Rabbit Serum Research Articles

Delineating Surface Epitopes of Lyme Disease Pathogen Targeted by Highly Protective Antibodies of New Zealand White Rabbits.

Lyme disease (LD), the most prevalent vector-borne illness in the United States and Europe, is caused by Borreliella burgdorferi No vaccine is available for humans. Dogmatically, B. burgdorferi can establish a persistent infection in the mammalian host (e.g., mice) due to a surface antigen, VlsE. This antigenically variable protein allows the spirochete to continually evade borreliacidal antibodies. However, our recent study has shown that the B. burgdorferi spirochete is effectively cleared by anti-B. burgdorferi antibodies of New Zealand White rabbits, despite the surface expression of VlsE. Besides homologous protection, the rabbit antibodies also cross-protect against heterologous B. burgdorferi spirochetes and significantly reduce the pathology of LD arthritis in persistently infected mice. Thus, this finding that NZW rabbits develop a unique repertoire of very potent antibodies targeting the protective surface epitopes, despite abundant VlsE, prompted us to identify the specificities of the protective rabbit antibodies and their respective targets. By applying subtractive reverse vaccinology, which involved the use of random peptide phage display libraries coupled with next-generation sequencing and our computational algorithms, repertoires of nonprotective (early) and protective (late) rabbit antibodies were identified and directly compared. Consequently, putative surface epitopes that are unique to the protective rabbit sera were mapped. Importantly, the relevance of newly identified protection-associated epitopes for their surface exposure has been strongly supported by prior empirical studies. This study is significant because it now allows us to systematically test the putative epitopes for their protective efficacy with an ultimate goal of selecting the most efficacious targets for development of a long-awaited LD vaccine.

Immunoproteomic analysis of Lawsonia intracellularis identifies candidate neutralizing antibody targets for use in subunit vaccine development

Lawsonia intracellularis is an obligate intracellular microorganism and the causative agent of porcine proliferative enteropathy. Due to its obligate intracellular nature, characterization of antigens and proteins involved in host-pathogen interaction and immune recognition have been difficult to achieve using conventional microbiological techniques. In this work, we used 2-dimensional gel electrophoresis coupled with Western-immunoblotting, mass spectrometry and bioinformatics to identify bacterial proteins that interact in vitro with pig intestinal cells (IPEC-1), have immunogenic properties and the potential to be used as subunit vaccine antigens. We detected eleven immunogenic bacterial proteins from which fliC (LI0710), LI1153 (annotated by NCBI as Putative protein N), and LI0649 (annotated as autotransporter) were predicted to be expressed on the outer membrane while LI0169 (oppA; annotated as ABC dipeptide transport system) was predicted to be periplasmic with a transmembrane domain forming a central pore through the plasma membrane. Genes coding for these four proteins were cloned and expressed in Escherichia coli and the corresponding recombinant proteins were purified using affinity chromatography. Porcine hyperimmune serum against whole Lawsonia lysate established that all four recombinant proteins were immunogenic. Further, rabbit hyperimmune sera generated against the vaccine strain of L. intracellularis and rabbit serum specific for each recombinant protein showed an inhibitory effect on the attachment and penetration of live, avirulent L. intracellularis, thus indicating that each protein is a potential neutralizing antibody target and a candidate for subunit vaccine formulation.

Immunological evidence for in\xa0vivo production of novel advanced glycation end-products from 1,5-anhydro-D-fructose, a glycogen metabolite

The anhydrofructose pathway is an alternate pathway for glycogen degradation by α-1,4-glucan lyase. The sugar 1,5-anhydro-D-fructose (1,5-AF) acts as the central intermediate of this pathway, but its physiological role of in mammals is unclear. Glycation reactions forming advanced glycation end-products (AGEs) are important in the development of complications of diabetes mellitus. We hypothesized that 1,5-AF may contribute to cellular damage by forming 1,5-AF-derived AGEs (AF-AGEs) with intracellular proteins. To clarify the role of 1,5-AF in protein modification, we created a novel antibody targeting AF-AGEs. Serum albumin modified by AF-AGEs was prepared by incubating rabbit serum albumin (RSA) or bovine serum albumin (BSA) with 1,5-AF. After immunizing rabbits with AF-AGEs-RSA, affinity chromatography of anti-AF-AGE antiserum was performed on a Sepharose 4B column coupled with AF-AGEs-BSA or N-(carboxymethyl)/N-(carboxyethyl)lysine-BSA. A novel immunopurified anti-AF-AGE antibody was obtained and was characterized using a competitive enzyme-linked immunosorbent assay. Then an AF-AGEs assay was established using this immunopurified antibody. This assay was able to detect AF-AGEs in human and animal serum samples. Finally, intracellular accumulation of AF-AGEs was shown to be associated with damage to cultured hepatocytes (HepG2 cells). This is the first report about in vivo detection of AF-AGEs with a novel structural epitope.

High-throughput RNA sequencing reveals the anti-inflammatory mechanism of baicalin on Propionibacterium acnes-induced acne in rabbits

Abstract Objective Propionibacterium acnes (P. acnes) plays an important role in the development of acne, an inflammatory skin disease with a high-incidence. In this study, we used high-throughput RNA sequencing (RNA-seq) to reveal the anti-inflammatory mechanism of baicalin on P. acnes-induced acne in rabbits. Methods The Kligman method was used to induce acne in the ears of New Zealand rabbits. The effect of baicalin on the acne model was evaluated by the number of acne lesions and hematoxylin and eosin (H&E) staining of acne tissues. Enzyme-linked immunoabsorbent assay was used to measure the protein expression levels of tumor necrosis factor α (TNFA), interleukin-1 β (IL1B), IL6, and IL8 in the serum of rabbits. RNA-seq was performed to investigate the mechanism of anti-inflammatory activities of baicalin on acne. Immunohistochemical analysis and Western blot were used to validate the expression levels of related proteins in acne tissues. Results Baicalin treatment significantly reduced the number of acne lesions and lesions of the ear as well as levels of serum inflammatory cytokines. RNA-seq data showed that baicalin treatment globally suppressed inflammation, especially the TNF signaling pathway and Staphylococcus aureus infection pathway, in the rabbit acne model. Conclusion Baicalin effectively ameliorates P. acnes-induced acne in rabbits by suppressing the inflammatory response in rabbits.

Экспериментальная модель лечения вагинальных дисбиозов с помощью фракции сывороточных антимикробных пептидов

Широкое использование антибиотиков и противогрибковых препаратов при лечении дисбиозов влагалища сопровождается появлением резистентных штаммов микроорганизмов. В этой связи актуальной является разработка новых препаратов, в частности, основанных на натуральных антимикробных пептидах (АМП), отличающихся более широким спектром действия и высокой активностью. Цель работы - изучение возможности использования сывороточных АМП в лечении вагинальных дисбиозов различной этиологии на мышиной модели. Методика. Активность АМП фракции сыворотки крови кролика оценивали в опытах in vitro и in vivo. В первом случае проверяли действие АМП на клетки Candida albicans, Escherichia coli и Staphylococcus aureus спектрофотометрическим методом. Данный метод основан на поглощении красителя бромкрезолового пурпурного клетками с нарушенной цитоплазматической мембраной и, как результат, снижении оптической плотности надосадочной жидкости в опытных вариантах по сравнению с контрольными. Во втором случае оценивали лечебный эффект концентрированного препарата сывороточных АМП на мышах, зараженных интравагинально теми же культурами. После заражения мышей пролечивали введением препарата тем же путем, а результат оценивали методом высевов из влагалища на селективные среды. Результаты. Установлено, что наиболее выраженное действие в опытах in vitro сывороточные АМП оказывали на клетки C. albicans (активность составила 32,9 % от контроля), тогда как менее выраженный эффект имел место в отношении E. coli (23,3 %) и S. aureus (14,4 %). Аналогичная закономерность имела место и в опытах in vivo: высев C. albicans после лечения препаратом АМП составил 44,6% от исходного в сравнении с 42,2% после лечения пимафуцином и 90,2% без лечения (плацебо); высев E. coli - 65,6% от исходного в сравнении с 26,3% после лечения метронидазолом и 94,8% в варианте плацебо; высев S. aureus - 76,9% от исходного в сравнении с 11,4% после лечения клиндамицином и 73,0% в варианте плацебо. Заключение. Наибольшей чувствительностью к сывороточным АМП среди изученных видов обладали клетки C. albicans, а наименьшей - S. aureus, причем как в опытах in vitro, так и in vivo. Препарат на основе АМП фракции сыворотки крови можно рассматривать как альтернативу традиционным препаратам при лечении вагинальных дисбиозов, особенно вульвовагинального кандидоза. Extensive use of antibiotics and antimycotics in the treatment of vaginal dysbiosis may result in emergence of resistant microbial strains. Therefore, development of new, broad-spectrum and highly active drugs, particularly based on antimicrobial peptides (AMP) is relevant. The aim of the present study was to evaluate a possibility of using serum AMP in the treatment of vaginal dysbiosis of different etiology on a murine model. Methods. Activity of the AMP fraction of rabbit serum was evaluated in in vitro and in vivo experiments. In the in vitro experiment, the effect of AMP on Candida albicans, Escherichia coli, and Staphylococcus aureus cells was measured spectrophotometrically. This method was based on uptake of the bromocresol purple stain by cytoplasmic membranes of destroyed cells, which resulted in decreased optical density of the supernatant in experimental variants compared to the control. In the in vivo experiments, the therapeutic effect of concentrated serum AMP was evaluated in mice intravaginally infected with the same microbial cultures. The infected mice were treated similarly with the AMP preparation, and the outcome was evaluated using the inoculation of plates with selective media by vaginal material. Results. The serum AMP fraction exerted the most noticeable effect in in vitro experiments on C. albicans cells (activity 32.9 % of control) vs. lower effects on E. coli (23.3 %) and S. aureus (14.4 %). Consistently in the in vivo experiments, the abundance of C. albicans colonies was 44.6% of the initial value after the AMP drug treatment compared to 42.2% after the pimafucin treatment and 90.2% in placebo. The abundance of E. coli colonies after the AMP drug treatment was 65.6% of the initial compared to 26.3% after the metronidazole treatment and 94.8% in placebo; for S. aureus, the abundance was 76.9% (AMP) compared to 11.4% (clindamycin) and 73.0% (placebo). Conclusion. Among the studied microorganisms, C. albicans had the highest susceptibility to serum AMP while S. aureus was the least susceptible both in in vitro and in vivo experiments. Drugs based on the serum AMP preparation may be considered as a possible alternative to traditional medications for the treatment of vaginal dysbiosis, especially for vulvovaginal candidiasis.

Development and characterization of novel anti-C5 monoclonal antibodies capable of inhibiting complement in multiple species.

SummaryOver the last decade there has been an explosion in complement therapies; one‐third of the drugs in the clinic or in development target C5 protein. Eculizumab, a monoclonal antibody (mAb) that binds C5 and blocks its cleavage by the convertase, is the current reference standard treatment for atypical haemolytic uraemic syndrome (aHUS) and paroxysmal nocturnal haemoglobinuria (PNH) and in clinical trials for many other diseases. Here we describe a panel of novel anti‐C5 mAb, including mAb that, like Eculizumab, are efficient inhibitors of complement but, unlike Eculizumab, inhibit across species, including human, rat, rabbit and guinea pig. Several inhibitory anti‐C5 mAb were identified and characterized for C5 binding and lytic inhibitory capacity in comparison to current therapeutic anti‐C5 mAb; three clones, 4G2, 7D4 and 10B6, were selected and further characterized for ligand specificity and affinity and cross‐species inhibitory activity. The mAb 10B6 was human‐specific whereas mAb 4G2 and 7D4 efficiently inhibited lysis by human, rabbit and rat serum, and weakly inhibited guinea pig complement; 7D4 also weakly inhibited mouse complement in vitro The rat C5‐cross‐reactive mAb 4G2, when administered intraperitoneally in a rat model of myasthenia gravis, effectively blocked the disease and protected muscle endplates from destruction. To our knowledge this is the first report of an anti‐C5 function blocking mAb that permits preclinical studies in rats.

Validation of Enzyme Immunoassay for Preclinical Pharmacokinetic Trials of Rituximab

An integral part of preclinical pharmacokinetic studies is the development of a bioanalytical method for determination of the drug in a biological fluid.The aim of the research was to assess the suitability of the test system based on enzyme-linked immunosorbent assay (ELISA) for quantitative determination of rituximab in the blood serum of laboratory animals after intravenous administration of rituximab at a dose corresponding to the therapeutic dose in humans. Th test system was developed by the Scientific and Production Center Probiotech.Materials and methods: the determination of rituximab in biological samples was carried out using a two-stage sandwich-type ELISA, followed by detection based on horseradish peroxidase. The ELISA results were recorded using a microplate photometer at a wavelength of 450 nm.Results: the experiments helped to establish the detection limit (0.24 ng/mL) and the lower limit of quantitation (1.00 ng/mL) of rituximab in rabbit blood serum, they also demonstrated high selectivity of analyte determination in a multicomponent biological matrix. The mean rituximab concentration was within 14 % of the nominal value in the entire working range of the method. The within-run and between-run precision of the assay did not exceed 7.4 %, the total error of the method did not exceed 20.1 %. The linearity of dilution makes it possible to use the assay for the analysis of biological samples with a wide range of rituximab concentrations. The stability of the analyte in the rabbit blood serum was confirmed by storing samples for 6 hours at room temperature, for 50 days at —35 °C, and after 3 freeze-thaw cycles. The validated immunoassay was successfully used to determine the rituximab concentration in biological samples obtained in the rituximab pharmacokinetic trial in rabbits. The accuracy of the results was confirmed for the entire range of the determined concentrations; parallelism was demonstrated between the calibration curve and the results of analysis of serially diluted rabbit serum samples with the maximum concentration of rituximab.Conclusions: the proposed enzyme immunoassay test system can be used for quantitative determination of rituximab in the blood serum of laboratory animals, as it meets acceptance criteria for all validation parameters described in the international guidelines on validation of bioanalytical methods.

Cloning, expression, characterization, and immunological properties of citrate synthase from Echinococcus granulosus.

The larval stages of the tapeworm Echinococcus granulosus (Cestoda: Taeniidae) are the causative agent of cystic echinococcosis, one of the most important parasitic zoonoses worldwide. E. granulosus has a complete pathway for the tricarboxylic acid cycle (TCA), in which citrate synthase (CS) is the key enzyme. Here, we cloned and expressed CS from E. granulosus (Eg-CS) and report its molecular characterization. The localization of this protein during different developmental stages and mRNA expression patterns during H2O2 treatment were determined. We found that Eg-CS is a highly conserved protein, consisting of 466 amino acids. In western blotting assays, recombinant Eg-CS (rEg-CS) reacted with E. granulosus-positive sheep sera and anti-rEg-CS rabbit sera, indicating that Eg-CS has good antigenicity and immunoreactivity. Localization studies, performed using immunohistochemistry, showed that Eg-CS is ubiquitously expressed in the larva, germinal layer, and adult worm sections of E. granulosus. Eg-CS mRNA expression levels increased following H2O2 exposure. In conclusion, citrate synthase might be involved in the metabolic process in E. granulosus. An assessment of the serodiagnostic potential of rEg-CS based on indirect ELISA showed that, although sensitivity (93.55%) and specificity (80.49%) are high, cross-reactivity with other parasites precludes its use as a diagnostic antigen.

ANTIFUNGAL ACTIVITY OF HUMAN AND SOME MAMMALS SERA

Aim. Estimation of activity of native human serum and its antimicrobial peptides fraction against clinically important yeasts and comparison with the activity of some mammals sera. Materials and methods. Pooled samples of human, bovine, rabbit and mouse sera and collection strains of yeasts Candida albicans, Rhodotorula mucilaginosa, Malassezia furfur, Cryptococcus neoformans, Geotrichum candidum, Trichosporon cutaneum, Saccharomyces cerevisiae were used in the study. Antimicrobial peptides fractions (AMP) were obtained by filtration through molecular filters with 100 kDa pores. Activity of sera and their AMP-fractions were estimated by spectrophotometric method. Results. Activity of native mammal sera varied in diapason 73÷89% independently from yeast genus, although AMP-fractions activity varied more significantly. The minimal sensitivity to AMP-fractions of sera demonstrated M. furfur (activity values were equal 0÷13,5%) and G. candidum (0÷6,5%), but the maximal — R. mucilaginosa (12,3÷56,4%), C. albicans (22,0÷32,9%), and C. neoformans (17,1÷29,9%). Activity values of AMP-fractions of human serum were correlated meaningfully with no of the values of other mammals (Pirson coefficient r=0,459÷0,527). Considerable correlation of the indexes took place between rabbit and bovine sera (r=0,827), as well as between rabbit and mouse sera (r = 0,753). Conclusion. The differences between AMP-fractions activity towards studied yeast genera/specia indicate the occurrence of its specificity probably related with structural organization of cytoplasmic membrane of yeast cells as well as with variations in AMP composition in different mammals.

PROPERTIES OF NATIVE PROTEIN-CONTAINING ANTIGENS OF STREPTOCOCCUS PNEUMONIAE

Aim. The study of immunochemical and immunobiological properties of native protein-containing antigens of pneumococcus. Materials and methods. The study was carried out on the strains of the Collective Usage Center «Collection of Mechnikov Res. Inst. for Vaccine and Sera». In the work studied the chemical composition, the molecular weight of the obtained antigens in SDS-electrophoresis and antibody titers in ELISA. Protective activity of protein-containing antigens of pneumococcus was determined in experiments of active protection of mice. Results. Protein-containing antigens of pneumococcus were isolated from S. pneumoniae serotypes 3, 6B, 10A, 14, 19F, 23F and 36. The chemical composition of the preparations contained from 16 to 35% protein. In SDS-electrophoresis in polyacrylamide gel it was established that the molecular weight of protein-containing antigens of pneumococcus ranged from 14 to 116 kDa. Using ELISA shows the cross-activity of native antigens. Virtually all drugs reacted with antimicrobial rabbit serum obtained to serotype 19F (p≤0.05). Serotype serum 14 was less active and only protein-containing pneumococcal antigens obtained from 14 and 19F serotypes (p≤0.05) interacted with it. In the precipitation test according to Ouchterlony it was confirmed that preparations of serotypes 3, 6B, 14, 19F and 36 reacted with rabbit immune serum obtained for S. pneumoniae 19F serotype. In immunoblotting it was found that protein-containing antigens of pneumococcus isolated from serotypes 3, 6B, 10A, 14, 19F and 36 were associated with monoclonal antibodies to pneumococcal protein — pneumolysin. In vivo experiments it was shown that protein-containing antigens of pneumococcus protected animals from intraperitoneal infection of S. pneumoniae in homologous and heterologous systems (p≤0.05). Conclusion. The revealed immunochemical and cross-protective activity of protein-containing antigens of pneumococcus in vitro and in vivo experiments allows to select drugs derived from serotypes 6B, 10A, 19F and 36, as the most promising for further study of the intraspecific protective activity of individual native proteins of pneumococcus.

High-throughput Luminex xMAP assay for simultaneous detection of antibodies against rabbit hemorrhagic disease virus, Sendai virus and rabbit rotavirus.

Rabbits are widely used as models in biological research, and the pathogen status of rabbits used in studies can directly affect the results of experiments. Serological surveillance is the common monitoring method used in laboratory animals. A rapid, sensitive, and cost-effective high-throughput Luminex xMAP assay could be an attractive alternative to labor-intensive enzyme-linked immunosorbent assay (ELISA) methods. In this study, recombinant proteins from rabbit hemorrhagic disease virus and rabbit rotavirus and whole viral lysates of Sendai virus were used as coating antigens in an xMAP assay for the simultaneous detection of antibodies against these pathogens. The xMAP assay showed high specificity, with no cross-reaction with other pathogens. The coefficient of variation for intra-assay and inter-assay comparisons was less than 3% and 4%, respectively, indicating good repeatability and stability of the assay. The xMAP assay exhibited similar limits of detection for rabbit hemorrhagic virus and Sendai virus and was less sensitive for the detection of rabbit rotavirus when compared with commercial ELISA kits. A total of 52 clinical samples were tested simultaneously using both the xMAP assay and ELISA kits. The results obtained using these two methods were 100% coincident. In summary, the novel xMAP assay offers an alternative choice for rapid and sensitive high-throughput detection of antibodies in rabbit serum and can be used as a daily monitoring tool for laboratory animals.Electronic supplementary materialThe online version of this article (10.1007/s00705-019-04226-9) contains supplementary material, which is available to authorized users.

Effect of Olive Cake Pulp as A Partial or A Complete Substitute of Wheat Bran in Growing Rabbits’ Diet on Growth Performance, Carcass Traits and Blood Constituents under North Sinai Conditions

Sixty weaned New Zealand white rabbits of both sexes aged 6 wk and weighed 715 g were randomly divided into four treatment groups (15 rabbits each) to evaluate the possibility of feeding growing rabbits on diets containing olive cake pulp (OCP) as partial or complete substitution of wheat bran. The first group (C) was fed the basal diet as control (0%OCP), while the other three treatment groups (L, M, H) were fed diets containing 15, 20 and 25%OCP, respectively replacing wheat bran in the basal diet. All the experimental diets contained nearly the same level of crude protein (CP) and digestible energy (DE). All the experimental diets were formulated to cover the nutrient requirements of rabbits. Results revealed that dietary treatments had no significant effect on live body weight (LBW), total weight gain (TWG), average daily gain (ADG) and daily fed intake (DFI) at different ages (6-14 wk). At the same time, LBW, TWG and ADG tended to be higher in rabbits fed M and H diets than those fed C and L diets. Daily feed intake of the L group tended to be lower (P>0.05) than that of the other groups (C, M and H). Feed conversion of H group was the best compared with the other groups (C, L and M groups). Glucose and triglycerides levels in blood serum of rabbits decreased significantly (P 0.05) by treatment. Almost carcass traits (empty carcass, edible giblets and dressing) were not affected (P>0.05) by treatment. From the economic point of view, it appears that the inclusion of OCP in growing rabbit diets by 15, 20, 25% instead of wheat bran as fed basis decreased feed cost/ kg gain by 9.11, 7.25 and 14.32%, respectively. The economic efficiency values of the experimental diets were increased by 23.88, 20.15 and 26.73%, respectively compared with the control diet. In conclusion, olive cake pulp (OCP) could be incorporated in growing rabbits diets up to 25% without adverse effects on growth performance, carcass traits, blood constituents and economic efficiency.

Identification of novel serum markers for the progression of coronary atherosclerosis in WHHLMI rabbits, an animal model of familial hypercholesterolemia

Background and aimsThe development of serum markers specific for coronary lesions is important to prevent coronary events. However, analyses of serum markers in humans are affected by environmental factors and non-target diseases. Using an appropriate model animal can reduce these effects. To identify specific markers for coronary atherosclerosis, we comprehensively analyzed the serum of WHHLMI rabbits, which spontaneously develop coronary atherosclerosis. MethodsFemale WHHLMI rabbits were fed standard chow. Serum and plasma were collected under fasting at intervals of 4 months from 4 months old, and a total of 313 lipid molecules, 59 metabolites, lipoprotein lipid levels, and various plasma biochemical parameters were analyzed. The severity of coronary lesions was evaluated with cross-sectional narrowing (CSN) corrected with a frequency of 75%–89% CSN and CSN> 90%. ResultsThere was a large variation in the severity of coronary lesions in WHHLMI rabbits despite almost no differences in plasma biochemical parameters and aortic lesion area between rabbits with severe and mild coronary lesions. The metabolites and lipid molecules selected as serum markers for coronary atherosclerosis were lysophosphatidylcholine (LPC) 22:4 and diacylglycerol 18:0–18:0 at 4 months old, LPC 20:4 (sn-2), ceramide d18:1–18:2, citric acid plus isocitric acid, and pyroglutamic acid at 8 months old, and phosphatidylethanolamine plasminogen 16:1p-22:2 at 16 months old. ConclusionsThese serum markers were coronary lesion-specific markers independent of cholesterol levels and aortic lesions and may be useful to detect patients who develop cardiovascular disease.

A practical strategy for immunofluorescent detecting multiple targets in mouse tissues without restrictions on the host specious resources of the primary antibodies

Commercial deficiency of practical system to label multiple targets in experimental mouse tissues significantly hinders the feasibility to study the potential association between/among multiple targets using tissue-based immunofluorescence (IF) staining. We have developed a new protocol to do dual – labeling immunofluorescences on mouse tissues by combining direct and indirect immunofluorescence, making it possible to use commercial antibodies from the same specious (rabbit) to detect multiple targets in formalin-fixed paraffin-embedded (FFPE) archival mouse tissues simultaneously. This method applies indirect immunofluorescence to assess the first antigen in mouse tissues by using a rabbit anti-mouse polyclonal antibody and goat anti-rabbit antibody. After that, normal rabbit serum was employed to blocking the free binding sites of the previous antibodies. Direct immunofluorescence was used to assess the second antigen by a commercial kit-labeled rabbit anti–human (mouse) antibody at different emission wavelength. At last, cell nuclei were co-stained by DAPI. The outcomes demonstrated that this protocol obtain promising signals of both antigens and the nuclei. Moreover, this method also works on infection disease models in which samples are often over fixed due to biosafety rules.

A Novel, Multiple-Antigen Pneumococcal Vaccine Protects against Lethal Streptococcus pneumoniae Challenge.

Current vaccination against Streptococcus pneumoniae uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from S. pneumoniae TIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains of S. pneumoniae were opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologous S. pneumoniae strains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection against S. pneumoniae.

Antibody-functionalized reduced graphene oxide films for highly selective capture and purification of aflatoxins

Pyrenylbutyric acid and streptavidin were coupled to films of reduced graphene oxide (rGO) and then conjugated to a biotinylated broad-spectrum monoclonal antibody against aflatoxins (AFs). It is shown that such films can efficiently and selectively capture AFs inculding AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2. The rGO films were characterized by using scanning electron microscopy, energy-dispersive spectroscopy, and raman spectroscopy. The selectivity and purification performance of the antibody-loaded rGO films were investigated. They were applied to the purification of extremely small samples (100μL) of AFs-spiked rabbit serum after enzymatic hydrolysis. The AFs were analyzed by ultra-performance liquid chromatography coupled to tandem mass spectrometry. The limits of detection for the six AFs investigated ranged from 50 to 170pg·mL-1. The average recoveries of AFs in spiked rabbit serum samples ranged from 55% to 75%, with relative standard deviations of less than 9.4%. Graphical abstract Design of a multifunctional sandwich film that consists of a reduced graphene oxide film base, a pyrenylbutyric acid middle layer and a broad-specificity anti-AF monoclonal antibody surface layer. It was successfully applied to the determination of aflatoxins in only 100μL of rabbit serum samples with satisfactory selectivity and acceptable accuracy.

Biochemical Patterns of Cardio-renal Biomarkers in Serum and Vitreous Humor of Rabbits after Chronic CO Exposure

Carbon monoxide (CO) is a colorless gas that can cause cellular damage in exposed hosts depending on the levels inhaled. There is an increase in idiopathic diseases without a known cause. In Nigeria, this has led to a call for profiling of CO, a gas routinely inhaled by its population. This study was designed to assess the effect of chronic CO inhalation on vitreous and serum cardiorenal biochemical parameters. A total of twenty rabbits were divided into four groups. With the exception of control rabbits (air only), others were exposed daily to 200 ppm CO for 30 min for 10, 20, or 30 days. Five (5) rabbits constituted each of the four groups. At the 30 minutes after the final exposure, rabbits were euthanized mechanically and their vitreous humor and cardiac blood extracted using standard procedures. Serum and vitreous humor extracted were analyzed using ion selective electrode and enzymatic methods.

Monoclonal and Polyclonal Antibodies Specific to Human Fibromodulin.

BackgroundThe unique expression of fibromodulin (FMOD) in patients with chronic lymphocytic leukemia (CLL) has been previously reported. Detecting FMOD in CLL patients using specific anti-FMOD mAbs might provide a promising method in detection, monitoring, and prognosis of CLL.ObjectivesIn this study, we aimed for producing specific antibodies against FMOD to facilitate further cohort study of CLL, thus addressing FMOD as a potential target of detection.Materials and MethodsHuman FMOD gene (1087 bp) was extracted from genome of the CLL patients, and was cloned into the expression vector of pET-22b (+). The recombinant FMOD protein (rFMOD) was expressed in Escherichia coli. The purified rFMOD protein was used as an immunogen in rabbit and mice. Hybridoma technology was used to develop the monoclonal antibodies (mAbs). Polyclonal antibody (pAb) was purified from the rabbit sera using affinity column. The reactivity of anti-FMOD antibodies was assessed in ELISA, immunocytochemistry (ICC) and Western blot.ResultsICC results showed that the anti-FMOD antibodies specifically detected FMOD in CLL PBMCs and cell lines. The developed anti-FMOD pAb detected FMOD in CLL lysates, compared to healthy PBMCs, in Western blot and ELISA.ConclusionsThe developed anti-FMOD mAbs, and pAb specifically detect FMOD in CLL samples and might be used as research tools for further investigations in CLL.

Construction and expression of a prokaryotic expression vector for the goat sry gene

Goats are economically important animals in the world, and their sex is an important factor in their economic efficiency. Reconstruction of a goat SRY gene expression vector can lay a foundation for studying the immunogenicity and sex determination of SRY protein at the molecular level. In this study, the coding region of the goat SRY gene was used as the target gene fragment for synthesis and optimization, and the cloning vector was used as a template to amplify the target gene and finally ligated to the expression vector pET-SUMO. The recombinant plasmid was then verified by the double restriction enzyme method and transformed into Escherichia coli (DE3). After the induction of expression by Isopropyl â-D-Thiogalactoside (IPTG), the cells were lysed, and SDS-PAGE electrophoresis was performed to observe the expression of the recombinant protein. Additionally, the immunological activity of the recombinant protein was assessed. The target gene was successfully ligated into the prokaryotic expression vector pET-28a; additionally, the prokaryotic expression plasmid pET-SUMO was successfully constructed, and the SRY antigen protein (42 kDa) was expressed. The titer of the rabbit antiserum (PAI-1608012-1) was more than 1:50000, as measured by ELISA, which demonstrated that the titer and the sensitivity of the rabbit serum reached the expected levels. In this study, the prokaryotic expression vector pET-SUMO was successfully constructed. The recombinant protein has high immunopotency and immunoreactivity, which lays a foundation for the preparation of antibodies and the molecular sexing of goats in the future.

Localization Patterns of Sumoylation Enzymes E1, E2 and E3 in Ocular Cell Lines Predict Their Functional Importance.

It is well established now that protein sumoylation acts as an important regulatory mechanism mediating control of ocular development through regulation of multiple transcription factors. Yet the functional mechanisms of each factor modulated remain to be further explored using the available in vitro systems. In this regard, various ocular cell lines including HLE, FHL124, αTN4-1, N/N1003A and ARPE-19 have been demonstrated to be useful for biochemical and molecular analyses of normal physiology and pathogenesis. We have recently examined that these cell lines express a full set of sumoylation enzymes E1, E2 and E3. Following this study, here we have examined the localization of these enzymes and determined their differential localization patterns in these major ocular cell lines. The 5 major ocular cell lines were cultured in Dulbecco's modified Eagle's medium (DMEM) containing fetal bovine serum (FBS) or rabbit serum (RBS) and 1% Penicillin- Streptomycin. The localization of the 3 major sumoylation enzymes in the 5 major ocular cell lines were determined with immunohistochemistry. The images were captured with a Zeiss LSM 880 confocal microscope. we have obtained the following results: 1) The sumoylation enzymes SAE1, UBC9 and PIAS1 are distributed in both nucleus and cytoplasm, with a much higher level concentrated in the nucleus and the neighboring cellular organelle zone in all cell lines; 2) The sumoylation enzyme UBA2 was highly concentrated in both cytoplasm membrane, cytoskeleton and nucleus of all cell lines; 3) The ligase E3, RanBP2 was exclusively localized in the nucleus with homogeneous distribution. Our results for the first time established the differential localization patterns of the three types of sumoylation enzymes in 5 major ocular cell lines. Our establishment of the differential localization patterns of the three types of sumoylation enzymes in these cell lines help to predict their functional importance of sumoylation in the vision system. Together, our results demonstrate that these cell lines can be used for assay systems to explore the functional mechanisms of sumoylation mediating ocular development and pathogenesis.