Giant-cell arteritis commonly relapses when glucocorticoids are tapered, and the prolonged use of glucocorticoids is associated with side effects. The effect of the interleukin-6 receptor alpha inhibitor tocilizumab on the rates of relapse during glucocorticoid tapering was studied in patients with giant-cell arteritis.

In this 1-year trial, we randomly assigned 251 patients, in a 2:1:1:1 ratio, to receive subcutaneous tocilizumab (at a dose of 162 mg) weekly or every other week, combined with a 26-week prednisone taper, or placebo combined with a prednisone taper over a period of either 26 weeks or 52 weeks. The primary outcome was the rate of sustained glucocorticoid-free remission at week 52 in each tocilizumab group as compared with the rate in the placebo group that underwent the 26-week prednisone taper. The key secondary outcome was the rate of remission in each tocilizumab group as compared with the placebo group that underwent the 52-week prednisone taper. Dosing of prednisone and safety were also assessed.

Sustained remission at week 52 occurred in 56% of the patients treated with tocilizumab weekly and in 53% of those treated with tocilizumab every other week, as compared with 14% of those in the placebo group that underwent the 26-week prednisone taper and 18% of those in the placebo group that underwent the 52-week prednisone taper (P<0.001 for the comparisons of either active treatment with placebo). The cumulative median prednisone dose over the 52-week period was 1862 mg in each tocilizumab group, as compared with 3296 mg in the placebo group that underwent the 26-week taper (P<0.001 for both comparisons) and 3818 mg in the placebo group that underwent the 52-week taper (P<0.001 for both comparisons). Serious adverse events occurred in 15% of the patients in the group that received tocilizumab weekly, 14% of those in the group that received tocilizumab every other week, 22% of those in the placebo group that underwent the 26-week taper, and 25% of those in the placebo group that underwent the 52-week taper. Anterior ischemic optic neuropathy developed in one patient in the group that received tocilizumab every other week.

Tocilizumab, received weekly or every other week, combined with a 26-week prednisone taper was superior to either 26-week or 52-week prednisone tapering plus placebo with regard to sustained glucocorticoid-free remission in patients with giant-cell arteritis. Longer follow-up is necessary to determine the durability of remission and safety of tocilizumab. (Funded by F. Hoffmann-La Roche; ClinicalTrials.gov number, NCT01791153 .).

Cytokines play an important role in controlling the homoeostasis of the immune system. Infection with HIV results in dysregulation of the cytokine profile in vivo and in vitro. During the course of HIV-1 infection secretion of T-helper type 1 (Th1) cytokines, such as <em>interleukin</em> (IL)-2, and antiviral interferon (IFN)-gamma, is generally decreased, whereas production of T helper type 2 (Th2) cytokines, IL-4, IL-10, proinflammatory cytokines (IL-1, IL-6, IL-8) and tumour necrosis factor (TNF)-alpha, is increased. Such abnormal cytokine production contributes to the pathogenesis of the disease by impairing cell-mediated immunity. A number of cytokines have been shown to modulate in vitro HIV-1 infection and replication in both CD4 T lymphocytes and cells of macrophage lineage. HIV-inductive cytokines include: TNF-alpha, TNF-beta, IL-1 and IL-6, which stimulate HIV-1 replication in T cells and monocyte-derived macrophages (MDM), IL-2, IL-7 and IL-<em>15</em>, which upregulate HIV-1 in T cells, and macrophage-colony stimulating factor, which stimulates HIV-1 in MDM. HIV-suppressive cytokines include: IFN-alpha, IFN-beta and IL-16, which inhibit HIV-1 replication in T cells and MDM, and IL-10 and IL-13, which inhibit HIV-1 in MDM. Bifunctional cytokines such as IFN-gamma, IL-4 and granulocyte-macrophage colony-stimulating factor have been shown to have both inhibitory and stimulatory effects on HIV-1. The beta-chemokines, macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta and RANTES are important inhibitors of macrophage-tropic strains of HIV-1, whereas the alpha-chemokine stromal-derived factor-1 suppresses infection of T-tropic strains of HIV-1. This review outlines the interactions between cytokines and HIV-1, and presents clinical applications of cytokine therapy combined with highly active antiretroviral therapy or vaccines.

METHODS

Herniated lumbar disc specimens were obtained from patients undergoing surgical discectomy for persistent radiculopathy and cultured in vitro to determine whether various biochemical agents were being produced.

OBJECTIVE

Our hypothesis is that biochemical mediators of inflammation and tissue degradation play a role in intervertebral disc degeneration and in the pathophysiology of radiculopathy.

BACKGROUND

Low back pain with or without radiculopathy is a significant clinical problem, but the etiology of low back pain and the exact pathophysiology of radiculopathy remain elusive. The biochemical events that occur with intervertebral disc degeneration and, in particular, the role of biochemical mediators of inflammation and tissue degradation have received sparse attention in the literature. There is some preliminary evidence that inflammatory mediators may have an important role in the pathophysiology of radiculopathy.

METHODS

Eighteen herniated lumbar discs were obtained from <em>15</em> patients undergoing disc surgery. The specimens were cultured and incubated for 72 hours, and the media were collected subsequently for biochemical analysis. Biochemical assays for matrix metalloproteinases, nitric oxide, prostaglandin E2, and a variety of cytokines were performed. As a control group, eight lumbar disc specimens were obtained from four patients undergoing anterior surgery for scoliosis and traumatic burst fractures, and similar biochemical analyses were performed.

RESULTS

The culture media from the herniated lumbar discs showed increased levels of matrix metalloproteinase activity compared with the control discs. Similarly, the levels of nitric oxide, prostaglandin E2, and interleukin-6 were significantly higher in the herniated discs compared with the control discs. Interleukin 1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, interleukin-1 receptor antagonist protein, and substance P were not detected in the culture media of either the herniated or control discs.

CONCLUSIONS

Herniated lumbar discs were making spontaneously increased amounts of matrix metalloproteinases, nitric oxide, prostaglandin E2, and interleukin-6. These products may be involved intimately in the biochemistry of disc degeneration and the pathophysiology of radiculopathy. Their exact roles certainly need further investigation, but their mere presence implicates biochemical processes in intervertebral disc degeneration.

BACKGROUND

Gene-based vaccine delivery is an important strategy in the development of a preventive vaccine for acquired immunodeficiency syndrome (AIDS). Vaccine Research Center (VRC) 004 is the first phase 1 dose-escalation study of a multiclade HIV-1 DNA vaccine.

METHODS

VRC-HIVDNA009-00-VP is a 4-plasmid mixture encoding subtype B Gag-Pol-Nef fusion protein and modified envelope (Env) constructs from subtypes A, B, and C. Fifty healthy, uninfected adults were randomized to receive either placebo (n=10) or study vaccine at 2 mg (n=5), 4 mg (n=20), or 8 mg (n=<em>15</em>) by needle-free intramuscular injection. Humoral responses (measured by enzyme-linked immunosorbant assay, Western blotting, and neutralization assay) and T cell responses (measured by enzyme-linked immunospot assay and intracellular cytokine staining after stimulation with antigen-specific peptide pools) were measured.

RESULTS

The vaccine was well tolerated and induced cellular and humoral responses. The maximal CD4(+) and CD8(+) T cell responses occurred after 3 injections and were in response to Env peptide pools. The pattern of cytokine expression by vaccine-induced HIV-specific T cells evolved over time, with a diminished frequency of interferon- gamma -producing T cells and an increased frequency of interleukin-2-producing T cells at 1 year.

CONCLUSIONS

DNA vaccination induced antibody to and T cell responses against 3 major HIV-1 subtypes and will be further evaluated as a potential component of a preventive AIDS vaccine regimen.

While the specificity and development of natural killer (NK) cells have been intensely studied, little is known about homeostasis of the mature NK population. Here we show that mouse NK cells undergo homeostatic proliferation when transferred into NK-deficient Rag-/- gammaC-/- hosts. Normal NK functional activity is maintained during this process, although there are some changes in NK phenotype. Using cell sorting, we demonstrate that mature (Mac-1hi) NK cells undergo homeostatic proliferation in an NK-deficient environment, yet immature (Mac-1lo) NK cells also proliferate in such hosts. We find that mature NK cells survive but do not proliferate in hosts which possess an endogenous NK pool. However, we go on to show that mature NK survival is critically dependent on <em>interleukin</em> (IL)-<em>15</em>. Surprisingly, NK survival is also compromised after transfer of cells into IL-<em>15</em>Ralpha-/- mice, implying that IL-<em>15</em> responsiveness by bystander cells is critical for NK maintenance. These data imply that, similar to T cells, homeostasis of the NK pool is much more dynamic than previously appreciated and this may be relevant to manipulation of NK cells for therapeutic purposes.

BACKGROUND

Neutrophil-induced cardiomyocyte injury requires the expression of myocyte intercellular adhesion molecule (ICAM)-1 and ICAM-1-CD11b/CD18 adhesion. We have previously demonstrated interleukin (IL)-6 activity in postischemic cardiac lymph; IL-6 is the primary stimulus for myocyte ICAM- 1 induction. Furthermore, we found that induction of IL-6 mRNA occurred very early on reperfusion of the infarcted myocardium. We hypothesized that the release of a preformed upstream cytokine induced IL-6 in leukocytes infiltrating on reperfusion.

RESULTS

Constitutive expression of TNF-alpha and not IL-1beta was demonstrated in the normal canine myocardium and was localized predominantly in cardiac mast cells. Mast cell degranulation in the ischemic myocardium was documented by demonstration of a rapid release of histamine and TNF-alpha in the cardiac lymph after myocardial ischemia. Histochemical studies with FITC-labeled avidin demonstrated degranulating mast cells only in ischemic samples of canine myocardium. Immunohistochemistry suggested that degranulating mast cells were the primary source of TNF-alpha in the ischemic myocardium. In situ hybridization studies of reperfused myocardium localized IL-6 mRNA in infiltrating mononuclear cells and in mononuclear cells appearing in the postischemic cardiac lymph within the first 15 minutes of reperfusion. Furthermore, isolated canine mononuclear cells incubated with postischemic cardiac lymph demonstrated significant induction of IL-6 mRNA, which was partially blocked with a neutralizing antibody to TNF-alpha.

CONCLUSIONS

Cardiac mast cells degranulate after myocardial ischemia, releasing preformed mediators, such as histamine and TNF-alpha. We suggest that mast cell-derived TNF-alpha may be a crucial factor in upregulating IL-6 in infiltrating leukocytes and initiating the cytokine cascade responsible for myocyte ICAM-1 induction and subsequent neutrophil-induced injury.

Certain cytokines that are produced in liver may act as growth factors to facilitate wound healing and, hence, may influence liver regeneration. However, this hypothesis has not been directly tested. To determine whether the cytokine response evoked by partial hepatectomy (PH) modulates the process of liver regeneration, adult male rats were injected intraperitoneally with either goat polyclonal antibodies to rat tumor necrosis factor (TNF; <em>15</em> micrograms/g body wt) or an equal amount of goat anti-rat immunoglobulin G 1 h before PH. Animals were killed at 12, 24, 48, or 72 h post-PH, 1 h after injection with [3H]thymidine. Serum TNF levels were measured with the L929 cytotoxicity assay, titers of antibody to TNF were determined by enzyme-linked immunoabsorbent assay, and <em>interleukin</em>-6 (IL-6) concentrations were measured by B9 cell bioassay. Liver regeneration was assessed by [3H]thymidine incorporation into hepatic DNA and by immunohistochemical evidence of proliferating cell nuclear antigen (PCNA) expression. Antibodies to TNF were detected in treated rats but not in controls. Titers were highest at 12 h and progressively fell. Although TNF was never detected in serum, treatment with anti-TNF pre-PH significantly inhibited increases in serum IL-6 concentration post-PH. Anti-TNF pretreatment also inhibited [3H]thymidine incorporation into DNA, as well as expression of PCNA by both hepatocytes and liver nonparenchymal cells. These data indicate that TNF positively modulates liver regeneration after PH.

<em>Interleukin</em> <em>15</em> (IL-<em>15</em>) promotes the survival of natural killer (NK) cells by preventing apoptosis through mechanisms unknown at present. Here we identify Bim, Noxa and Mcl-1 as key regulators of IL-<em>15</em>-dependent survival of NK cells. IL-<em>15</em> suppressed apoptosis by limiting Bim expression through the kinases Erk1 and Erk2 and mechanisms dependent on the transcription factor Foxo3a, while promoting expression of Mcl-1, which was necessary and sufficient for the survival of NK cells. Withdrawal of IL-<em>15</em> led to upregulation of Bim and, accordingly, both Bim-deficient and Foxo3a-/- NK cells were resistant to cytokine deprivation. Finally, IL-<em>15</em>-mediated inactivation of Foxo3a and cell survival were dependent on phosphotidylinositol-3-OH kinase. Thus, IL-<em>15</em> regulates the survival of NK cells at multiple steps, with Bim and Noxa being key antagonists of Mcl-1, the critical survivor factor in this process.

Transgenic (TG) mice expressing a high copy number of <em>interleukin</em> (IL)-7 cDNA under the control of the major histocomaptability complex (MHC) class II promoter display a 10-20-fold increase in total T cell numbers. Here, we show that the increase in T cell numbers in IL-7 TG mice is most apparent at the level of memory phenotype CD44hi CD122hi CD8+ cells. Based on studies with T cell receptor (TCR) TG mice crossed to IL-7 TG mice, increased levels of IL-7 may provide costimulation for TCR recognition of self-MHC ligands and thus cause naive CD8+ cells to proliferate and differentiate into memory phenotype cells. In addition, a marked increase in CD44hi CD122hi CD8+ cells was found in IL-7 TG IL-<em>15</em>(-) mice. Since these cell are rare in normal IL-<em>15</em>(-) mice, the dependency of memory phenotype CD8+ cells on IL-<em>15</em> can be overcome by overexpression of IL-7.

BACKGROUND

ST2 is an interleukin (IL)-1 receptor family member with membrane-bound (ST2L) and soluble (sST2) isoforms, and sST2 is a biomarker for poor outcome in patients with myocardial infarction (MI). IL-33, the recently discovered ligand for ST2, activates nuclear factor kappaB and thus may regulate apoptotic cell death. We tested the hypothesis that IL-33 is cardioprotective after MI through ST2 signaling.

RESULTS

IL-33 protected cultured cardiomyocytes from hypoxia-induced apoptosis, and this cardioprotection was partially inhibited by sST2. IL-33 induced expression of the antiapoptotic factors XIAP, cIAP1, and survivin. To define the cardioprotective role of IL-33 in vivo, we performed a blinded and randomized study of ischemia/reperfusion in rats. IL-33 reduced cardiomyocyte apoptosis, suppressed caspase-3 activity, and increased expression of IAP family member proteins. IL-33 decreased both infarct and fibrosis volumes at 15 days; furthermore, both echocardiographic and hemodynamic studies revealed that IL-33 improved ventricular function. To determine whether cardioprotection by IL-33 is mediated through ST2 signaling, a randomized and blinded study of ST2(-/-) versus wild-type littermate mice was performed in 98 mice subjected to MI. At 4 weeks after MI, IL-33 reduced ventricular dilation and improved contractile function in wild-type mice but not in ST2(-/-) mice. Finally, IL-33 improved survival after MI in wild-type but not in ST2(-/-) mice.

CONCLUSIONS

IL-33 prevents cardiomyocyte apoptosis and improves cardiac function and survival after MI through ST2 signaling.

OBJECTIVE

The objective of this phase III study was to determine the efficacy, safety, and pharmacokinetics of denileukin diftitox (DAB389IL-2, Ontak [Ligand Pharmaceuticals Inc, San Diego, CA]) in patients with stage Ib to IVa cutaneous T-cell lymphoma (CTCL) who have previously received other therapeutic interventions.

METHODS

Patients with biopsy-proven CTCL that expressed CD25 on>> or = 20% of lymphocytes were assigned to one of two dose levels (9 or 18 microg/kg/d) of denileukin diftitox administered 5 consecutive days every 3 weeks for up to 8 cycles. Patients were monitored for toxicity and clinical efficacy, the latter assessed by changes in disease burden and quality of life measurements. Antibody levels of antidenileukin diftitox and anti-interleukin-2 and serum concentrations of denileukin diftitox were also measured.

RESULTS

Overall, 30% of the 71 patients with CTCL treated with denileukin diftitox had an objective response (20% partial response; 10% complete response). The response rate and duration of response based on the time of the first dose of study drug for all responders (median of 6.9 months with a range of 2.7 to more than 46.1 months) were not statistically different between the two doses. Adverse events consisted of flu-like symptoms (fever/chills, nausea/vomiting, and myalgias/arthralgias), acute infusion-related events (hypotension, dyspnea, chest pain, and back pain), and a vascular leak syndrome (hypotension, hypoalbuminemia, edema). In addition, 61% of the patients experienced transient elevations of hepatic transaminase levels with 17% grade 3 or 4. Hypoalbuminemia occurred in 79%, including 15% with grade 3 or 4 changes. Tolerability at 9 and 18 microg/kg/d was similar, and there was no evidence of cumulative toxicity.

CONCLUSIONS

Denileukin diftitox has been shown to be a useful and important agent in the treatment of patients whose CTCL is persistent or recurrent despite other therapeutic interventions.

Caspases belong to a family of highly conserved aspartate-specific cysteine proteases and are members of the <em>interleukin</em>-1beta-converting enzyme family, present in multicellular organisms. The caspase gene family consists of <em>15</em> mammalian members that are grouped into two major sub-families, namely inflammatory caspases and apoptotic caspases. The apoptotic caspases are further subdivided into two sub-groups, initiator caspases and executioner caspases. The caspases form a caspase-cascade system that plays the central role in the induction, transduction and amplification of intracellular apoptotic signals for cell fate determination, regulation of immunity, and cellular proliferation and differentiation. The substrates of apoptotic caspases have been associated with cellular dismantling, while inflammatory caspases mediate the proteolytic activation of inflammatory cytokines. The activation of this delicate caspase-cascade system and its functions are regulated by a variety of regulatory molecules, such as the inhibitor of apoptosis protein (IAP), FLICE, calpain, and Ca(2+). Based on the available literature we have reviewed and discussed the members of the caspase family, caspase-cascade system, caspase-regulating molecules and their apoptotic and non-apoptotic functions in cellular life and death. Also recent progress in the molecular structure and physiological role of non-mammalian caspases such as paracaspases, metacaspases and caspase-like-protease family members are included in relation to that of mammalian species.

Intact human epidermis resists invasion by pathogenic microbes but the biochemical basis of its resistance is not well understood. Recently, an antimicrobial peptide, human beta-defensin-2, was discovered in inflamed epidermis. We used a recombinant baculovirus/insect cell system to produce human beta-defensin-2 and confirmed that at micromolar concentrations it has a broad spectrum of antimicrobial activity, with the striking exception of Staphylococcus aureus. Immunostaining with a polyclonal antibody to human beta-defensin-2 showed that the expression of human beta-defensin-2 peptide by human keratinocytes required differentiation of the cells (either by increased calcium concentration or by growth and maturation in epidermal organotypic culture) as well as a cytokine or bacterial stimulus. <em>Interleukin</em>-1alpha, <em>interleukin</em>-1beta, or live Pseudomonas aeruginosa proved to be the most effective stimuli whereas other bacteria and cytokines had little or no ability to induce human beta-defensin-2 synthesis. In <em>interleukin</em>-1alpha-stimulated epidermal cultures, human beta-defensin-2 first appeared in the cytoplasm in differentiated suprabasal layers of skin, next in a more peripheral web-like distribution in the upper layers of the epidermis, and then over a few days migrated to the stratum corneum. By semiquantitative Western blot analysis of epidermal lysates, the average concentration of human beta-defensin-2 in stimulated organotypic epidermal culture reached <em>15</em>--70 microg per gram of tissue, i.e., 3.5-16 microM, well within the range required for antimicrobial activity. Because of the restricted pattern of human beta-defensin-2 distribution in the epidermis, its local concentration must be much higher. Defensins and other antimicrobial peptides of inflamed epidermis are likely to play an important antimicrobial role in host defense against cutaneous pathogens.

Using animal models or healthy volunteers, injection of lipopolysaccharide (LPS) or bacteria causes activation of macrophages with excessive synthesis and secretion of proinflammatory cytokines. Although these models mimic the effects of LPS in the host, they may represent more of an experimental expression of endotoxemia than natural infection itself. Therefore, as an ex vivo model of sepsis, whole blood from <em>15</em> patients with severe sepsis and 20 control patients without infection was stimulated with LPS to study the kinetics of mRNA expression and release of proinflammatory cytokines, tumor necrosis factor (TNF)-alpha, <em>interleukin</em> (IL)-1 beta, and IL-6. Stimulation of whole blood with 1 microgram/mL LPS resulted in a maximum increase of cytokine secretion in the control group, while a marked (P < .01) depression of TNF-alpha, IL-1 beta, and IL-6 release was observed in the septic group, which persisted up to 10 days after study enrollment. While IL-1 beta mRNA expression was similar in peripheral blood mononuclear cells (PBMCs) harvested from LPS-stimulated whole blood in septic and control patients, the half-life and consequently the expression of TNF-alpha and IL-6 mRNA were strongly reduced in the septic group. These data indicate a downregulatory mechanism of cytokine release in whole blood from patients with severe sepsis that occurs on different levels. Although excessive secretion of proinflammatory cytokines has been considered deleterious for the host, the reduced capacity of PBMCs in whole blood from septic patients to synthesize and secrete proinflammatory cytokines to an inflammatory stimulus may result in immunodeficiency, because these cytokines in low concentrations are involved in the upregulation of essential cellular and humoral immune functions.

OBJECTIVE

Innate immune responses to oxidized low-density lipoprotein LDL (LDL) regulate the development of atherosclerosis. We demonstrated previously that an early form of oxidized LDL, minimally modified LDL (mmLDL), triggers cytoskeletal rearrangements in macrophages via CD14 and Toll-like receptor 4 (TLR4)/MD-2. Because lipopolysaccharide (LPS) activation of TLR4 leads to proinflammatory gene expression, in this study, we asked whether mmLDL also induced proinflammatory signaling.

RESULTS

We studied cytokine secretion and signaling in J774 and primary peritoneal macrophages stimulated with mmLDL, which was prepared by incubating LDL with cells expressing human <em>15</em>-lipoxygenase. MmLDL stimulated robust phosphoinositide 3-kinase (PI3K) activation, and Akt and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, which exceeded that induced by LPS. On the other hand, although mmLDL induced nuclear factor kappaB (NF-kappaB) p65 translocation to the nucleus, there was no detectable NF-kappaB activation. However, mmLDL induced early mRNA and protein expression of the cytokines MIP-2, MCP-1, tumor necrosis factor-alpha, and <em>interleukin</em>-6. Chemokine MIP-2 but not MCP-1 secretion depended on TLR4/MyD88, ERK1/2, and PI3K signaling. In turn, TLR4 regulated phosphorylation of ERK1/2 but not of Akt, suggesting that mmLDL-induced PI3K activation is TLR4 independent.

CONCLUSIONS

In macrophages, mmLDL activates TLR4-dependent and -independent signaling pathways, resulting in secretion of proinflammatory cytokines. These results provide new insights into the inflammatory origins of atherosclerosis.

OBJECTIVE

Immunotherapy is a promising antitumor strategy, which can be successfully combined with current anticancer treatments, as suggested by recent studies showing the paradoxical chemotherapy-induced enhancement of the immune response. The purpose of the present work is to dissect the biological events induced by chemotherapy that cooperate with immunotherapy in the success of the combined treatment against cancer. In particular, we focused on the following: (a) cyclophosphamide-induced modulation of several cytokines, (b) homeostatic proliferation of adoptively transferred lymphocytes, and (c) homing of transferred lymphocytes to secondary lymphoid organs and tumor mass.

METHODS

Here, we used the adoptive transfer of tumor-immune cells after cyclophosphamide treatment of tumor-bearing mice as a model to elucidate the mechanisms by which cyclophosphamide can render the immune lymphocytes competent to induce tumor rejection.

RESULTS

The transfer of antitumor immunity was found to be dependent on CD4(+) T cells and on the cooperation of adoptively transferred cells with the host immune system. Of note, tumor-immune lymphocytes migrated specifically to the tumor only in mice pretreated with cyclophosphamide. Cyclophosphamide treatment also promoted homeostatic proliferation/activation of transferred B and T lymphocytes. Optimal therapeutic responses to the transfer of immune cells were associated with the cyclophosphamide-mediated induction of a "cytokine storm" [including granulocyte macrophage colony-stimulating factor, <em>interleukin</em> (IL)-1beta, IL-7, IL-<em>15</em>, IL-2, IL-21, and IFN-gamma], occurring during the "rebound phase" after drug-induced lymphodepletion.

CONCLUSIONS

The ensemble of these data provides a new rationale for combining immunotherapy and chemotherapy to induce an effective antitumor response in cancer patients.

Germ-free <em>interleukin</em>-10 knockout (IL-10 KO) mice developed inflammatory bowel disease (IBD) after they were colonized with a pure culture of Enterococcus faecalis. E. faecalis not only induced IBD (primarily in colon and rectum) but rectal dysplasia and adenocarcinoma was also found in the IL-10 KO mice. Conventional (complex-intestinal flora) IL-10 KO mice developed IBD within 10 to <em>15</em> weeks of age and showed more pathology in the cecum (typhlitis) than we observed with E. faecalis-induced IBD in gnotobiotic IL-10 KO mice. Conversely, neither germ-free IL-10 mice nor IL-10 KO mice colonized as adults, with a pure culture of Candida albicans, Escherichia coli, Lactobacillus casei, L. reuteri, L. acidophilus, a Bifidobacterium sp., Lactococcus lactis, or a Bacillus sp. developed IBD during the 25- to 30-week study. E. faecalis is a common intestinal microbe of man and animals that can trigger IBD, dysplasia, and carcinoma in a genetically susceptible murine host.

OBJECTIVE

The goal was to develop multivariate logistic regression models for the outcome of bronchopulmonary dysplasia and/or death at postmenstrual age of 36 weeks by using clinical and cytokine data from the first 28 days.

METHODS

For 1067 extremely low birth weight infants in the Neonatal Research Network of the National Institute of Child Health and Human Development, levels of 25 cytokines were measured in blood collected within 4 hours after birth and on days 3, 7, 14, and 21. Stepwise regression analyses using peak levels of the 25 cytokines and <em>15</em> clinical variables identified variables associated with bronchopulmonary dysplasia/death. Multivariate logistic regression analysis was performed for bronchopulmonary dysplasia/death by using variables selected through stepwise regression. Similar analyses were performed by using average cytokine values from days 0 to 21, days 0 to 3, and days 14 to 21.

RESULTS

Of 1062 infants with available data, 606 infants developed bronchopulmonary dysplasia or died. On the basis of results from all models combined, bronchopulmonary dysplasia/death was associated with higher concentrations of interleukin 1beta, 6, 8, and 10 and interferon gamma and lower concentrations of interleukin 17, regulated on activation, normal T cell expressed and secreted, and tumor necrosis factor beta. Compared with models with only clinical variables, the addition of cytokine data improved predictive ability by a statistically significant but clinically modest magnitude.

CONCLUSIONS

The overall cytokine pattern suggests that bronchopulmonary dysplasia/death may be associated with impairment in the transition from the innate immune response mediated by neutrophils to the adaptive immune response mediated by T lymphocytes.

A continuous cell line (YT cells) with inducible receptor for T cell growth factor (TCGF)/<em>interleukin</em> 2 (IL 2) was established from a <em>15</em>-yr-old boy with acute lymphoblastic lymphoma and thymoma. YT cells were tetraploid, having 4q+ chromosomal markers, and proliferated continuously in vitro without conditioned medium (CM) or IL 2. They were weakly positive for OKT9, OKT11, and Tac antigen (Ag), a determinant closely associated with the receptor for IL 2 (IL 2-R), and were negative for OKT1, OKT3, OKT4, and OKT8 Ag. YT cells also expressed HNK-1 Ag and Fc receptors for IgG, which are expressed on natural killer (NK) cells. They retained a killing activity against human cell lines, including K562 (myeloid), T, and B cell lines. Unlike Tac Ag/IL 2-R(+) cell lines derived from adult T cell leukemia (ATL), YT cells were negative for HTLV, as proved by Southern blotting with cDNA for viral DNA. The expression of Tac Ag was markedly enhanced in 18 hr, when YT cells were incubated with CM from PHA-stimulated peripheral blood leukocytes (PBL) or spleen cells, as determined by immunofluorescence by using flow cytometry and binding assay with 125I-anti-Tac antibody (Ab). The binding study with 125I-labeled recombinant IL 2 showed 3.2 X 10(4) IL 2 receptor sites on YT cells precultured with CM. PHA-P and Con A neither agglutinate nor enhance the expression of IL 2-R/Tac antigen on these non-T cell line cells. Furthermore, neither recombinant IL 2 nor gamma-interferon could induce IL 2-R on YT cells, suggesting the presence of a unique IL 2-R inducing factor in PBL or spleen CM. Unlike Tac Ag on HTLV(+), ATL-derived cell lines (Hut-102, MT-1, ATL-2), the expression of Tac Ag on YT cells was down-regulated by anti-Tac Ab. The induction of Tac Ag/IL 2-R on YT cells seemed specific, because the enhancement of Tac Ag expression was not associated with that of Ia Ag and T9/transferrin receptor.

Many antigen-specific T cells die after exposure to antigen in animals. These cells also die if they are isolated from animals shortly after activation and cultured. Various cytokines were tested for their ability to interfere with this in vitro death. Surprisingly, tumor necrosis factor alpha and other inflammatory cytokines did not prevent the in vitro death of activated T cells, even though these cytokines do prevent activated T cell death in animals. Therefore, the inflammatory cytokines probably act on T cells in vivo via an intermediary factor. Four cytokines, <em>interleukin</em> (IL)-2, IL-4, IL-7, and IL-<em>15</em>, did prevent activated T cell death in vitro, with IL-4 and IL-<em>15</em> more effective than IL-2 or IL-7. These cytokines share a component of their receptors, the common gamma chain, gammac. Therefore, their collective ability to protect activated T cells from death may be mediated by signals involving gammac. To assess their activity in vivo, two of the cytokines, IL-2 and IL-4, were expressed in animals at local sites of superantigen responses. Both cytokines increased the numbers of T cells found at the local sites 14 days later. <em>Interleukin</em> 4 was more effective than IL-2, even though IL-2 stimulates T cell proliferation better than IL-4. This result suggested that IL-4 and related cytokines can promote T cell survival in vivo as well as in vitro. The ability of these cytokines to prevent the death of activated T cells may be important at certain stages of immune responses in animals.

BACKGROUND

Daclizumab, a humanised monoclonal antibody, modulates interleukin-2 signalling by blocking the α subunit (CD25) of the interleukin-2 receptor. We assessed whether daclizumab high-yield process (HYP) would be effective when given as monotherapy for a 1 year treatment period in patients with relapsing-remitting multiple sclerosis.

METHODS

We did a randomised, double-blind, placebo-controlled trial at 76 centres in the Czech Republic, Germany, Hungary, India, Poland, Russia, Ukraine, Turkey, and the UK between Feb 15, 2008, and May 14, 2010. Patients aged 18-55 years with relapsing-remitting multiple sclerosis were randomly assigned (1:1:1), via a central interactive voice response system, to subcutaneous injections of daclizumab HYP 150 mg or 300 mg, or placebo, every 4 weeks for 52 weeks. Patients and study personnel were masked to treatment assignment, except for the site pharmacist who prepared the study drug for injection, but had no interaction with the patient. The primary endpoint was annualised relapse rate. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00390221.

RESULTS

204 patients were assigned to receive placebo, 208 to daclizumab HYP 150 mg, and 209 to daclizumab HYP 300 mg, of whom 188 (92%), 192 (92%), and 197 (94%), respectively, completed follow-up to week 52. The annualised relapse rate was lower for patients given daclizumab HYP 150 mg (0·21, 95% CI 0·16-0·29; 54% reduction, 95% CI 33-68%; p<0·0001) or 300 mg (0·23, 0·17-0·31, 50% reduction, 28-65%; p=0·00015) than for those given placebo (0·46, 0·37-0·57). More patients were relapse free in the daclizumab HYP 150 mg (81%) and 300 mg (80%) groups than in the placebo group (64%; p<0·0001 in the 150 mg group and p=0·0003 in the 300 mg group). 12 (6%) patients in the placebo group, 15 (7%) of those in the daclizumab 150 mg group, and 19 (9%) in the 300 mg group had serious adverse events excluding multiple sclerosis relapse. One patient given daclizumab HYP 150 mg who was recovering from a serious rash died because of local complication of a psoas abscess.

CONCLUSIONS

Subcutaneous daclizumab HYP administered every 4 weeks led to clinically important effects on multiple sclerosis disease activity during 1 year of treatment. Our findings support the potential for daclizumab HYP to offer an additional treatment option for relapsing-remitting disease.

BACKGROUND

Biogen Idec and AbbVie Biotherapeutics Inc.

Leptin is 16 kDa adipokine that links nutritional status with neuroendocrine and immune functions. Initially thought to be a satiety factor that regulates body weight by inhibiting food intake and stimulating energy expenditure, leptin is a pleiotropic hormone whose multiple effects include regulation of endocrine function, reproduction, and immunity. Leptin can be considered as a pro-inflammatory cytokine that belongs to the family of long-chain helical cytokines and has structural similarity with <em>interleukin</em>-6, prolactin, growth hormone, IL-12, IL-<em>15</em>, granulocyte colony-stimulating factor and oncostatin M. Because of its dual nature as a hormone and cytokine, leptin links the neuroendocrine and the immune system. The role of leptin in the modulation of immune response and inflammation has recently become increasingly evident. The increase in leptin production that occurs during infection and inflammation strongly suggests that leptin is a part of the cytokine network which governs the inflammatory-immune response and the host defense mechanisms. Leptin plays an important role in inflammatory processes involving T cells and has been reported to modulate T-helper cells activity in the cellular immune response. Several studies have implicated leptin in the pathogenesis of autoimmune inflammatory conditions, such as experimental autoimmune encephalomyelitis, type 1 diabetes, rheumatoid arthritis, and intestinal inflammation. Very recently, a key role for leptin in osteoarthritis has been demonstrated: leptin indeed exhibits, in concert with other pro-inflammatory cytokines, a detrimental effect on articular cartilage by promoting nitric oxide synthesis in chondrocytes. Here, we review the recent advances regarding leptin biology with a special focus on those actions relevant to the role of leptin in the pathophysiology of inflammatory processes and immune responses.

OBJECTIVE

Inflammatory molecules have been demonstrated in the tear film of patients with severe dry eye disease (DED). However, little attention has been paid to the most frequent moderate forms of DED. This study analyzes tear cytokine levels and their clinical correlations in patients with moderate evaporative-type DED due to meibomian gland disease (MGD).

METHODS

Twenty three evaporative-type DED patients (46 eyes) of mild-to-moderate intensity and nine healthy subjects (18 eyes) were recruited. Two symptom questionnaires were self-answered and multiple DED-related clinical tests were performed. Unstimulated tears from each eye were isolated and were not pooled. Levels of <em>15</em> cytokines and chemokines were measured by multiplex bead analysis, compared with control levels, and correlated with clinical tests.

RESULTS

Fourteen out of the <em>15</em> molecules were reliably detected in 1 microl of unstimulated tears from DED patients. Epidermal growth factor (EGF), fractalkine/CX3CL1, interleukin (IL) 1-receptor antagonist (Ra), IL-8/CXCL8, interferon inducible protein (IP)-10/CXCL10, and vascular endothelial growth factor (VEGF) were found in 94%-100% of samples; IL-6 in 65% (significantly more detected in older patients); IL-1beta, interferon gamma (IFN-gamma), and IL-10 in 30%-48%; IL-17 in 13%; granulocyte macrophage colony stimulating factor (GM-CSF), IL-13, and tumor necrosis factor alpha (TNF-alpha) in 2%-9%; and IL-5 was never detected. EGF, fractalkine/CX3CL1, IL-1Ra, IP-10/CXCL10, and VEGF levels were significantly increased compared to normal controls. Pain was correlated with IL-6 and IL-8/CXCL8. Tear break-up time correlated inversely with IL1-Ra. Schirmer test and tear lysozyme levels negatively correlated with IL-1Ra, IL-8/CXCL8, fracktalkine/CX3CL1, IL-6, IP-10/CXCL10, and VEGF had the same tendency. Conjunctival staining correlated negatively with EGF and positively with IL-6.

CONCLUSIONS

In this sample of moderate evaporative-type DED patients, five inflammatory molecules were elevated. Fracktalkine was demonstrated to be present and elevated in tears in human DED. IL-1Ra, IL-6, IL-8/CXCL8, and EGF levels correlated with pain and with clinical parameters measuring tear stability, tear production or ocular surface integrity. These results suggest that inflammation plays a role not only in severe DED but also in moderate evaporative DED.

Among human natural killer (NK) cell intermediates in secondary lymphoid tissue (SLT), stage 3 CD34(-)CD117(+)CD161(+)CD94(-) immature NK (iNK) cells uniquely express aryl hydrocarbon receptor (AHR) and <em>interleukin</em>-22 (IL-22), supporting a role in mucosal immunity. The mechanisms controlling proliferation and differentiation of these cells are unknown. Here we demonstrate that the IL-1 receptor IL-1R1 was selectively expressed by a subpopulation of iNK cells that localized proximal to IL-1beta-producing conventional dendritic cells (cDCs) within SLT. IL-1R1(hi) iNK cells required continuous exposure to IL-1beta to retain AHR and IL-22 expression, and they proliferate in direct response to cDC-derived IL-<em>15</em> and IL-1beta. In the absence of IL-1beta, a substantially greater fraction of IL-1R1(hi) iNK cells differentiated to stage 4 NK cells and acquired the ability to kill and secrete IFN-gamma. Thus, cDC-derived IL-1beta preserves and expands IL-1R1(hi)IL-22(+)AHR(+) iNK cells, potentially influencing human mucosal innate immunity during infection.