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Biomedical subjects

James J Lee

Publications and source records attributed to James J Lee.

At least 19 recordsLinked to original sources

Robust inference and correlates from genetic associations with personality.

Personality traits describe stable differences in how people think, feel and behave, and how they interact with and experience their social and physical environments1,2. Many questions remain unanswered about associations between DNA and personality traits, such as their robustness, their generalizability and the biological and social pathways through which they act. Here we meta-analyse data across 46 cohorts comprising 611,037 to 1.14 million participants with European-like and African-like genomes for genome-wide association studies (GWAS) of the Big Five personality traits (extraversion, agreeableness, conscientiousness, neuroticism and openness to experience), and data from up to 50,725 participants for within-family GWAS. We identify 1,260 lead genetic variants associated with personality, including 824 novel variants3. Common genetic variants explain a moderate 4.8-9.3% of the variance in measures of each trait, and 9.3-13.3% among instruments with typical measurement reliability. Genetic associations with personality are highly consistent but not identical across geography, reporter (self versus close other), age group and measurement instrument, and we find minimal spousal assortment for personality in recent history. In contrast to many other social and behavioural traits4,5, within-family GWAS and polygenic index analyses indicate that genetic associations with personality are minimally confounded by the shared family environment. Polygenic prediction, genetic correlation and Mendelian randomization analyses indicate that personality traits have widespread, potentially causal associations with consequential behaviours and life outcomes. Overall, we find that the genetic architecture of personality is robustly generalizable, minimally confounded and widely relevant to human experience.

Journal Article↗

Eosinophilic granulocytes and damage-associated molecular pattern molecules (DAMPs): role in the inflammatory response within tumors.

The development of a tumor over many years typically leads to reciprocal alternations in the host and the tumor, enabling tumor growth paradoxically in the setting of substantial necrosis and inflammation. When evaluating a tumor, it is important to assess 3 elements: (1) the quantity and quality of tumor-associated leukocytes, (2) their state of activation, and (3) tumor microenvironment. Peripheral blood eosinophilia and tumor-associated tissue eosinophilia are frequently associated with some tumor types and also found after immunotherapy with IL-2, IL-4, granulocyte-macrophage colony-stimulating factor, and antibody to CTLA-4. Within several tumor types including gastrointestinal tumors, tumor-associated tissue eosinophilia is associated with a significantly better prognosis. The converse is true in other tumor types such as differentiated oral squamous cell carcinoma. On the basis of the emergent data, tumor-associated eosinophils have at least 2 dominant nonoverlapping activities: (1) destructive effector functions potentially limiting tumor growth as well as causing recruitment and activation of other leukocytes, (2) immunoregulative and remodeling activities which suppress immune response and promote tumor proliferation. The mechanism by which eosinophils in particular are recruited into tumor tissue is largely unknown. Candidates for causing eosinophil chemotaxis into tumor tissue are the released damage-associated molecular pattern molecules (DAMPs) including the nuclear protein high mobility group box 1. High mobility group box 1 is released upon necrotic cell death and secreted by many cells, particularly during periods of nutrient, hypoxic, or oxidant stress. This overview on eosinophil biology in the context of cancer and necrosis, introduces intriguing and novel strategies targeting eosinophils to enable more effective biologic therapy for cancer patients.

Eosinophils↗

CD69 expression on airway eosinophils and airway inflammation in a murine model of asthma.

BACKGROUND: Asthma is a chronic airway disease with inflammation characterized by physiological changes (airway hyper-responsiveness, AHR) and pathological changes (inflammatory cells infiltration and mucus production). Eosinophils play a key role in the allergic inflammation. But the causative relationship between eosinophils and airway inflammation is hard to prove. One of the reasons is lack of activation marker of murine eosinophils. We investigated the expression of CD69 on murine eosinophils in vitro, the relationship between the expression of CD69 on eosinophils from peripheral blood and bronchoalveolar lavage fluid and on airway inflammation in asthmatic mice. METHODS: Eosinophils from peripheral blood of IL-5 transgenic mice (NJ.1638) were purified. Mice were divided into five groups: wild type mice sensitized and challenged with saline (WS group), wild type mice sensitized and challenged with ovalbumin (WO group), IL-5(-/-) mice sensitized and challenged with saline and transferred with purified eosinophils (ISE group), IL-5(-/-) mice sensitized and challenged with OVA and transferred with purified eosinophils (IOE group), IL-5(-/-) mice sensitized and challenged with OVA and transferred with purified eosinophils, pretreated with anti CD4 monoclonal antibody (IOE+antiCD4mAb group). IL-5(-/-) mice were sensitized with OVA at day 0 and day 14, then challenged with OVA aerosol. On days 24, 25, 26 and 27 purified eosinophils were transferred intratracheally to IL-5(-/-) mice. On day 28, blood and BALF were collected and CD69 expression on eosinophils measured by flowcytometry. RESULTS: Purified eosinophils did not express CD69. But eosinophils cultured with PMA + MA, IFN-gamma, IL-5 or GM-CSF expressed CD69 strongly. Eosinophils from blood of WO, WS group did not express CD69 at all. The numbers of eosinophils in BALF of WO group, IOE group, ISE group and IOE + antiCD4mAb group were significantly higher than in mice of WS group which did not have eosinophils at all. CD69 expression on eosinophils in BALF of IOE and WO groups was strong. Eosinophils in BALF of ISE and IOE + antiCDmAb groups did not express CD69. The mucus production result was similar to CD69 expression. There were eosinophils infiltration in lung slides of all groups except WS group. CONCLUSION: Activation in airway of eosinophils could directly lead to airway inflammation.

Animals↗

Novel approach to inhibit asthma-mediated lung inflammation using anti-CD147 intervention.

Extracellular cyclophilins have been well described as chemotactic factors for various leukocyte subsets. This chemotactic capacity is dependent upon interaction of cyclophilins with the cell surface signaling receptor CD147. Elevated levels of extracellular cyclophilins have been documented in several inflammatory diseases. We propose that extracellular cyclophilins, via interaction with CD147, may contribute to the recruitment of leukocytes from the periphery into tissues during inflammatory responses. In this study, we examined whether extracellular cyclophilin-CD147 interactions might influence leukocyte recruitment in the inflammatory disease allergic asthma. Using a mouse model of asthmatic inflammation, we show that 1) extracellular cyclophilins are elevated in the airways of asthmatic mice; 2) mouse eosinophils and CD4+ T cells express CD147, which is up-regulated on CD4+ T cells upon activation; 3) cyclophilins induce CD147-dependent chemotaxis of activated CD4+ T cells in vitro; 4) in vivo treatment with anti-CD147 mAb significantly reduces (by up to 50%) the accumulation of eosinophils and effector/memory CD4+ T lymphocytes, as well as Ag-specific Th2 cytokine secretion, in lung tissues; and 5) anti-CD147 treatment significantly reduces airway epithelial mucin production and bronchial hyperreactivity to methacholine challenge. These findings provide a novel mechanism whereby asthmatic lung inflammation may be reduced by targeting cyclophilin-CD147 interactions.

Animals↗

When is a mouse basophil not a basophil?

The identification and characterization of mouse basophils have historically been hampered by the extreme rarity of this cell type. Virtually no photomicrographs of hematologically stained (eg, Wright-Giemsa) examples of mouse basophils exist in the literature. However, 4 recent studies in the past 2 years have used flow cytometry and a defined set of cell-surface markers to identify and subsequently isolate mouse "basophils," including the publication of stained cytospin preparations of these cells. Surprisingly, a reevaluation of the data from all 4 of the studies revealed several issues of concern that suggest that the cells under study are not necessarily basophils. Nonetheless, we propose that these studies do provide the foundation for a reevaluation of the defining characteristics of a basophil and/or provide support for the provocative conclusion that a new previously overlooked leukocyte subtype has been identified. The purpose of this commentary is to revisit these previously published studies, highlight the relevant issues, and provide a different perspective in the hope of developing a consensus within the research community as to the true identity of the "basophils" described in these studies.

Animals↗

Phase II trial of ixabepilone, an epothilone B analog, given daily for three days every three weeks, in metastatic breast cancer.

Twelve patients with metastatic breast cancer previously exposed to taxanes were treated on a Phase II trial with ixabepilone. Eligible patients had histologically confirmed metastatic breast cancer with measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST), and adequate hematopoietic, renal, and hepatic function. Ixabepilone 8 mg/m(2)/day was given intravenously daily for 3 days for the first 3-week cycle and increased to 10 mg/m(2)/day for subsequent cycles if patients did not have hematologic or other toxicity after the first cycle. Patients continued treatment until progressive disease or unacceptable toxicity. Three, 29, and 33 of 65 cycles administered were at the 7 mg/m(2), 8 mg/m(2) and 10 mg/m(2) dose levels respectively. Grade 4 leukopenia (n=1), grade 3 neutropenia (n=2), grade 2 neuropathy (n=3), and grade 2 transaminase elevation (n=2) were the most notable toxicities. Ten patients had stable disease for at least 6 weeks. No complete or partial responses were observed in 12 evaluable patients treated with ixabepilone daily for 3 days. Although ixabepilone was well-tolerated, the dose of 8-10 mg/m(2) daily for 3 days is not an effective therapy in metastatic breast cancer previously exposed to taxanes.

Adult↗

Schistosoma mansoni infection in eosinophil lineage-ablated mice.

We explore the controversial issue of the role of eosinophils in host defense against helminthic parasites using the established Schistosoma mansoni infection model in 2 novel mouse models of eosinophil lineage ablation (DeltadblGATA and TgPHIL). No eosinophils were detected in bone marrow of infected DeltadblGATA or TgPHIL mice, despite the fact that serum IL-5 levels in these infected mice exceeded those in infected wild type by approximately 4-fold. Liver granulomata from infected DeltadblGATA and TgPHIL mice were likewise depleted of eosinophils compared with those from their respective wild types. No eosinophil-dependent differences in granuloma number, size, or fibrosis were detected at weeks 8 or 12 of infection, and differential accumulation of mast cells was observed among the DeltadblGATA mice only at week 12. Likewise, serum levels of liver transaminases, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) increased in all mice in response to S mansoni infection, with no eosinophil-dependent differences in hepatocellular damage observed. Finally, eosinophil ablation had no effect on worm burden or on egg deposition. Overall, our data indicate that eosinophil ablation has no impact on traditional measures of disease in the S mansoni infection model in mice. However, eosinophils may have unexplored immunomodulatory contributions to this disease process.

Animals↗

Regulatory role of CD8+ T lymphocytes in bone marrow eosinophilopoiesis.

BACKGROUND: There is a growing body of evidence to suggest that CD8+ T lymphocytes contribute to local allergen-induced eosinophilic inflammation. Since bone marrow (BM) responses are intricately involved in the induction of airway eosinophilia, we hypothesized that CD8+ T lymphocytes, as well as CD4+ T lymphocytes, may be involved in this process. METHODS: Several approaches were utilized. Firstly, mice overexpressing interleukin-5 (IL-5) in CD3+ T lymphocytes (NJ.1638; CD3IL-5+ mice) were bred with gene knockout mice lacking either CD4+ T lymphocytes (CD4-/-) or CD8+ T lymphocytes (CD8-/-) to produce CD3IL-5+ knockout mice deficient in CD4+ T lymphocytes (CD3IL-5+/CD4-/-) and CD8+ T lymphocytes (CD3IL-5+/CD8-/-), respectively. Secondly, CD3+, CD4+ and CD8+ T lymphocytes from naïve CD3IL-5+ and C57BL/6 mice were adoptively transferred to immunodeficient SCID-bg mice to determine their effect on BM eosinophilia. Thirdly, CD3IL-5+, CD3IL-5+/CD8-/- and CD3IL-5+/CD4-/- mice were sensitized and allergen challenged. Bone marrow and blood samples were collected in all experiments. RESULTS: The number of BM eosinophils was significantly reduced in CD3IL-5+/CD8-/- mice compared to CD3IL-5+ mice and CD3IL-5+/CD4-/- mice. Serum IL-5 was significantly higher in CD3IL-5+/CD4-/- mice compared to CD3IL-5+ mice but there was no difference in serum IL-5 between CD3IL-5+/CD4-/- and CD3IL-5+/CD8-/- mice. Adoptive transfer of CD8+, but not CD4+ T lymphocytes from naïve CD3IL-5+ and C57BL/6 mice restored BM eosinophilia in immunodeficient SCID-bg mice. Additionally, allergen challenged CD3IL-5+/CD8-/- mice developed lower numbers of BM eosinophils compared to CD3IL-5+ mice and CD3IL-5+/CD4-/- mice. CONCLUSION: This study shows that CD8+ T lymphocytes are intricately involved in the regulation of BM eosinophilopoiesis, both in non-sensitized as well as sensitized and allergen challenged mice.

Adoptive Transfer↗

Changes in neurologic function tests may predict neurotoxicity caused by ixabepilone.

PURPOSE: To investigate baseline factors and neurologic function tests (NFTs) that may predict the development of grade 2 or higher peripheral neuropathy (PN) after treatment with ixabepilone, an epothilone microtubule-stabilizing agent with antitumor activity. PATIENTS AND METHODS: Advanced breast cancer patients were treated with ixabepilone (6 mg/m2) for 5 consecutive days every 3 weeks in a phase II clinical trial. Physical examinations, questionnaires, nerve conduction studies, and NFTs, including the Jebsen Test of Hand Function (JTH) and the Grooved Pegboard Test (GPT), were performed at baseline and during subsequent cycles. RESULTS: Forty-seven patients assessable for PN received a median of five cycles of therapy (range, one to 22 cycles). Nine of these patients developed grade 2 PN, and two developed grade 3 PN, with a median time to onset of 144 days (range, 6 to 189 days). Among these 11 patients, PN resolved in eight patients, with a median of 15 days (range, 6 to 346 days) after onset, but PN did not resolve in three patients during follow-ups at 76, 361, and 746 days after onset. GPT and changes of JTH scores at onset of PN were significantly different between patients with and without PN at comparable follow-up times (P = .006 and P = .002, respectively). Changes in GPT and JTH scores over the first two cycles were often associated with the development of PN by exploratory actuarial analysis. CONCLUSION: Serious ixabepilone-induced neuropathy was relatively rare on the treatment schedule used. NFTs, such as JTH and GPT, may have utility for predicting PN, but further testing is needed.

Adult↗

Pivotal Advance: eosinophil infiltration of solid tumors is an early and persistent inflammatory host response.

Tumor-associated eosinophilia has been observed in numerous human cancers and several tumor models in animals; however, the details surrounding this eosinophilia remain largely undefined and anecdotal. We used a B16-F10 melanoma cell injection model to demonstrate that eosinophil infiltration of tumors occurred from the earliest palpable stages with significant accumulations only in the necrotic and capsule regions. Furthermore, the presence of diffuse extracellular matrix staining for eosinophil major basic protein was restricted to the necrotic areas of tumors, indicating that eosinophil degranulation was limited to this region. Antibody-mediated depletion of CD4+ T cells and adoptive transfer of eosinophils suggested, respectively, that the accumulation of eosinophils is not associated with T helper cell type 2-dependent immune responses and that recruitment is a dynamic, ongoing process, occurring throughout tumor growth. Ex vivo migration studies have identified what appears to be a novel chemotactic factor(s) released by stressed/dying melanoma cells, suggesting that the accumulation of eosinophils in tumors occurs, in part, through a unique mechanism dependent on a signal(s) released from areas of necrosis. Collectively, these studies demonstrate that the infiltration of tumors by eosinophils is an early and persistent response that is spatial-restricted. It is more important that these data also show that the mechanism(s) that elicit this host response occur, independent of immune surveillance, suggesting that eosinophils are part of an early inflammatory reaction at the site of tumorigenesis.

Animals↗

Peripheral neuropathy induced by microtubule-stabilizing agents.

Microtubule-stabilizing agents (MTSAs), including the taxanes and epothilones, are effective chemotherapeutic agents for the treatment of many cancers. Neuropathy is a major adverse effect of MTSA-based chemotherapy, with severe peripheral neuropathy (grade 3 or 4) occurring in as many as 30% of patients treated with a MTSA. MTSA-induced neuropathy usually resolves gradually after cessation of the treatment. The most reliable method to accurately assess MTSA-induced neuropathy is by clinical evaluation, although additional techniques are being developed and evaluated. Among MTSA-induced neuropathy, the most extensively studied is that induced by taxanes; such a neuropathy usually presents as sensory neuropathy and is more common with paclitaxel than docetaxel. The incidence of MTSA-induced neuropathy seems to depend on the MTSA dose per treatment cycle, the schedule of treatment, and the duration of the infusion. Although there have been several small clinical trials with neuroprotective agents, early recognition and supportive care are the best approaches for prevention and management of MTSA-induced neuropathy. In the future, research should focus on elucidating the mechanism of MTSA-induced neuropathy, developing reliable in vivo and in vitro preclinical models to study MTSA-induced neuropathy, developing a more reliable grading system for MTSA-induced neuropathy, developing more reliable methods for evaluating MTSA-induced neuropathy, and evaluating the efficacy of potential neuroprotective agents in clinical trials.

Albumin-Bound Paclitaxel↗

Pro-oxidative diesel exhaust particle chemicals inhibit LPS-induced dendritic cell responses involved in T-helper differentiation.

BACKGROUND: Epidemiologic studies show that exposure to ambient particulate matter leads to asthma exacerbation. Diesel exhaust particles (DEPs), a model pollutant, act as an adjuvant for allergic sensitization. Increasing evidence shows that this effect could be mediated by an effect on dendritic cells (DCs). OBJECTIVE: Our aim was to elucidate the mechanism by which pro-oxidative DEP chemicals change DC function so that these antigen-presenting cells strengthen the immune response to an experimental allergen. METHODS: We exposed murine bone marrow-derived DCs and a homogeneous myeloid DC line, BC1, to DEPs and organic extracts made from these particles to determine how the induction of oxidative stress affects cellular maturation, cytokine production, and activation of antigen-specific T cells. RESULTS: DEP extracts induced oxidative stress in DCs. This change in redox equilibrium interfered in the ability of Toll-like receptor agonists to induce the expression of maturation receptors (eg, CD86, CD54, and I-A(d)) and IL-12 production. This perturbation of DC function was accompanied by decreased IFN-gamma and increased IL-10 induction in antigen-specific T cells. The molecular basis for the perturbation of DC function is the activation of a nuclear factor-erythroid 2 (NF-E2)-related factor 2-mediated signaling pathway that suppresses IL-12 production. NF-E2-related factor 2 deficiency abrogates the perturbation of DC function by DEPs. CONCLUSION: These data provide the first report that pro-oxidative DEP chemicals can interfere in T(H)1-promoting response pathways in a homogeneous DC population and provide a novel explanation for the adjuvant effect of DEPs on allergic inflammation. CLINICAL IMPLICATIONS: These data clarify the adjuvant effect of particulate air pollutants in allergic inflammatory disease.

Adjuvants, Immunologic↗

Validation of a new grading system for endoscopic examination of adenoid hypertrophy.

OBJECTIVE: To propose and validate a new subjective grading system of adenoid size with flexible fiberoptic evaluation. STUDY DESIGN AND SETTING: Digital video clips of 24 flexible fiberoptic nasopharyngeal exams were presented to 24 examiners (otolaryngology resident and consultant physicians) at a tertiary care institution. Examiners were asked to use the proposed grading system to rate adenoid hypertrophy. Kappa statistical analysis was used to evaluate the degree of intergrader agreement or disagreement. RESULTS: Statistical analysis of intergrader agreement demonstrated an overall Kappa score of 0.71 suggesting a "substantial" strength of agreement. The Kappa strength of agreement was found to be 0.83 (almost perfect) among consultant physicians and 0.62 (substantial) among resident physicians. CONCLUSIONS: The proposed adenoid staging system is a reliable and consistent method of staging adenoid tissue size. SIGNIFICANCE: This new validated grading system may be a useful standard for reporting adenoid size in future clinical outcome studies.

Adenoids↗

Lack of eosinophil peroxidase or major basic protein impairs defense against murine filarial infection.

Eosinophils are a hallmark of allergic diseases and helminth infection, yet direct evidence for killing of helminth parasites by their toxic granule products exists only in vitro. We investigated the in vivo roles of the eosinophil granule proteins eosinophil peroxidase (EPO) and major basic protein 1 (MBP) during infection with the rodent filaria Litomosoides sigmodontis. Mice deficient for either EPO or MBP on the 129/SvJ background developed significantly higher worm burdens than wild-type mice. Furthermore, the data indicate that EPO or MBP is involved in modulating the immune response leading to altered cytokine production during infection. Thus, in the absence of MBP, mice showed increased interleukin-10 (IL-10) production after stimulation of macrophages from the thoracic cavity where the worms reside. In addition to elevated IL-10 levels, EPO(-/-) mice displayed strongly increased amounts of the Th2 cytokine IL-5 by CD4 T cells as well as a significantly higher eosinophilia. Interestingly, a reduced ability to produce IL-4 in the knockout strains could even be seen in noninfected mice, arguing for different innate propensities to react with a Th2 response in the absence of either EPO or MBP. In conclusion, both of the eosinophil granule products MBP and EPO are part of the defense mechanism against filarial parasites. These data suggest a hitherto unknown interaction between eosinophil granule proteins, defense against filarial nematodes, and cytokine responses of macrophages and CD4 T cells.

Animals↗

Role of eosinophils and neutrophils in innate and adaptive protective immunity to larval strongyloides stercoralis in mice.

The goal of this study was to determine the roles of eosinophils and neutrophils in innate and adaptive protective immunity to larval Strongyloides stercoralis in mice. The experimental approach used was to treat mice with an anti-CCR3 monoclonal antibody to eliminate eosinophils or to use CXCR2-/- mice, which have a severe neutrophil recruitment defect, and then determine the effect of the reduction or elimination of the particular cell type on larval killing. It was determined that eosinophils killed the S. stercoralis larvae in naïve mice, whereas these cells were not required for the accelerated killing of larvae in immunized mice. Experiments using CXCR2-/- mice demonstrated that the reduction in recruitment of neutrophils resulted in significantly reduced innate and adaptive protective immunity. Protective antibody developed in the immunized CXCR2-/- mice, thereby demonstrating that neutrophils were not required for the induction of the adaptive protective immune response. Moreover, transfer of neutrophil-enriched cell populations recovered from either wild-type or CXCR2-/- mice into diffusion chambers containing larvae demonstrated that larval killing occurred with both cell populations when the diffusion chambers were implanted in immunized wild-type mice. Thus, the defect in the CXCR2-/- mice was a defect in the recruitment of the neutrophils and not a defect in the ability of these cells to kill larvae. This study therefore demonstrated that both eosinophils and neutrophils are required in the protective innate immune response, whereas only neutrophils are necessary for the protective adaptive immune response to larval S. stercoralis in mice.

Animals↗

Eosinophils can function as antigen-presenting cells to induce primary and secondary immune responses to Strongyloides stercoralis.

Several studies have demonstrated roles for eosinophils during innate and adaptive immune responses to helminth infections. However, evidence that eosinophils are capable of initiating an immune response to parasite antigens is lacking. The goal of the present in vitro study was to investigate the potential of eosinophils to serve as antigen-presenting cells (APC) and initiate an immune response to parasite antigens. Purified eosinophils were exposed to soluble Strongyloides stercoralis antigens, and the expression of various surface markers involved in cell activation was examined. Antigen-exposed eosinophils showed a sixfold increase in expression levels of CD69 and major histocompatibility complex (MHC) class II, a fourfold increase in levels of T-cell costimulatory molecule CD86, and a twofold decrease in levels of CD62L compared to eosinophils cultured in medium containing granulocyte-macrophage colony-stimulating factor. The ability of eosinophils to present antigen to T cells was determined by culturing them with T cells in vitro. Eosinophils pulsed with antigen stimulated antigen-specific primed T cells and CD4+ T cells to increase interleukin-5 (IL-5) production. The blocking of MHC class II expression on eosinophils inhibited their ability to induce IL-5 production by CD4+ T cells in culture. Antigen-pulsed eosinophils were able to prime naïve T cells and CD4+ T cells in culture and polarized them into Th2 cells producing IL-5 similar to that induced by antigen-loaded dendritic cells. These results demonstrate that eosinophils are capable of activating antigen-specific Th2 cells inducing the release of cytokines and assist in the priming of naïve T cells to initiate Th2 responses against infection. This study highlights the potential of eosinophils to actively induce immune responses against infection by amplifying antigen-specific Th2-cell responses.

Animals↗