Comparative study of sodium bicarbonate- and magnesium hydroxide-based gastric antacids for the effectiveness of Salmonella delivered Brucella antigens against wild type challenge in BALB/c mice

2021 ◽  
Vol 79 (2) ◽  
Author(s):  
Chamith Hewawaduge ◽  
Amal Senevirathne ◽  
Myeon-Sik Yang ◽  
Tae-Won Jeong ◽  
Bumseok Kim ◽  
...  
Keyword(s):  
Immune Responses ◽  
Oral Administration ◽  
Sodium Bicarbonate ◽  
Magnesium Hydroxide ◽  
Buffering Capacity ◽  
Live Attenuated Vaccine ◽  
Ph Buffering ◽  
In Vivo Experiments

ABSTRACT We compared the effects of two antacid formulations based on sodium bicarbonate and magnesium hydroxide on a Salmonella-delivered oral Brucella live attenuated vaccine. We conducted a series of in vitro and in vivo experiments to investigate the pH buffering capacity, buffering longevity and the effects of these formulations on the survival of Salmonella under neutralized pH conditions and its impact on immune responses. Magnesium hydroxide had a greater, stable and prolonged buffering capacity than sodium bicarbonate and was safer when administered orally. Oral administration of sodium bicarbonate resulted in discomfort as reflected by mouse behavior and mild muscle tremors, whereas mice treated with magnesium hydroxide and PBS were completely normal. Gastric survival studies using BALB/c mice revealed that a higher number of Salmonella reached the intestine when the magnesium hydroxide-based antacid buffer was administrated. Co-administration with attenuated Salmonella secreting Brucella antigens, SodC and Omp19 along with individual antacid formulations, significantly enhanced the antigen-specific protective immune responses against virulent Brucella challenge. Together, our results indicated that the pre vaccinated oral administration of bicarbonate-citric acid or magnesium hydroxide-based neutralizing buffers significantly counteract stomach acidity by maintaining the viability of an oral enteric vaccine formulation.

scholarly journals Foxp3 Silencing with Antisense Oligonucleotide Improves Immunogenicity of an Adjuvanted Recombinant Vaccine against Sporothrix schenckii

2021 ◽  
Vol 22 (7) ◽  
pp. 3470
Author(s):  
Alexander Batista-Duharte ◽  
Luis Sendra ◽  
Maria José Herrero ◽  
Deivys Leandro Portuondo ◽  
Damiana Téllez-Martínez ◽  
...  
Keyword(s):  
Immune Responses ◽  
Sporothrix Schenckii ◽  
Recombinant Vaccine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Murine Splenocytes ◽  
Treg Depletion ◽  
In Vivo Experiments

Background: In recent years, there has been great interest in developing molecular adjuvants based on antisense oligonucleotides (ASOs) targeting immunosuppressor pathways with inhibitory effects on regulatory T cells (Tregs) to improve immunogenicity and vaccine efficacy. We aim to evaluate the immunostimulating effect of 2′OMe phosphorothioated Foxp3-targeted ASO in an antifungal adjuvanted recombinant vaccine. Methods: The uptake kinetics of Foxp3 ASO, its cytotoxicity and its ability to deplete Tregs were evaluated in murine splenocytes in vitro. Groups of mice were vaccinated with recombinant enolase (Eno) of Sporothix schenckii in Montanide Gel 01 adjuvant alone or in combination with either 1 µg or 8 µg of Foxp3 ASO. The titers of antigen-specific antibody in serum samples from vaccinated mice (male C57BL/6) were determined by ELISA (enzyme-linked immunosorbent assay). Cultured splenocytes from each group were activated in vitro with Eno and the levels of IFN-γ and IL-12 were also measured by ELISA. The results showed that the anti-Eno antibody titer was significantly higher upon addition of 8 µM Foxp3 ASO in the vaccine formulation compared to the standard vaccine without ASO. In vitro and in vivo experiments suggest that Foxp3 ASO enhances specific immune responses by means of Treg depletion during vaccination. Conclusion: Foxp3 ASO significantly enhances immune responses against co-delivered adjuvanted recombinant Eno vaccine and it has the potential to improve vaccine immunogenicity.

scholarly journals In Vitro and In Vivo Analyses of Constitutive and In Vivo-Induced Promoters in Attenuated Vaccine and Vector Strains ofVibrio cholerae

2000 ◽  
Vol 68 (3) ◽  
pp. 1171-1175 ◽  
Author(s):  
Manohar John ◽  
Thomas I. Crean ◽  
Stephen B. Calderwood ◽  
Edward T. Ryan
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Antigen Expression ◽  
Live Attenuated Vaccine ◽  
Attenuated Vaccine ◽  
In Vivo Expression ◽  
Antibody Titers ◽  
Heterologous Antigens

ABSTRACT The optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of Vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. We therefore introduced plasmids expressing the B subunit of cholera toxin (CtxB) under the control of a number of promoters into V. choleraevaccine strain Peru2. We evaluated the tac promoter, which is constitutively expressed in V. cholerae, as well as the in vivo-induced V. cholerae heat shock htpGpromoter and the in vivo-induced V. cholerae iron-regulatedirgA promoter. The functionality of all promoters was confirmed in vitro. In vitro antigenic expression was highest in vaccine strains expressing CtxB under the control of thetac promoter (2 to 5 μg/ml/unit of optical density at 600 nm [OD600]) and, under low-iron conditions, in strains containing the irgA promoter (5 μg/ml/OD600). We orally inoculated mice with the various vaccine strains and used anti-CtxB immune responses as a marker for in vivo expression of CtxB. The vaccine strain expressing CtxB under the control of thetac promoter elicited the most prominent specific anti-CtxB responses in vivo (serum immunoglobulin G [IgG], P≤ 0.05; serum IgA, P ≤ 0.05; stool IgA,P ≤ 0.05; bile IgA, P ≤ 0.05), despite the finding that the tac and irgApromoters expressed equivalent amounts of CtxB in vitro. Vibriocidal antibody titers were equivalent in all groups of animals. Our results indicate that in vitro assessment of antigen expression by vaccine and vector strains of V. cholerae may correlate poorly with immune responses in vivo and that of the promoters examined, thetac promoter may be best suited for expression from plasmids of at least certain heterologous antigens in such strains.

scholarly journals Experimental DNA-Launched Live-Attenuated Vaccines Against Yellow Fever

2019 ◽  
Vol 18 (1) ◽  
pp. 18-25 ◽  
Author(s):  
P. Pushko ◽  
А. А. Ishmukhametov ◽  
P. P. Bredenbeek ◽  
I. S. Lukashevich
Keyword(s):  
Immune Responses ◽  
Dna Vaccine ◽  
Yellow Fever ◽  
Vaccine Virus ◽  
Genomic Rna ◽  
Dna Encoding ◽  
Live Attenuated Vaccine ◽  
Pathogenic Virus

Background DNA-launched vaccine is “manufactured” in vaccinated individuals and does not require traditional vaccine manufacturing facility and technology. Goals. Using yellow fever 17D vaccine, we have provided proof-of-concept evidence that these vaccine can be launched from DNA and induce specific immune responses against pathogenic virus causing yellow fever. The infectious DNA vaccine technology is based on the transcription of the full-length genomic RNA of the live-attenuated virus from plasmid DNA in vitro and in vivo. A few ng of infectious DNA encoding the fulllength genomic RNA are required to initiate the replication of the vaccine virus in vitro. The in vivo-generated viral RNA initiates limited replication of the vaccine virus, which in turn leads to efficient immunization. Electroporation in vivo has induced specific immune responses against pathogenic virus and protected mice against fatal disease. Here we describe a novel infectious DNA vaccine technology which combines advantages of naked DNA vaccination and live-attenuated vaccine efficacy. Conclusions If successful in further testing, this technology can dramatically change the way we make vaccines as well as vaccination practice. 

scholarly journals 846 Neospora caninum – an immunotherapeutic protozoan against solid cancers

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A899-A899
Author(s):  
Louis Lantier ◽  
Agathe Poupee-Beauge ◽  
Louis Lantier ◽  
Céline Ducournau ◽  
Anne Di Tommaso ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Neospora Caninum ◽  
Tumor Development ◽  
Molecular Therapy ◽  
List Type ◽  
In Vivo Experiments ◽  
Attenuated Viruses

BackgroundImmunotherapy induces, provides, and/or reactivates anti-tumor immune responses. Some microorganisms also can initiate response that lyzes infected tumor and/or stimulates systemic immunity. Attenuated viruses or bacteria are well studied as oncotherapeutics, but not protozoa except Toxoplasma gondii.1 We assessed the effect on tumors of other protozoa that were naturally non-pathogenic to humans. Thus, we discovered the ability to use Neospora caninum (Nc) in a manner and form that demonstrated a synergistic array of pertinent immunotherapeutic characteristics against solid cancers. Our first Article on Neospora as Onco-immunotherapeutic is currently under revision after review by the JITC. We report on the most recent data notably from Nc engineered to secrete human IL-15 within the tumor.MethodsIn vitro, the immunostimulatory properties of Nc strains wildtype and engineered to secrete human IL-15 were studied. In vivo experiments of treatment with of Nc tachyzoites2 administered locally (intra and peri tumoral) or remotely (subcutaneous) in a murine thymoma EG7 tumor and in human Merkel cell carcinoma (MCC).ResultsWe demonstrated that the treatment of thymoma EG7 by Nc strongly inhibited tumor development. Analysis of immune responses and interactions between Nc and tumor cells showed that Nc had the ability to lyze infected cancer cells, reactivated immune competence within the Tumor Microenvironment (TME), and activated the systemic immune system by promoting the recruitment of immune cells to the site of tumor. We also established in a NOD/SCID mouse model that Nc was able to induce a strong regression of human MCC. Recently, to further enhance oncotherapeutic effect, we engineered an Nc strain to secrete human IL-15 (cross reactive with mouse cells), associated with alpha subunit of IL-15 receptor, increasing its stability.3 This strain induced proliferation of human PBMCs and their secretion of IFN-γ. In the EG7 model, human IL-15 secreting Nc showed greater protection against tumor development, confirming enhancement of immunotherapy by engineering Nc to deliver/secrete IL-15.ConclusionsThese results highlight Neospora caninum as a potentially extremely efficient, and non-toxic anti-cancer agent, capable of being engineered to express at its surface or to secrete bio-drugs, like human IL-15 cytokine. Our work has identified the broad clinical possibilities of using N. caninum as an oncolytic protozoan in human medicine capable of vectoring molecular therapy, overcoming TME defenses.ReferencesFox BA, Butler KL, Guevara RB, Bzik DJ. Cancer therapy in a microbial bottle: Uncorking the novel biology of the protozoan Toxoplasma gondii. PLoS Pathog 2017;13(9):e1006523. https://doi.org/10.1371/journal.ppat.1006523Bjerkas I, Jenkins MC, Dubey JP. Identification and characterization of Neospora caninum tachyzoite antigens useful for diagnosis of neosporosis. Clin Diagn Lab Immunol 1994;1(2):214-221.Article for publication in the Journal of Immunotherapy of Cancer, under revision on September 20, 2020.

Preparation and Evaluation of Gemifloxacin Mesylate Floating Matrix Tablets in Healthy Human Volunteers

2017 ◽  
Vol 10 (1) ◽  
pp. 3623-3630
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Haarika B ◽  
Jyothi Sri S ◽  
K Abbulu
Keyword(s):  
Drug Release ◽  
Sodium Bicarbonate ◽  
Polymer Concentration ◽  
Hydroxypropyl Methylcellulose ◽  
Matrix Tablets ◽  
Physical Parameters ◽  
Drug Bioavailability ◽  
Floating Tablets

The purpose of present investigation was to develop floating matrix tablets of gemifloxacin mesylate, which after oral administration could prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. Tablets containing drug, various viscosity grades of hydroxypropyl methylcellulose such as HPMC K4M and HPMC K15M as matrix forming agent, Sodium bicarbonate as gas-forming agent and different additives were tested for their usefulness in formulating gastric floating tablets by direct compression method. The physical parameters, in vitro buoyancy, release characteristics and in vivo radiographic study were investigated in this study. The gemifloxacin mesylate floating tablets were prepared using HPMC K4M polymer giving more sustained drug release than the tablet containing HPMC K15M. All these formulations showed floating lag time of 30 to 47 sec and total floating time more than 12 h. The drug release was decreased when polymer concentration increases and gas generating agent decreases. Formulation that contains maximum concen-tration of both HPMC K15M and sodium bicarbonate (F9) showing sufficiently sustained with 99.2% of drug release at 12 h. The drug release from optimized formulation follows Higuchi model that indicates the diffusion controlled release. The best formulation (F9) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent and the tablet remained in the stomach for about 6 h.   

ANTITUMOR EFFECT OF COLLOIDAL SILVER BISILICATE IN EXPERIMENTAL IN VITRO AND IN VIVO STUDIES

2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Human Tumor ◽  
Significant Inhibition ◽  
In Vivo Studies ◽  
Ehrlich Carcinoma ◽  
In Vivo Experiments

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.

scholarly journals Lysosomotropic agents including azithromycin, chloroquine and hydroxychloroquine activate the integrated stress response

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ai-Ling Tian ◽  
Qi Wu ◽  
Peng Liu ◽  
Liwei Zhao ◽  
Isabelle Martins ◽  
...  
Keyword(s):  
Stress Response ◽  
Immune Responses ◽  
Initiation Factor ◽  
Integrated Stress Response ◽  
Serine Residue ◽  
Eif2α Phosphorylation ◽  
Lysosomotropic Agents ◽  
Cultured Human Cells

AbstractThe integrated stress response manifests with the phosphorylation of eukaryotic initiation factor 2α (eIF2α) on serine residue 51 and plays a major role in the adaptation of cells to endoplasmic reticulum stress in the initiation of autophagy and in the ignition of immune responses. Here, we report that lysosomotropic agents, including azithromycin, chloroquine, and hydroxychloroquine, can trigger eIF2α phosphorylation in vitro (in cultured human cells) and, as validated for hydroxychloroquine, in vivo (in mice). Cells bearing a non-phosphorylatable eIF2α mutant (S51A) failed to accumulate autophagic puncta in response to azithromycin, chloroquine, and hydroxychloroquine. Conversely, two inhibitors of eIF2α dephosphorylation, nelfinavir and salubrinal, enhanced the induction of such autophagic puncta. Altogether, these results point to the unexpected capacity of azithromycin, chloroquine, and hydroxychloroquine to elicit the integrated stress response.

scholarly journals Plant-Derived Extracellular Vesicles: Current Findings,Challenges, and Future Applications

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 411
Author(s):  
Nader Kameli ◽  
Anya Dragojlovic-Kerkache ◽  
Paul Savelkoul ◽  
Frank R. Stassen
Keyword(s):  
Human Health ◽  
Extracellular Vesicles ◽  
Preliminary Results ◽  
In Vivo Experiments ◽  
Health And Disease ◽  
Conducting Research ◽  
Protocol Standardization ◽  
Insight Into

In recent years, plant-derived extracellular vesicles (PDEVs) have gained the interest of many experts in fields such as microbiology and immunology, and research in this field has exponentially increased. These nano-sized particles have provided researchers with a number of interesting findings, making their application in human health and disease very promising. Both in vitro and in vivo experiments have shown that PDEVs can exhibit a multitude of effects, suggesting that these vesicles may have many potential future applications, including therapeutics and nano-delivery of compounds. While the preliminary results are promising, there are still some challenges to face, such as a lack of protocol standardization, as well as knowledge gaps that need to be filled. This review aims to discuss various aspects of PDEV knowledge, including their preliminary findings, challenges, and future uses, giving insight into the complexity of conducting research in this field.

scholarly journals Osteoprotective Effects of Loganic Acid on Osteoblastic and Osteoclastic Cells and Osteoporosis-Induced Mice

2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  
Keyword(s):  
Osteoclast Differentiation ◽  
Osteoblastic Differentiation ◽  
Common Disease ◽  
Root Extract ◽  
Mouse Bone Marrow ◽  
Mineral Density ◽  
Bone Mineral Density Loss ◽  
In Vivo Experiments

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

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