Assessment of the effects of a novel herbal immunomodulator drug [IMOD] on cytokine profiles in experimental canine visceral leishmaniasis: a preliminary survey

Cytokines play a fundamental role in the regulation of immune responses in remission and/or relapsing of leishmaniasis. Therefore, immunotherapy for the treatment of canine visceral leishmaniasis [CVL] has represented a principle approach in control of the infection. The present research aimed to evaluating the immunotherapeutic potential of a novel herbal immunomodulator drug [IMOD] on CVL. Twelve mongrel dogs were intravenously infected with Iranian strain of L. infantum and randomly divided into three groups; 1: negative control [non-infected], 2: immunotherapy with IMOD and 3: positive control [non-treated]. Cell proliferation and Th1-/Th2-type cytokines were measured in peripheral blood mononuclear cell [PBMC] by cell proliferation kit I [MTT] and enzyme-linked immunospot [ELISpot] assays, respectively. At the 60 days follow-up assessment, no adverse effects were observed in treated interventional group. Cellular proliferation assay indicated that PBMCs of IMOD group had higher stimulation index [SI] than positive control group [p <0.05]. Enhancement of CD4+ T cells such as IL-2, IL-4 and IL-10 were detected in negative control group due to in vitro IMOD stimulation 30 days post-treatment. In accordance to decreasing trends of Th1 and Th2 cytokines in positive control group, the mean number of IFN-gamma, IL-2, IL-4 and IL-10 spot forming cells [SFCs] down regulated for IMOD group during the study. These data indicate that IMOD had immunomodulatory potential but is not sufficient for total parasitic cure due to balance of Th1/Th2 cytokines. This is a preliminary study and we propose to undertake a series of experiments to evaluate the CVL due to in vitro modulatory effects of IMOD

Evaluation of a novel herbal immunomodulator drug [IMOD] in treatment of experimental canine visceral leishmaniasis

Toxicity and drug resistance against pentavalent antimonials, medications of choice in treatment of leishmaniasis for more than 5 decades, have become important subjects globally. This study was a randomized, open labeled trial that was designed to determine efficacy and safety of IMOD as a novel herbal immunomodulator drug for treatment of canine visceral leishmaniasis [CVL]. Twenty healthy mongrel dogs were infected with Iranian strain of L. Infantum amastigotes and randomly divided to 5 groups with four animals for each included on: I: negative control [non-infected] II: Glucantime[registered sign] III: Glucantime[registered sign] plus IMOD [immune-chemotherapy] IV: IMOD and V: positive control [non-treated]. Physical examination, hematological, biochemical, serological, parasitological, pathological and imaging evaluations were performed pre-/post- interventions every month for 3 months. Comparing with control groups [IandV], immune-chemotherapy group [Glucantime[registered sign] plus IMOD] showed significantly higher efficacy in resolving the clinical signs and hematobiochemistry factors. Based on our results, using IMOD in combination with meglumine antimoniate [Glucantime[registered sign]] has significantly improved CVL than the latter drug alone. So, it seems this new herbal medicine is useful as adjuvant therapy for canine visceral leishmaniasis

[Study on co-administration of GM-CSF, IL-15 on the enhancement of the immunogenicity of HIV-1 P24-Nef expression vector in BALB/c mouse model]

Today, AIDS is considered as a global problem and many efforts to generate an effective vaccine against this disease have been made, but remain inconclusive. DNA vaccines are a member of the new generation of vaccines that can efficiently stimulate the immune system. However, recent findings indicate low immunogenicity for these vaccines and it is believed that these types of vaccines require strategies that could infer more immunogenicity. The employment of adjuvants could be considered as one of the most important methods involved. In this study, a DNA vaccine candidate for HIV P24-Nef is constructed and then using genetic adjuvants IL-15 and GM-CSF, cellular immune responses have been studied. In this study the gene structure of HIV P24-Nef in eukaryotic expression vector was constructed and expression vectors of IL-15 and GM-CSF were used as adjuvants. After inoculation of the candidate vaccine to BALB/c mice, cytokine patterns, lymphocytes proliferation and cytotoxicity were analyzed. Our findings indicate that candidate vaccine significantly stimulated cellular immune responses. The usage of IL-15 and GM-CSF as DNA adjuvants together and separately with candidate vaccine has strengthened cellular immune responses significantly. Co-administration of DNA adjuvants significantly increased cellular immune responses when the ratio of the vaccine dose was more than the adjuvants. The sequences that we selected as candidate vaccine demonstrated good immunogenicity in mouse model and co-administration of IL-15 and GM-CSF DNA adjuvants increased cellular immune response to DNA vaccine construct

[Evaluation of immune responses from immunization of HIV-1 P24-Nef fusion peptide vaccine with monophosphoryl lipid A [MPL] in BALB/c mice]

Several vaccines against HIV have been investigated but none has been approved as an effective HIV vaccine. An approach that could induce stronger immune response against the pathogen is utilizing a multi-epitopic vaccine. This strategy was used in the design of several vaccines and resulted in improved immune responses. In this study a multi-epitopic fusion peptide including parts of HIV-1 Nef and P24 as a vaccine candidate was injected into mice and immune humoral responses measured with total antibody and IgG sub-classes using ELISA. Also measurement of cellular immune responses through evaluation of spleen cells proliferation response using MTT and cytotoxicity by LDH were performed. Finally, the cytokine pattern of IFN-gamma and IL-4 were also determined with ELISA. The results indicate that candidate vaccine stimulated mouse splenic lymphocyte proliferation response and also induced strong cytotoxicity responses. Analysis of humoral immune response has shown that the candidate vaccine has induced specific antibody production mainly of the IgG2a sub-class. Also cytokine pattern evaluation has shown that IFN-gamma secretion was dominant. The use of immunogen and conserved epitopes from P24 and Nef induced strong humoral and cellular immune responses and this construct could be candidate for further studies in animal models

Immunogenicity of a new HIV-1 DNA Construct in a BALB/c mouse model

Cell mediated immunity, especially cytotoxic T cell responses against HIV-1 infection, plays a critical role in controlling viral replication and disease progression. DNA vaccine is a novel technology which is known to stimulate strong cellular immune responses. Many DNA vaccines have been tested for HIV infection but there is still no effective vaccine against this infection. Construction of a vaccine consisting of multiple conserved and immunogenic epitopes may increase vaccine efficacy. In the present study a DNA vaccine candidate constructed from HIV-1 P24-Nef was evaluated and cellular immune responses were assessed in murine BALB/c model. HIV-1 P24-Nef gene was cloned in PCDNA3.1 expression vector. Mice were immunized with DNA construct and IL-4 and IFN-gamma evaluation was per-formed using ELISPOT. Cytotoxicity response was evaluated with Granzyme B ELIS-POT assay and lymphocyte proliferation was evaluated with LTT assay. Analysis of immune responses showed that, compared to control groups, the candidate vaccine induced production of higher levels of both IL-4 and IFN-gamma [p<0.05]. Cytotoxicity and lymphocyte proliferation responses of mice vaccinated with the candidate vaccine were significantly increased compared to control groups [p<0.05]. HIV-1 P24-Nef DNA construct displayed strong immunogenicity in a murine model