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PLoS Neglected Tropical Diseases Nov 2020Bungarus multicinctus is the most venomous snake distributed in China and neighboring countries of Myanmar, Laos, north Vietnam and Thailand. The high mortality rate of...
Immunoreactivity and neutralization study of Chinese Bungarus multicinctus antivenin and lab-prepared anti-bungarotoxin antisera towards purified bungarotoxins and snake venoms.
Bungarus multicinctus is the most venomous snake distributed in China and neighboring countries of Myanmar, Laos, north Vietnam and Thailand. The high mortality rate of B. multicinctus envenomation is attributed to the lethal components of α-, β-, γ- and κ- bungarotoxins contained in the venom. Although anti-B. multicinctus sera were produced in Shanghai, Taiwan and Vietnam, the most widely clinic used product was term as B. multicinctus antivenin and manufactured by Shanghai Serum Bio-technology Co. Ltd. In the present investigation, high purity α-, β- and γ-bungarotoxins were separately isolated from B. multicinctus crude venom. Rabbit anti- α-, β- and γ-bungarotoxin antisera were prepared by common methods, respectively. LD50 values of α-, β- and γ-bungarotoxins were systematically determined via three administration pathways (intraperitoneal, intramuscular and intravenous injections) in Kunming mice. LD50 values of β-bungarotoxin were closely related with injection routines but those of both α- and γ-bungarotoxins were not dependent on the injection routines. Commercial B. multicinctus antivenin showed strong immunoreaction with high molecular weight fractions of the B. multicinctus but weakly recognized low molecular weight fractions like α- and γ-bungarotoxins. Although B. multicinctus antivenin showed immunoreaction with high molecular weight fractions of Bungarus fasciatus, Naja atra, Ophiophagus hannah venoms but the antivenin only demonstrated animal protection efficacy against O. hannah venom. These results indicated that the high molecular weight fractions of the O. hannah played an important role in venom lethality but those of B. fasciatus and N. atra did not have such a role.
Topics: Animals; Antivenins; Bungarotoxins; Bungarus; China; Elapid Venoms; Immune Sera; Lethal Dose 50; Male; Mice; Neutralization Tests; Ophiophagus hannah; Rabbits
PubMed: 33253321
DOI: 10.1371/journal.pntd.0008873 -
Frontiers in Cellular and Infection... 2022multigene families are thought to play important roles in the pathogenesis of malaria. genes comprise the largest multigene family in many species. However, their...
multigene families are thought to play important roles in the pathogenesis of malaria. genes comprise the largest multigene family in many species. However, their expression pattern and localisation remain to be elucidated. Understanding protein subcellular localisation is fundamental to reveal the functional importance and cell-cell interactions of the PIR proteins. Here, we use the rodent malaria parasite, as a model to investigate the localisation pattern of this gene family. We found that most PIR proteins are co-expressed in clusters during acute and chronic infection; members of the S7 clade are predominantly expressed during the acute-phase, whereas members of the L1 clade dominate the chronic-phase of infection. Using peptide antisera specific for S7 or L1 PIRS, we show that these PIRs have different localisations within the infected red blood cells. S7 PIRs are exported into the infected red blood cell cytoplasm where they are co-localised with parasite-induced host cell modifications termed Maurer's clefts, whereas L1 PIRs are localised on or close to the parasitophorous vacuolar membrane. This localisation pattern changes following mosquito transmission and during progression from acute- to chronic-phase of infection. The presence of PIRs in Maurer's clefts, as seen for RIFIN and STEVOR proteins, might suggest trafficking of the PIRs on the surface of the infected erythrocytes. However, neither S7 nor L1 PIR proteins detected by the peptide antisera are localised on the surface of infected red blood cells, suggesting that they are unlikely to be targets of surface variant-specific antibodies or to be directly involved in adhesion of infected red blood cells to host cells, as described for VAR proteins. The differences in subcellular localisation of the two major clades of PIRs across the blood cycle, and the apparent lack of expression on the red cell surface strongly suggest that the function(s) of this gene family may differ from those of other multigene families of , such as the genes of .
Topics: Animals; Erythrocytes; Immune Sera; Malaria; Plasmodium; Plasmodium falciparum
PubMed: 35782145
DOI: 10.3389/fcimb.2022.877253 -
Molecular Medicine Reports Aug 2019The use of camptothecin and its analogues has increased in clinical settings and in agriculture. Therefore, camptothecins and their derivatives, metabolites and...
The use of camptothecin and its analogues has increased in clinical settings and in agriculture. Therefore, camptothecins and their derivatives, metabolites and degradation products are frequently found in the environment. Therefore, it is important to develop an ELISA for the quantification of camptothecins in human plasma, plants, animal tissues and other matrices. The present study developed a novel competitive indirect ELISA for camptothecin using a monoclonal antibody (MAb). In total, two haptens and various carrier proteins were tested to select the most suitable immunogen for the production of MAbs against camptothecin. Hapten 1 conjugated with keyhole limpet hemocyanin was selected for the preparation of MAb 5A3, and was used to establish a competitive indirect ELISA for camptothecin. A total of three derivatives of camptothecin used in clinical practice were examined. Topotecan showed an IC50 value of 0.68 µg/ml with a detection limit of 0.19 µg/ml, belotecan showed an IC50 value of 0.87 µg/ml with a detection limit of 0.22 µg/ml and irinotecan showed an IC50 value of 2.85 µg/ml with a detection limit of 0.47 µg/ml. The cross‑reactivity results suggested that the assay developed in the present study possessed a high sensitivity to camptothecin. Therefore, this immunoassay technique may be suitable for monitoring the levels of camptothecin in compound analysis, clinical applications, and analyses of food and environmental samples.
Topics: Animals; Antibodies, Monoclonal; Binding, Competitive; Camptothecin; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Female; Haptens; Hemocyanins; Humans; Immune Sera; Limit of Detection; Mice; Mice, Inbred BALB C; Protein Binding; Topotecan
PubMed: 31173229
DOI: 10.3892/mmr.2019.10342 -
The American Journal of Tropical... May 2017AbstractDengue virus infections have adversely impacted U.S. military operations since the Spanish-American War. The erosion of mission capabilities and lost duty days...
AbstractDengue virus infections have adversely impacted U.S. military operations since the Spanish-American War. The erosion of mission capabilities and lost duty days are underestimated. Appreciating the incidence and prevalence of dengue infections in U.S. military personnel is important to inform disease prevention strategies. Banked pre- and post-deployment serum samples from 1,000 U.S. military personnel with a single deployment to a dengue-endemic region were tested using a screening microneutralization assay to detect anti-dengue-virus-neutralizing antibodies. A total of 76 (7.6%) post-deployment samples were positive and 15 of the pre-deployment samples were negative. These figures represent an infection incidence of 1.5% and total of 17.6 seroconversions per 10,000 deployment months. These data represent a deploying military population with a relatively high background rate of dengue seropositivity, a low level of infection during deployment compared with background infection rates in the local populations, and the potential for worsening clinical attack rates with increased frequency of deployment. Additional studies are required to more clearly elucidate the dengue infection and disease risk in U.S. military personnel.
Topics: Adult; Africa; Antibodies, Viral; Asia, Southeastern; Blood Banks; Central America; Dengue; Dengue Virus; Endemic Diseases; Female; Humans; Immune Sera; Male; Middle Aged; Military Personnel; Retrospective Studies; Seroepidemiologic Studies; Travel; United States
PubMed: 28193746
DOI: 10.4269/ajtmh.16-0663 -
Folia Histochemica Et Cytobiologica 2017This review updates the findings about the anatomical distribution (using immunohistochemical techniques) and possible functions of D-glutamate in the central nervous... (Review)
Review
This review updates the findings about the anatomical distribution (using immunohistochemical techniques) and possible functions of D-glutamate in the central nervous system of mammals, as well as compares the distribution of D-glutamate with the distribution of the most studied D-amino acids: D-serine and D-aspartate. The protocol used to obtain highly specific antisera directed against D-amino acids is also reported. Immunoreactivity for D-glutamate was found in dendrites and cell bodies, but not in nerve fibers. Perikarya containing D-glutamate were found in the mesencephalon and thalamus. The highest density of cell bodies was found in the dorsal raphe nucleus, the mesencephalic central grey matter, the superior colliculus, and in the subparafascicular thalamic nucleus. In comparison with the distribution of immunoreactive cell bodies containing D-serine or D-aspartate, the distribution of D-glutamate-immunoreactive perikarya is less widespread. Currently, the physiological actions mediated by D-glutamate in the brain are unknown but the restricted neuroanatomical distribution of this D-amino acid suggests that D-glutamate could be involved in very specific physiological mechanisms. In this sense, the possible functional roles of D-glutamate are discussed.
Topics: Amino Acids; Animals; Central Nervous System; Glutamic Acid; Humans; Immune Sera; Immunohistochemistry
PubMed: 29363733
DOI: 10.5603/FHC.a2017.0023 -
Microbiology Spectrum Aug 2023Senecavirus A (SVA) is a type of nonenveloped single-stranded, positive-sense RNA virus. The VP2 protein is a structural protein that plays an important role in inducing...
Senecavirus A (SVA) is a type of nonenveloped single-stranded, positive-sense RNA virus. The VP2 protein is a structural protein that plays an important role in inducing early and late immune responses of the host. However, its antigenic epitopes have not been fully elucidated. Therefore, defining the B epitopes of the VP2 protein is of great importance to revealing its antigenic characterization. In this study, we analyzed B-cell immunodominant epitopes (IDEs) of the VP2 protein from the SVA strain CH/FJ/2017 using the Pepscan approach and a bioinformatics-based computational prediction method. The following four novel IDEs of VP2 were identified: IDE1, TKSDPPSSSTDQPTTT; IDE2, PDGKAKSLQELNEEQW; IDE3, VEMSDDYRTGKNMPF; and IDE4, PYFNGLRNRFTTGT. Most of the IDEs were highly conserved among the different strains. To our knowledge, the VP2 protein is a major protective antigen of SVA that can induce neutralizing antibodies in animals. Here, we analyzed the immunogenicity and neutralization activity of four IDEs of VP2. Consequently, all four IDEs showed good immunogenicity that could elicit specific antibodies in guinea pigs. A neutralization test showed that the peptide-specific guinea pig antisera of IDE2 could neutralize SVA strain CH/FJ/2017, and IDE2 was identified as a novel potential neutralizing linear epitope. This is the first time VP2 IDEs have been identified by using the Pepscan method and a bioinformatics-based computational prediction method. These results will help elucidate the antigenic epitopes of VP2 and clarify the basis for immune responses against SVA. The clinical symptoms and lesions caused by SVA are indistinguishable from those of other vesicular diseases in pigs. SVA has been associated with recent outbreaks of vesicular disease and epidemic transient neonatal losses in several swine-producing countries. Due to the continuing spread of SVA and the lack of commercial vaccines, the development of improved control strategies is urgently needed. The VP2 protein is a crucial antigen on the capsids of SVA particles. Furthermore, the latest research showed that VP2 could be a promising candidate for the development of novel vaccines and diagnostic tools. Hence, a detailed exploration of epitopes in the VP2 protein is necessary. In this study, four novel B-cell IDEs were identified using two different antisera with two different methods. IDE2 was identified as a new neutralizing linear epitope. Our findings will help in the rational design of epitope vaccines and further understanding of the antigenic structure of VP2.
Topics: Animals; Guinea Pigs; Capsid Proteins; Epitopes, B-Lymphocyte; Antibodies, Viral; Immune Sera
PubMed: 37428080
DOI: 10.1128/spectrum.04472-22 -
Journal of Virological Methods Oct 2023To investigate the cross-reactivity between the sera collected from Vaccinia Virus Tiantan Strain vaccinated rabbits and viral antigens of monkeypox virus.
AIM
To investigate the cross-reactivity between the sera collected from Vaccinia Virus Tiantan Strain vaccinated rabbits and viral antigens of monkeypox virus.
METHODS
Vaccinia viruses were prepared on chicken embryo fibroblasts (CEF) and Vero cells respectively named as CEF-VTT NVSI-1 and Vero-VTT NVSI-1. Rabbits were inoculated with a total of three doses of adjuvanted 1.3 × 10 PFU CEF-VTT NVSI-1 each dose or adjuvanted 3.9 × 10 PFU Vero-VTT NVSI-1 (Freunds complete adjuvant) via the subcutaneous route. We then performed the enzyme-linked immunosorbent assay (ELISA) and bio-layer interferometry (BLI) for determination of the binding activity and affinity of immune sera to five crucial surface antigens on monkeypox virus including A35, B6R, H3 and to corresponding homologous antigens A33R, B5 and L1R of vaccinia virus. For comparison, plaque reduction neutralizing tests were used to evaluate the neutralization of immune sera against vaccinia virus.
RESULTS
Both CEF-VTT NVSI-1 and Vero-VTT NVSI-1 vaccinations following planned schedule could induce neutralizing antibody titers greater than 1:2048 in rabbit sera. Binding antibodies targeting monkeypox viral antigens were confirmed by both indirect ELISA and BLI methods. Indirect ELISA for rabbit sera revealed 1:51200 binding antibody titers to A35/B6R/H3 monkeypox virus antigens while BLI tests yielded affinities at 2 × 10 to 8 × 10 between the sera and the three antigens. Similarly, such sera showed binding strength to vaccinia virus antigens A33R/B5/L1R consistent with that to three preceding monkeypox virus antigens. These results demonstrated the cross-reactivity between the sera of vaccinia virus vaccinated animals and monkeypox virus antigens. Traditional ELISA test and BLI method displayed a high consistency in antigen screening and they were further proved to correlate to the results of plaque reduction neutralizing test, which indicates that BLI could be utilized as an indirect alternative for assessment of neutralizing activity of samples in response to live virus.
CONCLUSIONS
Sera of vaccinia virus-vaccinated rabbits exhibited cross-reactivity with viral antigens of monkeypox virus. Potential in improving the accuracy of antigen discovery while reducing the lengthy work needed for the screening as BLI method possesses, it contributes greatly to the rapid preliminary evaluation of immune response generated by vaccines.
Topics: Animals; Chlorocebus aethiops; Chick Embryo; Rabbits; Vaccinia virus; Monkeypox virus; Vero Cells; Antigens, Viral; Chickens; Immune Sera; Antibodies, Viral; Vaccinia
PubMed: 37473582
DOI: 10.1016/j.jviromet.2023.114772 -
European Journal of Pharmacology Aug 2022Snake envenomation leads to the formation of damage-associated molecular patterns (DAMPs), which are mediated by endogenous intracellular molecules. These are recognized...
UNLABELLED
Snake envenomation leads to the formation of damage-associated molecular patterns (DAMPs), which are mediated by endogenous intracellular molecules. These are recognized by pattern-recognition receptors (PRRs) and can induce sterile inflammation.
AIMS
In the present study, we aim at understanding the mechanisms involved in DAMPs induced sterile inflammation to unravel the novel therapeutic strategies for treating snake bites. The potential of benzodiazepinone derivatives to act against snake venom induced inflammation has been explored in the present investigation.
MAIN METHODS
Three compounds VA 17, VA 43 and PA 03 were taken from our library of synthetic compounds. Oxidative stress markers such as lipid peroxidation, superoxide and nitric oxide were measured along with the analysis of DAMPs (IL6, HMGB1, vWF, S100b and HSP70). These compounds have been docked using molecular docking against the snake venom PLA structure (PDB code: 1OXL).
KEY FINDINGS
The compounds have been found to effectively neutralize viper and cobra venoms induced lethal activity both ex vivo and in vivo. The compounds have also neutralized the viper venom induced hemorrhagic, coagulant, anticoagulant reactions as well as inflammation. The fold of protection have always been found to be higher in case of ex vivo than in in vivo. These compounds have neutralized the venom induced DAMPs as exhibited by IL6, HMGB1, vWF, S100b and HSP70. The fold of neutralization is found to be higher in VA 43.
SIGNIFICANCE
The identified compounds could be used as potential candidates for developing treatment of snakebites in areas where antiserums are not yet available.
Topics: Animals; Antivenins; HMGB1 Protein; Inflammation; Interleukin-6; Molecular Docking Simulation; Snake Bites; Viper Venoms; von Willebrand Factor
PubMed: 35728626
DOI: 10.1016/j.ejphar.2022.175095 -
Carbohydrate Polymers Feb 2021Capsular polysaccharides (CPS) are the key virulent factors in the pathogenesis of Streptococcus pneumoniae. The previously unknown CPS structures of the pneumococcal...
Capsular polysaccharides (CPS) are the key virulent factors in the pathogenesis of Streptococcus pneumoniae. The previously unknown CPS structures of the pneumococcal serotype 28F and 28A were thoroughly characterized by NMR spectroscopy, chemical analysis and AF4-MALS-dRI. The following repeat unit structures were determined: -4)[α-l-Rhap-[4-P-2-Gro]]-(1-3)-α-d-Sug-[6-P-Cho]-(1-3)-β-l-Rhap-[2-OAc]-(1-4)-β-d-Glcp-(1-; 28F: Sug = Glcp, Mw: 540.5 kDa; 28A: Sug = GlcpNAc, Mw: 421.9 kDa; The correlation of CPS structures with biosynthesis showed that glycosyltransferase WciU in serotypes 28F and 28A had different sugar donor specificity toward α-d-Glcp and α-d-GlcNAcp, respectively. Furthermore, latex agglutination tests of de-OAc and de-PO CPS were conducted to understand cross-reactions between serogroup 28 with factor antiserum 23d. Interestingly, the de-OAc 28F and 28A CPS can still weakly react with factor antiserum 23d, while de-PO CPS did not react with factor antiserum 23d. This indicated that OAc group could affect the affinity and P-2-Gro was crucial for cross-reacting with factor antiserum 23d.
Topics: Amino Acid Sequence; Bacterial Capsules; Cross Reactions; Glycosyltransferases; Immune Sera; Latex Fixation Tests; Magnetic Resonance Spectroscopy; Molecular Structure; Molecular Weight; Polysaccharides, Bacterial; Serogroup; Streptococcus pneumoniae
PubMed: 33357884
DOI: 10.1016/j.carbpol.2020.117323 -
International Journal of Molecular... Mar 2023Polyomaviruses (PyVs) are highly prevalent in humans and animals. PyVs cause mild illness, however, they can also elicit severe diseases. Some PyVs are potentially...
Polyomaviruses (PyVs) are highly prevalent in humans and animals. PyVs cause mild illness, however, they can also elicit severe diseases. Some PyVs are potentially zoonotic, such as simian virus 40 (SV40). However, data are still lacking about their biology, infectivity, and host interaction with different PyVs. We investigated the immunogenic properties of virus-like particles (VLPs) derived from viral protein 1 (VP1) of human PyVs. We immunised mice with recombinant HPyV VP1 VLPs mimicking the structure of viruses and compared their immunogenicity and cross-reactivity of antisera using a broad spectrum of VP1 VLPs derived from the PyVs of humans and animals. We demonstrated a strong immunogenicity of studied VLPs and a high degree of antigenic similarity between VP1 VLPs of different PyVs. PyV-specific monoclonal antibodies were generated and applied for investigation of VLPs phagocytosis. This study demonstrated that HPyV VLPs are highly immunogenic and interact with phagocytes. Data on the cross-reactivity of VP1 VLP-specific antisera revealed antigenic similarities among VP1 VLPs of particular human and animal PyVs and suggested possible cross-immunity. As the VP1 capsid protein is the major viral antigen involved in virus-host interaction, an approach based on the use of recombinant VLPs is relevant for studying PyV biology regarding PyV interaction with the host immune system.
Topics: Humans; Animals; Mice; Capsid Proteins; Polyomavirus Infections; Simian virus 40; Antigens; Immune Sera
PubMed: 36902338
DOI: 10.3390/ijms24054907