Cytokine Production In Humans Research Articles

SARS-CoV-2 and helminth co-infections, and environmental pollution exposure: An epidemiological and immunological perspective.

Soil-transmitted helminths infect billions of people globally, particularly those residing in low- and middle-income regions with poor environmental sanitation and high levels of air and water pollution. Helminths display potent immunomodulatory activity by activating T helper type 2 (Th2) anti-inflammatory and Th3 regulatory immune responses. The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus that causes Coronavirus disease 2019 (COVID-19), can exacerbate Th1/Th17 pro-inflammatory cytokine production in humans, leading to a cytokine storm. Air pollutants (particulate matter, oxygen radicals, hydrocarbons and volatile organic compounds) and water pollutants (metals and organic chemicals) can also intensify Th1/Th17 immune response and could exacerbate SARS-CoV-2 related respiratory distress and failure. The present review focused on the epidemiology of SARS-CoV-2, helminths and fine particulate matter 2.5 µm or less in diameter (PM2.5) air pollution exposure in helminth endemic regions, the possible immunomodulatory activity of helminths against SARS-CoV-2 hyper-inflammatory immune response, and whether air and water pollutants can further exacerbate SARS-CoV-2 related cytokine storm and in the process hinder helminths immunomodulatory functionality. Helminth Th2/Th3 immune response is associated with reductions in lung inflammation and damage, and decreased expression levels of angiotensin-converting enzyme 2 (ACE2) receptors (SARS-CoV-2 uses the ACE2 receptors to infect cells and associated with extensive lung damage). However, air pollutants are associated with overexpression of ACE2 receptors in the epithelial cell surface of the respiratory tract and exhaustion of Th2 immune response. Helminth-induced immunosuppression activity reduces vaccination efficacy, and diminishes vital Th1 cytokine production immune responses that are crucial for combating early stage infections. This could be reversed by continuous air pollution exposure which is known to intensify Th1 pro-inflammatory cytokine production to a point where the immunosuppressive activities of helminths could be hindered. Again, suppressed activities of helminths can also be disadvantageous against SARS-CoV-2 inflammatory response. This “yin and yang” approach seems complex and requires more understanding. Further studies are warranted in a cohort of SARS-CoV-2 infected individuals residing in helminths and air pollution endemic regions to offer more insights, and to impact mass periodic deworming programmes and environmental health policies.

Cutting Edge: Homeostasis of Innate Lymphoid Cells Is Imbalanced in Psoriatic Arthritis.

Innate lymphoid cells (ILC) have a high potency for cytokine production independent of specific Ag stimulation. Imbalance of ILC subsets may influence cytokine production in humans and hence be associated with the development of inflammatory disease. Evidence for an imbalance of ILC homeostasis in human disease, however, is very limited to date. In this study we show that psoriatic arthritis (PsA), a severe disease of the joints depending on the activation of the IL-23/IL-17 pathway, is characterized by a skewed ILC homeostasis. Circulating ILC3s as potent source of IL-17/IL-22 were elevated in active PsA, whereas ILC2s, which produce proresolving cytokines, were decreased. The ILC2/ILC3 ratio was significantly correlated with clinical disease activity scores and the presence of imaging signs of joint inflammation and bone damage. Multivariable analysis showed that a high ILC2/ILC3 ratio is associated with remission in PsA, suggesting that specific alterations of ILC homeostasis control disease activity in PsA.

Subgingival Microbiome Colonization and Cytokine Production during Early Dental Implant Healing.

Little is known about longitudinal development of the peri-implant subgingival microbiome and cytokine production as a new sulcus forms after dental implant placement. Therefore, the purpose of this observational study was to evaluate simultaneous longitudinal changes in the oral microbiome and cytokine production in the developing peri-implant sulcus compared to control natural teeth. Four and 12weeks after implant placement and abutment connection, a dental implant and a natural tooth were sampled in 25 patients for subgingival plaque and gingival crevicular fluid (GCF [around teeth] and peri-implant crevicular fluid [PICF] around implants). DNA from plaque samples was extracted and sequenced using Illumina-based 16S rRNA sequencing. GCF and PICF samples were analyzed using a customized Milliplex human cytokine and chemokine magnetic bead panel. Beta diversity analysis revealed that natural teeth and implants had similar subgingival microbiomes, while teeth had greater alpha diversity than implants. At the genus level, however, few differences were noted between teeth and dental implants over 12weeks. Specifically, Actinomyces and Selenomonas were significantly elevated around teeth versus dental implants at both 4weeks and 12weeks, while Corynebacterium and Campylobacter were significantly elevated only at 4weeks around teeth. The only difference between PICF and GCF biomarkers was significantly elevated granulocyte-macrophage colony-stimulating factor levels around teeth versus dental implants at the 4-week visit. The subgingival microbiome and cytokine production were similar between teeth and implants during early healing, suggesting that these profiles are driven by the patient following dental implant placement and are not determined by anatomical niche. IMPORTANCE Dental implants are a common treatment option offered to patients for tooth replacement. However, little is known regarding initial colonization of the subgingival microbiome and simultaneous longitudinal cytokine production in humans during the early healing phase following implant placement. We report findings from an in vivo study that assessed initial colonization of the subgingival microbiome and concomitant early cytokine production in a newly formed anatomical space, namely, an implant sulcus. This approach may be useful in future interventional studies to influence dental implant success. Our data showed that the subgingival microbiome and cytokine profile were similar for control natural teeth and dental implants at both 4 and 12weeks after implant placement. These data suggest that these profiles are driven by the patient and not by anatomical location (i.e., tooth versus dental implant).

Balancing the autonomic nervous system to reduce inflammation in rheumatoid arthritis.

Imbalance in the autonomic nervous system (ANS) has been observed in many established chronic autoimmune diseases, including rheumatoid arthritis (RA), which is a prototypic immune-mediated inflammatory disease (IMID). We recently discovered that autonomic dysfunction precedes and predicts arthritis development in subjects at risk of developing seropositive RA. In addition, RA patients with relatively high vagus nerve tone (higher parasympathetic parameters, measured by heart rate variability) respond better to antirheumatic therapies. Together, these data suggest that the ANS may control inflammation in humans. This notion is supported by experimental studies in animal models of RA. We have found that stimulation of the so-called cholinergic anti-inflammatory pathway by efferent electrical vagus nerve stimulation (VNS) or pharmacological activation of the alpha7 subunit of nicotinic acetylcholine receptors (α7nAChR) improves clinical signs and symptoms of arthritis, reduces cytokine production and protects against progressive joint destruction. Conversely, increased arthritis activity was observed in alpha7nAChR knockout mice. These studies together with previous work in animal models of sepsis and other forms of inflammation provided the rationale for an experimental clinical trial in patients with RA. We could for the first time show that an implantable vagus nerve stimulator inhibits peripheral blood cytokine production in humans. VNS significantly inhibited TNF and IL-6 production and improved RA disease severity, even in some patients with therapy-resistant disease. This work strongly supports further studies using a bioelectronic approach to treat RA and other IMIDs.

Systemic Expression of Notch Ligand Delta-Like 4 during Mycobacterial Infection Alters the T Cell Immune Response.

The Notch ligand delta-like 4 (DLL4) is known to fine-tune the CD4+ T cell cytokine response. DLL4 is expressed on the surface of antigen-presenting cells (APCs) in a MyD88-dependent manner. We found that DLL4 expression was upregulated on bone marrow progenitor cells and APCs in mice infected with BCG Mycobacterium. Transfer of DLL4+ progenitor cells from infected hosts resulted in an increase DLL4+ myeloid cells in the spleen, indicating that expression of the dll4 gene is propagated throughout hematopoiesis. We also found an increase in DLL4+ monocytes from individuals who were infected with Mycobacterium tuberculosis. In latent individuals, DLL4 expression correlated with increased cytokine production from T cells in response to PPD stimulation. Finally, antibody blockade of DLL4 reduced T cell cytokine production from naïve T cells stimulated with antigen. These results demonstrate that the Notch ligand DLL4 can influence T cell cytokine production in both humans and mice, and further reveal that expression of DLL4 is upregulated on early hematopoietic progenitors in response to chronic mycobacterial infection. These data suggest that widespread DLL4 expression may occur as a result of mycobacterial infection, and that this expression may alter CD4+ T cell responses to both previously encountered and novel antigens.

A Functional Genomics Approach to Understand Variation in Cytokine Production in Humans

As part of the Human Functional Genomics Project, which aims to understand the factors that determine the variability of immune responses, we investigated genetic variants affecting cytokine production in response to exvivo stimulation in two independent cohorts of 500 and 200 healthy individuals. We demonstrate a strong impact of genetic heritability on cytokine production capacity after challenge with bacterial, fungal, viral, and non-microbial stimuli. In addition to 17 novel genome-wide significant cytokine QTLs (cQTLs), our study provides a comprehensive picture of the genetic variants that influence six different cytokines in whole blood, blood mononuclear cells, and macrophages. Important biological pathways that contain cytokine QTLs map to pattern recognition receptors (TLR1-6-10 cluster), cytokine and complement inhibitors, and the kallikrein system. The cytokine QTLs show enrichment for monocyte-specific enhancers, are more often located in regions under positive selection, and are significantly enriched among SNPs associated with infections and immune-mediated diseases. PAPERCLIP.

Abstract # 1797 Effects of corticotropin-releasing hormone on lymphocyte distribution and LPS-induced ex vivo cytokine production in humans: A pilot study

Corticotropin-releasing hormone (CRH) plays a major role in the activation of the hypothalamic–pituitary–adrenal axis and the sympathetic nervous system. However, the effects of peripheral CRH administration on immune functions are only partially known. In the present study, we used a clinically established CRH stimulation test to investigate potential CRH effects on blood immune cell distribution and ex vivo cytokine production in humans. Healthy male volunteers received an intravenous injection of either CRH (100 μ g, n = 7) or placebo (0.9% NaCl, n = 5) on two days with a 3-day washout phase in between. Blood samples, cardiovascular and psychological parameters were analyzed before (baseline) as well as 15, 30, 60, 120 and 180 min post injection. Results showed that CRH administration significantly increased cortisol and noradrenaline levels, heart rate, as well as self-reported side-effects and state anxiety. However, distribution of peripheral blood lymphocyte subsets and ex vivo lipopolysaccharide-stimulated production of IL-6 and TNF-alpha remained unaffected. Thus, even though peripheral administration of CRH induced pronounced neuroendocrine and psychological responses, it failed to affect lymphocyte circulation and cytokine release.

Prostaglandin D2 regulates human type 2 innate lymphoid cell chemotaxis

Prostaglandin D2 regulates human type 2 innate lymphoid cell chemotaxis

Sex and inflammation in respiratory diseases: a clinical viewpoint

This review discusses sex differences in the prognosis of acute or chronic inflammatory diseases. The consequences of severe inflammation vary in relation to sex, depending on illness duration. In the majority of acute diseases, males present higher mortality rates, whereas continuous chronic inflammation associated with tissue damage is more deleterious in females. The recruitment of cells, along with its clinical expression, is more significant in females, as reflected by higher inflammatory markers. Given that estrogens or androgens are known to modulate inflammation, their different levels in males and females cannot account for the sexual dimorphism observed in humans and animals from birth to death with regard to inflammation. Numerous studies evaluated receptors, cytokine production, and clinical outcomes in both animals and humans, revealing that estrogens clearly modulate the immune response, but the results are contradictory and difficult to link to hormone concentrations. Even in prepubescent children, the presentation of acute pneumonia or chronic diseases mimics the adult pattern. Several genes located on the X chromosome have been shown to encode molecules involved in inflammation. Moreover, 10% to 15% of the genes from silenced X chromosome may escape inhibition. Females are also a mosaic of cells with genes from either paternal or maternal X chromosome. Therefore, polymorphism of X-linked genes would result in the presence of two cell populations with distinct regulatory arsenals, providing females with greater diversity to fight against infectious challenges, in comparison with the uniform cell populations in hemizygous males. The similarities observed between males and Turner syndrome patients using an endotoxin stimulation model support the difference in gene expression between monosomy and disomy for the X chromosome. Considering the enhanced inflammation in females, cytokine production may be assumed to be higher in females than males. Even if all results are not clear-cut, nonetheless, many studies have reported higher cytokine levels in both male humans and animals than in females. High IL-6 levels in males correlated with poorer prognosis and shorter longevity. A sound understanding of the basic regulatory mechanisms responsible for these gender differences may lead to new therapeutic targets.

Magnesium Decreases Inflammatory Cytokine Production: A Novel Innate Immunomodulatory Mechanism

MgSO(4) exposure before preterm birth is neuroprotective, reducing the risk of cerebral palsy and major motor dysfunction. Neonatal inflammatory cytokine levels correlate with neurologic outcome, leading us to assess the effect of MgSO(4) on cytokine production in humans. We found reduced maternal TNF-α and IL-6 production following in vivo MgSO(4) treatment. Short-term exposure to a clinically effective MgSO(4) concentration in vitro substantially reduced the frequency of neonatal monocytes producing TNF-α and IL-6 under constitutive and TLR-stimulated conditions, decreasing cytokine gene and protein expression, without influencing cell viability or phagocytic function. In summary, MgSO(4) reduced cytokine production in intrapartum women, term and preterm neonates, demonstrating effectiveness in those at risk for inflammation-associated adverse perinatal outcomes. By probing the mechanism of decreased cytokine production, we found that the immunomodulatory effect was mediated by magnesium and not the sulfate moiety, and it was reversible. Cellular magnesium content increased rapidly upon MgSO(4) exposure, and reduced cytokine production occurred following stimulation with different TLR ligands as well as when magnesium was added after TLR stimulation, strongly suggesting that magnesium acts intracellularly. Magnesium increased basal IĸBα levels, and upon TLR stimulation was associated with reduced NF-κB activation and nuclear localization. These findings establish a new paradigm for innate immunoregulation, whereby magnesium plays a critical regulatory role in NF-κB activation, cytokine production, and disease pathogenesis.

Effect of acute hyperglycaemia and/or hyperinsulinaemia on proinflammatory gene expression, cytokine production and neutrophil function in humans

AimsType 2 diabetes is frequently associated with infectious complications. Swift activation of leucocytes is important for an adequate immune response. We determined the selective effects of hyperglycaemia and hyperinsulinaemia on lipopolysaccharide (LPS)-induced proinflammatory gene expression and cytokine production in leucocytes and on neutrophil functions.MethodsSix healthy humans were studied on four occasions for 6 h during: (i) lower insulinaemic euglycaemic clamp, (ii) lower insulinaemic hyperglycaemic clamp, (iii) hyperinsulinaemic euglycaemic clamp, and (iv) hyperinsulinaemic hyperglycaemic clamp. Target levels of plasma glucose were 12.0 mmol/l (hyperglycaemic clamps) or 5.0 mmol/l (euglycaemic clamps). Target plasma insulin levels were 400 pmol/l (hyperinsulinaemic clamps) or 100 pmol/l (lower insulinaemic clamps).ResultsHyperglycaemia reduced LPS-induced mRNA expression of nuclear factor of κ light polypeptide gene enhancer in B cells inhibitor alpha (NFKBIA), interleukin-1 alpha (IL1A) and chemokine (C-C motif) ligand 3 (CCL3), whereas during hyperinsulinaemia enhanced mRNA levels occurred in six out of eight measured inflammation-related genes, irrespective of plasma glucose levels. Combined hyperglycaemia and hyperinsulinaemia led to enhanced IL1A, interleukin-1 beta (IL1B) and CCL3 mRNA levels upon LPS stimulation. Neither hyperglycaemia nor hyperinsulinaemia altered cytokine protein production, neutrophil migration, phagocytic capacity or oxidative burst activity.ConclusionsThese results suggest that short-term hyperglycaemia and hyperinsulinaemia influence the expression of several inflammatory genes in an opposite direction, that the acute effects of hyperinsulinaemia on inflammatory mRNA levels may be stronger than those of hyperglycaemia, and that the effects of insulin, in particular, may be relevant in the concurrent presence of hyperglycaemia.Diabet. Med. 25, 157–164 (2008)

Cytokine response to vitamin E supplementation is dependent on pre‐supplementation cytokine levels

Vitamin E supplementation has been suggested to improve immune response in the aged in part by altering cytokine production. However, there is not a consensus regarding the effect of supplemental vitamin E on cytokine production in humans. There is evidence that baseline immune health can affect immune response to supplemental vitamin E in the elderly. Thus, the effect of vitamin E on cytokines may depend on their pre-supplementation cytokine response. Using data from a vitamin E intervention in elderly nursing home residents, we examined if the effect of vitamin E on ex vivo cytokine production of IL-1 beta, IL-6, TNF-alpha, and IFN-gamma depended on baseline cytokine production. We observed that the effect of vitamin E supplementation on cytokine production depended on pre-supplementation production of the respective cytokines. The interactions between vitamin E and baseline cytokine production were not explained by covariates known to impact cytokine production. Our results offer evidence that baseline cytokine production should be considered in studies that examine the effect of supplemental vitamin E on immune and inflammatory responses. Our results could have implications in designing clinical trials to determine the impact of vitamin E on conditions in which cytokines are implicated such as infections and atherosclerotic disease.

Immunomodulatory effects of the herbicide propanil on cytokine production in humans: In vivo and in vitro exposure

Propanil, 3,4-dichloropropionanilide, a commonly used herbicide, has been shown to induce effects on the mouse immune system. The aim of this study was to assess the immunotoxicity of propanil in occupationally exposed agricultural workers and to characterize its molecular mechanism of action. Seven agricultural workers intermittently exposed to propanil and 7 healthy matched controls entered the study. Data were collected through physical examination, and laboratory investigations addressed at the main serum, cellular, and functional immune parameters. The levels of exposure were assessed by determining the urine concentration of the major propanil metabolite, 3,4-dichloroaniline. The investigation of serum, cellular, and functional immune parameters suggested that propanil exposure results in a modest immunomodulatory effect, characterized by an increase in the plasma level of IgG 1 and in LPS-induced IL-6 release and, by a reduction in PHA-induced IL-10 and IFN release, associated with a reduced IFN/IL-4 ratio. As observed, following in vivo exposure, in vitro treatment of human peripheral blood leukocytes with propanil resulted in a dose-dependent reduction in PHA-induced IFN-gamma and IL-10 production, while LPS-induced TNF-α production was not affected indicating a direct effect of propanil on selected immune parameters. We demonstrated that propanil interfering with PHA-induced intracellular calcium increase modulated IL-10 and IFN-gamma transcription and translation, which indicates that propanil acts on early events triggered by PHA. Overall, our results suggest that human exposure to propanil has slight immunomodulatory effects, and point out that the inhibition of the PHA-induced intracellular calcium rise is an important target of propanil. These findings improve our understanding of the mechanism underlying propanil-induced immunotoxicity.

Selective Effect of Mercury on Th2-Type Cytokine Production in Humans

Mercury induces autoimmune disease and increases IL-4 production and IgE levels in certain rodent strains. The object of this study was to determine if mercury was capable of inducing Th2 cytokine production in human leucocytes. Human peripheral blood mononuclear cells (PBMC) were incubated with PMA/ionomycin or Con A in the presence or absence of methyl mercury (CH3Hg) or mercuric chloride (HgCl2). IL-4 and gamma-IFN were measured by ELISA. RESULTS: IL-4 production significantly increased at low concentrations of CH3Hg (0.5 uM, p < 0.01), while gamma-IFN production was suppressed starting at CH3Hg 2 uM (p = 0.004). Inorganic mercury (HgCl2) increased IL-4 only at concentrations 10–20 times higher than CH3Hg. These findings suggest a mechanism by which mercury could trigger or potentiate TH2 cytokine production in humans.

The role of leukemia-derived B7-H1 (PD-L1) in tumor–T-cell interactions in humans

Expression of the B7 homolog B7-H1 (PD1-Ligand) has been proposed to enable tumor cells to evade immune surveillance. Recently, B7-H1 on murine leukemia cells was reported to mediate resistance to cytolytic T-cell destruction. We here investigate the expression and function of the B7 homolog B7-H1 in human leukemia. Leukemia cells from 30 patients and 9 human leukemia cell lines were investigated for B7-H1 expression by flow cytometry. Functional relevance of B7-H1 for tumor-immune interactions was assessed by coculture experiments using purified, alloreactive CD4 and CD8 T cells in the presence of a neutralizing anti-B7-H1 antibody. Significant B7-H1 expression levels on leukemia cells were detected in 17 of 30 patients and in eight of nine cell lines. In contrast to various other tumor entities and the data reported from a murine leukemia system, no significant inhibitory effect of leukemia-derived B7-H1 on CD4 and CD8 cytokine production (IFN-gamma, IL-2), proliferation or expression of T-cell activation markers (ICOS, CD69) was observed. Furthermore, in the presence of neutralizing B7-H1 antibody (mAb 5H1) occurred no significant changes in T cell IFN-gamma or IL-2 production or proliferation. Our data demonstrate that leukemia-derived B7-H1 seems to have no direct influence on T-cell activation, proliferation, and cytokine production in humans. Further experiments are warranted to delineate factors and characterize yet-unidentified B7-H1 receptor(s) that determine inhibitory and stimulatory functions of B7-H1 in human leukemia.

The Role of Leukemia Derived B7-H1 in Tumor-T-Cell Interactions in Humans.

Objective: Expression of the B7-homologue B7-H1 (PD1-Ligand) has been proposed to enable tumor cells to evade immune surveillance. Recently, B7-H1 on murine leukemia cells was reported to mediate resistance to cytolytic T-cell destruction. In this study we investigated the expression and functional role of the B7-homologue B7-H1 in human leukemia.Patients and Methods: Leukemia cells from 20 patients and 9 human leukemia cell lines were investigated for B7-H1 expression by flow cytometry. Functional relevance of B7-H1 for tumor-immune interactions was assessed by coculture experiments using purified, alloreactive CD4 and CD8 T-cells in the presence of a neutralizing anti-B7-H1 antibody.Results: Significant B7-H1 expression levels on leukemia cells were detected in 13 of 20 patients and in 8 of 9 cell lines. In contrast to various other tumor entities and the data reported from a murine leukemia system we did not observe any significant inhibitory effect of leukemia-derived B7-H1 on CD4 and CD8 cytokine production (IFN-g, IL-2) or expression of T-cell activation markers (ICOS, CD69). In the presence of a neutralizing B7-H1 antibody (mAb 5H1) no significant changes in T cell IFN-g or IL-2 production were observed.Conclusions: Our data demonstrate that leukemia-derived B7-H1 seems to have no direct influence on T-cell activation and cytokine production in humans. Further experiments are warranted to delineate factors and characterize yet unidentified B7-H1 receptor(s) that determine inhibitory and stimulatory functions of B7-H1 in human leukemia.

Role of helminths in regulating mucosal inflammation

The rapid rise in prevalence of ulcerative colitis (UC) and Crohn's disease (CD) in highly developed countries suggests that environmental change engenders risk for inflammatory bowel disease (IBD). Eradication of parasitic worms (helminths) through increased hygiene may be one such change that has led to increased prevalence of these diseases. Helminths alter host mucosal and systemic immunity, inhibiting dysregulated inflammatory responses. Animals exposed to helminths are protected from experimental colitis, encephalitis, and diabetes. Patients with CD or UC improve when exposed to whipworm. Lamina propria (LP) mononuclear cells from helminth-colonized mice make less interleukin (IL)-12 p40 and IFN-gamma, but more IL-4, IL-13, IL-10, TGF-beta, and PGE(2) compared to LP mononuclear cells from naive mice. Systemic immune responses show similar skewing toward Th2 and regulatory cytokine production in worm-colonized animal models and humans. Recent reports suggest that helminths induce regulatory T cell activity. These effects by once ubiquitous organisms may have protected individuals from many of the emerging immune-mediated illnesses like IBD, multiple sclerosis, type I diabetes, and asthma.

Phase 2 trial of talabostat in stage IV melanoma

7570 Background: Talabostat (T) is an oral inhibitor of dipeptidyl peptidases such as fibroblast activation protein found on the stroma of tumors and in melanomas. Administration of T stimulates cytokine and chemokine production in humans and animals resulting in specific T-cell immunity and T-cell independent activity. In xenograft models of melanoma (A375, A2058), T significantly reduced tumor size >60% in immunodeficient mice. A clinical trial was initiated to evaluate the activity of this oral agent in melanoma. Methods: Open-label, single-arm, Phase 2 study in up to 30 evaluable patients with Stage IV melanoma using the Simon 2-stage design. Treatment is administered as six 3-week cycles of T-300μg administered orally BID Days 1–14. Dose-escalation of T to 400μg BID allowed in subsequent cycles depending on tolerability. T can be continued past 6 cycles at the discretion of the investigator. Patients must have an ECOG PS 0–2 with expected survival ≥12 weeks, measureable disease per RECIST, no active CNS metastases, LDH, ALT, and AST <3X ULN, and no more than 1 prior bio- or chemotherapy regimen for Stage IV melanoma. Primary endpoint is disease response; secondary endpoints include survival, PFS, duration of response, and cytokine expression in serum and biopsy tissue. Results: Ten patients (7 men and 3 women) have enrolled to date. The median age is 64 (range 37 to 76). Six patients received prior treatment, and 4 are treatment-naive for Stage IV disease. One patient has SD after 6 cycles of treatment, 2 had PD after 2 cycles, and 6 are awaiting a post-Cycle 2 assessment. The most frequently reported AEs are edema (40%), and fatigue, nausea, and myalgia/arthralgia (all 20%). One patient experienced Grade 3 events of edema, hypotension, acute prerenal failure, hyperkalemia, nausea, and vomiting. The patient was hydrated and continued on study medication. One patient died due to PD in Cycle 1 prior to a post-baseline assessment. Conclusions: In the initial cohort of 10 patients, 1 patient has SD at 18 weeks, and 2 patients had PD after 6 weeks on treatment. Six patients are on treatment awaiting post-baseline evaluations. The most common AEs have been edema, fatigue, nausea, and myalgia/arthralgia. Updated results will be presented at the annual meeting. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Point Therapeutics Point Therapeutics Point Therapeutics Point Therapeutics

Phase 2 trial of talabostat and docetaxel in patients with stage IIIb/IV NSCLC

7120 Background: Talabostat (T) is an oral inhibitor of dipeptidyl peptidases such as fibroblast activation protein found on the stroma of tumors. Administration of T stimulates cytokine and chemokine production in humans and animals. In a mouse xenograft model, T significantly enhanced the activity of docetaxel in the A549 model of NSCLC. Methods: Open-label, single-arm, Phase 2 study in up to 41 evaluable patients with Stage IIIB/IV NSCLC using the Simon 2-stage design. Two responses (PR or CR) by WHO criteria required in the first 21 evaluable patients (defined as completion of 2 cycles with a response assessment by the investigator) to expand enrollment to 41. Up to six 3-week cycles of docetaxel (D) 75mg/m2 (Day1) with appropriate pre-medication and T-200μg administered orally BID Days 2–15. Dose-escalation of T to 300μg BID allowed in subsequent cycles depending on tolerability. Single-agent T may be continued past 6 cycles at the discretion of the investigator. Prior failure of a platinum-based therapy required with no more than 2 prior regimens allowed. ECOG PS 0–1. Primary endpoint is disease response; secondary endpoints include survival, progression-free survival, and incidence of clinically-significant events of neutropenia or anemia. Results: In the first 21 evaluable patients (10 men, 11 women), the median age is 58 (range 34–80); 14 patients had 1 prior treatment and 7 had 2. Partial responses have been seen in 2 patients. The median PFS is 19 weeks. 8 patients have continued on single-agent T beyond 6 cycles, 4 of whom had SD for at least an additional 6 weeks. The most frequently reported adverse events are edema NOS/peripheral (71%), fatigue (57%), neutropenia and leukopenia (each 43%), cough, hypotension, LDH increase, and arthralgia (each 29%). Grade 3/4 events included neutropenia, leukopenia (each 25%), and febrile neutropenia, edema, and dyspnea (all 10%). 6 patients have died during the study; 5 due to PD and one to an unspecified cardiovascular event. Conclusions: In the initial cohort of 21 patients, 2 PRs were reported. The median PFS is 19 weeks. The most common AEs are edema, fatigue, and neutropenia/leukopenia. Enrollment continues. Updated study results for all 41 evaluable patients will be presented at the annual meeting. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Point Therapeutics Point Therapeutics Point Therapeutics Point Therapeutics

Infection outcome and cytokine gene expression in Brugia pahangi- infected gerbils (Meriones unguiculatus) sensitized with Brucella abortus.

Filarial infections have been associated with the development of a strongly polarized Th2 host immune response and a severe impairment of mitogen-driven proliferation and type 1 cytokine production in mice and humans. The role of this polarization in the development of the broad spectra of clinical manifestations of lymphatic filariasis is still unknown. Recently, data gathered from humans as well as from immunocompromised mouse models suggest that filariasis elicits a complex host immune response involving both Th1 and Th2 components. However, responses of a similar nature have not been reported in immunologically intact permissive models of Brugia infection. Brucella abortus-killed S19 was inoculated into the Brugia-permissive gerbil host to induce gamma interferon (IFN-gamma) production. Gerbils were then infected with B. pahangi, and the effect of the polarized Th1 responses on worm establishment and host cellular response was measured. Animals infected with both B. abortus and B. pahangi showed increased IFN-gamma and interleukin-10 (IL-10) and decreased IL-4 and IL-5 mRNA levels compared with those in animals infected with B. pahangi alone. These data suggest that the prior sensitization with B. abortus may induce a down regulation of the Th2 response associated with Brugia infection. This reduced Th2 response was associated with a reduced eosinophilia and an increased neutrophilia in the peritoneal exudate cells. The changes in cytokine and cellular environment did not inhibit the establishment of B. pahangi intraperitoneally. The data presented here suggest a complex relationship between the host immune response and parasite establishment and survival that cannot be simply ascribed to the Th1/Th2 paradigm.