Radiation exposure induces inflammasome pathway activation in immune cells.

Radiation exposure induces cell and tissue damage, causing local and systemic inflammatory responses. Because the inflammasome pathway is triggered by cell death and danger-associated molecular patterns, we hypothesized that the inflammasome may signal acute and chronic immune responses to radiation. Using a mouse radiation model, we show that radiation induces a dose-dependent increase in inflammasome activation in macrophages, dendritic cells, NK cells, T cells, and B cells as judged by cleaved caspase-1 detection in cells. Time course analysis showed the appearance of cleaved caspase-1 in cells by day 1 and sustained expression until day 7 after radiation. Also, cells showing inflammasome activation coexpressed the cell surface apoptosis marker annexin V. The role of caspase-1 as a trigger for hematopoietic cell losses after radiation was studied in caspase-1(-/-) mice. We found less radiation-induced cell apoptosis and immune cell loss in caspase-1(-/-) mice than in control mice. Next, we tested whether uric acid might mediate inflammasome activation in cells by treating mice with allopurinol and discovered that allopurinol treatment completely blocked caspase-1 activation in cells. Finally, we demonstrate that radiation-induced caspase-1 activation occurs by a Nod-like receptor family protein 3-independent mechanism because radiation-exposed Nlrp3(-/-) mice showed caspase-1 activation profiles that were indistinguishable from those of wild-type mice. In summary, our data demonstrate that inflammasome activation occurs in many immune cell types following radiation exposure and that allopurinol prevented radiation-induced inflammasome activation. These results suggest that targeting the inflammasome may help control radiation-induced inflammation.

Correlation between human tear cytokine levels and cellular corneal changes in patients with bacterial keratitis by in vivo confocal microscopy.

PURPOSE: We investigated bilateral tear cytokine levels in patients with unilateral bacterial keratitis (BK) as associated with in vivo confocal microscopic (IVCM) alterations in corneal nerves and dendritiform immune cells (DCs). METHODS: A total of 54 (13 BK, 13 contralateral, 28 healthy controls) tear samples was collected prospectively and analyzed by multiplex microbeads assay. The IVCM of the central cornea was performed on the same day, and assessed for corneal nerve and DC alterations. RESULTS: Interleukin-1ß, IL-6, and IL-8 were significantly elevated only in affected eyes (66.6 ± 26.8, 7174 ± 2430, and 810 ± 315 ρg/mL, respectively; P = 0.04, P < 0.001, and P < 0.001, respectively), compared to healthy controls (13.0 ± 4.0, 171.8 ± 32.1, and 56.5 ± 33.8 ρg/mL). Levels of chemokine ligand 2 (CCL-2), IL-10, and IL-17a were elevated only in contralateral eyes (813 ± 478, 86.7 ± 38.3, and 3350 ± 881 ρg/mL, respectively; P = 0.02, P = 0.01, and P = 0.04, respectively), compared to controls (73.7 ± 25.3, 17.5 ± 4.9, and 1350 ± 337 ρg/mL). Triggering receptor expressed on myeloid cells (TREM)-1 was significantly elevated in affected (551 ± 231 ρg/mL, P = 0.02) and contralateral unaffected (545 ± 298 ρg/mL, P = 0.03) eyes compared to controls (31.3 ± 12.4 ρg/mL). The density of DCs was significantly increased in affected (226.9 ± 37.3 cells/mm(2), P < 0.001) and unaffected (122.3 ± 23.7 cells/mm(2), P < 0.001) eyes compared to controls (22.7 ± 5.9 cells/mm(2)). Sub-basal nerve density significantly decreased in affected (3337 ± 1615 µm/mm(2), P < 0.001) and contralateral (13,230 ± 1635 µm/mm(2), P < 0.001) eyes compared to controls (21,200 ± 545 µm/mm(2)). Levels of IL-1ß, IL-6, and IL-8 were significantly correlated with DC density (R = 0.40, R = 0.55, and R = 0.31, all P < 0.02) and nerve density (R = -0.30, R = -0.53, and R = -0.39, all P < 0.01). CONCLUSIONS: Proinflammatory tear cytokines are elevated bilaterally in patients with unilateral BK, and are correlated strongly with alterations in DCs and nerve density as detected by IVCM.

The safety and tolerability of intravenous ASA404 when administered in combination with docetaxel (60 or 75 mg/m²) in Japanese patients with advanced or recurrent solid tumors.

OBJECTIVE: This Phase I study was carried out to assess the safety, tolerability, pharmacokinetics and preliminary efficacy of the flavonoid tumor-vascular disrupting agent ASA404 (vadimezan) in combination with docetaxel in Japanese patients with advanced or recurrent solid tumors. METHODS: Nine Japanese patients were given ASA404 (1800 mg/m(2)) plus two doses of docetaxel, 60 or 75 mg/m(2), administered every 3 weeks. RESULTS: Dose-limiting toxicity of Grade 3 febrile neutropenia was observed in one patient during Cycle 1 at Level 2 of ASA404 (1800 mg/m(2)) and docetaxel (75 mg/m(2)) treatment. The most frequently reported adverse events were neutropenia, fatigue, alopecia, decreased appetite, constipation and injection site pain. These adverse events were mainly Grade 1 or 2 in severity and, with the exception of injection site pain, were typically associated with docetaxel therapy. A partial response was observed in one patient, and five patients (55.6%) exhibited stable disease. Overall, the study demonstrated that ASA404 has an acceptable tolerability profile when combined with docetaxel at doses up to 75 mg/m(2) in Japanese patients with advanced solid tumors. CONCLUSIONS: The study supports the enrollment of Japanese patients in the Phase III study (ATTRACT-2) of ASA404 in combination with docetaxel for the second-line treatment of advanced non-small cell lung cancer. Clinicaltrials.gov identifier: NCT01285453.