Leila Safari Zanjani; Reza Shapoury; Mehrouz Dezfulian; Mehdi Mahdavi; Mehdi Shafieeardestani
Abstract
Background: Pseudomonas aeruginosa has an important role in nosocomial infections. Objective: To evaluate biological activity of the detoxified LPS (D-LPS) entrapped into Poly lactic-co-glycolic acid (PLGA) nanoparticles. Materials: LPS was extracted and detoxified from the P. aeruginosa strain PAO1. ...
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Background: Pseudomonas aeruginosa has an important role in nosocomial infections. Objective: To evaluate biological activity of the detoxified LPS (D-LPS) entrapped into Poly lactic-co-glycolic acid (PLGA) nanoparticles. Materials: LPS was extracted and detoxified from the P. aeruginosa strain PAO1. The D-LPS, conjugated to the PLGA nanoparticles with 1-ethyl-3-dimethyl aminopropyl carbodiimide (EDAC) and N-hydroxy-succinimide (NHS). The connection was evaluated by FTIR (Fourier transform infrared), Zetasizer, and Atomic Force Microscope (AFM). The BALB/c mice injected intramuscularly with the D-LPS-PLGA with two-week intervals and then challenged two weeks after the last immunization. The bioactivity of the induced specific antisera and cytokines responses against D-LPS-PLGA antigen was assessed by ELISA. Results: D-LPS-PLGA conjugation was confirmed by FTIR, Zetasizer, and AFM. The ELISA results showed that D-LPS was successful in the stimulation of the humoral immune response. The immune responses raised against the D-LPS-PLGA, significantly decreased bacterial titer in the spleen of the immunized mice after challenge with PAO1 strain in comparison with the control groups. Conclusion: The conjugation of the bacterial LPS to the PLGA nanoparticle increased their functional activity by decrease in bacterial dissemination and increase the killing of opsonized bacteria.
Mohsen Mohammadi; Zahra Kianmehr; Sussan Kaboudanian Ardestani; Behnaz Gharegozlou
Volume 11, Issue 3 , September 2014, , Pages 189-199
Abstract
Background: Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella ...
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Background: Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella abortus LPS is less toxic and has no pyrogenic properties compared to LPS from other gram negative bacteria. Objectives: To evaluate the adjuvant effect of B. abortus (vaccine strain, S19) LPS for tetanus toxoid antigen (TT) and to investigate the protective effect of different tetanus vaccine preparations. Methods: LPS was extracted and purified from B. abortus S19 and KDO, glycan, phosphate content, and protein contamination were measured. Adipic acid dihydrazide (ADH) was used as a linker for the conjugation of TT to LPS. Different amounts of B. abortus LPS, TT, TT conjugated with LPS, and TT mixed with LPS or complete Freund’s adjuvant (CFA) were injected into mice and antibody production against TT was measured. The protective effect of induced antibodies was determined by LD50. Results: Immunization of mice with TT+LPS produced the highest anti-TT antibody titer in comparison to the group immunized with TT without any adjuvant or the groups immunized with TT-LPS or TT+CFA. Tetanus toxid-S19 LPS also produced a 100% protective effect against TT in immunized mice. Conclusion: These data indicate that B. abortus LPS enhances the immune responses to TT and suggest the possible use of B. abortus LPS as an adjuvant in vaccine preparations.
Bahareh Abd Nikfarjam; Massoumeh Ebtekar; Farzaneh Sabouni; Zahra Pourpak; Maryam Kheirandish
Volume 10, Issue 2 , June 2013, , Pages 62-69
Abstract
Background: Astrocytes, which comprise ~90% of overall brain mass, are involved in brain immunity. These cells represent the non-professional class of CNS-resident APCs and may promote or inhibit CNS inflammation depending on the cytokines they secrete. IL-10 family of cytokines and their receptors, ...
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Background: Astrocytes, which comprise ~90% of overall brain mass, are involved in brain immunity. These cells represent the non-professional class of CNS-resident APCs and may promote or inhibit CNS inflammation depending on the cytokines they secrete. IL-10 family of cytokines and their receptors, IL-20R1 and IL-20R2, may have a role in shifting astrocytes to a neuroprotective or neurodegenerative function. Objective: To address the expression of IL-20R1 and IL-20R2 cytokine receptors in astrocytes and brain cortex of C57BL/6 mice. Methods: We investigated the expression of IL-20R1 and IL-20R2 in C57BL/6 mice astroglial cells and brain cortex in response to lipopolysaccharide (LPS), using reverse-transcription polymerase chain reaction (RTPCR) method. Results: Astrocytes were able to express IL-20R1 and IL-20R2 mRNA not only in response to LPS stimulation but also in the absence of LPS. Furthermore, we found the expression of IL-20R1 and IL-20R2 mRNA in the cortex of adult C57BL/6 mice. Conclusions: IL-20R1 and IL-20R2 are constitutively expressed in the brain. Since most neuropathological processes involve astrocytes and inflammatory cytokines, these findings have important implications for future therapeutic strategies.
Saeid Abediankenari; Yousef Yousedzadeh; Hossein Azadeh; Mohammad Vahedi
Volume 7, Issue 2 , June 2010, , Pages 83-87
Abstract
Background: Dendritic cells (DCs) are professional antigen presenting cells that have an important role in the initiation of immune response. The use of maturation factors in dendritic cell differentiation provides a promising approach in immunotherapy. Objective: In this study, we compared tumor necrosis ...
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Background: Dendritic cells (DCs) are professional antigen presenting cells that have an important role in the initiation of immune response. The use of maturation factors in dendritic cell differentiation provides a promising approach in immunotherapy. Objective: In this study, we compared tumor necrosis factor-α, polyribocytidylic acid, lipopolysacharide and CpG oligonucleotides in inducing dendritic cell maturation. Methods: We generated immature dendritic cells with GM-CSF in combination with IL-4 from peripheral blood mononuclear adherent cells and used tumor necrosis factor-α, polyribocytidylic acid, lipopolysacharide and CpG for the induction of dendritic cell maturation. CD83 maturation marker on the dendritic cells was analyzed by flowcytometry after 7 days. In addition, mixed leukocyte reaction between dendritic cells and T cells was performed by MTT proliferation assay. Results: Flow cytometry results demonstrated a comparable high level of CD83 expression on the mature dendritic cells generated by TNF-α, CpG, Poly I:C, and LPS treatment of the immature dendritic cells. However, a significantly poorer proliferation of lymphocytes cocultured with the Poly I:C-treated DCs was observed compared to the CpG-treated DCs in mixed leukocyte reaction (p=0.026). Conversely, a significantly stronger proliferation of lymphocytes was observed when cocultured with TNF-α-treated DCs compared to the LPS-treated DCs (p=0.025). Conclusion: Our results indicated that all of studied maturation inducing factors can be used in DC maturation but TNF-α and CpG were the preferred in vitro maturation factors. It is concluded that maturation of dendritic cells by CpG motif and TNF-α can be used to regulate immune responses.
