Search results for: Mouse Anti-MRSA Antibodies
#38383811 
2024/02/21
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Monophosphoryl lipid A as a co-adjuvant in methicillin-resistant Staphylococcus aureus vaccine development: improvement of immune responses in a mouse model of infection.
To increase the effectiveness of methicillin-resistant Staphylococcus aureus vaccines (MRSA), a new generation of immune system stimulating adjuvants is necessary, along with other adjuvants. In some vaccines, monophosphoryl lipid A (MPLA) as a toll-like receptor 4 agonist is currently used as an adjuvant or co-adjuvant. MPLA could increase the immune response and vaccine immunogenicity. The current investigation assessed the immunogenicity and anti-MRSA efficacy of recombinant autolysin formulated in MPLA and Alum as co-adjuvant/adjuvant. r-Autolysin was expressed and purified by Ni-NTA affinity chromatography and characterized by SDS-PAGE. Then, the vaccine candidate formulation in MPLAs and Alum was prepared. To investigate the immunogenic responses, total IgG, isotype (IgG1 and IgG2a) levels, and cytokines (IL-4, IL-12, TNF-α, and IFN-γ) profiles were evaluated by ELISA. Also, the bacterial burden in internal organs, opsonophagocytosis, survival rate, and pathobiology changes was compared among the groups. Results demonstrated that mice immunized with the r-Autolysin + Alum + MPLA Synthetic and r-Autolysin + Alum + MPLA Biologic led to increased levels of opsonic antibodies, IgG1, IgG2a isotype as well as increased levels of cytokines profiles, as compared with other experimental groups. More importantly, mice immunized with MPLA and r-Autolysin exhibited a decrease in mortality and bacterial burden, as compared with the control group. The highest level of survival was seen in the r-Autolysin + Alum + MPLA Synthetic group. We concluded that both MPLA forms, synthetic and biological, are reliable candidates for immune response improvement against MRSA infection.Mehdi Mirshekar, Setareh Haghighat, Zahra Mousavi, Amir Hossein Abdolghaffari, Mohammad Hossein Yazdi
1843 related Products with: Monophosphoryl lipid A as a co-adjuvant in methicillin-resistant Staphylococcus aureus vaccine development: improvement of immune responses in a mouse model of infection.
0.1ml (1mg/ml)100 μg100 μg100 μg100 μg96T0.1ml100 μg100 assays100 μg1mg100ug Lyophilized
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#37336068 2023/06/15
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Synthesis of structure-defined β-1,4-GlcNAc-modified wall teichoic acids as potential vaccine against methicillin-resistant Staphylococcus aureus.
Methicillin-resistant Staphylococcus aureus (MRSA) is a high priority pathogen due to its life-threating infections to human health. Development of prophylactic or therapeutic anti-MRSA vaccine is a potential approach to treat S. aureus infections and overcome the resistance crisis. β-1,4-GlcNAc glycosylated wall teichoic acids (WTAs) derived from S. aureus are a new type of antigen that is closely associated with β-lactam resistance. In this study, structure-defined β-1,4-GlcNAc-modified WTAs varied in chain length and numbers of GlcNAc modification were synthesized by an ionic liquid-supported oligosaccharide synthesis (ILSOS) strategy in high efficiency and chromatography-free approach. Then the obtained WTAs were conjugated with tetanus toxin (TT) as vaccine candidates and were further evaluated in a mouse model to determine the structure-immunogenicity relationship. In vivo immunological studies revealed that the WTAs-TT conjugates provoked robust T cell-dependent responses and elicited high levels of specific anti-WTAs IgG antibodies production associated with the WTAs structure including chain length as well as the β-1,4-GlcNAc modification pattern. Heptamer WTAs conjugate T6, carrying three copy of β-1,4-GlcNAc modified RboP, was identified to elicit the highest titers of specific antibody production. The T6 antisera exhibited the highest recognition and binding affinity and the most potent OP-killing activities to MSSA and MRSA cells. This study demonstrated that β-1,4-GlcNAc glycosylated WTAs are promising antigens for further development against MRSA.Peng Shen, Lele Zheng, Xinfang Qin, Dan Li, Zijiang Zhang, Jie Zhao, Han Lin, Haofei Hong, Zhifang Zhou, Zhimeng Wu
1053 related Products with: Synthesis of structure-defined β-1,4-GlcNAc-modified wall teichoic acids as potential vaccine against methicillin-resistant Staphylococcus aureus.
100 plates1g1 kit10 plates1 kit1,000 tests430 tests0.1 ml100 plates500 1 kit10 plates
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#32917596 2020/09/02
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Globally deimmunized lysostaphin evades human immune surveillance and enables highly efficacious repeat dosing.
There is a critical need for novel therapies to treat methicillin-resistant (MRSA) and other drug-resistant pathogens, and lysins are among the vanguard of innovative antibiotics under development. Unfortunately, lysins' own microbial origins can elicit detrimental antidrug antibodies (ADAs) that undermine efficacy and threaten patient safety. To create an enhanced anti-MRSA lysin, a novel variant of lysostaphin was engineered by T cell epitope deletion. This "deimmunized" lysostaphin dampened human T cell activation, mitigated ADA responses in human HLA transgenic mice, and enabled safe and efficacious repeated dosing during a 6-week longitudinal infection study. Furthermore, the deimmunized lysostaphin evaded established anti-wild-type immunity, thereby providing significant anti-MRSA protection for animals that were immune experienced to the wild-type enzyme. Last, the enzyme synergized with daptomycin to clear a stringent model of MRSA endocarditis. By mitigating T cell-driven antidrug immunity, deimmunized lysostaphin may enable safe, repeated dosing to treat refractory MRSA infections.Hongliang Zhao, Seth A Brooks, Susan Eszterhas, Spencer Heim, Liang Li, Yan Q Xiong, Yongliang Fang, Jack R Kirsch, Deeptak Verma, Chris Bailey-Kellogg, Karl E Griswold
1753 related Products with: Globally deimmunized lysostaphin evades human immune surveillance and enables highly efficacious repeat dosing.
4 Arrays/Slide4 Membranes/Box0.1 mg4 Membranes/Box4 Membranes/Box4 Arrays/Slide4 Arrays/Slide4 Membranes/Box4 Arrays/Slide4 Membranes/Box96 tests4 Membranes/Box
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#29082478 2017/10/30
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Production and Characterization of F(Ab') Fragments Obtained by Enzymatic Digestion from Murine Anti-MRSA PBP2a Monoclonal Antibodies.
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a worldwide health problem. In a previous study, a murine monoclonal antibody (mMAB), capable of binding to PBP2a within MRSA strains, was generated. F(ab') antibody fragments are widely described in the literature as immunochemical tools and reagents for diagnostics and therapeutics, particularly because of their low immunogenicity and rapid pharmacokinetics. In this study, F(ab') fragments from mMAB were generated by enzymatic digestion, using pepsin. They were purified by affinity chromatography using protein A and concentrated by a MWCO 50 kDa filtration unit. The results indicate that it is possible to obtain F(ab') fragments by pepsin digestion. ELISA, western blotting, and fluorescence microscopy data demonstrated that F(ab') affinity for PBP2a is not lost even after the enzymatic digestion process. As expected, in the pharmacokinetics tests, F(ab') presented a faster elimination (between 12 and 18 h) compared to IgG. These F(ab') fragments could be used in future immunodiagnostic applications, including in vitro or in situ radiolabeling and in the treatment of infections caused by this important pathogen.Anna Erika Vieira de Araujo, Natalia Plinio de Souza, Alvaro Paiva Braga de Sousa, Flavio Alves Lara, Jose Procopio Moreno Senna
1364 related Products with: Production and Characterization of F(Ab') Fragments Obtained by Enzymatic Digestion from Murine Anti-MRSA PBP2a Monoclonal Antibodies.
100 ul100.00 ug100.00 ug100.00 ug100.00 ug100.00 ug100.00 ug100.00 ug100 ul100ug/vial100.00 ug100.00 ug
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#25862372 2015/04/08
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Complement activation contributes to the anti-methicillin-resistant Staphylococcus aureus effect of natural anti-keratin antibody.
Methicillin-resistant Staphylococcus aureus (MRSA) remains a major public health problem worldwide because of its strong resistance to a variety of antibiotics. Natural immunoglobulin (Ig) M antibodies have been reported to protect against microbial infections. In the present study, the function of a monoclonal natural anti-keratin antibody IgM (named 3B4) in MRSA infection was evaluated. The binding of 3B4 to MRSA was studied using immunofluorescence assay and flow cytometry (FCM). The binding of 3B4 to mannose-binding lectin (MBL) and complement activation were detected by ELISA. For the in vivo study, transgenic mice for the VH gene from 3B4 (TgVH 3B4) were used. After infection, the bacterial burden was examined in the kidney, spleen and enterocelia. Inflammatory cytokine levels and the neutrophil ratio in peritoneal lavage fluid (PLF) were assessed by ELISA and FCM, respectively. Additionally, the total serum hemolytic activity (CH50) in the early stage of infection was detected by ELISA. The results showed that 3B4 bound directly to MRSA and MBL, and the interaction between 3B4 and MRSA/MBL led to the activation of the classic and the MBL pathway in vitro. After 48 h of MRSA infection, the bacterial load in the kidney, spleen and enterocelia was significantly decreased in TgVH 3B4 mice (P < 0.05) compared with wild-type mice. Levels of IL-6, TNF-α, and IFN-γ were increased after MRSA infection. The levels of IL-6 and TNF-α in TgVH 3B4 mice were decreased by 49.1% and 59.4% compared to wild-type mice. Additionally, the neutrophil ratio in the PLF of TgVH 3B4 mice was decreased by 65.9%. The CH50 value was significantly higher in TgVH 3B4 mice than in wild-type mice, indicating that 3B4 promoted the activation of the complement system in MRSA infected mice. The results reveal an important role of 3B4 in the anti-MRSA immune response, and the complement activation contributes to this effect.Jingang An, Zhengxiao Li, Yingying Dong, Jiawen Wu, Jianwen Ren
1275 related Products with: Complement activation contributes to the anti-methicillin-resistant Staphylococcus aureus effect of natural anti-keratin antibody.
500 100ug1 mg100ug1 mL100ug100μg200
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#17117366 2006/08/31
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Evaluation of the humoral immune response in BALB/c mice immunized with a naked DNA vaccine anti-methicillin-resistant Staphylococcus aureus.
Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen involved in nosocomial infections, leading to high rates of morbidity and mortality in hospitals worldwide. The methicillin resistance occurs due to the presence of an additional penicillin-binding protein, PBP2a, which has low affinity for beta-lactam antibiotics. In the past few years, vancomycin has been the only antibiotic option for treatment of infections caused by multiresistant MRSA; however, reports of vancomycin-resistant strains have generated great concerns regarding the treatment to overcome these infections. In the present study, we report preliminary results regarding the humoral immune response generated in BALB/c mice by two different doses of naked DNA vaccine containing an internal region, comprising the serine-protease domain, of the PBP2a of MRSA. The immunization procedure consisted of four immunizations given intramuscularly within 15-day intervals. Blood was collect weekly and anti-PBP2a-specific antibodies were screened by ELISA. BALB/c mice immunized with DNA vaccine anti-PBP2a have shown higher antibody titers mainly after the fourth immunization, and intriguingly, no correlation between the humoral immune response and DNA dose was observed. Our results suggest that the DNA vaccine anti-PBP2a induced an immune response by production of specific antibodies anti-MRSA in a non-dose-dependent manner, and it could represent a new and valuable approach to produce specific antibodies for passive immunization to overcome MRSA infections.D M Roth, J P M Senna, D C Machado