Tumor necrosis factor- alpha production to lipopolysaccharide stimulation by donor cells predicts the severity of experimental acute graft-versus-host disease.

Donor T cell responses to host alloantigen are known predictors for graft-versus-host disease (GVHD); however, the effect of donor responsiveness to an inflammatory stimulus such as lipopolysaccharide (LPS) on GVHD severity has not been investigated. To examine this, we used mouse strains that differ in their sensitivity to LPS as donors in an experimental bone marrow transplant (BMT) system. Lethally irradiated (C3FeB6)F1 hosts received BMT from either LPS-sensitive (LPS-s) C3Heb/Fej, or LPS-resistant (LPS-r) C3H/ Hej donors. Mice receiving LPS-r BMT developed significantly less GVHD as measured by mortality and clinical score compared with recipients of LPS-s BMT, a finding that was associated with significant decreases in intestinal histopathology and serum LPS and TNF-alpha levels. When donor T cell responses to host antigens were measured, no differences in proliferation, serum IFN-gamma levels, splenic T cell expansion, or CTL activity were observed after LPS-r or LPS-s BMT. Systemic neutralization of TNF-alpha from day -2 to +6 resulted in decreased intestinal pathology, and serum LPS levels and increased survival after BMT compared with control mice receiving Ig. We conclude that donor resistance to endotoxin reduces the development of acute GVHD by attenuating early intestinal damage mediated by TNFalpha. These data suggest that the responsiveness of donor accessory cells to LPS may be an important risk factor for acute GVHD severity independent of T cell responses to host antigens.     

Interleukin-18 regulates acute graft-versus-host disease by enhancing Fas-mediated donor T cell apoptosis.

Interleukin (IL)-18 is a recently discovered cytokine that modulates both T helper type 1 (Th1) and Th2 responses. IL-18 is elevated during acute graft-versus-host disease (GVHD). We investigated the role of IL-18 in this disorder using a well characterized murine bone marrow transplantation (BMT) model (B6 --> B6D2F1). Surprisingly, blockade of IL-18 accelerated acute GVHD-related mortality. In contrast, administration of IL-18 reduced serum tumor necrosis factor (TNF)-alpha and lipopolysaccharide (LPS) levels, decreased intestinal histopathology, and resulted in significantly improved survival (75 vs. 15%, P < 0.001). Administration of IL-18 attenuated early donor T cell expansion and was associated with increased Fas expression and greater apoptosis of donor T cells. The administration of IL-18 no longer protected BMT recipients from GVHD when Fas deficient (lpr) mice were used as donors. IL-18 also lost its ability to protect against acute GVHD when interferon (IFN)-gamma knockout mice were used as donors. Together, these results demonstrate that IL-18 regulates acute GVHD by inducing enhanced Fas-mediated apoptosis of donor T cells early after BMT, and donor IFN-gamma is critical for this protective effect.     

Differential roles of IL-1 and TNF-α on graft-versus-host disease and graft versus leukemia

We demonstrate an increase in graft-versus-host disease (GVHD) after experimental bone marrow transplant (BMT) when cyclophosphamide (Cy) is added to an otherwise well-tolerated dose (900 cGy) of total body irradiation (TBI). Donor T cell expansion on day +13 was increased after conditioning with Cy/TBI compared with Cy or TBI alone, although cytotoxic T lymphocyte (CTL) function was not altered. Histological analysis of the gastrointestinal tract demonstrated synergistic damage by Cy/TBI and allogeneic donor cells, which permitted increased translocation of LPS into the systemic circulation. TNF-alpha and IL-1 production in response to LPS was increased in BMT recipients after Cy/TBI conditioning. Neutralization of IL-1 significantly reduced serum LPS levels and GVHD mortality, but it did not affect donor CTL activity. By contrast, neutralization of TNF-alpha did not prevent GVHD mortality but did impair CTL activity after BMT. When P815 leukemia cells were added to the bone marrow inoculum, allogeneic BMT recipients given the TNF-alpha inhibitor relapsed at a significantly faster rate than those given the IL-1 inhibitor. To confirm that the role of TNF-alpha in graft versus leukemia (GVL) was due to effects on donor T cells, cohorts of animals were transplanted with T cells from either wild-type mice or p55 TNF-alpha receptor-deficient mice. Recipients of TNF-alpha p55 receptor-deficient T cells demonstrated a significant impairment in donor CTL activity after BMT and an increased rate of leukemic relapse compared with recipients of wild-type T cells. These data highlight the importance of conditioning in GVHD pathophysiology, and demonstrate that TNF-alpha is critical to GVL mediated by donor T cells, whereas IL-1 is not.     

IL-11 separates graft-versus-leukemia effects from graft-versus-host disease after bone marrow transplantation

We recently showed that IL-11 prevents lethal graft-versus-host disease (GVHD) in a murine bone marrow transplantation (BMT) model of GVHD directed against MHC and minor antigens. In this study, we have investigated whether IL-11 can maintain a graft-versus-leukemia (GVL) effect. Lethally irradiated B6D2F1 mice were transplanted with either T cell-depleted (TCD) bone marrow (BM) alone or with BM and splenic T cells from allogeneic B6 donors. Animals also received host-type P815 mastocytoma cells at the time of BMT. Recipients were injected subcutaneously with recombinant human IL-11 or control diluent twice daily, from 2 days before BMT to 7 days after BMT. TCD recipients all died from leukemia by day 23. All control- and IL-11-treated allogeneic animals effectively rejected their leukemia, but IL-11 also reduced GVHD-related mortality. Examination of the cellular mechanisms of GVL and GVHD in this system showed that IL-11 selectively inhibited CD4-mediated GVHD, while retaining both CD4- and CD8-mediated GVL. In addition, IL-11 treatment did not affect cytolytic effector functions of T cells after BMT either in vivo or in vitro. Studies with perforin-deficient donor T cells demonstrated that the GVL effect was perforin dependent. These data demonstrated that IL-11 can significantly reduce CD4-dependent GVHD without impairing cytolytic function or subsequent GVL activity of CD8(+) T cells. Brief treatment with IL-11 shortly after BMT may therefore represent a novel strategy for separating GVHD and GVL.     

LPS antagonism reduces graft-versus-host disease and preserves graft-versus-leukemia activity after experimental bone marrow transplantation.

Acute graft-versus-host disease (GVHD) and leukemic relapse remain the two major obstacles to successful outcomes after allogeneic bone marrow transplantation (BMT). Recent studies have demonstrated that the loss of gastrointestinal tract integrity, and specifically the translocation of LPS into the systemic circulation, is critical to the induction of cytokine dysregulation that contributes to GVHD. Using a mouse BMT model, we studied the effects of direct LPS antagonism on GVHD severity and graft-versus-leukemia (GVL) activity. Administration of B975, a synthetic lipid-A analogue from day 0 to day +6, reduced serum TNF-alpha levels, decreased intestinal histopathology, and resulted in significantly improved survival and a reduction in clinical GVHD, compared with control-treated animals. Importantly, B975 had no effect on donor T cell responses to host antigens in vivo or in vitro. When mice received lethal doses of P815 tumor cells at the time of BMT, administration of B975 did not impair GVL activity and resulted in significantly improved leukemia-free survival. These findings reveal a critical role for LPS in the early inflammatory events contributing to GVHD and suggest that a new class of pharmacologic agents, LPS antagonists, may help to prevent GVHD while preserving T cell responses to host antigens and GVL activity.     

PKCθ is required for alloreactivity and GVHD but not for immune responses toward leukemia and infection in mice

When used as therapy for hematopoietic malignancies, allogeneic BM transplantation (BMT) relies on the graft-versus-leukemia (GVL) effect to eradicate residual tumor cells through immunologic mechanisms. However, graft-versus-host disease (GVHD), which is initiated by alloreactive donor T cells that recognize mismatched major and/or minor histocompatibility antigens and cause severe damage to hematopoietic and epithelial tissues, is a potentially lethal complication of allogeneic BMT. To enhance the therapeutic potential of BMT, we sought to find therapeutic targets that could inhibit GVHD while preserving GVL and immune responses to infectious agents. We show here that T cell responses triggered in mice by either Listeria monocytogenes or administration of antigen and adjuvant were relatively well preserved in the absence of PKC isoform θ (PKCθ), a key regulator of TCR signaling. In contrast, PKCθ was required for alloreactivity and GVHD induction. Furthermore, absence of PKCθ raised the threshold for T cell activation, which selectively affected alloresponses. Most importantly, PKCθ-deficient T cells retained the ability to respond to virus infection and to induce GVL effect after BMT. These findings suggest PKCθ is a potentially unique therapeutic target required for GVHD induction but not for GVL or protective responses to infectious agents.     

Enhanced allostimulatory activity of host antigen-presenting cells in old mice intensifies acute graft-versus-host disease

Older bone marrow transplantation (BMT) recipients are at heightened risk for acute graft-versus-host disease (GVHD) after allogeneic BMT, but the causes of this association are poorly understood. Using well-characterized murine BMT models we have explored the mechanisms of increased GVHD in older mice. GVHD mortality, morbidity, and pathologic and biochemical indices were all worse in old recipients. Donor T cell responses were significantly increased in old recipients both in vivo and in vitro when stimulated by antigen-presenting cells (APCs) from old mice, which also secreted more TNF-alpha and IL-12 after LPS stimulation. In a B6 --> B6D2F1 model, CD4(+) donor T cells but not CD8(+) T cells mediated more severe GVHD in old mice. We confirmed the role of aged APCs in GVHD using B6D2F1 BM chimeras created with either old or young BM. Four months after chimera creation, allogeneic BMT from B6 donors caused significantly worse GVHD in old BM chimeras. APCs from these mice also stimulated greater responses from allogeneic cells in vitro. These data demonstrate a hitherto unsuspected mechanism of amplified donor T cell responses by aged allogeneic host APCs that increases acute GVHD in aged recipients in this BMT model.     

The cytokine-adhesion molecule cascade in ischemia/reperfusion injury of the rat kidney. Inhibition by a soluble P-selectin ligand.

Ischemia/reperfusion (I/R) injury associated with renal transplantation may influence both early graft function and late changes. The initial (</= 7 d) events of warm and in situ perfused cold ischemia of native kidneys in uninephrectomized rats were examined. mRNA expression of the early adhesion molecule, E-selectin, peaked within 6 h; PMNs infiltrated in parallel. T cells and macrophages entered the injured kidney by 2-5 d; the associated upregulation of MHC class II antigen expression suggested increased immunogenicity of the organ. Th1 products (IL-2, TNFalpha, IFNgamma) and macrophage-associated products (IL-1, IL-6, TGFbeta) remained highly expressed after 2 d. To examine directly the effects of selectins in I/R injury, a soluble P-selectin glycoprotein ligand (sPSGL) was used. Ischemic kidneys were perfused in situ with 5 microg of sPSGL in UW solution; 50 microg was administered intravenously 3 h after reperfusion. E-selectin mRNA remained at baseline, leukocytes did not infiltrate the injured organs throughout the 7-d period, and their associated products were markedly inhibited. Class II expression did not increase. No renal dysfunction secondary to I/R occurred. The early changes of I/R injury may be prevented by treatment with soluble P- and E-selectin ligand. This may reduce subsequent host inflammatory responses after transplantation.     

A novel mechanism of glucocorticoid-induced immune suppression: the inhibiton of T cell-mediated terminal maturation of a murine dendritic cell line.

Working with the murine epidermal-derived dendritic cell (DC) line XS52, we have observed previously that antigen-specific interaction with T cells stimulates their "terminal maturation" into fully professional DC. In this study we examined the impact of dexamethasone (DEX) on this T cell-induced event. When added to cocultures of XS52 DC and the KLH-specific Th1 clone HDK-1 in the presence of antigen, DEX at relatively low concentrations (10(-9)-10(-7) M) prevented substantially or completely each of the changes that typify terminal maturation, including (a) secretion of relatively large amounts of IL-1beta, IL-6, and TNFalpha; (b) loss of CD115 (colony-stimulating factor-1 receptor) expression and proliferative responsiveness to colony-stimulating factor-1; and (c) elevated expression of CD86 (B7-2). XS52 cells also underwent terminal maturation upon exposure to lipopolysaccharide alone, and DEX also inhibited effectively each of the same changes, indicating that DC can serve as the direct target of DEX. By contrast, DEX inhibited XS52 DC-stimulated IL-2 secretion by HDK-1 T cells, but not other changes that accompany T cell activation, including the secretion of IFNgamma and TNFalpha and the elevated expression of CD25, CD28, and CD44. These results reveal a new immunosuppressive mechanism of glucocorticoid action, that is, direct inhibition of T cell-mediated terminal maturation by DC.     

Disruption of antigen-induced inflammatory responses in CD40 ligand knockout mice.

The objective of this study was to investigate the contribution of the interaction between CD40 and its ligand (CD40L) to antigen-induced airways inflammatory responses. To this end, we used a model involving ovalbumin (OVA) sensitization followed by OVA aerosol challenge in CD40L knockout (KO) mice. OVA-specific IgE and IgG1 were detected in the serum of the sensitized control, but not in CD40L-KO mice. After antigen challenge, sensitized control mice developed airway inflammation that was primarily eosinophilic. This inflammatory response was dramatically reduced in CD40L-KO mice. In contrast, similar numbers of eosinophils were observed in both the bone marrow and the peripheral blood in the sensitized controls and mutant strains after antigen challenge. To investigate the mechanisms underlying these findings, we examined levels of the cytokines IL-5, IL-4, and TNFalpha in both bronchoalveolar lavage (BAL) and serum. Similar levels of IL-5 were detected in BAL and serum of control and CD40L-KO mice; however, negligible levels of IL-4 in BAL and serum and of TNFalpha in BAL were detected in CD40L-KO mice when compared with control mice. Furthermore, we demonstrated that endothelial cell expression of vascular cell adhesion molecule 1 in OVA-sensitized and -challenged CD40L-KO mice was, as detected by immunohistochemistry, markedly decreased compared with that observed in similarly treated control mice. In addition, we locally overexpressed IL-4 and TNFalpha by using an adenoviral (Ad)-mediated gene transfer approach. Intranasal administration of either Ad/TNFalpha or Ad/IL-4 into OVA-sensitized and -challenged CD40L-KO mice did not reconstitute airway eosinophilia. However, concurrent administration of Ad/TNFalpha and Ad/IL-4 upregulated endothelial expression of vascular cell adhesion molecule 1, and resulted in full reconstitution of the inflammatory response in the airways. Together, these findings demonstrate the importance of the CD40-CD40L costimulatory pathway in the full expression of the inflammatory response in the airways.     

Donor-derived interferon gamma is required for inhibition of acute graft-versus-host disease by interleukin 12.

We have demonstrated that a single injection of interleukin (IL)-12 on the day of bone marrow transplantation (BMT) inhibits acute graft-versus-host disease (GVHD) in mice. This effect of IL-12 can be diminished by anti-interferon (IFN)-gamma mAb. To determine the mechanism by which IFN-gamma affects IL-12-mediated GVHD protection, we have compared the effect of IL-12 on GVHD in C57BL/6 wild-type (WT) or IFN-gamma gene knockout (GKO) recipients of fully major histocompatibility complex plus minor antigen-mismatched allogeneic BMT from WT or GKO BALB/c mice. Lethal acute GVHD was readily induced in the absence of IFN-gamma. IL-12 inhibited GVHD mortality to a similar extent in WT and GKO recipients of WT allogeneic BMT. However, neither WT nor GKO recipients were protected by IL-12 from GVHD induced by GKO allogeneic BMT. Moreover, the effective inhibition of host-reactive donor T cell activation and expansion that is associated with IL-12-mediated GVHD protection was dependent on the ability of BALB/c donors to produce IFN-gamma. These results demonstrate that (a) acute GVHD can be induced in the absence of IFN-gamma, (b) host IFN-gamma does not play a critical role in IL-12-induced GVHD protection, and (c) the protective effect of IL-12 against GVHD is dependent on the ability of the donor to produce IFN-gamma.     

Role of interleukin-18 in acute graft-vs-host disease

Allogeneic hematopoietic cell transplantation (HCT) has emerged as an important therapeutic option for several malignant and nonmalignant diseases. In addition to delivering systemic chemoradiotherapy, the therapeutic potential of allogeneic HCT relies on the graft-vs-leukemia (GVL) effect, which eradicates residual malignant cells by way of immunologic mechanisms. Unfortunately, GVL effects are closely associated with graft-vs-host disease (GVHD), the major complication of allogeneic HCT. Separation of the toxicity of acute GVHD from the beneficial GVL effects remains a major challenge to expanding the utility of this effective treatment modality. The pathophysiology of acute GVHD involves dysregulation of inflammatory cytokine cascades and donor T-cell responses to host alloantigens. Interleukin 18 (IL-18) is a recently discovered cytokine with potent immunomodulatory effects. This unique cytokine has the capacity to induce Th1 or Th2 polarization, depending on the immunologic context. The level of IL-18 is increased in acute GVHD, but this cytokine's role in the pathophysiology of acute GVHD is complex. It reduces the severity of acute GVHD as a T helper 1 (Th1)-inducing cytokine when administered early after bone-marrow transplant to the lethally irradiated recipients. When administered to the donor, it can also reduce the severity of acute GVHD, as a T helper 2 (Th2)-inducing cytokine. Despite reducing the severity of acute GVHD, IL-18 preserves the GVL effect after bone-marrow transplant. Thus IL-18 has the remarkable capacity to modulate acute GVHD when administered either to the donor or the recipient through distinct mechanisms.     

Antibody to the ligand of CD40, gp39, blocks the occurrence of the acute and chronic forms of graft-vs-host disease.

Chronic and acute graft-versus-host disease (cGVHD and aGVHD) result from donor cells responding to host disparate MHC alleles. In cGVHD (H-2d-->H-2bd), heightened polyclonal immunoglobulin production is due to the interaction of donor allospecific helper T cells (Th) and the host B cells. In vivo administration of antibody to the ligand for CD40, gp39, blocked cGVHD-induced serum anti-DNA autoantibodies, IgE production, spontaneous immunoglobulin production in vitro, and associated splenomegaly. Antibody production remained inhibited for extended periods of time after termination of anti-gp39 administration. Antiallogeneic CTL responses induced in a GVHD were also prevented by the in vivo administration of anti-gp39 as was the associated splenomegaly. These data suggest that CD40-gp39 interactions are critical in GVHD and that CD40-gp39 may be a valuable ligand-receptor pair for targeting immunotherapeutic agents to control GVHD.     

Injurious ventilatory strategies increase cytokines and c-fos m-RNA expression in an isolated rat lung model.

We examined the effect of ventilation strategy on lung inflammatory mediators in the presence and absence of a preexisting inflammatory stimulus. 55 Sprague-Dawley rats were randomized to either intravenous saline or lipopolysaccharide (LPS). After 50 min of spontaneous respiration, the lungs were excised and randomized to 2 h of ventilation with one of four strategies: (a) control (C), tidal volume (Vt) = 7 cc/kg, positive end expiratory pressure (PEEP) = 3 cm H2O; (b) moderate volume, high PEEP (MVHP), Vt = 15 cc/kg; PEEP = 10 cm H2O; (c) moderate volume, zero PEEP (MVZP), Vt = 15 cc/kg, PEEP = 0; or (d) high volume, zero PEEP (HVZP), Vt = 40 cc/kg, PEEP = 0. Ventilation with zero PEEP (MVZP, HVZP) resulted in significant reductions in lung compliance. Lung lavage levels of TNFalpha, IL-1beta, IL-6, IL-10, MIP-2, and IFNgamma were measured by ELISA. Zero PEEP in combination with high volume ventilation (HVZP) had a synergistic effect on cytokine levels (e.g., 56-fold increase of TNFalpha versus controls). Identical end inspiratory lung distention with PEEP (MVHP) resulted in only a three-fold increase in TNFalpha, whereas MVZP produced a six-fold increase in lavage TNFalpha. Northern blot analysis revealed a similar pattern (C, MVHP < MVZP < HVZP) for induction of c-fos mRNA. These data support the concept that mechanical ventilation can have a significant influence on the inflammatory/anti-inflammatory milieu of the lung, and thus may play a role in initiating or propagating a local, and possibly systemic inflammatory response.     

Generation and maturation of dendritic cells for clinical application under serum-free conditions

Monocyte-derived dendritic cells (MoDCs) in clinical use for cancer immunotherapy are ideally generated in serum-free medium (SFM) with inclusion of a suitable maturation factor toward the end of the incubation period. Three good manfacturing practice (GMP) grade SFMs (AIM-V, X-VIVO 15, and X-VIVO 20) were compared with RPMI-1640, supplemented with 10% fetal bovine serum or 10% human serum. DCs generated for 7 days in SFM were less mature and secreted less interleukin (IL) 12p70 and IL-10 than DCs generated in 10% serum. DC yield was comparable in SFMs, and a greater proportion of cells was viable after maturation. Toll-like receptor (TLR) ligands were compared for their ability to induce cytokine secretion under serum-free conditions in the presence of interferon (IFN) gamma. With the exception of Poly I:C, TLR ligands stimulated high levels of IL-10 secretion. High levels of IL-12p70 were induced by two TLR4-mediated stimuli, lipopolysaccharide and Ribomunyl, a clinical-grade bacterial extract. When T-cell responses were compared in allogeneic mixed leukocyte reaction, DCs stimulated with Ribomunyl induced higher levels of IFNgamma than DCs stimulated with the cytokine cocktail: tumor necrosis factor-alpha, IL-1beta, IL-6, and prostaglandin E2. In the presence of IL-10 neutralizing antibodies, DC IL-12p70 production and T-cell IFNgamma were increased in vitro. Similarly, DCs stimulated with Ribomunyl, IFNgamma, and anti-IL-10 induced high levels of tetanus toxoid-specific T-cell proliferation and IFNgamma secretion. Thus, MoDCs generated in SFM efficiently stimulate T-cell IFNgamma production after maturation in the presence of a clinical-grade TLR4 agonist and IL-10 neutralization.     

基因工程化Treg细胞对小鼠异基因骨髓移植后急性移植物抗宿主病的作用

目的 探讨输注慢病毒载体介导的鼠基因工程调节性T淋巴细胞(Treg细胞)对小鼠异基因骨髓移植后移植物抗宿主病(GVHD)的影响.方法 利用慢病毒载体介导,将鼠Foxp3基因转导入BALB/c小鼠的CD4+CD25-T淋巴细胞,即为基因工程Treg细胞.建立小鼠异基因骨髓移植模型,在移植时联合输注基因工程Treg,通过受...     

Chlamydia LPS and MOMP seropositivity are associated with different cytokine profiles in patients with coronary heart disease

BACKGROUND: Persistent Chlamydia pneumoniae infection within atherosclerotic plaques are possible stimulators of inflammation in atherosclerosis. Why the microbe develops persistency in some individuals is unknown, but experimental studies in cell cultures and animals have demonstrated the levels of gamma interferon (IFNgamma) and interleukin 10 (IL-10) to be of crucial importance. DESIGN: We wanted to evaluate whether Chlamydia seropositivity in patients with coronary heart disease (CHD) (n = 193) was associated with elevated IFNgamma and IL-10. Two methods for detection of Chlamydia antibodies were included as well as analysis of tumour necrosis factor alpha (TNFalpha), soluble vascular cell adhesion molecule 1 (sVCAM-1) and soluble E-selectin for the evaluation of vascular inflammation. RESULTS: We found that patients with IgA antibodies towards Chlamydia lipopolysaccharide (LPS) had elevated levels of IFNgamma (P = 0.048), IL-10 (P = 0.029), TNFalpha (P = 0.009) and sE-selectin (P = 0.045), while Chlamydia LPS IgG seropositivity predicted elevated levels of IL-10 (P = 0.013). Patients with IgA antibodies towards C. pneumoniae major outer membrane protein (MOMP) without simultaneous LPS IgA seropositivity had lower levels of IFNgamma and sVCAM-1 when compared to patients with Chlamydia LPS IgA alone (P = 0.005 for IFNgamma, P = 0.016 for VCAM-1) and patients with combined Chlamydia MOMP and LPS IgA seropositivity (P = 0.046 and P = 0.013, respectively). CONCLUSIONS: In summary, we demonstrated an association between Chlamydia LPS IgA seropositivity and elevated levels of IFNgamma, IL-10, TNFalpha, sVCAM-1 and sE-selectin in CHD patients that might indicate persistent Chlamydia infection and a proinflammatory state. On the other hand, C. pneumoniae MOMP antibodies were not associated with elevated inflammatory markers and might merely be indicative of past infection, possibly with successful microbe clearance.     

霉酚酸酯联合CsA和短程MTX预防非亲缘异基因骨髓移植的急性GVHD

目的　评价霉酚酸酯（MMF）联合环孢菌素A（CsA）和短程甲氨蝶呤(MTX)预防非亲缘异基因骨髓移植中急性移植物抗宿主病（aGVHD）的有效性和安全性。方法　12例患者非亲缘异基因骨髓移植当天始联合应用MMF（骁悉胶囊）1.0 g/d,CsA 3 mg     

Circadian rhythm of cytokine secretion following thermal injury in mice: implications for burn and trauma research

Although there are many reports of circadian variation in hormone secretion, there are only a few reports on the relationship between circadian rhythm and cytokine production. The aim of the present studies was to investigate whether there is a circadian effect on cytokine production of splenic lymphocytes and adherent splenocytes in mice after burn or sham injury. We selected day 7 after injury for our determinations because we have previously shown day 7 is the time of maximal suppression of T cell IL-2 and IFNgamma production and maximal increase in adherent cell proinflammatory cytokine secretion in this model. IL-2 and TNFalpha were chosen as reference cytokines since the former is known to be produced by T cells and the latter by adherent cells of the innate immune system. The results showed that seven days after sham or thermal injury both T cell IL-2 and adherent cell TNFalpha production were altered by time of injury or time of cell harvest. IL-2 secretion was significantly decreased in burn compared to sham animals when splenocytes were harvested in the morning; the decrease was non-significant when splenocytes were harvested in the afternoon. TNFalpha secretion was significantly increased in burn vs. sham adherent cells only when injury took place in the morning. The observed circadian variations in cytokine production could have a significant effect on cytokine levels measured in clinical and animal studies of injury and may explain some of the reported discrepancies among these studies.     

IL-6 is an antiinflammatory cytokine required for controlling local or systemic acute inflammatory responses.

IL-6 is induced often together with the proinflammatory cytokines TNFalpha and IL-1 in many alarm conditions, and circulating IL-6 plays an important role in the induction of acute phase reactions. However, whether this endogenous IL-6 plays any additional pro- or antiinflammatory roles in local or systemic responses remains unclear. In this study, the role of IL-6 in acute inflammatory responses was investigated in animal models of endotoxic lung or endotoxemia by using IL-6+/+ and IL-6-/- mice. Aerosol exposure of endotoxin induced increased IL-6 and proinflammatory cytokines TNFalpha and MIP-2 and a neutrophilic response in the lung of IL-6+/+ mice. However, the levels of TNFalpha and MIP-2 and neutrophilia were significantly higher in the lung of IL-6-/- mice. The rate of neutrophil apoptosis in these mice was similar to that in IL-6+/+ mice. A low constitutive level of antiinflammatory cytokine IL-10 was not enhanced by endotoxin and remained similar in the lung in both IL-6+/+ and IL-6-/- mice. Systemically, intraperitoneal delivery of endotoxin resulted in much more pronounced circulating levels of TNFalpha, MIP-2, GM-CSF, and IFNgamma in IL-6-/- mice than in IL-6+/+ mice, and administration of recombinant IL-6 to IL-6-/- mice abolished these differences. In contrast, circulating IL-10 levels were induced to a similar degree in both IL-6+/+ and IL-6-/- mice. Thus, our studies reveal that endogenous IL-6 plays a crucial antiinflammatory role in both local and systemic acute inflammatory responses by controlling the level of proinflammatory, but not antiinflammatory, cytokines, and that these antiinflammatory activities by IL-6 cannot be compensated for by IL-10 or other IL-6 family members.