Interplay of oxidative stress and antioxidant bio markers in oil adjuvant Brucella melitensis vaccinated and challenged mice.

The intracellular nature of Brucella leads to rise in oxidative stress due to bacterial invasion, particularly at the site of predilection spleen and lymph nodes. The present study aimed to evaluate the erythrocytic and tissue specific oxidative stress responses induced during oil adjuvant killed Brucella melitensis vaccination. The results of the study clearly implicated a significant increase in level of catalase, and superoxide dismutase (SOD) activity and lipid peroxidation (LPO), and total protein content in erythrocytes after vaccination. The activity of glutathione-S-transferase (GST) was unaltered during the period of experiment. The catalase activity and GSH content was significantly increased in lung and spleen tissues. The tissues GST levels increased significantly in all tissues, while tissue SOD level increased significantly only in lung tissues. Thus, it can be inferred that oil adjuvant based Brucella vaccine induces negligible signs of inflammatory pathophysiology and supports the development of significant level of protection against virulent Brucella challenge.

Development and evaluation of in murine model, of an improved live-vaccine candidate against brucellosis from to Brucella melitensis vjbR deletion mutant.

Brucellosis is an infectious disease that brings enormous economic burdens for developing countries. The Brucella melitensis (B. melitensis) M5-90 vaccine strain (M5-90) has been used on a large scale in China, but may cause abortions if given to pregnant goats or sheep subcutaneously during the late stages of gestation. Moreover, the vaccine M5-90 cannot differentiate natural from vaccinated infection. Therefore, a safer and more potent M5-90 vaccine is required. In this study, a vjbR mutant of M5-90 (M5-90ΔvjbR) was constructed and overcame these drawbacks. M5-90ΔvjbR strain showed reduced survival capability in murine macrophages (RAW 264.7) and BALB/c mice and induced high protective immunity in mice. In addition, M5-90ΔvjbR induced an anti-Brucella-specific immunoglobulin G (IgG) response and stimulated the expression of gamma interferon (INF-γ) and interleukin-4 (IL-4) in vaccinated mice. Furthermore, M5-90ΔvjbR induced IgG response and stimulated the secretion of IFN-γ and IL-4 in immunized sheep. Moreover, the VjbR antigen allowed serological differentiation between infected and vaccinated animals. These results suggest that M5-90ΔvjbR is an ideal live attenuated and efficacious live vaccine candidate against B. melitensis 16 M infection.

Use of S-[2,3-bispalmitoyiloxy-(2R)-propyl]-R-cysteinyl-amido-monomethoxy polyethylene glycol as an adjuvant improved protective immunity associated with a DNA vaccine encoding Cu,Zn superoxide dismutase of Brucella abortus in mice.

This study was conducted to evaluate the immunogenicity and protective efficacy of a DNA vaccine encoding Brucella abortus Cu,Zn superoxide dismutase (SOD) using the Toll-like receptor 2/6 agonist S-[2,3-bispalmitoyiloxy-(2R)-propyl]-R-cysteinyl-amido-monomethoxy polyethylene glycol (BPPcysMPEG) as an adjuvant. Intranasal coadministration of BPPcysMPEG with a plasmid carrying the SOD-encoding gene (pcDNA-SOD) into BALB/c mice elicited antigen-specific humoral and cellular immune responses. Humoral responses were characterized by the stimulation of IgG2a and IgG1 and by the presence of SOD-specific secretory IgA in nasal and bronchoalveolar lavage fluids. Furthermore, T-cell proliferative responses and increased production of gamma interferon were also observed upon splenocyte restimulation with recombinant SOD. Cytotoxic responses were also stimulated, as demonstrated by the lysis of RB51-SOD-infected J774.A1 macrophages by cells recovered from immunized mice. The pcDNA-SOD/BPPcysMPEG formulation induced improved protection against challenge with the virulent strain B. abortus 2308 in BALB/c mice over that provided by pcDNA-SOD, suggesting the potential of this vaccination strategy against Brucella infection.

Evaluation of the immunogenicity and the protective efficacy in mice of a DNA vaccine encoding SP41 from Brucella melitensis.

INTRODUCTION: Brucella melitensis is a facultative intracellular Gram-negative bacterial pathogen that may enter the host via ingestion or inhalation, or through conjunctiva or skin abrasions. Some Brucella spp surface proteins (SPs) play an important role in bacterial adhesion and invasion and thus represent targets for the host immune system. Brucella spp surface protein with apparent molecular mass of 41 kDa interacts selectively with HeLa cells. METHODOLOGY: To evaluate the role of SP41 (41 kDa) as a DNA vaccine against Brucella spp., pCISP41, a plasmid construct for protein expression in mammalian cells, was established. Exogenous SP41 was detected in pCISP41-transfected Vero cell line by immune blotting using specific polyclonal antibody. The protective role of pCISP41 against B. melitensis 16M in mice was evaluated by measuring B and T cell responses in comparison to those achieved with attenuated B. melitensis Rev. 1 vaccine. RESULTS: BALB/c mice injected with pCISP41 were able to develop SP41-specific serum immunoglobulin G (IgG) antibodies. In addition, splenocytes from DNA-SP41-vaccinated mice elicited a T-cell-proliferative response and also induced gamma interferon (IFN-γ) production, but not interleukin-5 (IL-5), suggesting the induction of a T-helper-1-dominated immune response. Vaccination with attenuated B. melitensis Rev.1 strain induced better protection levels than DNA vaccination with SP41 against B. melitensis 16M in mice. CONCLUSIONS: Such responses play an important role against intracellular infecting agents such as Brucella spp. Altogether, our data suggest that SP41 may represent a promising candidate for DNA vaccination against brucellosis, but more investigation to increase its protective efficacy should be done.

Co-immunization with interlukin-18 enhances the protective efficacy of liposomes encapsulated recombinant Cu-Zn superoxide dismutase protein against Brucella abortus.

Brucellosis is a worldwide zoonotic disease caused by Brucella abortus and a number of closely related species. Brucellosis has severe impact on the health and economic prosperity of the developing countries due to the persistent nature of infection and unavailability of effective control measures. The Cu-Zn superoxide dismuatse (SOD) protein of Brucella have been extensively studied as a major antigen involved in bacterial evading mechanism of host defence. Being a critical pro-inflammatory cytokine interleukin-18 (IL-18) plays key role in induction of immune mediated protection against intracellular pathogens. In the present study, we aimed to investigate the immunogenic potential of fusogenic liposomes (escheriosomes) encapsulated recombinant Cu-Zn SOD (rSOD) protein alone or in combination with recombinant IL-18 (rIL-18). Escheriosomes encapsulated rSOD mediated immune responses were further increased upon co-immunization with rIL-18. Furthermore, immunization with escheriosomes encapsulated rSOD alone or in combination with rIL-18, increased resistance in mice against challenge with B. abortus 544.

[Experimental evaluation of the brucellosis therapeutic vaccine efficacy].

Use of antibiotics can't completely solve the problem of brucellosis treatment, especially its chronic forms, because antibacterial preparations do not eliminate main pathogenetic factor of the disease--sensibilization of the macroorganism. It makes actual the question about complex immuno- and antibacterial therapy. Long-term clinical experience proved high effectiveness of a therapeutic brucellosis vaccine. Earlier this preparation was manufactured in Research Institute of Vaccines and Sera in Tbilisi (Georgia). To date new composition of components of the vaccine has been developed, and manufacturing and control methods have been improved. Marked desensitizing effect of the vaccine and its stimulatory action on cellular and humoral immunity has been observed. In 2002 technological normative documentation for manufacturing and use of the vaccine was developed in the Research Institute of Microbiology (Kirov) and production of the vaccine began.

Biological half-life of ovine antibody in neonatal lambs and adult sheep following passive immunization.

Neonatal lambs and adult wethers were passively immunized with ovine antibody directed against ovalbumin or Brucella abortus. Estimates for the biological half-lives of the antibodies ranged from 18 to 24 days in neonatal lambs and 12 to 17 days in adult wethers. The evidence suggested that both normal and immunosuppressed wethers which were passively immunized with serum antibody catabolized this antibody at a faster rate than did neonatal lambs. The data provided no support for the hypothesis that the growth factors and immunomodulatory factors, which are known to be present in colostrum, can influence the biological half-life of homologous antibody following passive immunization.

[Morphofunctional evaluation of the immunogenicity of a live brucellosis vaccine]. / Morfofunktsional'naia otsenka immunogennosti zhivoi brutselleznoi vaktsiny.

The possibility of evaluating the immunogenic potency of brucellosis vaccine BA-19 by immunological methods has been shown. Morphometry and the quantitative evaluation of globulin-producing cells in lymphoid organs by direct and indirect immunofluorescent techniques serve as informative evaluation tests. The marker method with the evaluation of lymphocyte classes by acid and alkaline phosphatases and the electrophoretic motility characteristics of T- and B-lymphocytes, used in combination with the above-mentioned methods, present information on immunogenesis. The immunoperoxidase method and the values of the opsonophagocytic index characterize the state of phagocytosis and the persistence of the antigen.

Immunogenic activity of a cell wall fraction extracted from Brucella abortus in guinea-pigs.

A cell wall fraction (F8) extracted by boiling sodium dodecylsulfate at 4 % from Brucella abortus 99S was used with oil adjuvant to vaccinate groups of ten guinea-pigs, at doses equivalent to 1 X 10(9) and 1 X 10(10) bacteria, once or twice at 3 month intervals. H38 vaccine, a total cell vaccine from formalized B. melitensis 53 H38, was used as a reference, at doses 3 X 10(8) and 3 X 10(9) bacteria. These doses were chosen since they have about the same vaccinal activity in mice being respectively equal to 10 and 100 mice optimal dose (MOD). One extra-group of guinea-pigs received two injections of 100 microgram of smooth-lipopolysaccharide (LPS-S) of B. melitensis 16M, in adjuvant. Control group received the adjuvant only. Guinea-pigs were challenged 3 months after the last vaccination with 5,000 colony-forming units of B. abortus 544, and autopsied 40 days later. The spleen and 8 lymph nodes were cultured: a guinea-pig is considered as protected if no Brucella was found in any sample. Protection afforded by the two vaccines is dose-dependent. H38 vaccine gives a better protection (infected 24 %) than F8 (46 %) since a higher dose is needed to obtain the same level of protection: i. e., 100 MOD of F8 is about equal to 10 MOD of H38 (35 and 37 % respectively). Contrary to what was previously shown in mice, recall does not improve the immunity and LPS-S does not vaccinate at all.