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2.
Environ Sci Technol ; 58(4): 1882-1893, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38214663

RESUMO

The expansion of renewable energy and the large-scale deployment of carbon dioxide (CO2) capture and storage (CCS) can decarbonize the power sector. The use of CO2 to extract geothermal heat from naturally porous and permeable sedimentary basins to generate electricity (CO2-plume geothermal (CPG) system) presents an opportunity to simultaneously generate renewable energy and geologically store CO2. In this study, we estimate the life cycle greenhouse gas (GHG) impacts of CPG systems through 12 scenarios in which CPG systems are combined with one of six CO2 sources (e.g., bioenergy with carbon capture and storage (BECCS) and iron and steel facilities) and operate in two geological settings. We find the life cycle GHG emissions of CPG systems ranging from -0.25 to -6.18 kg CO2eq/kWh. CPG systems can achieve the highest emissions reductions when utilizing the CO2 captured from BECCS. We evaluate uncertainty through a Monte Carlo simulation, demonstrating consistent net reductions in life cycle emissions and a local, one-parameter-at-a-time sensitivity analysis that identifies the CO2 capture capacity as the high-impact parameter of the results. Through the production of electricity, CPG systems can provide additional environmental benefits to the deployment of large-scale CCS.


Assuntos
Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Dióxido de Carbono/análise , Energia Renovável , Efeito Estufa
3.
PeerJ ; 11: e16611, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38144203

RESUMO

This study aims to investigate the regulatory mechanism of choline (CH) on triglyceride (TG) synthesis in cows, with a specific focus on its potential association with high milk fat percentage in the gut of the Zhongdian yak. By employing combined metagenomics and metabolomics analysis, we establish a correlation between CH and milk fat production in yaks. Bovine mammary epithelial cells (MAC-T) were exposed to varying CH concentrations, and after 24 h, we analyzed the expression levels of key proteins (membrane glycoprotein CD36 (CD36); adipose differentiation-related protein (ADFP); and ubiquintin (UB)), cellular TG content, lipid droplets, and cell vitality. Additionally, we evaluated the genes potentially related to the CH-mediated regulation of TG synthesis using real-time qPCR. CH at 200 µM significantly up-regulated CD36, ADFP, UB, and TG content. Pathway analysis reveals the involvement of the ubiquitination pathway in CH-mediated regulation of TG synthesis. These findings shed light on the role of CH in controlling TG synthesis in MAC-T cells and suggest its potential as a feed additive for cattle, offering possibilities to enhance milk fat production efficiency and economic outcomes in the dairy industry.


Assuntos
Leite , Linfócitos T , Feminino , Animais , Bovinos , Leite/metabolismo , Linfócitos T/metabolismo , Lipogênese , Ubiquitinação , Triglicerídeos/metabolismo
4.
Front Vet Sci ; 10: 1206346, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37592942

RESUMO

The composition and abundance of microorganisms in the gastrointestinal tract of cows are complex and extensive, and they play a crucial role in regulating nutrient digestion, absorption, maintaining digestive tract stability, and promoting the production and health of the host. The fermentation carried out by these microorganisms in the gastrointestinal tract is fundamental to the health and productivity of cows. Rumen microorganisms produce the majority of enzymes required to break down feed substrates, such as cellulose, protein, lipids, and other plant materials, through fermentation. This process provides energy metabolism substrates that satisfy approximately 70% of the host's energy requirements for physiological activities. Gut microorganisms primarily decompose cellulose that is difficult to digest in the rumen, thereby providing heat and energy to the hosts. Additionally, they have an impact on host health and productivity through their role in immune function. Understanding the composition and function of the cow gut microbiota can help regulate dairy cattle breeding traits and improve their health status. As a result, it has become a popular research topic in dairy cattle breeding. This article provides a review of the composition, structure, physiological characteristics, and physiological effects of the cow gut microbiota, serving as a theoretical foundation for future studies that aim to utilize the gut microbiota for dairy cattle breeding or improving production traits. It may also serve as a reference for research on gut microbiota of other ruminants.

5.
Neurooncol Adv ; 5(1): vdad066, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37324218

RESUMO

Background: Although the epidermal growth factor receptor (EGFR) is a frequent oncogenic driver in glioblastoma (GBM), efforts to therapeutically target this protein have been largely unsuccessful. The present preclinical study evaluated the novel EGFR inhibitor WSD-0922. Methods: We employed flank and orthotopic patient-derived xenograft models to characterize WSD-0922 and compare its efficacy to erlotinib, a potent EGFR inhibitor that failed to provide benefit for GBM patients. We performed long-term survival studies and collected short-term tumor, plasma, and whole-brain samples from mice treated with each drug. We utilized mass spectrometry to measure drug concentrations and spatial distribution and to assess the impact of each drug on receptor activity and cellular signaling networks. Results: WSD-0922 inhibited EGFR signaling as effectively as erlotinib in in vitro and in vivo models. While WSD-0922 was more CNS penetrant than erlotinib in terms of total concentration, comparable concentrations of both drugs were measured at the tumor site in orthotopic models, and the concentration of free WSD-0922 in the brain was significantly less than the concentration of free erlotinib. WSD-0922 treatment provided a clear survival advantage compared to erlotinib in the GBM39 model, with marked suppression of tumor growth and most mice surviving until the end of the study. WSD-0922 treatment preferentially inhibited phosphorylation of several proteins, including those associated with EGFR inhibitor resistance and cell metabolism. Conclusions: WSD-0922 is a highly potent inhibitor of EGFR in GBM, and warrants further evaluation in clinical studies.

6.
Animals (Basel) ; 12(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36552471

RESUMO

This study aimed to evaluate the effectiveness of oral gavage of dextran sodium sulfate (DSS) to establish an enteric inflammation model in broilers. Forty 1-day-old male, yellow-feathered broilers were randomly divided into 2 groups with 5 replicates of 4 birds each for a 42-day trial. The experiment design used 2 groups: (1) the control group (CT), normal broilers fed a basal diet, and (2) the DSS group, DSS-treated broilers fed a basal diet. The DSS group received 1 mL of 2.5% DSS solution once a day by oral gavage from 21 to 29 days of age. The results showed that compared with those in CT, DSS treatment significantly increased histological scores for enteritis and mucosal damage at 29 and 42 days of age (p < 0.01) and the disease activity index (DAI) from 23 to 29 days of age (p < 0.01). DSS-treated broilers showed poor growth performance at 42 days of age, including decreased body weight and average daily gain and an increased feed conversion ratio (p < 0.01). DSS also caused gross lesions and histopathological damage in the jejunum of broilers, such as obvious hemorrhagic spots, loss of villus architecture, epithelial cell disruption, inflammatory cell infiltration, and decreased villus height. These results suggest that oral gavage of DSS is an effective method for inducing mild and non-necrotic enteric inflammation in broilers.

7.
PeerJ ; 10: e14444, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518262

RESUMO

Background: Yak cows produce higher quality milk with higher concentrations of milk fat than dairy cows. Recently, studies have found the yak milk yield and milk fat percentage have decreased significantly over the past decade, highlighting the urgency for yak milk improvement. Therefore, we aimed to analyze how the gut microbiome impacts milk fat synthesis in Zhongdian yak cows. Methods: We collected milk samples from Zhongdian yak cows and analyzed the milk fat percentage, selecting five Zhongdian yak cows with a very high milk fat percentage (>7%, 8.70 ± 1.89%, H group) and five Zhongdian yak cows with a very low milk fat percentage (<5%, 4.12 ± 0.43%, L group), and then obtained gut samples of these ten Zhongdian yak cows through rectal palpation. Gut metagenomics, metabolomics, and conjoint metagenomics and metabolomics analyses were performed on these samples, identifying taxonomic changes, functional changes, and changes in gut microbes-metabolite interactions within the milk fat synthesis-associated Zhongdian yak cows gut microbiome, to identify potential regulatory mechanisms of milk fat at the gut microbiome level in Zhongdian yak cows. Results: The metagenomics analysis revealed Firmicutes and Proteobacteria were significantly more abundant in the gut of the high-milk fat Zhongdian yak cows. These bacteria are involved in the biosynthesis of unsaturated fatty acids and amino acids, leading to greater efficiency in converting energy to milk fat. The metabolomics analysis showed that the elevated gut metabolites in high milk fat percentage Zhongdian yak cows were mainly enriched in lipid and amino acid metabolism. Using a combined metagenomic and metabolomics analysis, positive correlations between Firmicutes (Desulfocucumis, Anaerotignum, Dolosiccus) and myristic acid, and Proteobacteria (Catenovulum, Comamonas, Rubrivivax, Marivita, Succinimouas) and choline were found in the gut of Zhongdian yak cows. These interactions may be the main contributors to methanogen inhibition, producing less methane leading to higher-efficient milk fat production. Conclusions: A study of the gut microbe, gut metabolites, and milk fat percentage of Zhongdian yak cows revealed that the variations in milk fat percentage between yak cows may be caused by the gut microbes and their metabolites, especially Firmicutes-myristic acid and Proteobacteria-choline interactions, which are important to milk fat synthesis. Our study provides new insights into the functional roles of the gut microbiome in producing small molecule metabolites and contributing to milk performance traits in yak cows.


Assuntos
Microbioma Gastrointestinal , Leite , Animais , Feminino , Bovinos , Leite/química , Multiômica , Metabolômica , Firmicutes , Ácidos Mirísticos/análise
8.
Toxicol Sci ; 189(1): 32-50, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35583313

RESUMO

Bispecific T-cell engager (BiTE) molecules have great potential to treat cancer. Nevertheless, dependent on the targeted tumor antigen, the mechanism of action that drives efficacy may also contribute to on-target/off-tumor toxicities. In this study, we characterize an anti-CD70 half-life extended BiTE molecule (termed N6P) which targets CD70, a TNF family protein detected in several cancers. First, the therapeutic potential of N6P was demonstrated using in vitro cytotoxicity assays and an orthotopic xenograft mouse study resulting in potent killing of CD70+ cancer cells. Next, in vitro characterization demonstrated specificity for CD70 and equipotent activity against human and cynomolgus monkey CD70+ cells. To understand the potential for on-target toxicity, a tissue expression analysis was performed and indicated CD70 is primarily restricted to lymphocytes in normal healthy tissues and cells. Therefore, no on-target toxicity was expected to be associated with N6P. However, in a repeat-dose toxicology study using cynomolgus monkeys, adverse N6P-mediated inflammation was identified in multiple tissues frequently involving the mesothelium and epithelium. Follow-up immunohistochemistry analysis revealed CD70 expression in mesothelial and epithelial cells in some tissues with N6P-mediated injury, but not in control tissues or those without injury. Collectively, the data indicate that for some target antigens such as CD70, BiTE molecules may exhibit activity in tissues with very low antigen expression or the antigen may be upregulated under stress enabling molecule activity. This work illustrates how a thorough understanding of expression and upregulation is needed to fully address putative liabilities associated with on-target/off-tumor activity of CD3 bispecific molecules.


Assuntos
Anticorpos Biespecíficos , Neoplasias , Animais , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Complexo CD3/metabolismo , Meia-Vida , Humanos , Macaca fascicularis , Camundongos , Neoplasias/metabolismo , Linfócitos T
9.
Phys Rev E ; 104(1-2): 015109, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34412304

RESUMO

Drop-carrier particles (DCPs) are solid microparticles designed to capture uniform microscale drops of a target solution without using costly microfluidic equipment and techniques. DCPs are useful for automated and high-throughput biological assays and reactions, as well as single-cell analyses. Surface energy minimization provides a theoretical prediction for the volume distribution in pairwise droplet splitting, showing good agreement with macroscale experiments. We develop a probabilistic pairwise interaction model for a system of such DCPs exchanging fluid volume to minimize surface energy. This leads to a theory for the number of pairwise interactions of DCPs needed to reach a uniform volume distribution. Heterogeneous mixtures of DCPs with different sized particles require fewer interactions to reach a minimum energy distribution for the system. We optimize the DCP geometry for minimal required target solution and uniformity in droplet volume.

10.
PeerJ ; 8: e9542, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194328

RESUMO

In our previous study, we found that VPS28 (vacuolar protein sorting 28 homolog) could alter ubiquitylation level to regulate milk fat synthesis in bovine primary mammary epithelial cells (BMECs). While the information on the regulation of VPS28 on proteome of milk fat synthesis is less known, we explored its effect on milk fat synthesis using isobaric tags for relative and absolute quantitation assay after knocking down VPS28 in BMECs. A total of 2,773 proteins in three biological replicates with a false discovery rate of less than 1.2% were identified and quantified. Among them, a subset of 203 proteins were screened as significantly down-(111) and up-(92) regulated in VPS28 knockdown BMECs compared with the control groups. According to Gene Ontology analysis, the differentially expressed proteins were enriched in the "proteasome," "ubiquitylation," "metabolism of fatty acids," "phosphorylation," and "ribosome." Meanwhile, some changes occurred in the morphology of BMECs and an accumulation of TG (triglyceride) and dysfunction of proteasome were identified, and a series of genes associated with milk fat synthesis, ubiquitylation and proteasome pathways were analyzed by quantitative real-time PCR. The results of this study suggested VPS28 regulated milk fat synthesis was mediated by ubiquitylation; it could be an important new area of study for milk fat synthesis and other milk fat content traits in bovine.

11.
Mol Cell Proteomics ; 19(1): 11-30, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31591262

RESUMO

Glycosylation is a topic of intense current interest in the development of biopharmaceuticals because it is related to drug safety and efficacy. This work describes results of an interlaboratory study on the glycosylation of the Primary Sample (PS) of NISTmAb, a monoclonal antibody reference material. Seventy-six laboratories from industry, university, research, government, and hospital sectors in Europe, North America, Asia, and Australia submitted a total of 103 reports on glycan distributions. The principal objective of this study was to report and compare results for the full range of analytical methods presently used in the glycosylation analysis of mAbs. Therefore, participation was unrestricted, with laboratories choosing their own measurement techniques. Protein glycosylation was determined in various ways, including at the level of intact mAb, protein fragments, glycopeptides, or released glycans, using a wide variety of methods for derivatization, separation, identification, and quantification. Consequently, the diversity of results was enormous, with the number of glycan compositions identified by each laboratory ranging from 4 to 48. In total, one hundred sixteen glycan compositions were reported, of which 57 compositions could be assigned consensus abundance values. These consensus medians provide community-derived values for NISTmAb PS. Agreement with the consensus medians did not depend on the specific method or laboratory type. The study provides a view of the current state-of-the-art for biologic glycosylation measurement and suggests a clear need for harmonization of glycosylation analysis methods.


Assuntos
Anticorpos Monoclonais/química , Produtos Biológicos , Biofarmácia/métodos , Anticorpos Monoclonais/metabolismo , Glicômica/métodos , Glicopeptídeos/metabolismo , Glicosilação , Humanos , Laboratórios , Polissacarídeos/metabolismo , Processamento de Proteína Pós-Traducional , Proteômica/métodos
12.
Biochem Biophys Res Commun ; 510(4): 606-613, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30739790

RESUMO

In a previous genome-wide association study on milk production traits in Chinese Holstein population, we revealed VPS28 gene was highly expressed in mammary gland tissue and a -58C > T mutation in 5'-UTR of it was significantly associated with milk fat content traits. In this study, we explored the effect of this -58C > T mutation on VPS28, and found it could significantly decrease promoter activity of VPS28 by reducing transcription factor binding sites. To identify the potential functional SNP involved, we performed RNAi experiment in BMECs, the results showed that VPS28 knockdown could increase the expression of ADFP and CD36, lead accumulation of ubiquitinated proteins, long chain fatty acids and triglyceride, and decrease the proteasome activity. Therefore, our study demonstrates that the -58C > T mutation could facilitate milk fat synthesis in two ways. The one is involved in ESCRTs signaling, it could directly lead an accumulation of ubqiuitinated membrane proteins to promote the long chain fatty acids uptake to incorporation into TG. The other is involved in ubiquitination-proteasome system, it could indirectly lead a dysfunction of proteasome to accumulate the ubqiuitinated proteins to promote TG synthesis. In conclusion, our study demonstrates that VPS28 could be a strong candidate gene for milk fat content traits, and in particular, the -58C > T mutation in 5'-UTR of VPS28 could be a functional mutation for its effects on milk fat content.


Assuntos
Bovinos/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Gorduras/metabolismo , Glândulas Mamárias Animais/metabolismo , Leite/metabolismo , Regiões 5' não Traduzidas , Animais , Células Cultivadas , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismo , Feminino , Glândulas Mamárias Animais/citologia , Mutação Puntual , Ubiquitinação , Regulação para Cima
13.
Virology ; 529: 57-64, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30665098

RESUMO

The results of the RV144 vaccine clinical trial showed a correlation between high level of anti-V1V2 antibodies (Abs) and a decreased risk of acquiring HIV-1 infection. This turned the focus of HIV vaccine design to the induction of elevated levels of anti-V2 Abs to increase vaccine efficacy. In plasma samples from HIV-1 infected Cameroonian individuals, we observed broad variations in levels of anti-V2 Abs, and 6 of the 79 plasma samples tested longitudinally displayed substantial deficiency of V2 Abs. Sequence analysis of the V2 region from plasma viruses and multivariate analyses of V2 characteristics showed a significant difference in several features between V2-deficient and V2-reactive plasma Abs. These results suggest that HIV vaccine immunogens containing a shorter V2 region with fewer glycosylation sites and higher electrostatic charges can be beneficial for induction of a higher level of anti-V2 Abs and thus contribute to HIV vaccine efficacy.


Assuntos
Anticorpos Anti-HIV/sangue , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1 , Vacinas contra a AIDS/imunologia , Camarões/epidemiologia , Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Análise Multivariada , Carga Viral
14.
Front Immunol ; 9: 2441, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30416503

RESUMO

Prophylactic HIV vaccines must elicit antibodies (Abs) against the virus envelope glycoproteins (Env) to effectively prevent HIV infection. We investigated a vaccine platform that utilizes immune complexes made of Env proteins gp120 and monoclonal Abs (mAbs) against different gp120 epitopes. We previously observed alterations in V3 antigenicity upon formation of certain gp120/mAb complexes and demonstrated the ability of these complexes to modulate the elicitation of V3 Ab responses. However, the effects on the V1V2 domain, an important target for Abs that correlate with vaccine-induced protection against HIV, have not been studied, nor have immune complex vaccines made with non-B subtype Env. This study compared subtypes B (JRFL) and CRF_01.AE (A244) Env gp120 proteins in complex with selected gp120-specific mAbs. Allosteric and antigenic changes were detected on these immune complexes, indicating that gp120/mAb interaction induces alterations on the Env surface that may modify the Env immunogenic properties. To evaluate this idea, mice were immunized with gp120/mAb complexes or their uncomplexed gp120 counterparts. The overall serum IgG titers elicited against gp120 were comparable, but a marked skewing toward V1V2 or V3 was evident and dependent on the gp120 strain and the specificity of the mAb used to form the complexes. Compared with uncomplexed gp120JRFL, gp120JRFL complexed with CD4bs or V1V2 mAbs, but not with C2 or V3 mAbs, elicited V3 Abs of greater titers and breadth, and Abs more capable of neutralizing tier 1 virus. Epitope mapping revealed a shift to a more conserved site in the V3 crown. However, the complexes did not enhance V1V2 Ab response, and the elicited V1V2 Abs were not cross-reactive. This profile contrasts with Ab responses to gp120A244/mAb complexes. Notably, gp120A244/mAb complexes induced higher levels of V1V2 Abs with some cross-reactivity, while also stimulating weak or strain-specific V3 Abs. Sera from gp120A244/mAb complex-immunized animals displayed no measurable virus neutralization but did mediate Ab-dependent cellular phagocytosis, albeit at levels similar to that induced by gp120A244 alone. These data indicate the potential utility of immune complexes as vaccines to shape Ab responses toward or away from Env sites of interest.


Assuntos
Vacinas contra a AIDS/imunologia , Complexo Antígeno-Anticorpo/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/sangue , Complexo Antígeno-Anticorpo/administração & dosagem , Linhagem Celular , Epitopos/imunologia , Feminino , Anticorpos Anti-HIV/sangue , Infecções por HIV/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Células THP-1
15.
Vaccine ; 35(10): 1464-1473, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28185743

RESUMO

The V3 loop in the HIV envelope gp120 is one of the immunogenic sites targeted by Abs. The V3 crown in particular has conserved structural elements recognized by cross-reactive neutralizing Abs, indicating its potential contribution in protection against HIV. Crystallographic analyses of anti-V3 crown mAbs in complex with the V3 peptides have revealed that these mAbs recognize the conserved sites on the V3 crown via two distinct strategies: a cradle-binding mode (V3C) and a ladle-binding (V3L) mode. However, almost all of the anti-V3 crown mAbs studied in the past were isolated from chronically HIV-infected individuals. The extents to which the two types of anti-V3 crown Abs are generated by vaccination are unknown. This study analyzed the prevalence of V3C-type and V3L-type Ab responses in HIV-infected individuals and in HIV envelope-immunized humans and animals using peptide mimotopes that distinguish the two Ab types. The results show that both V3L-type and V3C-type Abs were generated by the vast majority of chronically HIV-infected humans, although the V3L-type were more prevalent. In contrast, only one of the two V3 Ab types was elicited in vaccinated humans or animal models, irrespective of HIV-1 envelope clades, envelope constructs (oligomeric or monomeric), and protocols (DNA plus protein or protein alone) used for vaccinations. The V3C-type Abs were produced by vaccinated humans, macaques, and rabbits, whereas the V3L-type Abs were made by mice. The V3C-type and V3L-type Abs generated by the vaccinations were able to mediate virus neutralization. These data indicate the restricted repertoires and the species-specific differences in the functional V3-specific Ab responses induced by the HIV envelope vaccines. The study implies the need for improving immunogen designs and vaccination strategies to broaden the diversity of Abs in order to target the different conserved epitopes in the V3 loop and, by extension, in the entire HIV envelope.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Anti-HIV/sangue , Antígenos HIV/imunologia , Infecções por HIV/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/administração & dosagem , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/metabolismo , Cristalografia por Raios X , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/metabolismo , Antígenos HIV/química , Antígenos HIV/metabolismo , Humanos , Macaca , Camundongos , Ligação Proteica , Conformação Proteica , Coelhos , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo
16.
J Virol ; 91(8)2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28122974

RESUMO

In light of the weak or absent neutralizing activity mediated by anti-V2 monoclonal antibodies (MAbs), we tested whether they can mediate Ab-dependent cellular phagocytosis (ADCP), which is an important element of anti-HIV-1 immunity. We tested six anti-V2 MAbs and compared them with 21 MAbs specific for V3, the CD4-binding site (CD4bs), and gp41 derived from chronically HIV-1-infected individuals and produced by hybridoma cells. ADCP activity was measured by flow cytometry using uptake by THP-1 monocytic cells of fluorescent beads coated with gp120, gp41, BG505 SOSIP.664, or BG505 DS-SOSIP.664 complexed with MAbs. The measurement of ADCP activity by the area under the curve showed significantly higher activity of anti-gp41 MAbs than of the members of the three other groups of MAbs tested using beads coated with monomeric gp41 or gp120; anti-V2 MAbs were dominant compared to anti-V3 and anti-CD4bs MAbs against clade C gp120ZM109 ADCP activity mediated by V2 and V3 MAbs was positive against stabilized DS-SOSIP.664 trimer but negligible against SOSIP.664 targets, suggesting that a closed envelope conformation better exposes the variable loops. Two IgG3 MAbs against the V2 and V3 regions displayed dominant ADCP activity compared to a panel of IgG1 MAbs. This superior ADCP activity was confirmed when two of three recombinant IgG3 anti-V2 MAbs were compared to their IgG1 counterparts. The study demonstrated dominant ADCP activity of anti-gp41 against monomers but not trimers, with some higher activity of anti-V2 MAbs than of anti-V3 and anti-CD4bs MAbs. The ability to mediate ADCP suggests a mechanism by which anti-HIV-1 envelope Abs can contribute to protective efficacy.IMPORTANCE Anti-V2 antibodies (Abs) correlated with reduced risk of HIV-1 infection in recipients of the RV144 vaccine, suggesting that they play a protective role, but a mechanism providing such protection remains to be determined. The rare and weak neutralizing activities of anti-V2 MAbs prompted us to study Fc-mediated activities. We compared anti-V2 MAbs with other MAbs specific for V3, CD4bs, and gp41 for Ab-dependent cellular phagocytosis (ADCP) activity, implicated in protective immunity. The anti-V2 MAbs displayed stronger activity than other anti-gp120 MAbs in screening against one of two gp120s and against DS-SOSIP, which mimics the native trimer. The activity of anti-gp41 MAbs was superior in targeting monomeric gp41 but was comparable to that seen against trimers, which may not adequately expose gp41 epitopes. While anti-envelope MAbs in general mediated ADCP activity, anti-V2 MAbs displayed some dominance compared to other MAbs. Our demonstration that anti-V2 MAbs mediate ADCP activity suggests a functional mechanism for their contribution to protective efficacy.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/imunologia , Monócitos/imunologia , Fagocitose , Anticorpos Monoclonais/isolamento & purificação , Sítios de Ligação , Linhagem Celular , Citometria de Fluxo , Anticorpos Anti-HIV/isolamento & purificação , Humanos , Imunoglobulina G/imunologia
17.
Vaccine ; 34(24): 2713-21, 2016 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-27102818

RESUMO

RV144 vaccinees with low HIV-1 Envelope-specific IgA antibodies (Abs) also had Abs directed to the hypervariable region 3 (V3) that inversely correlated with infection risk. Thus, anti-V3 HIV-1 Abs may contribute to protection from HIV-1 infection. The V3 region contains two dominant clusters of epitopes; one is preferentially recognized by mAbs encoded by VH5-51 and VL lambda genes, while the second one is recognized by mAbs encoded by other VH genes. We designed a study in rhesus macaques to induce anti-V3 Abs specific to each of these two dominant clusters of V3 epitopes to test whether the usage of the VH5-51 gene results in different characteristics of antibodies. The two C4-V3 immunogens used for immunization were each comprised of a fusion of the C4 peptide containing the T cell epitope and a V3 mimotope peptide mimicking the V3 epitope. The C4-447 peptide was designed to target B cells with several VH1-VH4 genes, the C4-VH5-51 peptide was designed to specifically target B cells with the VH5-51 gene. Six animals in two groups were immunized five times with these two immunogens, and screening of 10 sequential plasma samples post immunization demonstrated that C4-447 induced higher titers of plasma anti-V3 Abs and significantly more potent neutralizing activities against tier 1 and some tier 2 pseudoviruses than C4-VH5-51. Levels of anti-V3 Abs in buccal secretions were significantly higher in sequential samples derived from C4-447- than from C4-VH5-51-immunized animals. The titers of anti-V3 Abs in plasma strongly correlated with their levels in mucosal secretions. The results show that high titers of vaccine-induced anti-V3 Abs in plasma determine the potency and breadth of neutralization, as well as the rate of transduction of Abs to mucosal tissues, where they can play a role in preventing HIV-1 infection.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/sangue , Epitopos de Linfócito T/imunologia , Anticorpos Anti-HIV/sangue , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Formação de Anticorpos , Especificidade de Anticorpos , Linfócitos B/imunologia , Feminino , HIV-1 , Macaca mulatta , Masculino , Testes de Neutralização , Peptídeos/imunologia
18.
J Phys Chem A ; 120(5): 737-46, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26735613

RESUMO

The catalytic degradation of lignin is of considerable interest because the depolymerization of lignin to small molecules is the initial step for the conversion of lignin to biofuels and other useful chemicals. Because of the complex structure of lignin, methoxyethane was used in this study as a representative model of the most common linkage within lignin, the ß-O-4 linkage. The completely renormalized coupled cluster with singles, doubles, and perturbative triples [CR-CCSD(T)] method was used to calculate the energetics of the C-O bond cleavage in methoxyethane by late 3d, 4d, and 5d transition metal atoms and to evaluate the performance of a set of density functionals (BLYP, B97D, TPSS, M06L, B3LYP, PBE0, M06, TPSSh, and B2PLYP) in predicting the reaction energetics.

19.
Biochem Biophys Res Commun ; 465(1): 59-63, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26231798

RESUMO

Glucose as one of the nutrition factors plays a vital role in the regulation of milk fat synthesis. Ubiquitin-proteasome system (UPS) is a vital proteolytic pathway in all eukaryotic cells through timely marking, recognizing and degrading the poly-ubiquitinated protein substrates. Previous studies indicated that UPS plays a considerable role in controlling the triglyceride (TG) synthesis. Therefore, the aim of this study is to confirm the link between high-glucose and UPS and its regulation mechanism on milk fat synthesis in BMEC (bovine mammary epithelial cells). We incubated BMEC with normal (17.5 mm/L) and high-glucose (25 mm/L) with and without proteasome inhibitor epoxomicin and found that, compared with the control (normal glucose and without proteasome inhibitor), both high-glucose concentration and proteasome inhibitor epoxomicin could increase the accumulation of TG and poly-ubiquitinated proteins, and reduce significantly three proteasome activities (chymotrypsin-like, caspase-like, and trypsin-like). In addition, high-glucose concentration combined with proteasome inhibitor further enhanced the increase of the poly-ubiquitinated protein level and the decrease of proteasome activities. Our results suggest that the regulation of high-glucose on milk fat synthesis is mediated by UPS in BMEC, and high-glucose exposure could lead to a hypersensitization of BMEC to UPS inhibition which in turn results in increased milk fat synthesis.


Assuntos
Células Epiteliais/metabolismo , Glucose/farmacologia , Glândulas Mamárias Animais/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Triglicerídeos/biossíntese , Ubiquitina/metabolismo , Animais , Bovinos , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Glucose/metabolismo , Lactação/fisiologia , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/efeitos dos fármacos , Oligopeptídeos/farmacologia , Cultura Primária de Células , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia
20.
BMC Cancer ; 15: 170, 2015 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-25881012

RESUMO

BACKGROUND: Relatively poor penetration and retention in tumor tissue has been documented for large molecule drugs including therapeutic antibodies and recombinant immunoglobulin constant region (Fc)-fusion proteins due to their large size, positive charge, and strong target binding affinity. Therefore, when designing a large molecular drug candidate, smaller size, neutral charge, and optimal affinity should be considered. METHODS: We engineered a recombinant protein by molecular engineering the second domain of VEGFR1 and a few flanking residues fused with the Fc fragment of human IgG1, which we named HB-002.1. This recombinant protein was extensively characterized both in vitro and in vivo for its target-binding and target-blocking activities, pharmacokinetic profile, angiogenesis inhibition activity, and anti-tumor therapeutic efficacy. RESULTS: HB-002.1 has a molecular weight of ~80 kDa, isoelectric point of ~6.7, and an optimal target binding affinity of <1 nM. The pharmacokinetic profile was excellent with a half-life of 5 days, maximal concentration of 20.27 µg/ml, and area under the curve of 81.46 µg·days/ml. When tested in a transgenic zebrafish embryonic angiogenesis model, dramatic inhibition in angiogenesis was exhibited by a markedly reduced number of subintestinal vessels. When tested for anti-tumor efficacy, HB-002.1 was confirmed in two xenograft tumor models (A549 and Colo-205) to have a robust tumor killing activity, showing a percentage of inhibition over 90% at the dose of 20 mg/kg. Most promisingly, HB-002.1 showed a superior therapeutic efficacy compared to bevacizumab in the A549 xenograft model (tumor inhibition: 84.7% for HB-002.1 versus 67.6% for bevacizumab, P<0.0001). CONCLUSIONS: HB-002.1 is a strong angiogenesis inhibitor that has the potential to be a novel promising drug for angiogenesis-related diseases such as tumor neoplasms and age-related macular degeneration.


Assuntos
Adenocarcinoma/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Fragmentos Fc das Imunoglobulinas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Neovascularização Fisiológica/efeitos dos fármacos , Proteínas Recombinantes de Fusão/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/farmacologia , Adenocarcinoma/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Desenho de Fármacos , Feminino , Células Endoteliais da Veia Umbilical Humana/fisiologia , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Imunoglobulina G/química , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes de Fusão/farmacocinética , Proteínas Recombinantes de Fusão/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/farmacologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/química , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/farmacocinética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Peixe-Zebra/embriologia
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