548 research outputs found
Epidermal I-J-Bearing Cells Are Responsible for Transferable Suppressor Cell Generation After Immunization of Mice with Ultraviolet Radiation-Treated Epidermal Cells
Subcutaneous immunization of mice with hapten-coupled, ultraviolet radiation (UVR)-treated epidermal cells (EC) results in a hyporesponsive delayed-type hypersensitivity (DTH) response associated with the appearance of afferent-acting, hapten-specific T suppressor (Ts) cells. Depletion of I-J-bearing cells from the EC population prior to UVR-exposure and hapten coupling prevents the appearance of these Ts cells. However, non- UVR-treated EC depleted of I-J-bearing cells and hapten-coupled are capable of immunizing mice for a DTH response. Therefore, the set of I-J-bearing EC appears to be distinct from classic Langerhans cells. A novel set of 1-J-bearing EC appears to be responsible for Ts activation after subcutaneous immunization with hapten-coupled UVR-treated EC
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Fab@Home Model 2: Towards Ubiquitous Personal Fabrication Devices
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Lack of the purinergic receptor P2X7 results in resistance to contact hypersensitivity
Engagement of P2X7 on mouse dendritic cells, presumably by ATP released in response to contact allergen, is needed for IL-1β production and the sensitization phase of contact hypersensitivity
Long non-coding RNA GRASLND enhances chondrogenesis via suppression of the interferon type II signaling pathway
The roles of long noncoding RNAs (lncRNAs) in musculoskeletal development, disease, and regeneration remain poorly understood. Here, we identified the novel lncRN
The role of released ATP in killing Candida albicans and other extracellular microbial pathogens by cationic peptides
A unifying theme common to the action of many cationic peptides that display lethal activities against microbial pathogens is their specific action at microbial membranes that results in selective loss of ions and small nucleotides chiefly ATP. One model cationic peptide that induces non-lytic release of ATP from the fungal pathogen Candida albicans is salivary histatin 5 (Hst 5). The major characteristic of Hst 5-induced ATP release is that it occurs rapidly while cells are still metabolically active and have polarized membranes, thus precluding cell lysis as the means of release of ATP. Other cationic peptides that induce selective release of ATP from target microbes are lactoferricin, human neutrophil defensins, bactenecin, and cathelicidin peptides. The role of released extracellular ATP induced by cationic peptides is not known, but localized increases in extracellular ATP concentration may serve to potentiate cell killing, facilitate further peptide uptake, or function as an additional signal to activate the host innate immune system at the site of infection
Low zone tolerance requires ICAM-1 expression to limit contact hypersensitivity elicitation.
Painting subsensitizing doses of contact sensitizers on skin (low-dose tolerization) induces antigen (Ag)-specific tolerance, known as low zone tolerance (LZT), which has been experimentally demonstrated by the inhibition of contact hypersensitivity (CHS). Although LZT resulted from the inhibition of the sensitization phase, the effects on the effector/elicitation phase remain unknown. L-selectin and ICAM-1 regulate leukocyte influx into inflamed tissues during the elicitation phase of CHS. LZT was investigated in mice lacking either L-selectin or ICAM-1 to evaluate the roles these leukocyte receptors play in LZT during the elicitation phase. Low-dose tolerization effectively suppressed CHS in wild-type and L-selectin-deficient mice, but not in ICAM-1-deficient mice. Low-dose-tolerized ICAM-1-deficient splenocytes effectively suppressed the elicitation phase in naive wild-type recipients. Sensitized ICAM-1-deficient splenocytes showed normal proliferative responses to the sensitizing Ag and generated normal CHS in wild-type recipients. Thus, ICAM-1 deficiency did not affect sensitization. LZT was associated with a lack of ICAM-1 upregulation after elicitation, suggesting a potentially mechanistic role for ICAM-1. The blockade of IL-10, a possible mediator of LZT, produced by hapten-specific suppressor cells, abrogated LZT and restored ICAM-1 upregulation. These results indicate that low-dose tolerization controls CHS by abrogating ICAM-1 upregulation during the elicitation phase
High-Anxious Individuals Show Increased Chronic Stress Burden, Decreased Protective Immunity, and Increased Cancer Progression in a Mouse Model of Squamous Cell Carcinoma
In spite of widespread anecdotal and scientific evidence much remains to be understood about the long-suspected connection between psychological factors and susceptibility to cancer. The skin is the most common site of cancer, accounting for nearly half of all cancers in the US, with approximately 2–3 million cases of non-melanoma cancers occurring each year worldwide. We hypothesized that a high-anxious, stress-prone behavioral phenotype would result in a higher chronic stress burden, lower protective-immunity, and increased progression of the immuno-responsive skin cancer, squamous cell carcinoma. SKH1 mice were phenotyped as high- or low-anxious at baseline, and subsequently exposed to ultraviolet-B light (1 minimal erythemal dose (MED), 3 times/week, 10-weeks). The significant strengths of this cancer model are that it uses a normal, immunocompetent, outbred strain, without surgery/injection of exogenous tumor cells/cell lines, and produces lesions that resemble human tumors. Tumors were counted weekly (primary outcome), and tissues collected during early and late phases of tumor development. Chemokine/cytokine gene-expression was quantified by PCR, tumor-infiltrating helper (Th), cytolytic (CTL), and regulatory (Treg) T cells by immunohistochemistry, lymph node T and B cells by flow cytometry, adrenal and plasma corticosterone and tissue vascular-endothelial-growth-factor (VEGF) by ELISA. High-anxious mice showed a higher tumor burden during all phases of tumor development. They also showed: higher corticosterone levels (indicating greater chronic stress burden), increased CCL22 expression and Treg infiltration (increased tumor-recruited immuno-suppression), lower CTACK/CCL27, IL-12, and IFN-γ gene-expression and lower numbers of tumor infiltrating Th and CTLs (suppressed protective immunity), and higher VEGF concentrations (increased tumor angiogenesis/invasion/metastasis). These results suggest that the deleterious effects of high trait anxiety could be: exacerbated by life-stressors, accentuated by the stress of cancer diagnosis/treatment, and mediate increased tumor progression and/or metastasis. Therefore, it may be beneficial to investigate the use of chemotherapy-compatible anxiolytic treatments immediately following cancer diagnosis, and during cancer treatment/survivorship
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