Microbial Antigen-Presenting Extracellular Vesicles Derived from Genetically Modified Tumor Cells Promote Antitumor Activity of Dendritic Cells.

Tumor-derived extracellular vesicles (EVs), as tumor vaccines, carry tumor-associated antigens (TAAs), and were expected to transfer TAAs to antigen-presenting cells. However, treatment with tumor-derived EVs exhibited no obvious antitumor effect on the established tumors, likely due to their immuno-suppressive functions, and also to the poor immunogenicity of TAAs. In order to improve the immune stimulating properties, EVs expressing a highly immunogenic bacterial antigen, 6 kDa early secretory antigenic target (ESAT-6), from Mycobacterium tuberculosis were prepared by genetically modifying the parent tumor cells with a plasmid coding for ESAT-6. Cultured B16 tumor cells were transfected with a ternary complex system consisting of pDNA, polyethylenimine (PEI), and chondroitin sulfate. The cells that were transfected with the ternary complex secreted EVs with a higher number of ESAT-6 epitopes than those transfected by a conventional DNA/PEI binary complex, due to the low cytotoxicity, and durable high expression efficiency of the ternary complex systems. The EVs presenting the ESAT-6 epitope (ESAT-EV) were collected and explored as immune modulatory agents. Dendritic cells (DCs) were differentiated from mouse bone marrow cells and incubated with ESAT-EV. After incubating with the EVs for one day, the DCs expressed a significantly higher level of DC maturation marker, CD86. The DCs treated with ESAT-EV showed a significantly improved antitumor activity in tumor-bearing mice.

Development of the Japanese version of the Westmead Home Safety Assessment for the elderly in Japan.

OBJECTIVE: Home safety assessment and intervention is a key component in the management of fall risk in elderly people. However, a standardised assessment for home safety has not yet been established in Japan. We developed a Japanese version of the Westmead Home Safety Assessment by partially modifying the original version according to house structures and lifestyles in Japan and examined its inter-rater reliability and content validity. METHODS: Japanese elderly in the community who had fear of falls were recruited to investigate the reliability of the Japanese version of the Westmead Home Safety Assessment. Two occupational therapists simultaneously visited a participant's home to perform the Japanese version of the Westmead Home Safety Assessment independently. Further, an expert panel of 18 occupational therapists evaluated the relevance of each item of the Japanese version of the Westmead Home Safety Assessment. RESULTS: Fifty elderly people (aged 78.2 ± 7.1 years) participated in this reliability study. The most frequent hazards were identified as internal steps/stairs, seating, bathroom, bath, and external steps/stairs. Forty-nine items (69%) in the Japanese version of the Westmead Home Safety Assessment were rated to have fair to good (0.40 < κ < 0.75) or excellent (κ ≥ 0.75) reliability as well as excellent validity (item content validity ≥0.78). These items were concerned with basic activities of daily living and some simple instrumental activities of daily living. The scale content validity was 0.78 ± 0.16 but was not excellent (scale content validity index <0.90). CONCLUSIONS: This study suggested that 49 items in the Japanese version of the Westmead Home Safety Assessment were appropriate for home safety assessment for Japanese elderly. Further research is necessary to improve the reliability and validity of the present version of the Japanese version of the Westmead Home Safety Assessment for this population.

Innate immunity mediated by dendritic cells/macrophages plays a central role in the early period in tumor treatment using gene of Mycobacterium tuberculosis antigen.

By using a complex of DNA, polyethylenimine and chondroitin sulfate, the in vivo transfection of early secretory antigenic target-6 (ESAT-6) gene into tumor cells was found to cause significant suppression of the tumor growth. In order to apply the method in clinical cancer treatment in dogs and cats, mechanisms underlying the suppressive effects were investigated in a tumor-bearing mouse model. The transfection efficiency was only about 10%, but the transfection of ESAT-6 DNA nevertheless induced systemic immune responses against ESAT-6. By triple injection of ESAT-6 DNA at three day intervals, the tumor was significantly reduced and almost disappeared by 5 days after the start of treatment, and did not increase for more than 15 days after the final treatment. In the immunohistochemistry, a larger number of dendritic cells (DCs)/macrophages expressing ionized calcium-binding adapter molecule 1 and CD3+ T cells was observed in tumors treated with ESAT-6 DNA, and their population further increased significantly by day 5. Moreover, the amount of tumor necrosis factor, which is an apoptosis-inducing factor produced mainly by DCs/macrophages, was greater in the ESAT-6 DNA treated tumors than in controls, and increased with repeat of the treatment. These results indicate that in vivo transfection of ESAT-6 DNA into tumor cells elicits significant inhibition of tumor growth by inducing potent activity of innate immunity mediated by DCs/macrophages, which may be followed by adaptive immunity against tumor associated antigens, elicited by the costimulation with ESAT-6 antigen.

Exosomes derived from tumor cells genetically modified to express Mycobacterium tuberculosis antigen: a novel vaccine for cancer therapy.

OBJECTIVES: To examine the potential of exosomes derived from the tumor cells, which had been genetically modified to express a Mycobacterium tuberculosis antigen, as a cancer vaccine aimed at overcoming the weak immunogenicity of tumor antigens. RESULTS: We transfected B16 melanoma cells with a plasmid encoding the M. tuberculosis antigen, early secretory antigenic target-6 (ESAT-6). The secreted exosomes bearing both tumor-associated antigens and the pathogenic antigen (or their epitopes) were collected. When the exosomes were injected into foot pads of mice, they significantly (p < 0.05) evoked cellular immunity against both ESAT-6, and B16 tumor cells. Intra-tumoral injection of the exosomes significantly suppressed (p < 0.001) tumor growth in syngeneic B16 tumor-bearing mice, while the exosomes derived from the non-transfected B16 cells showed no effect on tumor growth, although both exosomes should have similar tumor antigens. CONCLUSIONS: Exosomes bearing both tumor antigens and the M. tuberculosis antigen (or their epitopes) have a high potential as a candidate for cancer vaccine to overcome the immune escape by tumor cells.

Spalt-mediated dve repression is a critical regulatory motif and coordinates with Iroquois complex in Drosophila vein formation.

Veins are longitudinal cuticular structures that maintain shape of the wing. Drosophila melanogaster has six longitudinal veins (L1-L6) and two cross veins. The Zn-finger transcription factors of Spalt-complex (Sal) are required for positioning of the L2 and L5, and the homeodomain transcription factors of Iroquois complex (Iro-C) are required for formation of the L3 and L5 veins. The homeodomain transcriptional repressor Defective proventriculus (Dve) is uniformly expressed in the wing pouch of the larval imaginal disc. However, dve mutant wings showed loss of the L2 and L5, but not of the L3 and L4 veins. Temporal dve knockdown experiments indicate that the Dve activity is required for vein formation from late third larval instar to the prepupal stage. In the prepupal wing, Dve expression becomes nearly complementary to that of Sal through the Sal-mediated dve repression. Furthermore, coexpression of Dve and Iro-C relieved of Sal-mediated repression is required for the L5 formation in a dose-dependent manner. The relationship between Sal, Dve, and Iro-C in wing vein specification is quite similar to that in ommatidial cell-type specification. Our results provide information about the conserved function of dve regulatory motifs in cell differentiation.

Integrating child health services into malaria control services of village malaria workers in remote Cambodia: service utilization and knowledge of malaria management of caregivers.

BACKGROUND: Malaria and other communicable diseases remain major threats in developing countries. In Cambodia, village malaria workers (VMWs) have been providing malaria control services in remote villages to cope with the disease threats. In 2009, the VMW project integrated child health services into the original malaria control services. However, little has been studied about the utilization of VMWs' child health services. This study aimed to identify determinants of caregivers' VMW service utilization for childhood illness and caregivers' knowledge of malaria management. METHODS: A cross-sectional study was conducted in 36 VMW villages of Kampot and Kampong Thom provinces in July-September 2012. An equal number of VMW villages with malaria control services only (M) and those with malaria control plus child health services (M+C) were selected from each province. Using structured questionnaires, 800 caregivers of children under five and 36 VMWs, one of the two VMWs who was providing VMW services in each study village were interviewed. RESULTS: Among the caregivers, 23% in M villages and 52% in M+C villages utilized VMW services for childhood illnesses. Determinants of caregivers' utilization of VMWs in M villages included their VMWs' length of experience (AOR = 11.80, 95% confidence interval [CI] = 4.46-31.19) and VMWs' service quality (AOR = 2.04, CI = 1.01-4.11). In M+C villages, VMWs' length of experience (AOR = 2.44, CI = 1.52-3.94) and caregivers' wealth index (AOR = 0.35, CI = 0.18-0.68) were associated with VMW service utilization. Meanwhile, better service quality of VMWs (AOR = 3.21, CI = 1.34-7.66) and caregivers' literacy (AOR = 9.91, CI = 4.66-21.05) were positively associated with caregivers' knowledge of malaria management. CONCLUSIONS: VMWs' service quality and length of experience are important determinants of caregivers' utilization of VMWs' child health services and their knowledge of malaria management. Caregivers are seeking VMWs' support for childhood illnesses even if they are providing only malaria control services. This underlines the importance of scaling-up VMWs' capacity by adding child health services of good quality, which will result in improving child health status in remote Cambodia.