alpha and IL-1beta, together with the anti-inflammatory cytokines IL-10, IL-13, and transforming growth factor beta. Our data are consistent with a role for proinflammatory cytokines in the initiation of pathology during prion disease and an attempt by anti-inflammatory cytokines to regulate the ensuing, invariably fatal pathology.