Mucosal innate lymphoid cell (ILC) subsets promote immune responses to pathogens by producing distinct signature cytokines in response to changes in the cytokine microenvironment. We previously identified human ILC3 distinguished by <em>interleukin</em>-22 (IL-22) secretion. Here we characterized a human ILC1 subset that produced interferon-γ (IFN-γ) in response to IL-12 and IL-<em>15</em> and had a unique integrin profile, intraepithelial location, hallmarks of TGF-β imprinting, and a memory-activated phenotype. Because tissue-resident memory CD8(+) T cells share this profile, intraepithelial ILC1 may be their innate counterparts. In mice, intraepithelial ILC1 were distinguished by CD160 expression and required Nfil3- and Tbx21-encoded transcription factors for development, but not IL-<em>15</em> receptor-α, indicating that intraepithelial ILC1 are distinct from conventional NK cells. Intraepithelial ILC1 were amplified in Crohn's disease patients and contributed to pathology in the anti-CD40-induced colitis model in mice. Thus, intraepithelial ILC1 may initiate IFN-γ responses against pathogens but contribute to pathology when dysregulated.

Several studies have shown a relationship between <em>interleukin</em> (IL) 6 levels and insulin resistance. We here show that human subcutaneous adipose cells, like 3T3-L1 cells, are target cells for IL-6. To examine putative mechanisms and cross-talk with insulin, 3T3-L1 adipocytes were cultured for different times with IL-6 and tumor necrosis factor alpha (TNF-alpha). IL-6, in contrast to TNF-alpha, did not increase pS-307 of insulin-receptor substrate (IRS)-1 or JNK activation. However, IL-6, like TNF-alpha exerted long term inhibitory effects on the gene transcription of IRS-1, GLUT-4, and peroxisome proliferator-activated receptor gamma. This effect of IL-6 was accompanied by a marked reduction in IRS-1, but not IRS-2, protein expression, and insulin-stimulated tyrosine phosphorylation, whereas no inhibitory effect was seen on the insulin receptor tyrosine phosphorylation. Consistent with the reduced GLUT-4 mRNA, insulin-stimulated glucose transport was also significantly reduced by IL-6. An important interaction with TNF-alpha was found because TNF-alpha markedly increased IL-6 mRNA and protein secretion. These results show that IL-6, through effects on gene transcription, is capable of impairing insulin signaling and action but, in contrast to TNF-alpha, IL-6 does not increase pS-307 (or pS-612) of IRS-1. The link between IL-6 and insulin resistance in man was further corroborated by the finding that the expression of IL-6, like that of TNF-alpha and IL-8, was markedly increased ( approximately <em>15</em>-fold) in human fat cells from insulin-resistant individuals. We conclude that IL-6 can play an important role in insulin resistance in man and, furthermore, that it may act in concert with other cytokines that also are up-regulated in adipose cells in insulin resistance.

<em>Interleukin</em> (IL)-21 is the most recently recognized of the cytokines that share the common cytokine receptor gamma chain (gamma(c)), which is mutated in humans with X-linked severe combined immunodeficiency. We now report that IL-21 synergistically acts with IL-<em>15</em> to potently promote the proliferation of both memory (CD44high) and naive (CD44low) phenotype CD8+ T cells and augment interferon-gamma production in vitro. IL-21 also cooperated, albeit more weakly, with IL-7, but not with IL-2. Correspondingly, the expansion and cytotoxicity of CD8+ T cells were impaired in IL-21R-/- mice. Moreover, in vivo administration of IL-21 in combination with IL-<em>15</em> boosted antigen-specific CD8+ T cell numbers and resulted in a cooperative effect on tumor regression, with apparent cures of large, established B16 melanomas. Thus, our studies reveal that IL-21 potently regulates CD8+ T cell expansion and effector function, primarily in a synergistic context with IL-<em>15</em>.

BACKGROUND

An effective vaccine for malaria is urgently needed. Naturally acquired immunity to malaria develops slowly, and induction of protection in humans can be achieved artificially by the inoculation of radiation-attenuated sporozoites by means of more than 1000 infective mosquito bites.

METHODS

We exposed <em>15</em> healthy volunteers--with 10 assigned to a vaccine group and 5 assigned to a control group--to bites of mosquitoes once a month for 3 months while they were receiving a prophylactic regimen of chloroquine. The vaccine group was exposed to mosquitoes that were infected with Plasmodium falciparum, and the control group was exposed to mosquitoes that were not infected with the malaria parasite. One month after the discontinuation of chloroquine, protection was assessed by homologous challenge with five mosquitoes infected with P. falciparum. We assessed humoral and cellular responses before vaccination and before the challenge to investigate correlates of protection.

RESULTS

All 10 subjects in the vaccine group were protected against a malaria challenge with the infected mosquitoes. In contrast, patent parasitemia (i.e., parasites found in the blood on microscopical examination) developed in all five control subjects. Adverse events were mainly reported by vaccinees after the first immunization and by control subjects after the challenge; no serious adverse events occurred. In this model, we identified the induction of parasite-specific pluripotent effector memory T cells producing interferon-gamma, tumor necrosis factor alpha, and interleukin-2 as a promising immunologic marker of protection.

CONCLUSIONS

Protection against a homologous malaria challenge can be induced by the inoculation of intact sporozoites. (ClinicalTrials.gov number, NCT00442377.)

Recognition of self-antigens is required for regulatory T (Treg) cells to exert dominant tolerance. However, the mechanism by which self-reactive thymocytes are diverted into the Treg cell subset is unclear. To address this question, we looked for the immediate precursors to Treg cells within Foxp3(-)CD4+CD8(-) thymocytes. By using intrathymic transfer, we found that the CD25hi subset is highly enriched in Treg cell precursors. This was supported by tracking of thymocyte development via analysis of T cell receptor (TCR) repertoires in a TCR-beta transgenic model. These Treg cell precursors exist at a developmental stage where they are poised to express Foxp3 without further TCR engagement, requiring only stimulation by <em>interleukin</em>-2 (IL-2) or IL-<em>15</em>. Thus, we propose that the selection of self-reactive thymocytes into the Treg cell subset occurs via an instructive rather than stochastic-selective model whereby TCR signals result in the expression of proximal IL-2 signaling components facilitating cytokine-mediated induction of Foxp3.

The generation and efficient maintenance of antigen-specific memory T cells is essential for long-lasting immunological protection. In this study, we examined the role of <em>interleukin</em> (IL)-<em>15</em> in the generation and maintenance of virus-specific memory CD8 T cells using mice deficient in either IL-<em>15</em> or the IL-<em>15</em> receptor alpha chain. Both cytokine- and receptor-deficient mice made potent primary CD8 T cell responses to infection with lymphocytic choriomeningitis virus (LCMV), effectively cleared the virus and generated a pool of antigen-specific memory CD8 T cells that were phenotypically and functionally similar to memory CD8 T cells present in IL-<em>15</em>(+/+) mice. However, longitudinal analysis revealed a slow attrition of virus-specific memory CD8 T cells in the absence of IL-<em>15</em> signals. This loss of CD8 T cells was due to a severe defect in the proliferative renewal of antigen-specific memory CD8 T cells in IL-<em>15</em>(-/-) mice. Taken together, these results show that IL-<em>15</em> is not essential for the generation of memory CD8 T cells, but is required for homeostatic proliferation to maintain populations of memory cells over long periods of time.

Memory T cells maintain their numbers for long periods after antigen exposure. Here we show that CD8+ T cells of memory phenotype divide slowly in animals. This division requires <em>interleukin</em>-<em>15</em> and is markedly increased by inhibition of <em>interleukin</em>-2 (IL-2). Therefore, the numbers of CD8+ memory T cells in animals are controlled by a balance between IL-<em>15</em> and IL-2.

Whether the recently identified innate lymphocyte population coexpressing natural killer cell receptors (NKRs) and the nuclear receptor RORγt is part of the NK or lymphoid tissue inducer (LTi) cell lineage remains unclear. By using adoptive transfer of genetically tagged LTi-like cells, we demonstrate that NKR⁻RORγt(+) innate lymphocytes but not NK cells were direct progenitors to NKR(+)RORγt(+) cells in vivo. Genetic lineage tracing revealed that the differentiation of LTi-like cells was characterized by the stable upregulation of NKRs and a progressive loss of RORγt expression. Whereas <em>interleukin</em>-7 (IL-7) and intestinal microbiota stabilized RORγt expression within such NKR-LTi cells, IL-12 and IL-<em>15</em> accelerated RORγt loss. RORγt(+) NKR-LTi cells produced IL-22, whereas RORγt⁻ NKR-LTi cells released IFN-γ and were potent inducers of colitis. Thus, the RORγt gradient in NKR-LTi cells serves as a tunable rheostat for their functional program. Our data also define a previously unappreciated role of RORγt⁻ NKR-LTi cells for the onset or maintenance of inflammatory bowel diseases.

The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a ligand-dependent nuclear receptor that has been implicated in the modulation of critical aspects of development and homeostasis, including adipocyte differentiation, glucose metabolism and macrophage development and function. PPAR-gamma is activated by a range of synthetic and naturally occurring substances, including antidiabetic thiazolidinediones, polyunsaturated fatty acids, <em>15</em>-deoxy-delta prostaglandin J2 and components of oxidized low-density lipoprotein, such as 13-hydroxyoctadecadienoic acid (13-HODE) and <em>15</em>-hydroxyeicosatetraenoic acid (<em>15</em>-HETE). However, the identities of endogenous ligands for PPAR-gamma and their means of production in vivo have not been established. In monocytes and macrophages, 13-HODE and <em>15</em>-HETE can be generated from linoleic and arachidonic acids, respectively, by a 12/<em>15</em>-lipoxygenase that is upregulated by the TH2-derived cytokine <em>interleukin</em>-4. Here we show that <em>interleukin</em>-4 also induces the expression of PPAR-gamma and provide evidence that the coordinate induction of PPAR-gamma and 12/<em>15</em>-lipoxygenase mediates <em>interleukin</em>-4-dependent transcription of the CD36 gene in macrophages. These findings reveal a physiological role of 12/<em>15</em>-lipoxygenase in the generation of endogenous ligands for PPAR-gamma, and suggest a paradigm for the regulation of nuclear receptor function by cytokines.

We have evaluated the role of nitric oxide (NO) on the activity of the constitutive and induced forms of cyclooxygenase (COX; COX-1 and COX-2, respectively). Induction of NO synthase (NOS) and COX (COX-2) in the mouse macrophage cell line RAW264.7 by Escherichia coli lipopolysaccharide (1 microgram/ml, 18 h) caused an increase in the release of nitrite (NO2-) and prostaglandin E2 (PGE2), products of NOS and COX, respectively. Production of both NO2- and PGE2 was blocked by the NOS inhibitors NG-monomethyl-L-arginine or aminoguanidine. The effects of NG-monomethyl-L-arginine or aminoguanidine were reversed by coincubation with L-Arg, the precursor for NO synthesis, but not by D-Arg. RAW264.7 cells stimulated for 18 h with lipopolysaccharide in L-Arg-free medium (to reduce NO generation by the endogenous NOS pathway) failed to release NO2- and accumulated at least 4-fold less PGE2 when compared to cells in the presence of L-Arg. PGE2 production elicited by a <em>15</em>-min arachidonic acid treatment of lipopolysaccharide-induced RAW264.7 cells in L-Arg-deficient medium was decreased 3-fold when compared to the release obtained with cells induced in medium containing L-Arg. To examine the NO activation of the induced form of COX in the absence of an endogenous L-Arg, human fetal fibroblasts were first stimulated for 18 h with <em>interleukin</em> 1 beta. These cells released PGE2 but not NO2-, consistent with the induction of COX but not NOS in the fibroblast. Exogenous NO either as a gaseous solution or released by a NO donor, sodium nitroprusside or glyceryl trinitrate, increased COX activity in the <em>interleukin</em> 1 beta-stimulated fibroblasts by 5-fold; these effects were abolished by coincubation with hemoglobin (10 microM), which binds and inactivates NO, but not by methylene blue, an inhibitor of the soluble guanylate cyclase. Furthermore, sodium nitroprusside (0.25-1 mM) increased arachidonic acid-stimulated PGE2 production by murine recombinant COX-1 and COX-2. These results demonstrate that NO enhances COX activity through a mechanism independent of cGMP and suggest that, in conditions in which both the NOS and COX systems are present, there is an NO-mediated increase in the production of proinflammatory prostaglandins that may result in an exacerbated inflammatory response. The data suggest that NO directly interacts with COX to cause an increase in the enzymatic activity.

OBJECTIVE

To compare selected immunohistological features of inflammation in synovial tissue from patients with early and late osteoarthritis (OA).

METHODS

Synovial tissue samples were obtained from 10 patients with knee pain, normal radiographs, and arthroscopic manifestations of OA (early OA), and from <em>15</em> patients with OA undergoing knee joint arthroplasty (late OA). Conventional immunohistochemical techniques were used to measure microscopic manifestations of inflammation. The inflammatory cell infiltrate, blood vessel formation, and angiogenic factors, NF-kappaB activation, expression of tumour necrosis factor alpha (TNFalpha) and <em>interleukin</em> 1beta (IL1beta), and the presence of cyclo-oxygenase (COX)-1 and COX-2 were quantified. Fibroblast-like synoviocytes (FLS) were isolated from early and late OA tissue samples to compare in vitro production of prostaglandin E2 (PGE2)

RESULTS

Synovial tissue from patients with early OA demonstrated significantly greater CD4+ (p = 0.017) and CD68+ (p<0.001) cell infiltration, blood vessel formation (p = 0.01), vascular endothelial growth factor (p = 0.001), and intercellular adhesion molecule-1 expression (p<0.001). Numbers of cells producing TNFalpha and IL1beta were also significantly greater in early OA (p<0.001). Manifestations of inflammation in early OA were associated with increased expression of the NF-kappaB1 (p<0.001) and RelA (p = 0.0<em>15</em>) subunits, and with increased COX-2 expression (p = 0.04). Cytokine-induced PGE2 production by cultured FLS was similar in both groups.

CONCLUSIONS

Increased mononuclear cell infiltration and overexpression of mediators of inflammation were seen in early OA, compared with late OA. Isolated FLS were functionally similar in both groups, consistent with microenvironmental differences in the synovial tissue during different phases of OA. These observations may have important therapeutic implications for some patients during the early evolution of OA.

The prognostic value of several immunologic markers were compared in Los Angeles Multicenter AIDS Cohort Study (MACS) participants, most of whom had been infected with HIV for >8 years. Markers studied included CD4+ cell number, flow cytometric measurements of CD8+ cell expression of CD38 and HLA-DR antigens, and serum markers of immune activation including neopterin, beta2-microglobulin, soluble <em>interleukin</em>-2 receptor, soluble CD8, and soluble tumor necrosis factor receptor-alpha (TNF-alpha) type II. Cox proportional hazards models indicated that elevated CD38 on CD8, a flow cytometric measurement of CD8+ T-lymphocyte activation, was the most predictive marker of those studied for development of a clinical AIDS diagnosis and death. As compared with the reference group, who had CD38 on CD8 <2470 molecules per CD8+ cell and in whom 4 of 99 developed clinical AIDS within 3 years, participants with CD38 on CD8 between 2470 and 3899, 3900 and 7250, and >7250 had relative risks (and numbers developing AIDS within 3 years) of 5.0 (<em>15</em> of 81), 12.3 (24 of 60), and 41.4 (36 of 49), respectively. The strong prognostic value of CD38 on CD8 measurements and the fundamental importance of chronic immune activation in the pathogenesis of HIV disease suggests that this marker might have utility in the clinical management of HIV-infected persons.

BACKGROUND

The cryopyrin-associated periodic syndrome (CAPS) is a rare inherited inflammatory disease associated with overproduction of interleukin-1. Canakinumab is a human anti-interleukin-1beta monoclonal antibody.

METHODS

We performed a three-part, 48-week, double-blind, placebo-controlled, randomized withdrawal study of canakinumab in patients with CAPS. In part 1, 35 patients received 150 mg of canakinumab subcutaneously. Those with a complete response to treatment entered part 2 and were randomly assigned to receive either 150 mg of canakinumab or placebo every 8 weeks for up to 24 weeks. After the completion of part 2 or at the time of relapse, whichever occurred first, patients proceeded to part 3 and received at least two more doses of canakinumab. We evaluated therapeutic responses using disease-activity scores and analysis of levels of C-reactive protein (CRP) and serum amyloid A protein (SAA).

RESULTS

In part 1 of the study, 34 of the 35 patients (97%) had a complete response to canakinumab. Of these patients, 31 entered part 2, and all 15 patients receiving canakinumab remained in remission. Disease flares occurred in 13 of the 16 patients (81%) receiving placebo (P<0.001). At the end of part 2, median CRP and SAA values were normal (<10 mg per liter for both measures) in patients receiving canakinumab but were elevated in those receiving placebo (P<0.001 and P=0.002, respectively). Of the 31 patients, 28 (90%) completed part 3 in remission. In part 2, the incidence of suspected infections was greater in the canakinumab group than in the placebo group (P=0.03). Two serious adverse events occurred during treatment with canakinumab: one case of urosepsis and an episode of vertigo.

CONCLUSIONS

Treatment with subcutaneous canakinumab once every 8 weeks was associated with a rapid remission of symptoms in most patients with CAPS. (ClinicalTrials.gov number, NCT00465985.)

Human recombinant tumor necrosis factor (rTNF) was found to act directly on cultured human vascular endothelium to induce a tissue factor-like procoagulant activity (PCA). After a 4-hr incubation in rTNF (100 units/ml), serially passaged endothelial cells isolated from umbilical veins, saphenous veins, iliac arteries, and thoracic aortae demonstrated a dramatic increase (4- to <em>15</em>-fold, 21 experiments) in total cellular PCA as measured with a one-stage clotting assay. rTNF-induced PCA was also expressed at the surface of intact viable endothelial monolayers. Induction of PCA by rTNF was concentration dependent (maximum, 500 units/ml), time dependent, reversible, and blocked by cycloheximide and actinomycin D, and it occurred without detectable endothelial cell damage. Actions of rTNF were compared with those of natural human <em>interleukin</em> 1 (IL-1) derived from stimulated monocytes and two distinct species of recombinant IL-1, each of which also induced endothelial PCA. The use of recombinant polypeptides and specific neutralizing antisera established the distinct natures of the mediators. The kinetics of the endothelial PCA responses to TNF and IL-1 were similar, demonstrating a rapid rise to peak activity at approximately equal to 4 hr, and a decline toward basal levels by 24 hr. This characteristic decline in PCA after prolonged incubation with TNF or IL-1 was accompanied by selective endothelial hyporesponsiveness to the initially stimulating monokine. Interestingly, the effects of TNF and IL-1 were found to be additive even at apparent maximal doses of the individual monokines. Endothelial-directed actions of TNF, alone or in combination with other monokines, may be important in the initiation of coagulation and inflammatory responses in vivo.

BACKGROUND

Studies of human tumor-infiltrating lymphocytes (TILs) derived from patients with a variety of histologic types of cancer have demonstrated that cellular immune reactions against established malignancy exist in humans.

OBJECTIVE

We report the results of using autologous TILs plus high-dose bolus interleukin 2 (IL-2), with or without the concomitant administration of cyclophosphamide, in the treatment of 86 consecutive patients with metastatic melanoma.

METHODS

From May 1987 through December 1992, 86 patients (38 female and 48 male) with metastatic melanoma were treated (145 courses) with autologous TILs plus high-dose intravenous bolus IL-2 (720,000 IU/kg every 8 hours). TILs plus IL-2 were administered in two cycles separated by approximately 2 weeks. Two treatment cycles constituted one treatment course. Patients received a maximum of 15 doses of IL-2 per cycle given every 8 hours until grade 3 or 4 toxicity was reached that could not easily be reversed by standard supportive measures. All patients received concomitant medications to abrogate some of the side effects of IL-2 administration: acetaminophen (650 mg every 4 hours), indomethacin (50 mg every 8 hours), and ranitidine (150 mg every 12 hours). Fifty-seven of the 86 patients received a single intravenous dose of 25 mg/kg cyclophosphamide approximately 36 hours before receiving the first intravenous infusion of TILs plus IL-2. Six weeks after treatment, all known sites of disease were evaluated.

RESULTS

The overall objective response rate in these patients was 34% and was similar in patients receiving TILs and IL-2 alone (31%) or in conjunction with cyclophosphamide (35%). There was no significant difference in the objective response rate in patients whose therapy with high-dose IL-2 had failed (32%) compared with patients not previously treated with IL-2 (34%). The frequency of response to treatment was greater in those patients who were treated with TILs from younger cultures (P = .0001), TILs with shorter doubling times (P = .03), and TILs that exhibited higher lysis against autologous tumor targets (P = .0008). Patients who received TILs generated from subcutaneous tumor deposits had higher response rates (49%) compared with those receiving TILs from lymph nodes (17%; P = .006). There was one treatment-related death due to respiratory insufficiency.

CONCLUSIONS

Treatment with TILs and IL-2 with or without cyclophosphamide can result in objective responses in about one third of patients with metastatic melanoma. The side effects of treatment are transient in most patients, and this treatment can be safely administered. These results illustrate the potential value of immune lymphocytes for the treatment of patients with melanoma.

BACKGROUND

Elderly persons with chronic kidney disease have substantial risk for cardiovascular mortality, but the relative importance of traditional and novel risk factors is unknown.

OBJECTIVE

To compare traditional and novel risk factors as predictors of cardiovascular mortality.

METHODS

A total of 5808 community-dwelling persons aged 65 years or older living in 4 communities in the United States participated in the Cardiovascular Health Study cohort. Participants were initially recruited from 1989 to June 1990; an additional 687 black participants were recruited in 1992-1993. The average length of follow-up in this longitudinal study was 8.6 years.

METHODS

Cardiovascular mortality among those with and without chronic kidney disease. Chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 mL/min per 1.73 m2.

RESULTS

Among the participants, 1249 (22%) had chronic kidney disease at baseline. The cardiovascular mortality risk rate was 32 deaths/1000 person-years among those with chronic kidney disease vs 16/1000 person-years among those without it. In multivariate analyses, diabetes, systolic hypertension, smoking, low physical activity, nonuse of alcohol, and left ventricular hypertrophy were predictors of cardiovascular mortality in persons with chronic kidney disease (all P values <.05). Among the novel risk factors, only log C-reactive protein (P = .05) and log <em>interleukin</em> 6 (P<.001) were associated with the outcome as linear predictors. Traditional risk factors were associated with the largest absolute increases in risks for cardiovascular deaths among persons with chronic kidney disease: for left ventricular hypertrophy, there were 25 deaths per 1000 person-years; current smoking, 20 per 1000 person-years; physical inactivity, <em>15</em> per 1000 person-years; systolic hypertension, 14 per 1000 person-years; diabetes, 14 per 1000 person-years; and nonuse of alcohol, 11 per 1000 person-years vs 5 deaths per 1000 person-years for those with increased C-reactive protein and 5 per 1000 person-years for those with increased <em>interleukin</em> 6 levels. A receiver operating characteristic analysis found that traditional risk factors had an area under the curve of 0.73 (95% confidence interval, 0.70-0.77) among those with chronic kidney disease. Adding novel risk factors only increased the area under the curve to 0.74 (95% confidence interval, 0.71-0.78; P for difference = .<em>15</em>).

CONCLUSIONS

Traditional cardiovascular risk factors had larger associations with cardiovascular mortality than novel risk factors in elderly persons with chronic kidney disease. Future research should investigate whether aggressive lifestyle intervention in patients with chronic kidney disease can reduce their substantial cardiovascular risk.

BACKGROUND

The relevance to coronary heart disease (CHD) of cytokines that govern inflammatory cascades, such as interleukin-6 (IL-6), may be underestimated because such mediators are short acting and prone to fluctuations. We evaluated associations of long-term circulating IL-6 levels with CHD risk (defined as nonfatal myocardial infarction [MI] or fatal CHD) in two population-based cohorts, involving serial measurements to enable correction for within-person variability. We updated a systematic review to put the new findings in context.

RESULTS

Measurements were made in samples obtained at baseline from 2,138 patients who had a first-ever nonfatal MI or died of CHD during follow-up, and from 4,267 controls in two cohorts comprising 24,230 participants. Correction for within-person variability was made using data from repeat measurements taken several years apart in several hundred participants. The year-to-year variability of IL-6 values within individuals was relatively high (regression dilution ratios of 0.41, 95% confidence interval [CI] 0.28-0.53, over 4 y, and 0.35, 95% CI 0.23-0.48, over 12 y). Ignoring this variability, we found an odds ratio for CHD, adjusted for several established risk factors, of 1.46 (95% CI 1.29-1.65) per 2 standard deviation (SD) increase of baseline IL-6 values, similar to that for baseline C-reactive protein. After correction for within-person variability, the odds ratio for CHD was 2.14 (95% CI 1.45-3.15) with long-term average ("usual") IL-6, similar to those for some established risk factors. Increasing IL-6 levels were associated with progressively increasing CHD risk. An updated systematic review of electronic databases and other sources identified 15 relevant previous population-based prospective studies of IL-6 and clinical coronary outcomes (i.e., MI or coronary death). Including the two current studies, the 17 available prospective studies gave a combined odds ratio of 1.61 (95% CI 1.42-1.83) per 2 SD increase in baseline IL-6 (corresponding to an odds ratio of 3.34 [95% CI 2.45-4.56] per 2 SD increase in usual [long-term average] IL-6 levels).

CONCLUSIONS

Long-term IL-6 levels are associated with CHD risk about as strongly as are some major established risk factors, but causality remains uncertain. These findings highlight the potential relevance of IL-6-mediated pathways to CHD.

Antigen injection into animals causes antigen-specific T cells to become activated and, rapidly thereafter, die. This antigen-induced death is inhibited by inflammation. To find out how inflammation has this effect, various cytokines were tested for their ability to interfere with the rapid death of activated T cells. T cells were activated in vivo, isolated, and cultured with the test reagents. Two groups of cytokines were active, members of the <em>interleukin</em> 2 family and the interferons (IFNs) alpha and beta. This activity of IFN-alpha/beta has not been described previously. It was due to direct effects of the IFNs on the T cells and was not mediated by induction of a second cytokine such as <em>interleukin</em> <em>15</em>. IFN-gamma did not slow the death of activated T cells, and therefore the activity of IFN-alpha/beta was not mediated only by activation of Stat 1, a protein that is affected by both classes of IFN. IFN-alpha/beta did not raise the levels of Bcl-2 or Bcl-XL in T cells. Therefore, their activity was distinct from that of members of the <em>interleukin</em> 2 family or CD28 engagement. Since IFN-alpha/beta are very efficiently generated in response to viral and bacterial infections, these molecules may be among the signals that the immune system uses to prevent activated T cell death during infections.

The rapid advancement of nanotechnology has created a vast array of engineered nanomaterials (ENMs) which have unique physical (size, shape, crystallinity, surface charge) and chemical (surface coating, elemental composition and solubility) attributes. These physicochemical properties of ENMs can produce chemical conditions to induce a pro-oxidant environment in the cells, causing an imbalanced cellular energy system dependent on redox potential and thereby leading to adverse biological consequences, ranging from the initiation of inflammatory pathways through to cell death. The present study was designed to evaluate size-dependent cellular interactions of known biologically active silver nanoparticles (NPs, Ag-<em>15</em> nm, Ag-30 nm, and Ag-55 nm). Alveolar macrophages provide the first defense and were studied for their potential role in initiating oxidative stress. Cell exposure produced morphologically abnormal sizes and adherence characteristics with significant NP uptake at high doses after 24 h. Toxicity evaluations using mitochondrial and cell membrane viability along with reactive oxygen species (ROS) were performed. After 24 h of exposure, viability metrics significantly decreased with increasing dose (10-75 microg/mL) of Ag-<em>15</em> nm and Ag-30 nm NPs. A more than 10-fold increase of ROS levels in cells exposed to 50 microg/mL Ag-<em>15</em> nm suggests that the cytotoxicity of Ag-<em>15</em> nm is likely to be mediated through oxidative stress. In addition, activation of the release of traditional inflammatory mediators were examined by measuring levels of cytokines/chemokines, including tumor necrosis factor (TNF-alpha), macrophage inhibitory protein (MIP-2), and <em>interleukin</em>-6 (IL-6), released into the culture media. After 24 h of exposure to Ag-<em>15</em> nm nanoparticles, a significant inflammatory response was observed by the release of TNF-alpha, MIP-2, and IL-1beta. However, there was no detectable level of IL-6 upon exposure to silver nanoparticles. In summary, a size-dependent toxicity was produced by silver nanoparticles, and one predominant mechanism of toxicity was found to be largely mediated through oxidative stress.

OBJECTIVE

To determine the efficacy of treatment using high-dose bolus interleukin 2 (IL-2) in patients with metastatic melanoma or renal cell cancer.

METHODS

Consecutive series of all patients treated with high-dose IL-2 in the Surgery Branch of the National Cancer Institute from September 1985 through December 1992.

METHODS

Two hundred eighty-three patients with metastatic melanoma or metastatic renal cell cancer who had failed standard treatment for their cancers.

METHODS

Patients received IL-2 at a dose of 720,000 IU/kg intravenously every 8 hours for a maximum of 15 doses per cycle. Two cycles constituted a treatment course, and patients with stable or responding disease received additional treatment courses. A total of 447 courses of treatment were administered.

METHODS

Regression of measurable tumor, durability of response to treatment, and survival.

RESULTS

Nine patients (7%) with metastatic melanoma achieved complete regression of all disease and 14 patients (10%) had partial regression. Ten patients (7%) with metastatic renal cell cancer experienced complete regression and 20 patients (13%) had partial regression. Of the 19 patients with complete regression, 15 have remained in complete remission from 7 to 91 months after treatment. Three treatment-related deaths (1.1%) occurred early in this series, but as experience with the administration of this IL-2 regimen increased, no treatment-related deaths occurred in 214 patients treated during the last 5 years of the study.

CONCLUSIONS

Biologic therapy with IL-2 can cause significant antitumor effects in patients with advanced metastatic melanoma or renal cell cancer. Because IL-2 does not have a direct effect on cancer cells but rather mediates its antitumor activity by altering host immune reactions, these data represent the best available evidence that immunologic therapy for cancer can be effective in selected patients.

The <em>interleukin</em> 2 receptor gamma chain (IL-2R gamma) is a component of the receptors for IL-2, IL-4, IL-7, and IL-<em>15</em>. Mutations in IL-2R gamma in man appear responsible for the X chromosome-linked immunodeficiency SCIDX1, characterized by a defect in T-cell and natural killer (NK)-cell differentiation with the presence of poorly functioning B cells. To explore at which level IL-2R gamma affects lymphoid development in vivo, we have analyzed mice derived from embryonic stem (ES) cells with mutant IL-2R gamma loci generated by Cre/loxP-mediated recombination. In the peripheral blood of chimeric animals, lymphoid cells derived from IL-2R gamma- ES cells were not detected, although control ES cells carrying an IL-2R gamma gene with embedded loxP sites gave rise to T-, B-, and NK-cell lineages. Germline IL-2R gamma-deficient male animals, however, developed some mature splenic B and T cells, although the absolute number of lymphocytes was almost 10-fold reduced. In contrast, there was a complete disappearance of NK cells (over 350-fold reduction). Development of gut-associated intraepithelial lymphocytes was also severely diminished, and Peyer's patches were not detected. In vitro mitogenic responses of thymocytes, IL-4-directed immunoglobulin class switch of splenocytes, and NK activity were defective. Thus, IL-2R gamma facilitates mainstream B- and T-cell generation and function and also appears to be essential for NK-cell development.

The genetic transfer of antigen receptors provides a means to rapidly generate autologous tumor-reactive T lymphocytes. However, recognition of tumor antigens by cytotoxic T cells is only one step towards effective cancer immunotherapy. Other crucial biological prerequisites must be fulfilled to expand tumor-reactive T cells that retain a functional phenotype, including in vivo cytolytic activity and the ability to travel to tumor sites without prematurely succumbing to apoptosis. We show that these requirements are met by expanding peripheral blood T cells genetically targeted to the CD19 antigen in the presence of CD80 and <em>interleukin</em>-<em>15</em> (IL-<em>15</em>). T cells expanded in the presence of IL-<em>15</em> uniquely persist in tumor-bearing severe combined immunodeficiency (SCID)-Beige mice and eradicate disseminated intramedullary tumors. Their anti-tumor activity is further enhanced by in vivo co-stimulation. In addition, transduced T cells from patients with chronic lymphocytic leukemia (CLL) effectively lyse autologous tumor cells. These findings strongly support the clinical feasibility of this therapeutic strategy.

OBJECTIVE

The objective of this study was to investigate whether high levels of serum interleukin (IL)-6, C-reactive protein (CRP), and alpha1-antichymotrypsin (ACT) were associated with the loss of muscle strength or muscle mass (sarcopenia) in older persons.

METHODS

The study included 986 men and women of the Longitudinal Aging Study Amsterdam, with a mean age of 74.6 years (standard deviation 6.2).

METHODS

Grip strength (n = 986) and appendicular muscle mass (n = 328, using dual-energy x-ray absorptiometry) were obtained in 1995 and 1996 and repeated after a 3-year follow-up. Loss of muscle strength was defined as a loss of grip strength greater than 40%, and sarcopenia was defined as a loss of muscle mass greater than 3%, approximating the lowest 15% of the study sample.

RESULTS

Multiple linear and logistic regression analyses revealed that higher levels of IL-6 were associated with greater decline in muscle strength, which decreased by -3.21 kg (standard error 0.81) per standard deviation increase in log-transformed IL-6. After adjustment for confounders, including sociodemographic, health, and lifestyle factors, high IL-6 (>5 pg/mL) and high CRP (>6.1 mug/mL) were associated with a 2 to 3-fold greater risk of losing greater than 40% of muscle strength. Persons with high levels of ACT (>181% of the normal human pooled plasma) were 40% less likely to experience loss of muscle strength and tended (P = .07) to have a smaller decline in muscle mass compared with those in the lowest quartile of ACT. No consistent associations of IL-6 and CRP with sarcopenia were found.

CONCLUSIONS

The findings of this prospective, population-based study suggest that higher levels of IL-6 and CRP increase the risk of muscle strength loss, whereas higher levels of ACT decrease the risk of muscle strength loss in older men and women.

In addition to activating T and B lymphocytes, <em>interleukin</em> 1 (IL-1) induces several hematologic and metabolic changes typical of host responses to infection and injury. We now report a new biological property, namely, the induction of hypotension. Rabbits given a single intravenous injection of recombinant human IL-1-beta (5 micrograms/kg) rapidly developed decreased systemic arterial pressure, which reached the lowest levels after 50-60 min and slowly returned to pre-IL-1 values after 3 h. Associated with the hypotension, systemic vascular resistance and central venous pressure fell, while cardiac output and heart rate increased. These responses were prevented by ibuprofen given <em>15</em> min before the IL-1. A bolus injection of IL-1 followed by a 2-h infusion sustained the hypotension and was associated with leukopenia and thrombocytopenia. Ibuprofen given at the mid-point of the infusion reversed the changes in all hemodynamic parameters, but had no effect on the leukopenia or thrombocytopenia. Tumor necrosis factor (TNF) also induced a shock-like state in rabbits. When the dose of IL-1 or TNF was reduced to 1 microgram/kg, no hemodynamic changes were observed; however, the combination of these low doses of both cytokines resulted in a profound shock-like state including histological evidence of severe pulmonary edema and hemorrhage. Pretreatment with ibuprofen prevented the hemodynamic, leukocyte, and platelet changes induced by the low-dose cytokine combination, and ameliorated the pulmonary tissue damage. These results demonstrate that IL-1, like TNF, possesses the ability to induce hemodynamic and hematological changes typical of septic shock, and that the combination of IL-1 and TNF is more potent than either agent alone. These effects seem to require cyclooxygenase products, and suggest that intravenous cyclooxygenase inhibitors may be of therapeutic value in patients with IL-1/TNF-mediated shock.