Protection of insects against virus infection by apoptosis-dependent phagocytosis

We investigated whether phagocytosis participates in the protection of insects from viral infection using the natural host???virus interaction between Drosophila melanogaster and Drosophila C virus (DCV). Drosophila S2 cells were induced to undergo apoptotic cell death upon DCV infection. However, UV-inactivated virus was unable to cause apoptosis, indicating the need for productive infection for apoptosis induction. S2 cells became susceptible to phagocytosis by hemocyte-derived l(2)mbn cells after viral infection, and the presence of phagocytes in S2 cell cultures reduced viral proliferation. Phagocytosis depended, in part, on caspase activity in S2 cells, as well as the engulfment receptors Draper and integrin ???? in phagocytes. To validate the in vivo situation, adult flies were abdominally infected with DCV, followed by the analysis of fly death and viral growth. DCV infection killed flies in a dose-responding manner, and the activation of effector caspases was evident, as revealed by the cleavage of a target protein ectopically expressed in flies. Furthermore, hemocytes isolated from infected flies contained DCV-infected cells, and preinjection of latex beads to inhibit the phagocytic activity of hemocytes accelerated fly death after viral infection. Likewise, viral virulence was exaggerated in flies lacking the engulfment receptors, and was accompanied by the augmented proliferation of virus. Finally, phagocytosis of DCV-infected cells in vitro was inhibited by phosphatidylserine-containing liposome, and virus-infected flies died early when a phosphatidylserine-binding protein was ectopically expressed. Collectively, our study demonstrates that the apoptosis-dependent, phosphatidylserine-mediated phagocytosis of virus-infected cells plays an important role in innate immune responses against viral infection in Drosophila

The Impact of Immunosenescence on Immune Responses: A Challenge on Influenza Vaccination in the Elderly

The global population of people older than 65 years is estimated to rise dramatically due to advances in average life expectancy. A massive increase in the numbers of elderly persons; from 600 million at present to nearly 2 billion in 2050, is expected to happen worldwide and, approximately, 25 % of the population in developed countries will be older than 65. To date, the ageing population presents a challenge for the public healthcare system since the elderly suffer from more frequent and severe infections compare to their younger counterparts. In addition, poor outcomes from infections tend to be experienced by aged people in comparison to the younger population. Influenza, particularly, is an example of a common infection which causes annual epidemics, and in the elderly, is associated with increased morbidity. In fact, one of the ten major causes of death in the elderly is influenza. One of the main reasons for the increase of infections observed in the elderly is believed to be a gradual deterioration of the immune system that occur with ageing which leads to a decline in the response to infection by both the innate and adaptive immune systems, namely immunosenescence. Basically, since the immune response in the elderly declines and the outcome of infect-ion is often poor, prevention of infection becomes critically important . Vaccination against important infectious pathogens such as influenza, could provide a sufficient protection in the elderly and in this case is recommended by the World Health Organization. Unfortunately, immunosenescence not only impairs the ability of the immune system to fend off infection but also its capacity to respond to immunisation, as shown by the reduced efficacy of annual influenza vaccination in the elderly, with an efficacy of 17-53% in the elderly compare to 70-90% in healthy adults. Despite considerable progress in influenza vaccine development and our understanding in immunosenescence mechanisms, we still do not have a clear understanding regarding the impact of immunosenescence on the effectiveness of influenza vaccination in the elderly. It is important to identify this issue since several studies have reported the effectiveness of influenza vaccination in the elderly during seasonal outbreak while other studies present contradictory results. Further elucidation of the relationship between immunosene-scence and infuenza vaccination efficacy would reveal the way to improve immune response of the aged people and therefore, improve their quality of life during influenza outbreak

Review : Penggunaan Drosophila Melanogaster Sebagai Organisme Model Dalam Penemuan Obat: Review : Application of Drosophila Melanogaster as Model Organism in Drug Discovery

Uji pra-klinis kandidat obat baru menggunakan organisme model yang sesuai adalah salah satu fase yang wajib dilaksanakan dalam proses penemuan obat. Namun, seiring dengan meningkatnya perhatian masyarakat dunia terhadap etika penggunaan organisme model tradisional seperti mencit dan tikus, keberadaan organisme model alternatif pun sangat diperlukan. Untuk tujuan tersebut, lalat buah Drosophila melanogaster merupakan salah satu model yang patut diperhitungkan. Selain sejarah penggunaannya yang telah cukup lama, organisme model ini merupakan serangga di Balik kesuksesan ilmuwan dalam mempelajari patogenesis penyakit mulai dari penyakit neurodegeneratif hingga sindrom metabolik terkait obesitas dan diabetes melitus. Oleh karena itu, tidaklah mengherankan jika delapan medali Nobel telah diberikan kepada para peneliti yang menggunakan Drosophila dalam eksperimen mereka. Pemetaan genom yang telah berhasil dilakukan menunjukkan bahwa Drosophila memiliki kemiripan genetik sekitar 75% dengan manusia. Ditunjang dengan ketersediaan berbagai model penyakit baik melalui manipulasi genetik (mutan/transgenik) maupun melalui induksi secara kimiawi, Drosophila merupakan organisme model yang sangat menjanjikan untuk digunakan dalam riset biomedik. Dengan tersedianya berbagai model penyakit dan informasi terkait Drosophila melanogaster yang mudah untuk diakses, penggunaan model penyakit berbasis lalat buah dalam proses penemuan obat merupakan salah satu terobosan yang layak untuk dipertimbangkan. Bukan tidak mungkin jika di kemudian hari model mungil ini akan menggantikan penggunaan hewan model tradisional dalam pengujian pra-klinik kandidat obat baru

Green tea extract-mediated augmentation of imipenem antibacterial activity against Enterobacter cloacae clinical isolates

The emergence of pathogenic bacteria with β-lactam antibiotics-resistant profile has threatened the continued use of such antibiotics in the future. This research was conducted to investigate the antimicrobial activity of green tea ethanol extract (GTE) and its ability to improve the antibacterial action of several β-lactam antibiotics against Enterobacter cloacae clinical isolates. The simplicia of green tea was extracted by sonication for 30 minutes using 50% ethanol solvent, and the total phenolic content of the GTE was subsequently determined. Next, the GTE used in testing against two clinical isolates of E. cloacae was obtained from the Pathology Laboratory of Wahidin Sudiro Husodo Hospital in Makassar. The sensitivity of bacteria to GTE was confirmed using the agar diffusion method, the Vitek® rapid method, and the double-disk synergistic test. Antibacterial activity of antibiotics, GTE, and combination of antibiotics with GTE were then tested against clinical isolates of E. cloacae using the checkerboard microdilution assay. The results showed that GTE contained 51.64 ± 0.21 % measured as gallic acid equivalent and 37.95 + 5.17 % Epigallocatechin gallate (EGCG). The confirmatory test results indicated that one clinical isolate of E. cloacae (code 13/04) was resistant to amoxicillin-clavulanate but did not produce an extended-spectrum β-lactamase (ESBL). Another clinical E. cloacae isolate (code 275B/06) was indicated to produce ESBL and demonstrated to yield resistance to amoxicillin-clavulanate and cefotaxime. The minimum inhibitory concentration of GTE against the two clinical isolates of E. cloacae was >8000 ppm (8 mg/ml). In conclusion, GTE could not increase the antibacterial activity of amoxicillin and cefotaxime, but it was sufficient to improve the activity of imipenem against the tested isolates of E. cloacae

Antiviral Role of Apoptosis-Dependent Phagocytosis of Virus-Infected Cells in Drosophila

13301甲第4369号博士(創薬科学)金沢大学博士論文本文Full 以下に掲載：Journal of Immunology 195(12) pp.5696-5706 2015. American Association of Immunologists. 共著者：Firzan Nainu, Yumiko Tanaka, Akiko Shiratsuchi, Yoshinobu Nakanish

EFFECT OF GREEN TEA EXTRACT ON MODULATING THE ANTIBACTERIAL ACTIVITY OF STANDARD ANTIBIOTICS AGAINST THE CLINICAL ISOLATES OF Acinetobacter baumannii

Most of the clinical isolates of Acinetobacter baumannii are found resistant to the β-lactam antibiotics. This research aimed to determine the ability of green tea extract in modulating the antibacterial activity of standard antibiotics amoxicillin, cefotaxime, and imipenem against the clinical isolates of A. baumannii. The clinical isolates used in this study were collected from the Laboratory of Clinical Pathology, Wahidin Sudiro Husodo Hospital Makassar, Indonesia. To determine whether the bacterial isolate is resistant, the experiment was carried out using disk agar diffusion and Vitek-2 methods. Further, the antibacterial activity of the green tea, selected antibiotics, and their combination was determined by using a checkerboard microdilution assay. Results of the study revealed that among the selected two clinical isolates one of the A. baumannii isolates was found resistant to selected standard amoxicillin-clavulanate, cefotaxime, and imipenem, while the other one was found sensitive. Further, green tea extract with a concentration of up to 1.2 mg/ml didn't have any significant effect on the inhibition of A. baumannii growth. Similarly, at the same concentration (1.2 mg/ml) no modulation effect of green tea extract was reported on the antibacterial activity of amoxicillin, cefotaxime, and imipenem against the A. baumannii isolates

Fruit fly as a model organism in the study of human diseases and drug discovery

Drug discovery is a dynamic yet an ever-lasting topic in medicine that heavily relies on the application of modelorganisms. Through the use of suitable model organisms, pre-clinical testing of new drug candidates can be carried out tensively prior to further testing with humans. This has been proven, so far, as one of efficient ways to limit the emergence of new substances that are potentially harmful to individuals. Nevertheless, increasing public interest in the thical issues raised by the use of live model organisms, such as mice and rats, pushes urgent needs for alternative modelorganisms. To this end, fruit fly Drosophila melanogaster might be an appropriate model organism to be accounted r.With its long-standing history of use, Drosophila is an insect behind the revelation of striking similarity to humans as to basic biological mechanisms and their tight controls to maintain homeostasis. Impairment of such events in rosophila is linked to the emergence of metabolic-related diseases such as obesity and diabetes mellitus, the unsolved cases of neurodegenerative diseases, and the fall of host immune responses against various infectious agents. With a igh genetic similarity, about 75%, to humans, ease of maintenance, and the availability of various disease models constructed through genetic manipulation and/or chemical induction, Drosophila has been a very promising model organism in he field of drug discovery. With this in mind, it would be not surprising if this tiny yet powerful model organism will soon substitute our current in vivo platform in the pre-clinical testing of new drug candidates

Sensor Asam Nukleat Sebagai Aktivator Imunitas Intrinsik Terhadap Patogen Intraseluler: Nucleic Acid Sensors as Activators of Intrinsic Immunity Against Intracellular Pathogens

Vertebrata, termasuk manusia, dilengkapi dengan sistem imun alamiah dan sistem imun adaptif yang saling bekerjasama untuk melindungi tubuh dari material berbahaya, termasuk berbagai patogen dan sel-sel kanker. Kedua sistem imun tersebut secara rutin melakukan pengecekan terhadap beragam material yang ada di dalam tubuh. Salah satu cara yang digunakan oleh sistem imun dalam melaksanakan tugasnya adalah melalui pengaktifan sensor asam nukleat yang berfungsi untuk memberikan informasi keberadaan DNA atau RNA asing maupun kemungkinan adanya salinan DNA inang di sitoplasma atau lokasi lain yang tidak semestinya. Ketika genom patogen terdeteksi oleh sensor-sensor tersebut, selanjutnya efektor sistem imun akan diaktivasi melalui serangkaian proses dan berakhir dengan eradikasi asam nukleat target atau bahkan induksi apoptosis sel yang bersangkutan. Beberapa sensor asam nukleat yang telah ditemukan antara lain adalah Toll-like receptor (TLR), RIG-I-like receptors (RLRs), cyclic GMP-AMP synthase (cGAS), dan interferon-γ-inducible protein 16 (IFI16). Namun, sejumlah patogen telah memiliki mekanisme untuk menghindari sensor-sensor tersebut sehingga infeksi tetap dapat terjadi. Dengan demikian, berbagai penelitian untuk meningkatkan pengetahuan tentang bagaimana sensor asam nukleat bekerja sebagai salah satu respon imun intraseluler serta mekanisme terbentuknya resistensi patogen terhadap deteksi sensor tersebut sangat penting untuk didorong. Hal ini akan memberikan wawasan baru dalam pengembangan berbagai sediaan farmasi terkait seperti vaksin dan antimikroba intraseluler

Fungi Endofit dari Tanaman Secang (Caesalpinia Sappan L) sebagai Penghasil Senyawa Antioksidan: Endophytic Fungi From Secang (Caesalpinia Sappan L) AS Producer Of Antioxidant Compounds

Endophytic fungi are microbes that reside symbiotically in the plant tissues with undetected negative impacts to their host plants. These fungi are able to produce elements similar to those produced by their host plants. Secang (Caesalpinia sappan L.) has been known as one of the medicinal plants that contains compounds with antioxidant activity thus promote a hypothesis that its endophytic fungi may yield a similar antioxidant effect. In this study, the isolation of endophytic fungi from Secang as the producer of antioxidant compounds was carried out. At the initial stage, endophytic fungi were isolated from the leaves, the twigs, the stems, and the rootsof Secang using the agar plate method. Pure fungi isolates were then subjected to fermentation process using the PDBgrowth medium supplemented with yeast extractand wereconstantly shaken for 12 days at a speed of 200 rpm to produce secondary metabolites. Fermentatesobtained from all fungi isolates were then extracted using ethyl acetate and further tested for their antioxidant activities. In this study, of 19 isolates that were obtained from four parts of the Secang, five fungi isolates, coded as IFD1, IFD4, IFR5, IFA1, and IFA2 were found to yield antioxidant activities demonstrated by the presence of yellow spots on the chromatogram. elementary schools representatives “not good ranking”, the education did not influence their knowledge with a p value of 0.149. Analysis of the Wilcoxon test in all elementary schools showed a p value p ≤ 0,001, which meant that education had an influence on the knowledge of fifth grade students in elementary schools in Palu City

Inflammation-mediated Phenoconversion: A Potential Threat to COVID-19 Pharmacotherapy

One of the important hallmarks of coronavirus disease 2019 (COVID-19) is the existence of severe inflammatory responses. Many reports indicated that inflammatory mediators might suppress the biological functions of some drug metabolizing enzymes and transporters, and therefore result in a transient mismatch between their genotype and phenotype expressions, a phenomenon which is called phenoconversion. The incidence might be clinically relevant to the COVID-19 patients with comorbidities. The patients are treated with multiple drugs that are prone to be altered pharmacokinetically by inflammation-mediated phenoconversion, leading to the modification of their effectiveness and safety. In this review, we discuss the regulation of inflammatory responses during COVID-19 infection and the evidence as well as potential mechanisms of inflammation-mediated phenoconversion. We also provide possible clinical implications of such phenoconversion events as a potential threat in the management of COVID-19 patients