159 research outputs found
Immune response of healthy horses to DNA constructs formulated with a cationic lipid transfection reagent
Background Deoxyribonucleic acid (DNA) vaccines are used for experimental
immunotherapy of equine melanoma. The injection of complexed linear DNA
encoding interleukin (IL)-12/IL-18 induced partial tumour remission in a
clinical study including 27 grey horses. To date, the detailed mechanism of
the anti-tumour effect of this treatment is unknown. Results In the present
study, the clinical and cellular responses of 24 healthy horses were monitored
over 72 h after simultaneous intradermal and intramuscular application of
equine IL-12/IL-18 DNA (complexed with a transfection reagent) or comparative
substances (transfection reagent only, nonsense DNA, nonsense DNA depleted of
CG). Although the strongest effect was observed in horses treated with
expressing DNA, horses in all groups treated with DNA showed systemic
responses. In these horses treated with DNA, rectal temperatures were elevated
after treatment and serum amyloid A increased. Total leukocyte and neutrophil
counts increased, while lymphocyte numbers decreased. The secretion of tumour
necrosis factor alpha (TNFα) and interferon gamma (IFNγ) from peripheral
mononuclear blood cells ex vivo increased after treatments with DNA, while
IL-10 secretion decreased. Horses treated with DNA had significantly higher
myeloid cell numbers and chemokine (C-X-C motif) ligand (CXCL)-10 expression
in skin samples at the intradermal injection sites compared to horses treated
with transfection reagent only, suggesting an inflammatory response to DNA
treatment. In horses treated with expressing DNA, however, local CXCL-10
expression was highest and immunohistochemistry revealed more intradermal
IL-12-positive cells when compared to the other treatment groups. In contrast
to non-grey horses, grey horses showed fewer effects of DNA treatments on
blood lymphocyte counts, TNFα secretion and myeloid cell infiltration in the
dermis. Conclusion Treatment with complexed linear DNA constructs induced an
inflammatory response independent of the coding sequence and of CG motif
content. Expressing IL-12/IL-18 DNA locally induces expression of the
downstream mediator CXCL-10. The grey horses included appeared to display an
attenuated immune response to DNA treatment, although grey horses bearing
melanoma responded to this treatment with moderate tumour remission in a
preceding study. Whether the different immunological reactivity compared to
other horses may contributes to the melanoma susceptibility of grey horses
remains to be elucidated
Therapeutic T cells induce tumor-directed chemotaxis of innate immune cells through tumor-specific secretion of chemokines and stimulation of B16BL6 melanoma to secrete chemokines
Background: The mechanisms by which tumor-specific T cells induce regression of established metastases are not fully characterized. In using the poorly immunogenic B16BL6-D5 (D5) melanoma model we reported that T cell-mediated tumor regression can occur independently of perforin, IFN-gamma or the combination of both. Characterization of regressing pulmonary metastases identified macrophages as a major component of the cells infiltrating the tumor after adoptive transfer of effector T cells. This led us to hypothesize that macrophages played a central role in tumor regression following T-cell transfer. Here, we sought to determine the factors responsible for the infiltration of macrophages at the tumor site. Methods: These studies used the poorly immunogenic D5 melanoma model. Tumor-specific effector T cells, generated from tumor vaccine-draining lymph nodes (TVDLN), were used for adoptive immunotherapy and in vitro analysis of chemokine expression. Cellular infiltrates into pulmonary metastases were determined by immunohistochemistry. Chemokine expression by the D5 melanoma following co-culture with T cells, IFN-gamma or TNF-alpha was determined by RT-PCR and ELISA. Functional activity of chemokines was confirmed using a macrophage migration assay. T cell activation of macrophages to release nitric oxide (NO) was determined using GRIES reagent. Results: We observed that tumor-specific T cells with a type 1 cytokine profile also expressed message for and secreted RANTES, MIP-1 alpha and MIP-1 beta following stimulation with specific tumor. Unexpectedly, D5 melanoma cells cultured with IFN-gamma or TNF-alpha, two type 1 cytokines expressed by therapeutic T cells, secreted Keratinocyte Chemoattractant (KC), MCP-1, IP-10 and RANTES and expressed mRNA for MIG. The chemokines released by T cells and cytokine-stimulated tumor cells were functional and induced migration of the DJ2PM macrophage cell line. Additionally, tumor-specific stimulation of wt or perforin-deficient (PKO) effector T cells induced macrophages to secrete nitric oxide (NO), providing an additional effector mechanism for T cell-mediated tumor regression. Conclusion: These data suggest two possible sources for chemokine secretion that stimulates macrophage recruitment to the site of tumor metastases. Both appear to be initiated by T cell recognition of specific antigen, but one is dependent on the tumor cells to produce the chemokines that recruit macrophages
Relevance of Stress and Female Sex Hormones for Emotion and Cognition
There are clear sex differences in incidence and onset of stress-related and other psychiatric disorders in humans. Yet, rodent models for psychiatric disorders are predominantly based on male animals. The strongest argument for not using female rodents is their estrous cycle and the fluctuating sex hormones per phase which multiplies the number of animals to be tested. Here, we will discuss studies focused on sex differences in emotionality and cognitive abilities in experimental conditions with and without stress. First, female sex hormones such as estrogens and progesterone affect emotions and cognition, contributing to sex differences in behavior. Second, females respond differently to stress than males which might be related to the phase of the estrous cycle. For example, female rats and mice express less anxiety than males in a novel environment. Proestrus females are less anxious than females in the other estrous phases. Third, males perform in spatial tasks superior to females. However, while stress impairs spatial memory in males, females improve their spatial abilities, depending on the task and kind of stressor. We conclude that the differences in emotion, cognition and responses to stress between males and females over the different phases of the estrous cycle should be used in animal models for stress-related psychiatric disorders
Managing formalization to increase global team effectiveness and meaningfulness of work in multinational organizations
Global teams may help to integrate across locations, and yet, with formalized rules and procedures, responsiveness to those locations’ effectiveness, and the team members’ experiences of work as meaningful may suffer. We employ a mixed-methods approach to understand how the level and content of formalization can be managed to resolve these tensions in multinationals. In a sample of global teams from a large mining and resources organization operating across 44 countries, interviews, observations, and a quantitative 2-wave survey revealed a great deal of variability between teams in how formalization processes were enacted. Only those formalization processes that promoted knowledge sharing were instrumental in improving team effectiveness. Implementing rules and procedures in the set-up of the teams and projects, rather than during interactions, and utilizing protocols to help establish the global team as a source of identity increased this knowledge sharing. Finally, we found members’ personal need for structure moderated the effect of team formalization on how meaningful individuals found their work within the team. These findings have significant implications for theory and practice in multinational organizations
Immune response of healthy horses to DNA constructs formulated with a cationic lipid transfection reagent
Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Fermilab Tevatron
We have measured the number of like-sign (LS) and opposite-sign (OS) lepton pairs arising from double semileptonic decays of b and (b) over bar hadrons, pair produced at the Fermilab Tevatron collider. The data samples were collected with the Collider Detector at Fermilab during the 1992-1995 collider run by triggering on the existence of mumu or emu candidates in an event. The observed ratio of LS to OS dileptons leads to a measurement of the average time-integrated mixing probability of all produced b-flavored hadrons which decay weakly, (χ) over bar =0.152+/-0.007 (stat)+/-0.011 (syst), that is significantly larger than the world average (χ) over bar =0.118+/-0.005
Measurement of the Ratio of b Quark Production Cross Sections in Antiproton-Proton Collisions at 630 GeV and 1800 GeV
We report a measurement of the ratio of the bottom quark production cross
section in antiproton-proton collisions at 630 GeV to 1800 GeV using bottom
quarks with transverse momenta greater than 10.75 GeV identified through their
semileptonic decays and long lifetimes. The measured ratio
sigma(630)/sigma(1800) = 0.171 +/- .024 +/- .012 is in good agreement with
next-to-leading order (NLO) quantum chromodynamics (QCD)
Observation of the narrow state X(3872)-\u3e J/psi pi(+)pi(-) in (p)over-barp collisions at root s=1.96 TeV
We report the observation of a narrow state decaying into J/psipi(+)pi(-) and produced in 220 pb(-1) of (p) over barp collisions at roots=1.96 TeV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c(2), with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson
Search for lepton flavor violating decays of a heavy neutral particle in p(p)over-bar collisions at root s=1.8 TeV
We report on a search for a high mass, narrow width particle that decays directly to emu, etau, or mutau. We use approximately 110 pb(-1) of data collected with the Collider Detector at Fermilab from 1992 to 1995. No evidence of lepton flavor violating decays is found. Limits are set on the production and decay of sneutrinos with R-parity violating interactions
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