Agus Setiyono

Some characteristics of a cellular receptor for virulent infectious bursal disease virus by using flow cytometry

SummaryA flow cytometric virus binding assay that directly visualizes the binding of infectious bursal disease virus (IBDV) to its target cells was established. The chicken B lymphoblastoid cell line, LSCC-BK3, which is permissive for IBDV infection, bound high levels of the virus. Another B lymphoblastoid cell line, LSCC-1104-B1, bound low levels of the virus, although it was nonpermissive. No virus binding was detected in nonpermissive T lymphoblastoid cell lines. In the binding assay to heterogeneous cell populations of chicken lymphocytes, IBDV (a highly virulent OKYM strain) bound to 94% cells in the lymphocytes prepared from the bursa of Fabricius, 37% cells in those prepared from the spleen, 3% cells in those prepared from the thymus, and 21% cells in those prepared from the blood. Most of the cells, which bound the virus, were surface immunoglobulin M (SIgM)-positive, but a small number of them were SIgM-negative. Additionally, the binding of IBDV to the LSCC-BK3 cells was affected by treatment of the cells with proteases and N-glycosylation inhibitors. These findings may indicate that the IBDV host range is mainly controlled by the presence of a virus receptor composed of N-glycosylated protein associated with the subtle differentiation stage of B-lymphocytes represented mostly by SIgM-bearing cells.

Molecular detection of a novel paramyxovirus in fruit bats from Indonesia

BackgroundFruit bats are known to harbor zoonotic paramyxoviruses including Nipah, Hendra, and Menangle viruses. The aim of this study was to detect the presence of paramyxovirus RNA in fruit bats from Indonesia.MethodsRNA samples were obtained from the spleens of 110 fruit bats collected from four locations in Indonesia. All samples were screened by semi-nested broad spectrum reverse transcription PCR targeting the paramyxovirus polymerase (L) genes.ResultsSemi-nested reverse transcription PCR detected five previously unidentified paramyxoviruses from six fruit bats. Phylogenetic analysis showed that these virus sequences were related to henipavirus or rubulavirus.ConclusionsThis study indicates the presence of novel paramyxoviruses among fruit bat populations in Indonesia.

Infectious Bursal Disease Live Vaccines: Changes in the Virus Population During Serial Passage in Chickens and Chicken Embryo Fibroblast Cells

Two attenuated infectious bursal disease virus strains used as commercial live vaccine were passaged five successive times in specific-pathogen-free chickens and chicken embryo fibroblast (CEF) cells. Both attenuated strains increased in virulence during the passage in susceptible chickens as evidenced by the decrease in bursa/body weight ratios. A direct nucleotide sequence analysis of the VP2 hypervariable domain amplified by the reverse transcription-polymerase chain reaction revealed that the nucleotide at position 890 (T) in both strains was A after the passage in chicken. In addition, the nucleotide at position 890 (A) was T or C after the subsequent passage in CEF cells. Because of the nucleotide differences, the amino acid residue at position 253 (His) in both vaccines was Gln after the passage in chickens, and the amino acid residue Gln was changed back to His during the subsequent passage in CEF cells. The digestion of the amplified fragment with restriction endonucleases Stul and Ncol, which recognize the sequence difference at position 890, showed that the population of the virus that had amino acid Gln at position 253 was gradually increased during the passage in chickens. Conversely, the population of the virus that had amino acid His at position 253 was gradually increased during the subsequent passage in CEF cells.

New Criteria for Immunofluorescence Assay for Q Fever Diagnosis in Japan

ABSTRACT A study was made to evaluate the cutoff value of indirect immunofluorescent-antibody (IFA) test for Q fever diagnosis in Japan. We used 346 sera, including 16 from confirmed Q fever cases, 304 from Japanese pneumonia patients, and 26 from negative cases. Thirteen sera from the confirmed Q fever cases with an immunoglobulin M (IgM) titer of ≥1:128 and/or IgG titer of ≥1:256 by the IFA test were positive by both enzyme-linked immunosorbent assay (ELISA) and Western blotting assay (WBA), whereas 298 sera from pneumonia patients and 26 negative sera with an IgM titer of ≤1:16 and an IgG titer of ≤1:32 by the IFA test were negative by both ELISA and WBA. In the proposed “equivocal area,” with an IgM titer of ≥1:32 and ≤1:64 and/or an IgG titer of ≥1:64 and ≤1:128, we found 9 sera, 3 from confirmed Q fever cases and 6 from Japanese pneumonia patients, by the IFA test. Three sera from the confirmed Q fever cases and one of the sera from pneumonia patients were IgM and/or IgG positive by both ELISA and WBA. These results suggest that a single cutoff value for the IFA test may cause false-positive and false-negative results. In conclusion, this study showed that an “equivocal area” should be used for the IFA test rather than a single cutoff value and that sera in the equivocal area should be tested by additional serological assays for confirmation.

Isolation and characterization of a novel alphaherpesvirus in fruit bats.

ABSTRACT Bats are known to harbor emerging RNA viruses. Recent studies have used high-throughput sequencing technology to identify various virus species, including DNA viruses that are harbored by bats; however, little is known about the nature of these potentially novel viruses. Here, we report the characterization of a novel herpesvirus isolated from an Indonesian pteropodid bat. The virus, tentatively named fruit bat alphaherpesvirus 1 (FBAHV1), has a double-stranded DNA genome of 149,459 bp. The phylogenetic analyses suggested that FBAHV1 is phylogenetically grouped with simplexviruses within the subfamily Alphaherpesvirinae. Inoculation of FBAHV1 into laboratory mice caused a lethal infection. Virus infection was observed in lung, liver, and brain tissue. Serological and PCR screening revealed that fruit bats infected with FBAHV1 or its related virus are widely distributed in Indonesia. The identification of FBAHV1 makes a considerable contribution to our understanding of simplexviruses associated with bats. IMPORTANCE Bats are known to harbor emerging viruses, such as lyssaviruses, henipaviruses, severe acute respiratory syndrome-like coronaviruses, and filoviruses. Although alphaherpesviruses are disseminated in humans and other animals, there is little information about their distribution in bats. Here, we isolated a previously unknown alphaherpesvirus from an Indonesian fruit bat. Genome sequence analysis suggested that the virus is a member of the genus Simplexvirus within the subfamily Alphaherpesvirinae, which also includes common human viruses, such as herpes simplex virus 1 and herpes simplex virus 2. FBAHV1 is the first bat-derived alphaherpesvirus whose complete genome has been sequenced.

Detection of novel polyomaviruses in fruit bats in Indonesia

Bats are an important natural reservoir for a variety of viral pathogens, including polyomaviruses (PyVs). The aims of this study were: (i) to determine which PyVs are present in bats in Indonesia and (ii) to analyze the evolutionary relationships between bat PyVs and other known PyVs. Using broad-spectrum polymerase chain reaction (PCR)-based assays, we screened PyV DNA isolated from spleen samples from 82 wild fruit bats captured in Indonesia. Fragments of the PyV genome were detected in 10 of the 82 spleen samples screened, and eight full-length viral genome sequences were obtained using an inverse PCR method. A phylogenetic analysis of eight whole viral genome sequences showed that BatPyVs form two distinct genetic clusters within the proposed genus Orthopolyomavirus that are genetically different from previously described BatPyVs. Interestingly, one group of BatPyVs is genetically related to the primate PyVs, including human PyV9 and trichodysplasia spinulosa-associated PyV. This study has identified the presence of novel PyVs in fruit bats in Indonesia and provides genetic information about these BatPyVs.

Immunoregulatory effects of AFP domains on monocyte-derived dendritic cell function

BackgroundAlpha-fetoprotein (AFP) is a tumor-associated glycoprotein that functions in regulation of both ontogenic and oncogenic growth. Recent study showed that AFP can induce apoptosis or impair monocyte-derived dendritic cell (MDDC) function. However, it is still unclear which AFP domain (D-AFP) plays major role in this function.ResultsAs expected monocytes cultured in the presence of Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) and Interleukin-4 (IL-4) developed into MDDC. Up-regulation of HLA-DR and CD11c as well as loss of CD14 molecules could be observed. Full length AFP (FL-AFP), domain 2 AFP (D2-AFP) and D3-AFP, but not D1-AFP, significantly inhibited the expression of HLA-DRhigh/CD11chigh and CD80+/CD86high molecules. In contrast, CD83 expression was substantially down-regulated in all samples. Expression of CD40 was significantly suppressed by FL-AFP but not by any D-AFPs. Finally, both FL-AFP and D-AFP impaired the MDDC ability to secrete IL-12 (p70).ConclusionsD2- and D3- but not D1-AFP extensively suppresses the MDDC function. All the recombinant AFP proteins impaired the ability of MDDC to secrete IL-12.

Divergent bufavirus harboured in megabats represents a new lineage of parvoviruses.

Bufavirus is a recently recognized member of the genus Protoparvovirus in the subfamily Parvovirinae. It has been reported that human bufavirus was detected predominantly in patients with diarrhoea in several countries. However, little is known about bufavirus or its close relatives in nonhuman mammals. In this study, we performed nested-PCR screening and identified bufavirus from 12 megabats of Pteropus spp. in Indonesia. Furthermore, we determined nearly the full genome sequence of a novel megabat-borne bufavirus, tentatively named megabat bufavirus 1. Phylogenetic analyses showed that megabat bufavirus 1 clustered with known protoparvoviruses, including human bufavirus but represented a distinct lineage of bufavirus. Our analyses also inferred phylogenetic relationships among animal-borne bufaviruses recently reported by other studies. Recombination analyses suggested that the most common recent ancestor of megabat bufavirus 1 might have arisen from multiple genetic recombination events. These results characterized megabat bufavirus 1 as the first protoparvovirus discovered from megabats and indicates the high genetic divergence of bufavirus.

Pathotypic characterization of Newcastle disease virus isolated from vaccinated chicken in West Java, Indonesia

Aim: This research was conducted to differentiate and characterize eight Newcastle disease virus (NDV) isolates collected from vaccinated chicken at commercial flocks in West Java, Indonesia, in 2011, 2014 and 2015 by pathotype specific primers. Materials and Methods: A total of eight NDV isolates collected from clinical outbreaks among commercial vaccinated flocks in West Java, Indonesia, in 2011, 2014, and 2015 were used in this study. Reverse transcription-polymerase chain reaction was used to detect and differentiate virulence of NDV strains, using three sets of primers targeting their M and F gene. First primers were universal primers to detect NDV targeting matrix (M) gene. Other two sets of primers were specific for the fusion (F) gene cleavage site sequence of virulent and avirulent NDV strains. Results: Our results showed that three isolates belong to NDV virulent strains, and other five isolates belong to NDV avirulent strains. The nucleotide sequence of the F protein cleavage site showed 112K/R-R-Q/R-K-R/G-F117 on NDV virulent strains and 112G-K/R-Q-G-R-L117 on NDV avirulent strain. Conclusion: Result from the current study suggested that NDV virulent strain were circulating among vaccinated chickens in West Java, Indonesia; this might possess a risk of causing ND outbreaks and causing economic losses within the poultry industry.

Production and characterization of Newcastle disease antibody as a reagent to develop a rapid immunodiagnostic test tool

Aim: This research was conducted to produce and characterize ND antibody as reagent candidate to develop a rapid immunodiagnostic test tool. Materials and Methods: Four New Zealand White rabbits were used in this study and divided into two groups. First group was injected by Sato ND antigen, and second group was injected by genotype VII ND antigen. This study is divided into three steps: (a) ND antibody production, (b) ND antibody purification, and (c) ND antibody characterization. First group was rabbit injected by Sato NDV (5×108.25 egg lethal doses (ELD)50/ml) and second group was injected by genotype VII NDV (5×106.5 ELD50/ml). Antigen induction was performed by subcutaneous administrated for first (day 1) and second (day 14) injection and intravenous administrated for third (day 30) injection. Blood was collected on day 8 after third injection. Results: Antibody production increased on second antigen injection and reached a peak on day 9 after second antigen injection. Sato and genotype VII ND antibody can be produced without adjuvant within 38 days with the highest titer 210. Based on antibody titer data, both antigens induced antibody production in a similar trend. The characterization antibody by SDS-PAGE indicated that molecular weight of immunoglobulin G (IgG) is 154.93 kDa (whole IgG), heavy chain 54.39 kDa, and light chain 27.74 kDa. ND antibodies have specificity to homologous and heterologous NDVs in varying virulence. Conclusion: Sato and genotype VII ND antibodies have been successfully produced within 38 days without adjuvant. Specificity of ND antibodies to NDVs in varying virulence and cross-reaction between Sato ND antibody and genotype VII ND antibody indicates that the characterized ND antibodies can be used as a reagent to develop rapid immunodiagnostic test tools.