The potential effect of melatonin on in vitro oocyte maturation and embryo development in animals.

Melatonin is a hormone mainly secreted by the pineal gland during the circadian cycle, with low levels during the daytime and prominent levels during the night. It is involved in numerous physiological functions including the immune system, circadian rhythm, reproduction, fertilization, and embryo development. In addition, melatonin exerts anti-inflammatory and antioxidant effects inside the body by scavenging reactive oxygen and reactive nitrogen species, increasing antioxidant defenses, and blocking the transcription factors of pro-inflammatory cytokines. Its protective activity has been reported to be effective in various reproductive biotechnological processes, including in vitro maturation, embryo development, and survival rates. In this comprehensive review, our objective is to summarize and debate the potential mechanism and impact of melatonin on oocyte maturation and embryo development through various developmental routes in different mammalian species.

Cu-doped Fe3O4 nanoparticles for efficient detoxification of epsilon toxin: Toward substituting magnetically recyclable detoxifying agent for formaldehyde.

This research presents the synthesis and characterization of Cu-doped Fe3O4 (Cu-Fe3O4) nanoparticles as a magnetically recoverable and reusable detoxifying agent for the efficient and long-lasting neutralization of bacterial toxins. The nanoparticles were synthesized using the combustion synthesis method and characterized through SEM, XRD, BET, TGA, and VSM techniques. The detoxification potential of Cu-Fe3O4 was compared with traditional formaldehyde (FA) in detoxifying epsilon toxin (ETx) from Clostridium perfringens Type D, the causative agent of enterotoxemia in ruminants. In vivo residual toxicity tests revealed that Cu-Fe3O4 could detoxify ETx at a concentration of 2.0 mg mL-1 within 4 days at room temperature (RT) and 2 days at 37 °C, outperforming FA (12 and 6 days at RT and 37 °C, respectively). Characterization studies using dynamic light scattering (DLS) and circular dichroism (CD) highlighted lower conformational changes in Cu-Fe3O4-detoxified ETx compared to FA-detoxified ETx. Moreover, Cu-Fe3O4-detoxified ETx exhibited exceptional storage stability at 4 °C and RT for 6 months, maintaining an irreversible structure with no residual toxicity. The particles demonstrated remarkable reusability, with the ability to undergo five continuous detoxification batches. This study provides valuable insights into the development of an efficient and safe detoxifying agent, enabling the production of toxoids with a native-like structure. The magnetically recoverable and reusable nature of Cu-Fe3O4 nanoparticles offers practical advantages for easy recovery and reuse in detoxification reactions.

Effect of formalin percentage, incubation time and temperature on Clostridium chauvoei culture inactivation and immunogenicity.

OBJECTIVES: In order to find the optimal inactivation conditions for Clostridium chauvoei culture, different factors were investigated and the immunogenicity of inactivated cultures was studied. METHODS: C. chauvoei was cultured with different formalin percentages (0.3, 0.5 or 0.7% V/V), inactivation temperatures (37 °C or room temperature) and incubation times (one or two weeks). Sterility tests were performed and residual formaldehyde and pH were measured. Rabbits were immunized twice with inactivated cultures and sera were used for detection of immune response. RESULTS: In the one-week experiment, 0.5 and 0.7% formalin inactivated the bacteria after one week, and the percentage of 0.3 inactivated after three weeks. The residual formaldehyde at weeks 1 and 8 was not significantly different. In the two-week experiment, cultures treated with 0.3 and 0.5% formalin were inactivated after four weeks, and those with 0.7% formalin were inactivated after three weeks. Residual formaldehyde at week 8 differed significantly from that of week 1. Residual formaldehyde was affected by incubation temperature since it was lower at 37 °C than in room temperature. Also, a significant effect was observed for formalin on pH, as higher formalin contents led to lower pH values of the cultures. ELISA showed the lowest antibody titer achieved by 0.7% formalin group. Antibody titer was not different between 0.3 and 0.5% formalin. CONCLUSIONS: The best condition for inactivation of C. chauvoei was considered as one-week incubation with 0.5% formalin at 37 °C, leading to a high antibody response.

Major pathogenic Clostridia in human and progress toward the clostridial vaccines.

The Clostridium genus is composed of a large spectrum of heterogeneous bacteria. They are Gram-positive, mostly mesophilic, and anaerobic spore-forming strains. Clostridia are widely distributed in oxygen-free habitats. They are found principally in the soil and intestines of ruminants as normal flora, but also are the cause of several infections in humans. The infections produced by important species in humans include botulism, tetanus, pseudomembranous colitis, antibiotics-associated diarrhea, and gas gangrene. Immunization with toxoid or bacterin-toxoid or genetically modified or other vaccines is a protective way against clostridial infection. Several experimental or commercial vaccines have been developed worldwide. Although conventional vaccines including toxoid vaccines are very important, the new generation of vaccines is an effective alternative to conventional vaccines. Recent advances have made it possible for new vaccines to increase immunogenicity. This review discusses briefly the important species of clostridia in humans, their toxins structure, and vaccine development and usage throughout the world.

Genetic Polymorphisms in MicroRNA-196a2 and the Risk of Human Abortion Related to Mycoplasma hominis.

Mutations in some miRNAs are associated with human recurrent pregnancy loss (RPL). In parallel, Mycoplasma spp. are one of the most common infections in pregnant women. The objective of this study was to identify the relationship between miRNA196a-2 gene polymorphism and Mycoplasma hominis (M. hominis) infection as a possible cause of human abortion. A total of 160 cervical swab specimens were collected from women (80 samples with at least one abortion as case, and 80 samples without abortion as control). A PCR-based method using 16S rRNA gene and tetra primer amplification refractory mutation system-polymerase chain (Tetra-ARMS-PCR) were used to identify the presence of M. hominis infections and miRNA196a-2 genotypes of studied women, respectively. Results showed that 22.5% of women with abortion and 7.5% of women without abortion were infected with M. hominis, thereby suggesting a significant difference between the two groups (P < 0.05). Tetra-ARMSPCR indicated that no significant difference in frequency of genotypes existed between women experimenting abortion and control group. Independently to the presence of M. hominis infection, a significant difference (P < 0.05) was observed in genotypic frequencies of miRNA196a-2 between RPL women and those with one abortion. Estimation of the Odds Ratios indicated that the chance of recurrent abortions in TT genotypes of miRNA196a-2 was about three times more likely than CC in non-infected individuals and about five times more likely than CC in M. hominis-infected patients. Our results proposed the role of miRNA196a-2 genotypes in RPL either in M. hominis-infected or non-infected individuals.

Molecular Characterization of a New Nosema bombycis Strain Detected in Iranian Silkworm Farms.

PURPOSE: Pebrine as the most dangerous disease of silkworm mostly caused by Nosema species has caused huge economic losses. There is no information on the species and the genomic sequences of the pebrine-causing microsporidia in Iran. METHODS: In the present research, we tried to determine the sequences of two regions of rDNA using molecular methods. First, infected larvae and mother moths were collected from several farms in the north of Iran for identification and molecular characterization of microsporidian isolates. After extracting the spores and genomic DNA from the collected samples, two fragments of internal transcribed spacer (ITS) rDNA and small subunit (SSU) rDNA were amplified and sequenced, and registered in NCBI database and then, the phylogenetic tree was drawn. RESULTS: Results showed the obtained sequences (ITS rDNA: Accession No. MZ322002 and SSU rDNA: Accession No. MZ314703) represent a new strain of Nosema bombycis, which differs from the sequences deposited in the NCBI. CONCLUSION: The new N. bombycis strain identified in our study will help in control and management of the pebrine disease by specific detection of the infectious agent.

Evaluation of cellular and humoral immune response in chickens immunized with flagellin-adjuvanted inactivated newcastle disease virus.

The aim of the present study was to evaluate the potential effect of flagellin as adjuvant in Newcastle disease virus (NDV) vaccine on the cellular and humoral immunity in chickens. Fifty-six specific pathogen-free chickens were assigned to seven groups of eight chickens and immunized twice with a two-week interval, intramuscularly. Group 1, received phosphate buffered saline as control (C), groups 2, 3, 4, 5, 6 and 7 were immunized with inactivated NDV [Ag], Ag + full FliC protein [AgF], Ag + truncated Flic protein [AgT], Ag + native Flic protein [AgN], commercial NDV vaccine [Vac] and Vac + N [VacN], respectively. After 45 days, spleen and bursa of Fabricius samples were collected and analyzed by flow cytometry and responses in control/vaccinated chickens were studied by immunophenotyping. Humoral response was also, evaluated by ELISA during the experiment. Results showed that immunized chickens with Ag + flagellin proteins had significantly higher frequency of circulating CD3+, CD4+ and CD8+ T cells in bursa of Fabricius in AgF, AgT and AgN, respectively, compared with other groups. Similar results were observed for spleen; however, the highest frequency of circulating CD3+, CD4+ and CD8+ T cells belonged to AgT and AgF, respectively. ELISA results showed that all flagellin-adjuvanted groups had higher antibody titers than other groups with the highest antibody response in VacN. It can be concluded that flagellin may induce both humoral and cellular immune responses against ND and is suggested for use as an efficient adjuvant.

A simple method for purification of epsilon toxin of Clostridium perfringens type D for serum neutralization assay.

Enterotoxaemia, a disease that affects domestic ruminants, is caused by the epsilon toxin of Clostridium perfringens type D and B. Control and prophylaxis are based on systemic vaccination of small ruminant herds with epsilon toxoid. Purified epsilon toxin is an essential material for vaccine evaluation. It is also necessary for diagnosis of enterotoxaemia disease in the field by in vitro tests including ELISA. The aim of this study was to set up a method for preparation of functional purified epsilon toxin of C. perfringens type D to be used in serum neutralization test. In this study, epsilon toxin was prepared from C. perfringens type D culture precipitated with ammonium sulfate, dialyzed against phosphate buffered saline (PBS) buffer and then, purified using chromatography system. Then, the purified epsilon toxin was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Toxin function was confirmed by cell culture and minimum lethal dose (MLD) assays. Also rabbits were immunized by vaccine in two turns with a 28-day interval. Then, blood samples were collected, and serum neutralization (SN) test was carried out. Results showed that the purified toxin was suitable for SN assay. Our purification method was simple, fast and cost-effective for preparation of epsilon toxin.

Vaccination against pathogenic clostridia in animals: a review.

Clostridium is a Gram-positive, rod-shaped, anaerobic, and spore-forming bacterium, which is found in the surrounding environments throughout the world. Clostridium species cause botulism, tetanus, enterotoxaemia, gas gangrene, necrotic enteritis, pseudomembranous colitis, blackleg, and black disease. Clostridium infection causes severe economic losses in livestock and poultry industries. Vaccination seems to be an effective way to control Clostridial diseases. This review discusses the toxins and vaccine development of the most common pathogenic Clostridium species in animals, including Clostridium perfringens, Clostridium novyi, Clostridium chauvoei, and Clostridium septicum. In this comprehensive study, we will review different kinds of clostridial toxins and the vaccines that are experimentally or practically available and will give a short description on each vaccine focusing on its applications, advantages, and disadvantages.

Comparison of flagellin and an oil-emulsion adjuvant in inactivated Newcastle disease vaccine in stimulation of immunogenic parameters.

The present study was designed to investigate the potential application of native (N) and recombinant (truncated modified [tmFliC] and full-length [flFliC]) flagellin proteins along with inactivated Newcastle disease virus (NDV). Fifty six SPF chickens were immunized twice with PBS (control), inactivated NDV (Ag), inactivated NDV/flFliC (AgF), inactivated NDV/tmFliC (AgT), inactivated NDV/N (AgN), commercial vaccine containing Montanide (Vac) and Vac/N (VacN), with a two-week interval. Blood was collected weekly and spleens were harvested after chickens were sacrificed. Interleukin-6 (IL-6) and tumor necrotic factor-α (TNF-α) gene expression in peripheral blood mononuclear cells were analyzed by Real-Time PCR. Antibody response was assessed by haemagglutination inhibition (HI). Cellular activity was quantified by MTT assay. Results showed that the most IL-6 and TNF-α gene expression was observed in AgF group (P < 0.01). The lowest gene expression among vaccinated groups was observed in Ag group for IL-6 and Ag and Vac group for TNF-α. The highest HI titer was observed in Vac, VacN, AgF and AgT groups. The AgF group showed the highest cellular activity (P < 0.01). In conclusion, flagellin-adjuvanted groups showed a pro-inflammatory effect and acted similarly to or better than the Vac group. Hence, flagellin can be proposed as a potential adjuvant for ND vaccine.

Are Epitopic Sites of 3AB and 3D Nonstructural Proteins Sufficient for Detection of Foot and Mouth Disease?

An efficient method for detection of foot and mouth disease (FMD) and, particularly, differentiation of vaccinated from infected animals is the use of nonstructural (NS) proteins as antigens in Enzyme-Linked Immunosorbent Assay (ELISA) Kits. In this study, only epitopic regions of 3AB and 3D NS proteins were used for recombinant protein production, as a cost-effective method instead of peptide synthesis, for application in in-house ELISA diagnostic kits. Specific primers were designed according to the antigenic regions of 3AB (C-terminus of 3A and the whole 3B) and 3D (N-terminus) proteins, and the polymerase chain reaction (PCR) amplification was performed. Purified amplicons were cloned into pET21a (+) vectors and then transformed into Escherichia coli (BL21). Thereafter, bacteria were induced with 1 mM isopropyl ß-d-1-thiogalactopyranoside (IPTG) for expression of antigenic proteins. Antigenic 3AB protein was expressed in soluble form, but 3D protein was extracted from the bacterial lysate. Protein expression was confirmed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses. An indirect ELISA was developed for each protein, and the diagnostic sensitivity and specificity were determined. The 3AB-ELISA showed higher sensitivity and specificity than 3D-ELISA (95.24% and 100%, compared with 90.48% and 88.71%, respectively). The epitopic 3AB-ELISA developed here can be used for detection and differentiation of FMD infected from vaccinated animals, but the epitopic 3D-ELISA showed lower efficiency in screening for FMD status.

Effect of flagellin on inhibition of infectious mechanisms by activating opsonization and salmonella flagellum disruption.

Some serovars of salmonella cause huge global diseases such as enteric fever and invasive non typhoidal Salmonella disease. Flagellin as a key antigenic component of salmonella, can induce humoral and cellular immunity responses. In this research, we performed an opsonophagocytic killing assay (OPKA) as an important mechanism of the host-defense system, for salmonella to study the activity of anti-sera of native FliC, truncated modified recombinant FliC (tmFliC) and full length recombinant FliC proteins (flFliC). Also, the potency of antibodies for inhibiting bacterial movement was evaluated by traditional and newly-designed motility inhibition assay methods. Results showed both recombinant FliC anti-sera and native FliC (nFliC) anti-serum had the ability to opsonize Salmonella typhimurim, which led to bacterial clearance by mice macrophages. Also, inhibition of bacterial motility was observed for all anti-sera. Anti-nFliC and anti-flFliC sera showed higher effects on Salmonella typhimurim motility than that of tmFliC. In traditional method, about 88%, 86% and 80% inhibition were observed by using 5% nFliC, anti-flFliC and anti-tmFliC sera, respectively. In the newly-designed method using SIM (Sulfide indole motility) medium, results confirmed the traditional method for motility inhibition. Our findings suggest that salmonella fliC as a protective antigen may disrupt the flagellum apparatus activity.

Effect of C-Terminus Modification in Salmonella typhimurium FliC on Protein Purification Efficacy and Bioactivity.

Recombinant flagellin (FliC) has shown low efficacy in purification because of inclusion bodies formation and aggregation. We hypothesized preserving TLR5 binding site of FliC and removing some amino acids could be responsible for aggregation and solubility improvement. Hence, a bioinformatics study was performed to find hotspots in aggregate formation. Protein modeling was carried out by SWISS-MODEL and I-TASSER servers and models were compared by MATRAS server and Chimera 1.11.2. Gene modification was carried out based on bioinformatics studies. Genes, (truncated modified fliC (tmFliC) and full-length fliC (flFliC)), were cloned and expressed in pET-21a vector. Protein purification was carried out using HIS-Tag method. Proliferation assay and also induction of IL-8 in HEK293 cells were performed to confirm bioactivity function of tmFliC. Bioinformatics results showed that partial deletion of C-terminus may increase solubility without unfavorable effect on TLR5 recognition. Also, model comparison showed that this protein may preserve 3D structure. In addition, GlobPlot server demonstrated that tmFliC formed its globular domains which were important in TLR5 recognition. As we expected, high purification efficacy for tmFliC compared with flFliC was also obtained in experimental studies and a proper function for tmFliC was observed. The tmFliC enhanced cell proliferation in HEK293 cells compare with control after 24 h. Also, IL-8 level was increased with stimulation by tmFliC after 24 h. In conclusion, reducing hydrophobicity in C-terminus and deleting necessary amino acids for filament formation may increase protein solubility.

Immunostimulatory effects of truncated and full-length flagellin recombinant proteins.

Problems regarding purification efficacy in recombinant technologies is due to the protein structure. Experimental manipulation of genes and the subsequent proteins may overcome this issue. In order to improve production efficacy and maintain immunestimulatory effect of flagellin, the Toll-like Receptor 5 (TLR5) ligand and a potent adjuvant, we performed a bioinformatic study to find the best model for FliC manipulation. Truncated modified FliC (tmFliC) and full length FliC (flFliC) genes were cloned and expressed in pET-21a vector and protein purification was carried out using an improved His-Tag method. Polyclonal antibodies were generated against flFliC and tmFliC in New Zealand white rabbits. IgG response to the recombinant proteins was determined by ELISA. Cross-reactivity assay was performed by ELISA for all proteins and bacteria. Immunogenicity of tmFliC and flFliC was evaluated in chicken cells, and expression level of tumor necrotic factor-α (TNF-α) and interleukin-6 (IL-6) were relatively analyzed by Real-Time-PCR. Results showed high purification efficacy for tmFliC. Antibody titer of tmFliC was significantly higher than that of flFliC. In addition, the cross-reactivity assay for both proteins and Salmonella was positive which indicates similar epitopic regions. Stimulation of both FliCs significantly increased TNF-α and IL-6 expression in peripheral blood mononuclear cells (PBMCs) and splenocytes, with higher effect observed with flFliC. IL-8 protein level increased after 6 and 24 h stimulation with different concentrations of tmFliC and flFliC. These results suggest that the aimed gene modification in fliC gene produces a bioactive immunostimulant type of flagellin which upregulates TLR5 downstream genes as well as in flFliC.

Evolution and species-specific conservation of toll-like receptors in terrestrial vertebrates.

Toll-like receptors (TLRs) are known for their essential roles in promotion of innate immunity and induction of adaptive immunity through recognition of pathogen-associated molecular patterns (PAMPs) or danger associated molecular patterns (DAMPs). TLR genes are excellent models for the study of the selective pressure enforced by microorganisms on the host genome. Phylogenetic analyses have shown that interactions between pathogens and immune systems have changed during evolution. Selective pressure for maintenance of specific pathogen recognition has led to evolution of TLRs under both positive and purifying selection. However, intracellular and cell-surface TLRs have been affected differently due to their variation in conservational constraints. In this review, we summarize some of the main studies on the influence of selection on shaping the evolution of several TLR gene families in different terrestrial vertebrate species. We also describe the effect of evolution on the function of different TLRs and their specific conservations in these species and show similarities and differences in evolutionary patterns of TLR orthologs among species as well as among TLR gene families.

Dominance effects estimation of TLR4 and CACNA2D1 genes for health and production traits using logistic regression.

Knowledge of nonadditive variance and genetic effects can be helpful in explaining the total genetic variation formost of the traits. The objective of this study was to estimate dominance effects of several single-nucleotide polymorphism (SNP) genotypes for the production traits and clinical mastitis residual (CMR), in Holstein dairy cattle in a case-control study. Records of 305 days lactation were obtained for production traits and CMR. Animals were selected based on extreme values for CMR from mixed model analyses. Samples were genotyped for four SNP-single genotypes and their associations with production traits (breeding values for protein and fat yield, and protein and fat percentage) were estimated by applying logistic regression analyses. Calculation of contrast between both homozygous and heterozygous genotypes permitted to estimate dominance effects, which ranged from -0.49 to 0.35 standard deviation units for the production traits and clinical mastitis (CM), respectively. Results showed that the dominance effects may be important in contribution of total genetic effects for production traits and CM. Therefore, evaluation of animals based on additive variance alone and disregarding nonadditive effects may lead to failure in selection programmes and exactly estimating the genetic variation. The method that we used would help breeders in accurately estimation of genotypic values in a new genomic selection scenario including dominance effects.

Expressional and Bioinformatic Analysis of Bovine Filia/Ecat1/Khdc3l Gene: A Comparison with Ovine Species.

Maternal effect genes have highly impressive effects on pre-implantation development. Filia/Ecat1/Khdc3l is a maternal effect gene found in mouse oocytes and embryos, loss of which causes a 50% decrease in fertility. In the present study, we investigated Filia mRNA expression in bovine oviduct, 30- to 40-day fetus, liver, heart, lung, and oocytes (as a positive control), by RT-PCR and detected it only in oocytes. A 443 bp fragment was amplified only in oocytes and was sequenced as a part of bovine predicted Filia mRNA. We analyzed bovine and ovine Filia N-terminal peptide sequence in PHYRE2, and a KH domain was predicted. Protein alignment using ClustalW indicated a highly identical N-terminal extention between the 2 species. Immunohistochemical analysis using anti-bovine Filia antibody showed the expression of Filia protein in the zone surrounding the nuclear membrane, and in the subcortex of ovine oocytes of primary and antral follicles. However, in the bovine, Filia has been found through the oocyte cytoplasm of antral follicles, and here it is further confirmed in the primary follicles. Our data suggests a difference in Filia expression pattern between cow and sheep, although the sequence is highly conserved.