Background & Objectives: Lipopolysaccharide (LPS) is the main antigenic structure expressed on the surface of smooth strains of Brucella. It has been shown that Outer membrane vesicle (OMV) of Neisseria meningitidis efficiently promote IgG and IgM response against the administrated antigen as an adjuvant. The aim of this study is to evaluate the effect of LPS-OMV noncovalent complex in producing of T helper 1 cytokine (IFN-γ) and T helper 2 cytokines (IL-4 and IL-10) in mice.

  Methods: LPS extracted by an optimized method based on hot phenol-water extraction. Groups of six BALB/c mice were injected subcutaneously with LPS alone, LPS with Freund adjuvant and LPS-OMV complex on 0, 14 and 28 days. Levels of IFN-γ, IL-4 and IL-10 were evaluated in spleen cell suspension supernatant by ELISA.

  Result: Immunization with B. abortus LPS significantly induced high level of IFN-γ in comparison to the other groups immunized with LPS-OMV and LPS+ adjuvant (p<0.05). In contrast, lower levels of IL-4 and IL-10 were elicited by LPS in the rest groups. Immunization with the non-covalent complex of B. abortus LPS-N. meningitidis serogroup B OMV caused a significant increase of IL-4 and IL-10 compared with the mice immunized with B. abortus LPS (p<0.05), while the titer of IFN-γ is still significantly higher than IL-4 and IL-10 (p<0.05).

  Conclusion: The raise of IFN-γ following the immunization with all of the compounds (LPS, LPS-OMV non-covalent complex and LPS+adjuvant) indicates the activation of Th₁ population that would be correlated to the clearance of the organism due to the amplification of anti-microbial activity of Polymorphonuclear cells. Low levels of IL-4 and IL-10 following the immunization with all compounds would be a sign of Th₁ responses dominancy or inhibition of Th₂ population proliferation and activity. Such a cytokine pattern would be a sign of the efficiency of brucellosis subunit vaccine because Th₂ responses basically have no role in the immune responses against Brucella and may lead to the persistence of intracellular infection.

  Background & Objectives : Several studies have been conducted to explore anti-HIV drugs. Discovery and study of novel anti-HIV-1 compounds need live viruses and has serious biosafety concerns. In this research we reported a novel and safe system for assaying the cytopathic effects of HIV by using single cycle replicable (SCR) HIV-1 virions.

  Methods: To produce the SCR HIV-1 virions, pMD2G, pmzNL4-3 and pSPAX2 plasmids were co-transfected into HEK293T cells. Different amount of SCR virions were used to infect target cells (MT-2). Within the infected cells, the number of formed syncytia was counted under the light microscopy. The lethal effects of the SCR HIV virions were measured using XTT proliferation assay.

  Results: Formation of syncytia among SCR HIV infected cells was detectable 24 hours after infection. Highest amount of syncytia was seen 72 hours after infection. Increase in the amount of virions caused increasing of syncytia and the cytopathic effects of SCR HIV-1. Infection with more than 1600ng P24 SCR HIV decreased the syncytium formation and viability of all cells. The calculated IC50 (50 percent inhibitory capacity) for nevirapine and BMS806 using this method was 50nM and 30nM, respectively.

  Conclusion: SCR HIV-1 virions are replicable only for one cycle. Using these virions can improve the safety of HIV researches. Herein, we optimized the assaying of HIV induced cytopathic effects by using SCR HIV-1 (NL4-3) virions. The accuracy of this method was accepted by quantifying the anti-HIV-1 effects of nevirapine and BMS806 by (SCR) HIV-1 virions.

  Adjuvants are chemicals, microbial components, or mammalian proteins that enhance the immune response to vaccine antigens. Reducing vaccine-related adverse effects and inducing specific types of immunity has led to the development of numerous new adjuvants. Adjuvants in experimental and commercial vaccines include aluminum salts (alum), oil emulsions, saponins, immune-stimulating complexes (ISCOMs), liposomes, microparticles, nonionic block copolymers, derivatized polysaccharides, cytokines, and a wide variety of bacterial derivatives. The mechanisms of action of these diverse compounds are different. Factors influencing the selection of an adjuvant include animal species, specific pathogen, vaccine antigen, route of immunization, and type of immunity needed. In this paper we review the current adjuvant types, structure and mechanism of action and their application in the design and production of animal and human vaccines to provide a source for students and researchers in related fields .