CD44 is widely expressed on the surface of most tissues and all hematopoietic cells, and regulates many genes associated with cell adhesion, migration, proliferation, differentiation, and survival. CD44 has also been studied as a therapeutic target in several cancers. Previously, an anti-CD44 monoclonal antibody (mAb), C 44 Mab-5 (IgG 1 , kappa) was established by immunizing mice with CD44-overexpressing Chinese hamster ovary (CHO)-K1 cells. C 44 Mab-5 recognized all CD44 isoforms, and showed high sensitivity for flow cytometry and immunohistochemical analysis in oral cancers. However, as the IgG 1 subclass of C 44 Mab-5 lacks antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), the antitumor activity of C 44 Mab-5 could not be determined. In the present study, we converted the mouse IgG 1 subclass antibody C 44 Mab-5 into an IgG 2a subclass antibody, 5-mG 2a , and further produced a defucosylated version, 5-mG 2a-f, using FUT8-deficient ExpiCHO-S (BINDS-09) cells. Defucosylation of 5-mG 2a-f was confirmed using fucose-binding lectins, such as AAL and PhoSL. The dissociation constants (K D) for 5-mG 2a-f against SAS and HSC-2 oral cancer cells were determined through flow cytometry to be 2.8x10-10 M and 2.6x10-9 M, respectively, indicating that 5-mG 2a-f possesses extremely high binding affinity. Furthermore, immunohistochemical staining using 5-mG 2a-f specifically stained the membranes of oral cancer cells. In vitro analysis demonstrated that 5-mG 2a-f showed moderate ADCC and CDC activities against SAS and HSC-2 oral cancer cells. In vivo analysis revealed that 5-mG 2a-f significantly reduced tumor development in SAS and HSC-2 xenografts in comparison to control mouse IgG, even after injection seven days post-tumor inoculation. Collectively, these results suggest that treatment with 5-mG 2a-f may represent a useful therapy for patients with CD44-expressing oral cancers.

BackgroundHepatitis E virus (HEV) infection is a significant public health concern in Asia, and swine is an important source of sporadic HEV infection in human. However, no epidemiological data are available regarding HEV infection among the swine or human population in the Philippines. To assess the HEV infection status among pigs in rural areas, we investigated the molecular characteristics and seroprevalence of HEV among household-raised pigs in San Jose, Tarlac Province, the Philippines.ResultSerum and rectal swab samples were collected from 299 pigs aged 2–24 months from 155 households in four barangays (villages) between July 2010 and June 2011. Enzyme-linked immunosorbent assay (ELISA) revealed that 50.3% [95% confidence interval (CI) 44.5–56.2%] and 22.9% (95% CI 18.2–28.1%) of pigs tested positive for anti-HEV IgG and IgM, respectively. HEV RNA was detected in the feces of 22 pigs (7.4%, 95% CI 4.7–10.9%). A total of 103 households (66.5%, 95% CI 58.4–73.8%) had at least one pig that tested positive for anti-HEV IgG or IgM or HEV RNA. The prevalence of anti-HEV IgG and IgM in breeding pig (8–24 months) were higher than that in growing pigs (2–4 months) (p < 0.0001 and p = 0.008, respectively). HEV RNA was more frequently detected in 2–4-month-old pigs (9.2%, 95% CI 5.4–14.6%) than in ≥5-month-old pigs (4.8%, 95% CI 1.1–8.5%) without statistical significance (p = 0.142). HEV RNA showed 0–27.6% nucleotide difference at the partial ORF2 gene among the detected viruses, and a majority of them belonged to subtype 3a (20/22, 90.9%).ConclusionWe found a high prevalence of HEV antibodies in the household-raised pig population in rural areas of the Philippines, which indicates the potential risk of HEV infection among local residents. Only genotype 3 of HEV was observed, and genetically diverse strains of HEV were found to be circulating in pigs in this study.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-015-0322-z) contains supplementary material, which is available to authorized users.

Economic loss due to viral endothelial cell necrosis of eel (VECNE) of Anguilla japonica is a serious problem for the cultured Japanese eel market. However, the viral genome responsible for VECNE is unknown. We recently developed a rapid determination system for viral nucleic acid sequences (RDV) to determine viral genome sequences. In this study, viral DNA fragments were obtained using RDV, and approximately 15-kbp circular full genome sequences were determined using a next-generation sequencing system, overlapping PCR, and Southern blot analysis. One open reading frame (ORF) was homologous to the large T-antigen of polyomavirus; other ORFs have no homology with any nucleic or amino acid sequences of polyomavirus. Therefore, as this DNA virus might comprise a novel virus family, we provisionally named it Japanese eel endothelial cells-infecting virus (JEECV). JEECV was detected in both naturally and experimentally infected eels, suggesting that JEECV potentially causes VECNE.

We report a patient with congenital Chagas disease in Japan. This report reemphasizes the role of neglected and emerging tropical diseases in the era of globalization. It also indicates the need for increased vigilance for detecting Chagas disease in non–disease-endemic countries.