Loxoprofen sodium induces the production of complement C5a in human serum.

Basophil activation test (BAT) is an in vitro allergy test that is useful to identify allergens that cause IgE-dependent allergies. The test has been used to detect not only food allergies and allergies caused by environmental factors but also to detect drug hypersensitivity, which has been known to include IgE-independent reactions. In our preliminary studies in which BAT was applied to detect hypersensitivity of loxoprofen, a non-steroidal anti-inflammatory drug (NSAID), conventional BAT with incubation for 30min did not show basophil activation by means of increased CD203c expression. In this study, we extended the incubation time to 24h on the basis of the hypothesis that loxoprofen indirectly activates basophils. Basophils from healthy control donors as well as allergic patients showed up-regulation of CD203c after incubation with loxoprofen for 24h. Activation was induced using loxoprofen-treated serum. Proteomic and pharmacologic analyses revealed that serum incubation with loxoprofen generated an active complement component C5a, which induced CD203c expression via binding to the C5a receptor on basophils. Because C3a production was also detected after incubation for 24h, loxoprofen is likely to stimulate the complement classical pathway. Our findings suggest that the complement activation is involved in drug hypersensitivity and the suppression of this activation may contribute to the elimination of false positive of BAT for drug allergies.

Proteomic identification of autoantibodies in sera from patients with ovarian cancer as possible diagnostic biomarkers.

BACKGROUND/AIM: Accumulating evidence shows that various types of cancers induce a specific immune response resulting in the production of antibodies against self-components (autoantibodies). The aim of the present study was to identify antigens for autoantibodies in sera from patients with ovarian cancer, especially clear cell carcinoma (CCC), as novel diagnostic markers for the disease. MATERIALS AND METHODS: The reactivity of individual sera from patients was examined by two-dimensional (2-D) immunoblotting using lysates of CCC cell lines, ES-2 and RMG-1, as antigens to identify autoantigens. ELISA was established to quantitatively measure autoantibody titer of patients' sera. RESULTS: Autoantibodies against RhoGDI were induced in sera of ovarian cancer patients. Elevated levels of autoantibodies against heterogeneous nuclear ribonucleoprotein L (hnRNPL) and a mitochondrial protein, dihydrolipoamide dehydrogenase (DLD), were detected in patients with CCC. CONCLUSION: Autoantibodies against RhoGDI and hnRNPL and DLD may serve as novel diagnostic markers for ovarian cancer and CCC, respectively.

Proteomic identification of dihydrolipoamide dehydrogenase as a target of autoantibodies in patients with endometrial cancer.

BACKGROUND/AIM: Accumulating evidence shows that various types of cancers induce a specific immune response, resulting in the production of antibodies against self-components (autoantibodies). The aim of the present study was to identify antigens for autoantibodies in sera from endometrial cancer patients as novel diagnostic markers for the disease. MATERIALS AND METHODS: The reactivity of individual sera from patients was examined by 2-dimensional (2-D) immunoblotting using HeLa cell lysates as antigens to identify autoantigens. ELISA was established to quantitatively measure autoantibody titer of patients' sera. RESULTS: A mitochondrial protein, dihydrolipoamide dehydrogenase (DLD), was identified as an autoantigen specific to endometrial cancer patients. The levels of immunoglobulin (Ig)A but not IgG autoantibody to DLD were significantly increased in the sera of endometrial cancer patients. CONCLUSION: IgA autoantibody against DLD could be a novel diagnostic marker for endometrial cancer.

DNA-binding profiling of human hormone nuclear receptors via fluorescence correlation spectroscopy in a cell-free system.

The nuclear hormone receptors (NHRs), a family of transcription factors, bind directly to the hormone response elements (HREs) to regulate gene expression. In this study, we describe a comprehensive NHR-HRE profiling analysis with a new high-throughput DNA binding assay system utilizing wheat germ cell-free protein production and fluorescence correlation spectroscopy (FCS). This approach revealed NHR binding to natural response elements and new heterodimeric NHR-HRE bindings. We analyzed 408 possible binding combinations between 34 human NHRs and 12 different HREs, and identified 205 NHR-HRE binding combinations, 124 of which have not been previously reported. Thus, this study provides a novel biochemical classification of the human NHRs, as well as describing a novel approach to the large-scale analysis of DNA-protein interactions.