Bor-Chun Weng

Direct Enhancement of the Phagocytic and Bactericidal Capability of Abdominal Macrophage of Chicks by β-1,3–1,6-Glucan

Salmonella enterica serovar Enteritidis is the major zoonotic and intracellular pathogen. Different strategies have been developed to prevent the S. Enteritidis infection. The beta-1,3-1,6-glucan of Schizophyllum commune was used as an immunological booster to determine the minimal dietary level of beta-glucan that would restrict S. Enteritidis infection through the effects of beta-glucan on the activity of macrophages and direct physical protection of the intestine. One-day-old male Single Comb White Leghorn chicks were used in all trials. In trials 1 and 2, the 0.1% beta-1,3-1,6-glucan treatment completely eliminated the viable S. Enteritidis from spleen and liver in an oral challenge of 10(8) S. Enteritidis without any harmful effect on BW, serum proteins, and immunoglobulin. Instead of a 21-d feeding period of beta-glucan, a 14-d treatment was enough to eliminate the S. Enteritidis in spleen and liver. In trial 3, an increase in the relative weight of bursa of Fabricius and phytohemagglutinin-P-inducing cutaneous basophil hypersensitivity was observed (P < 0.05). In trials 2, 3, and 4, the direct or indirect effect of beta-1,3-1,6-glucan on abdominal macrophages was examined. Sterilized 3% Sephadex G-50 was injected to induce abdominal (peritoneal) phagocytes in chicks fed with or without 0.1% beta-1,3-1,6-glucan. Significantly increased phagocytic and bactericidal capability to S. Enteritidis was found in abdominal macrophages either pretreated or in vitro treated with 0.1% beta-1,3-1,6-glucan. In conclusion, in addition to the physical properties to block S. Enteritidis entrance, 0.1% dietary beta-1,3-1,6-glucan may enhance the host defense to S. Enteritidis by directly upregulating the phagocytosis and bactericidal activity of abdominal macrophages in chicks.

Genomic diversity and molecular differentiation of Riemerella anatipestifer associated with eight outbreaks in five farms

Riemerella anatipestifer causes infectious serositis of ducks and geese. The genomic diversity of R. anatipestifer associated with outbreaks in waterfowls was studied using 24 multidrug-resistant R. anatipestifer isolates collected from the visceral organs of ducks and geese from seven outbreaks in four goose farms and one outbreak in one duck farm. Seven methods were used to differentiate these isolates. Plasmid patterns differed in plasmid number and size, ranging from 2.9 kb to 20 kb, and provided seven profiles. Divergent nucleotide sequences (predominant in 670 to 830 base pairs) of the ompA gene categorized the 24 isolates into three groups based on cluster analysis and polymerase chain reaction–restriction fragment length polymorphism. Repetitive-sequence polymerase chain reaction and pulsed-field gel electrophoresis analysis revealed the highest genotypic variations among the isolates. Genotypes and serotypes differed among farms and within the same farm and even within a single goose. In conclusion, a difference in R. anatipestifer genotypes and serotypes was observed for multiple outbreaks in waterfowls.

Clonal dissemination of the multi-drug resistant Salmonella enterica serovar Braenderup, but not the serovar Bareilly, of prevalent serogroup C1 Salmonella from Taiwan

BackgroundNontyphoidal Salmonella is the main cause of human salmonellosis. In order to study the prevalent serogroups and serovars of clinical isolates in Taiwan, 8931 Salmonellae isolates were collected from 19 medical centers and district hospitals throughout the country from 2004 to 2007. The pulsed-field eletrophoresis types (PFGE) and antibiotic resistance profiles of Salmonella enterica serovars Bareilly (S. Bareilly) and Braenderup (S. Braenderup) were compared, and multi-drug resistance (MDR) plasmids were characterized.ResultsOver 95% of human salmonellosis in Taiwan was caused by five Salmonella serogroups: B, C1, C2-C3, D1, and E1. S. Typhymurium, S. Enteritidis, S. Stanley and S. Newport were the four most prevalent serovars, accounting for about 64% of isolates. While only one or two major serovars from four of the most prevalent serogroups were represented, four predominant serovars were found in serogroup C1 Salmonellae. The prevalence was decreasing for S. Choleraeuis and S. Braenderup, and S. Virchow and increasing for S. Bareilly. S. Braenderup mainly caused gastroenteritis in children; in contrast, S. Bareiley infected children and elderly people. Both serovars differed by Xba I-PFGE patterns. Almost all S. Bareilly isolates were susceptible to antibiotics of interest, while all lacked plasmids and belonged to one clone. Two distinct major clones in S. Braenderup were cluster A, mainly including MDR isolates with large MDR plasmid from North Taiwan, and cluster B, mainly containing susceptible isolates without R plasmid from South Taiwan. In cluster A, there were two types of conjugative R plasmids with sizes ranging from 75 to 130 kb. Type 1 plasmids consisted of replicons F1A/F1B, blaTEM, IS26, and a class 1 integron with the genes dfrA12-orfF-aadA2-qacE Δ1-sulI. Type 2 plasmids belonged to incompatibility group IncI, contained tnpA-blaCMY-2-blc-sugE genetic structures and lacked both IS26 and class 1 integrons. Although type 2 plasmids showed higher conjugation capability, type 1 plasmids were the predominant plasmid.ConclusionsSerogroups B, C1, C2-C3, D1, and E1 of Salmonella caused over 95% of human salmonellosis. Two prevalent serovars within serogroup C1, S. Bareilly and cluster B of S. Braenderup, were clonal and drug-susceptible. However, cluster A of S. Braenderup was MDR and probably derived from susceptible isolates by acquiring one of two distinct conjugative R plasmids.

Comparison of the Association of Age with the Infection of Salmonella and Salmonella enterica Serovar Typhimurium in Pekin Ducks and Roman Geese

Nontyphoid Salmonella have a broad host range in poultry and mammals, and serovar Typhimurium is a threat to public health. In this study, normal and sick ducks and geese were collected from 12 farms in Taiwan to investigate the age-associated infection of Salmonella and Salmonella Typhimurium in Roman geese (Anser anser domesticus) and Pekin ducks (Anas platyrhynchos domesticus). In normal birds, the prevalence of Salmonella differed between species, and with age [e.g., 1-wk group, 37.5% (30/80) for ducks and 5.2% (6/116) for goslings (P < 0.05) vs. 4-wk group, 1% (1/96) for ducks and 12.1% (21/174) for geese]. Salmonella Typhimurium was identified from the visceral organs of moribund young geese suffering with colibacillosis and riemerellosis isolated from 2 goose farms (farm A and B, respectively). At farm B, 22.9% (27/118) of 4-wk geese with diarrhea were Salmonella Typhimurium-positive compared with 4.6% (8/174) of 4-wk normal geese. All Salmonella Typhimurium strains except one harbored a 94.7-kb virulence plasmid. Subcutaneous injection of Salmonella Typhimurium isolate 91NGL1 resulted in different clinical signs and pathogenesis between ducks and geese. In addition, the mean infectivity dose ratios of ducks to geese were 3.2 and 85.0 for 4- and 12-d birds, respectively, suggesting that goslings were more susceptible to Salmonella Typhimurium and resistance to Salmonella Typhimurium increased with age, especially for ducks. Therefore, Salmonella Typhimurium infection should be more common in goose farms than in duck farms, especially in the younger birds.

The anticancer effect of protein-extract from Bidens alba in human colorectal carcinoma SW480 cells via the reactive oxidative species- and glutathione depletion-dependent apoptosis.

Bidens alba has been used for healing cuts, injuries, swellings, hypertension, jaundice, and diabetes in some countries. However, the effect of B. alba on human cancer remains poorly understood. The goal of this study was to investigate whether B. alba protein-extract could have an anticancer property against human colorectal cancer. The human colorectal cancer SW 480 cells treated with the protein-extract of B. alba would cause marked DNA damages and apoptosis-related cellular morphologies. Treatment with 225 microg/ml B. alba protein-extract also led to the SW480 cells to produce readily intracellular reactive oxygen species (ROS) after 1h of treatment and last to 24 h. The intracellular glutathione (GSH) depletion occurred after 12-24h of treatment. The treatment of the protein-extract would also caused mitochondrial transmembrane potential (DeltaPsi(m)) to decrease and cytosolic cytochrome c to increase. The caspase 3/7 activities were activated from 3 to 6 h after the treatment. The percentages of apoptosis induced by the protein-extract of B. alba decreased 26.4%, 10.1%, and 29.4% when the SW 480 cells were pretreated with Vitamin C, N-acetylcysteine, and Boc-Asp(OMe)-fmk, respectively. Taken together, we demonstrated for the first time that the protein-extract of B. alba could induce apoptosis that was related to the ROS production and GSH depletion in human colorectal cancer. The protein-extract of B. alba might have therapeutic value against the human colorectal cancer.

Effects of caponization and testosterone implantation on immunity in male chickens

This study examined the effects of caponization using different doses of testosterone (TES) on sexuality, hematology, and immune responses in male chickens. Healthy male chickens were caponized at 12 wk of age and selected at 16 wk of age for a 10-wk experiment. Fifteen intact male and 15 caponized male chickens were assigned to trial 1. In trial 2, ten sham-operated male chickens (sham) and 40 capons (randomly divided into 4 treatments) were implanted with cholesterol (CHOL, 9.24+/-0.36 mg), low TES (5.88+/-0.23 mg), medium TES (9.81+/-0.17 mg), or high TES (16.7+/-0.24 mg) administered at 16, 20, and 24 wk of age. Results from trial 1 showed caponization decreased the comb length, height and weight, and hematocrit (P<0.05) and increased the hemagglutination inhibition (HI; 1 wk postchallenge) and hemagglutination titer after Newcastle disease virus (NDV) and SRBC injections (P<0.05). In trial 2, the medium TES increased the comb length and height as compared with the CHOL group. Only the high TES increased the comb weight (P<0.05). The HI titer (1 wk postchallenge) in the CHOL group was higher than the sham (P<0.05). The medium TES decreased the HI titer (P<0.05) to the level of the sham (P>0.05). The phytohemagglutinin response was higher in the high TES group 24 h postinjection (P<0.05) and in the medium TES 48 h postinjection (P<0.05) as compared with the CHOL group. High dose TES implantation decreased the white blood cell counts as compared with the CHOL and sham groups (P<0.05). It appears that caponization decreased the blood androgen concentration and enhanced the humoral (anti-NDV and anti-SRBC) immune response. Testosterone implantation up to a threshold concentration could inhibit the humoral (anti-NDV) immune response and increase the cell-mediated (phytohemagglutinin) immune response.

Effects of caponization and different forms of exogenous androgen implantation on immunity in male chicks

This study determined the caponization effects on the immune responses in male chicks. Different forms of exogenous androgen implantation on male chick immunity were compared. Healthy, uniform male Single Comb White Leghorn chicks were caponized at 3 wk of age. Birds were housed in individual cages (35 x 30 x 40 cm, length x width x height). Each of 27 sham-operated (sham) and caponized (capon) male chickens were used for trial 1. Trial 2 used 60 capons divided into 4 treatments with implants of either 1 mm i.d. x 3 mm o.d. 58 mg of cholesterol, testosterone (TES), 5alpha-dihydrotestosterone (5alpha-DHT), or 19-nortestosterone (19-NorT). The exogenous androgen was implanted immediately after caponization and resupplied every 4 wk for an entire 13-wk feeding trial. The results from trial 1 showed that the relative bursa weight increased compared with the sham treatment (P < 0.05). The 2 wk post-Newcastle disease virus titer and the delayed-type hypersensitivity (DTH) of 48 h post-phytohemagglutinin phosphate (PHA-P) injection were increased compared with the sham treatment (P < 0.05). In trial 2, implanted 5alpha-DHT and 19-NorT could decrease the relative bursa weight in capons (P < 0.05). The 2 wk post-Newcastle disease virus titer in the 5alpha-DHT group was higher than that in the cholesterol group (P < 0.05). The 19-NorT group had the highest (P < 0.05) PHA-P response. Peripheral blood lymphocyte subset population analysis revealed that the percentage of CD4 T cells in the TES group was lower (P < 0.05) compared with that of the 5alpha-DHT group. Differently, the percentage of CD8 T cells in the TES and 19-NorT groups was higher (P < 0.05) than that in the 5alpha-DHT group. Male chicks that were caponized had increased bursa weight and PHA-P response, whereas different forms of exogenous androgen implantation reverted the phenomena in an order of potency of 5alpha-DHT and 19-NorT > TES, and the PHA-P response was TES > 5alpha-DHT >19-NorT.

Site-directed in vitro immunization leads to a complete human monoclonal IgG4λ that binds specifically to the CDR2 region of CTLA-4 (CD152) without interfering the engagement of natural ligands

BackgroundThe ability to acquire fully human monoclonal antibodies (mAbs) with pre-defined specificities is critical to the development of molecular tags for the analysis of receptor function in addition to promising immunotherapeutics. Yet most of the arriving affinity maturated and complete human immunoglobulin G (IgG) molecules, which are actually derived from single human B cells, have not widely been used to study the conserved self antigens (Ags) such as CD152 (cytotoxic T lymphocyte antigen-4, CTLA-4) because proper hosts are lacking.ResultsHere we developed an optimized protocol for site-directed in vitro immunizing peripheral blood mononuclear cells (PBMC) by using a selected epitope of human CD152, an essential receptor involved in down-regulation of T cell activation. The resultant stable trioma cell lines constantly produce anti-CD152 mAb (γ4λhuCD152), which contains variable (V) regions of the heavy chain and the light chain derived from the VH3 and Vλ human germline genes, respectively, and yet displays an unusual IgG4 isotype. Interestingly, γ4λhuCD152 has a basic pI not commonly found in myeloid monoclonal IgG4λs as revealed by the isoelectric focusing (IEF) analysis. Furthermore, γ4λhuCD152 binds specifically, with nanomolar affinity, to an extracellular constituency encompassing the putative second complementarity determining region (CDR2) of CD152, whereby it can react to activated CD3+ cells.ConclusionIn a context of specific cell depletion and conditioned medium,in vitro induction of human Abs against a conserved self Ag was successfully acquired and a relatively basic mAb, γ4λhuCD152, with high affinity to CDR2 of CD152 was thus obtained. Application of such a human IgG4λ mAb with designated CDR2 specificity may impact upon and prefer for CD152 labeling both in situ and ex situ, as it does not affect the binding of endogenous B7 ligands and can localize into the confined immunological synapse which may otherwise prevent the access of whole IgG1 molecules.

Immunomodulatory effects of hedysarum polybotrys extract in mice macrophages, splenocytes and leucopenia

Astragali Radix (Huang-Qi) is a popular herbal medicine commonly used as a constituent in tonic herbal preparations. Hedysarum polybotrys Handel-Mazzetti is one species used of Astragali Radix. In this study, the immunomodulatory properties of H. polybotrys were explored by LPS-activated and SNP-treated RAW 264.7 cells and splenocytes and, daunoblastina-induced leucopenia BALB/c mice. Formononetin was used as the bioactive marker to monitor the quality of the H. polybotrys extracts. H. polybotrys was extracted with hot-water and methanol, and MeOH extract partitioned with H2O (M-H) and ethyl acetate (M-EA) to yield four different fractions. M-EA had the highest formononetin and total proanthocyanidin content and showed stronger inhibitory effects on the production and expression of NO, PGE2, iNOS and COX-2 in LPS-activated RAW 264.7 cells and splenocytes than the other fractions. In addition, M-EA significantly stimulated the proliferation of LPS-activated RAW 264.7 cells and splenocytes, enhanced NO radicals scavenging and attenuated NO-induced cytotoxicity. Furthermore, M-EA also significantly increased the rate of recovery of white blood cells level in daunoblastina-induced leucopenia mice. These evidences suggest that this traditional Qi-tonifying herb has potential effects in clinical conditions when immune-enhancing and anti-inflammatory effect is desired.