Evaluation of the Immunogenicity of Recombinant Espb, Espc Proteins from Mycobacterium Tuberculosis and the Fusion Espc/Espb Protein in BALB/C Mice.

Background: Two newly identified proteins, EspB and EspC are involved in the pathogenesis of Mycobacterium tuberculosis. The objective of the present study was to evaluate the immunogenicity of recombinant EspC, EspB, and EspC/EspB fusion proteins in mice. Methods: BALB/c mice were immunized subcutaneously with recombinant EspC, EspB, and fusion EspC/EspB proteins, three times with along with Quil-A as an adjuvant. The cellular and humoral immune responses were evaluated by quantifying IFN-γ, IL-4, IgG, IgG1, and IgG2a antibodies against the antigens. Results: The results showed that the mice immunized with recombinant EspC, EspB, and EspC/EspB proteins did not produce IL-4, whereas IFN-γ was secreted in response to all three proteins. EspC/EspB group produced significant amounts of IFN-γ in response to stimulation with all the three recombinant proteins (P<0.001). In mice immunized with EspC, high levels of IFN-γ were detected in response to EspC/EspB, and EspC (P<0.0001); while mice immunized with EspB produced lower levels of IFN-γ in response to EspC/EspB, and EspB (P<0.05).Mice immunized with recombinant EspC, EspB, and EspC/EspB proteins exhibited significantly high levels of IgG and IgG2a/IgG1 ratio (P< 0.001). Moreover, high levels of IgG and IgG2a were detected in the sera of mice immunized with EspC/EspB fusion protein. Conclusions: All the three recombinant proteins induced Th1-type immune responses in mice against EspB and EspC; however, EspC/EspB protein is more desirable due to the presence of epitopes from both EspC and EspB proteins and the production of immune responses against both.

Molecular identification of Phlebotomus kandelakii apyrase and assessment of the immunogenicity of its recombinant protein in BALB/c mice.

Sand fly salivary proteins have immunomodulatory and anti-inflammatory features; hence, they are proven to perform important roles in the early establishment of Leishmania parasite in the vertebrate host. Among them, salivary apyrase with anti-hemostatic properties has a crucial role during the blood meal process. In the present study, a Genome-Walking method was used to characterize a full-length nucleotide sequence of Phlebotomus (P.) kandelakii apyrase (Pkapy). Bioinformatics analyses revealed that Pkapy is a ~ 36 kDa stable and hydrophilic protein that belongs to the Cimex family of apyrases. Moreover, recombinant proteins of Pkapy and P. papatasi apyrase (Ppapy) were over-expressed in Escherichia coli BL2 (DE3) and their antigenicity in BALB/c mice was evaluated. Dot-blot and ELISA results indicated that both recombinant apyrases could induce antibodies in BALB/c. Moreover, a partial cross-reactivity between Pkapy and Ppapy was found. In vitro stimulation of splenocytes from immunized mice with the recombinant proteins indicated cross-reactive T cell proliferative responses. Cytokine analysis revealed significant production of IFN-γ (p < 0.001) and IL-10 (p < 0.01) in response to Pkapy. In conclusion, the full-length nucleotide sequence and molecular characteristics of Pkapy were identified for the first time. Immunologic analyses indicated that Pkapy and Ppapy are immunogenic in BALB/c mice and show partial cross-reactive responses. The immunity to Pkapy was found to be a Th1-dominant response that highlights its potential as a component for an anti-Leishmania vaccine.

Combination of STAT3 inhibitor with Herceptin reduced immune checkpoints expression and provoked anti-breast cancer immunity: An in vitro study.

Breast cancer (BC) is the most prevalent diagnosed cancer among women. Herceptin blocks the effects of Her-2 and tumour cell growth. Despite many achievements using Herceptin in Her-2+ invasive BC treatment, there are treatment failures and resistances. The signal transducer and activator of transcription 3 (STAT3) is persistently activated in BC and is associated with immune suppression and tumour cell proliferation. We evaluated whether STAT3 inhibition could increase Herceptin impact on in vitro reduction of immune checkpoint inhibitors and polarize T cells to a protective immune response. We treated SK-BR-3 cells with Herceptin and the STAT3-inhibitor (FLLL32) and assessed the apoptosis and expression of apoptosis-related proteins, VEGF, Her-2 and apoptosis targets of STAT3. PBMCs were isolated from healthy donors and co-cultured with SK-BR-3 cells in the presence or absence of Herceptin and FLLL32. PD-L1, CTLA-4, TIM-3 and T-cell intracellular cytokines were then evaluated. Our results demonstrated that STAT3 inhibition and Herceptin increased SK-BR-3 cell apoptosis, significantly. STAT3 inhibition through combination treatment had a more significant effect on regulating PD-1, TIM-3 and CTLA-4 expression on PBMCs. Alternatively, the combination of FLLL32 and Herceptin promoted T helper-1 protective immune response. The combination of FLLL32 and Herceptin suppress the expression of immune checkpoints and provoke the T-helper1 immune response in lymphocytes. Our analysis indicates STAT3 as a promising target that improves Herceptin's role in breast cancer cell apoptosis.

Cutaneous leishmaniasis: multiomics approaches to unravel the role of immune cells checkpoints.

INTRODUCTION: Cutaneous leishmaniasis (CL) is the most frequent form of leishmaniases, associated with skin inflammation and ulceration. Understanding the interaction of different phagocytic cells in the recognition and uptake of different Leishmania species is critical for controlling the infection. Phagocytic cells have a pivotal role as professional antigen-presenting cells that bridge the innate and adaptive immunity and shape the outcome of the disease. AREAS COVERED: Here we reviewed new technologies with high-throughput data collection capabilities along with systems biology approaches which are recently being used to decode the paradox of CL immunology. EXPERT OPINION: We emphasized on the crosstalk between DC and T-cells while focusing on the immune checkpoints interactions between the human immune system and the Leishmania species. Further, we discussed omics technologies including bulk RNA sequencing, reverse transcriptase-multiplex ligation dependent probe amplification (RT-MLPA), and proximity extension assay (PEA) in studies on human blood or tissue-driven samples from CL patients in which we have so far been involved.

Immunoinformatics Evaluation of a Fusion Protein Composed of Leishmania infantum LiHyV and Phlebotomus kandelakii Apyrase as a Vaccine Candidate against Visceral Leishmaniasis.

Background: Visceral leishmaniasis (VL) is a lethal parasitic disease, transmitted by sand fly vectors. Immunomodulatory properties of sand fly saliva proteins and their protective effects against Leishmania infection in pre-exposed animals suggest that a combination of an antigenic salivary protein along with a Leishmania antigen can be considered for designing a vaccine against leishmaniasis. Methods: Three different fusion forms of L. infantum hypothetical protein (LiHyV) in combination with Phlebotomus kandelakii salivary apyrase (PkanAp) were subjected to insilico analyses. Major Histocompatibility Complex (MHC) class I and II epitopes in both humans and BALB/c mice were predicted. Antigenicity, immunogenicity, epitope conservancy, toxicity, and population coverage were also evaluated. Results: Highly antigenic promiscuous epitopes consisting of truncated LiHyV (10-285) and full-length PkanAp (21-329) were identified in human and was named Model 1. This model contained 25 MHC-I and 141 MHC-II antigenic peptides which among them, MPANSDIRI and AQSLFDFSGLALDSN were fully conserved. LALDSNATV, RCSSALVSI, ALVSINVPL, SAVESGALF of MHC-I epitopes, and 28 MHC-II binding epitopes showed 60% conservancy among various clades. A population coverage with a rate of >75% in the Iranian population and >70% in the whole world was also identified. Conclusion: Based on this in-silico approach, the predicted Model 1 could potentially be used as a vaccine candidate against VL.

Blood transcriptional profiles distinguish different clinical stages of cutaneous leishmaniasis in humans.

Cutaneous leishmaniasis (CL) is a neglected tropical disease with severe morbidity and socioeconomic sequelae. A better understanding of underlying immune mechanisms that lead to different clinical outcomes of CL could inform the rational design of intervention measures. While transcriptomic analyses of CL lesions were recently reported by us and others, there is a dearth of information on the expression of immune-related genes in the blood of CL patients. Herein, we investigated immune-related gene expression in whole blood samples collected from individuals with different clinical stages of CL along with healthy volunteers in an endemic CL region where Leishmania (L.) tropica is prevalent. Study participants were categorized into asymptomatic (LST+) and healthy uninfected (LST-) groups based on their leishmanin skin test (LST). Whole blood PAXgene samples were collected from volunteers, who had healed CL lesions, and patients with active L. tropica cutaneous lesions. Quality RNA extracted from 57 blood samples were subjected to Dual-color reverse-transcription multiplex ligation-dependent probe amplification (dcRT-MLPA) assay for profiling 144 immune-related genes. Results show significant changes in the expression of genes involved in interferon signaling pathway in the blood of active CL patients, asymptomatics and healed individuals. Nonetheless, distinct profiles for several immune-related genes were identified in the healed, the asymptomatic, and the CL patients compared to the healthy controls. Among others, IFI16 and CCL11 were found as immune transcript signatures for the healed and the asymptomatic individuals, respectively. These results warrant further exploration to pinpoint novel blood biomarkers for different clinical stages of CL.

A Historic Review of the Role of CD4+ T-Cell Subsets in Development of the Immune Responses against Cutaneous and Visceral Leishmaniases

The heterogeneity of CD4+ T cells has been investigated since the late 1970s, when their Th1 and Th2 subsets were coined. Later studies on the cutaneous form of the Leishmaniasis were focused on the experimental models of Leishmania major infection using the susceptible BALB/c and the resistant C57BL/6 mice. At the early 21st century, the regulatory T-cells subpopulation was introduced and its role in concomitant immunity, responsible for lifelong resistance of the host to the reinfection was proposed. Subsequent studies, mainly focused on the visceral form of the infection pointed to the role of IL-17, produced by Th17 subset of CD4+ T cells that along the neutrophils were shown to have important yet equivocal functions in protection against or exacerbation of the infection. Altogether, the current knowledge indicates that the above four subsets could orchestrate the immune, the regulatory and the inflammatory responses of the host against different forms of leishmaniases.

Dr. Abolghasem Bahrami (1894­1950): Physician, Pasteurian, and a Pioneer of Microbiology and Public Health Planning in Iran

Dr. Abolghasem Bahrami was among the generation of Iranian scientists in the early twentieth century who gained most of their knowledge through resources available inside the country. Educated at Dar-ul-Funun Medical School, he was a physician with a great talent in learning, especially self-teaching natural sciences and European languages. He joined the Pasteur Institute of Iran (IPI) at the early days of its foundation and became an integral contributor to this institution during the first twenty-five years of its mission. One of his first assignments at IPI was to help initiating an anti-rabies department by bringing back the rabies vaccine and its manufacturing equipment from Institut Pasteur of Paris. During his IPI years, aside from managerial tasks, he actively participated in upgrading the medical treatments and protocols used for controlling many infectious diseases. He functioned twice as the provisional director of IPI (1925-1926 and 1937-1946) and is considered as the first Iranian director of the Institute. Meanwhile, Dr. Bahrami was a significant contributor to the public health system and assumed several responsibilities such as Chief Quarantine Medical Officer, Chief of Public Health, and the Head of Public Health Administration, in order to improve public health planning throughout the country.

An overview of the sand fly salivary proteins in vaccine development against leishmaniases.

Leishmaniases are a group of vector-borne parasitic diseases transmitted through the infected sand flies. Leishmania parasites are inoculated into the host skin along with sand fly saliva. The sand fly saliva consists of biologically active molecules with anticoagulant, anti-inflammatory, and immunomodulatory properties. Such properties help the parasite circumvent the host's immune responses. The salivary compounds support the survival and multiplication of the parasite and facilitate the disease progression. It is documented that frequent exposure to uninfected sand fly bites produces neutralizing antibodies against specific salivary proteins and further activates the cellular mechanisms to prevent the establishment of the disease. The immune responses due to sand fly saliva are highly specific and depend on the composition of the salivary molecules. Hence, thorough knowledge of these compounds in different sand fly species and information about their antigenicity are paramount to designing an effective vaccine. Herein, we review the composition of the sand fly saliva, immunomodulatory properties of some of its components, immune responses to its proteins, and potential vaccine candidates against leishmaniases.

Evaluation of Cellular Immune Responses in Dogs Immunized with Alum-Precipitated Autoclaved Leishmania major along with BCG and Imiquimod.

BACKGROUND: We aimed to investigate the potential effects of BCG and imiquimod on improvement of current experimental L. major vaccine against dogs in an endemic area of Zoonotic visceral leishmaniasis (ZVL) in Iran. METHODS: During 2012 till 2014, seven mixed-breed shepherd dogs with no anti-Leishmania antibodies and no response to Leishmanin reagent were immunized with 2 doses of alum-precipitated autoclaved L. major (Alum-AML) while BCG and imiquimod (for skin pre-treatment) were used as adjuvants. The productions of a few characteristic cytokines of T-helper immune responses and the development of delayed-type hypersensitivity (DTH) of the immunized animals were then evaluated, up to 300 days. Blood samples were collected at 0, 30, 80 and 300 d post-vaccination and the concentrations of IFN-γ, IL10, IL-12 and TGF-ß cytokines secreted from PBMCs at these time-points were quantified by ELISA. DTH was evaluated by Leishmanin skin test (LST). RESULTS: Although a similar LST conversion was observed at all time-points, the cytokine measurement results indicated significantly higher levels of IFN-γ at day 80 and elevated levels of IL-10 at days 80 and 300, post-vaccination. Moreover, a significantly higher IFN-γ/IL-10 ratio was observed at day 30 post-vaccination compared to the other time-points. CONCLUSION: Although a Th1-like response could be observed at day 30 post-vaccination, the development of cytokine profiles was inclined toward mixed Th1 and Th2 responses at days 80 and 300 post-vaccination. This situation may indicate the requirement of an additional boosting by this Alum-AML formula, in order to induce long-lasting protection against ZVL.

High resolution melting assay in discrimination of the main etiologic agents of leishmaniasis in Iran.

BACKGROUND AND OBJECTIVES: The three old world Leishmania species i.e., L. major, L. tropica, and L. infantum are considered as potential etiological agents of the various clinical forms of leishmaniasis in Iran. Different species co-exist in some areas. Accurate differentiation between the species is essential for choosing an appropriate therapy. Conventional and gold standard methods for the detection and characterization of parasites are time-consuming, laborious, and have low sensitivity. A polymerase chain reaction followed by high resolution melting (PCR-HRM) analysis has been employed for detection and species identification. Most of the studies suffer from the use of multiple targets and/or requiring more than one reaction to identify a single sample. The present study aimed to design a PCR method based on the amplification of kinetoplast DNA minicircles (kDNA) and HRM analysis of the amplicons for rapid discrimination of the three mentioned species. MATERIALS AND METHODS: DNA from reference strains including L. major, L. tropica, and L. infantum and fifty-eight strains subjected to PCR-HRM analysis targeting kDNA. All the samples were also analyzed by conventional kDNA-PCR. RESULTS: The PCR-HRM analysis allowed discrimination between the three Old World species. The normalized HRM curves for the amplicons of kDNA indicated a unique and repeatable melting plot for each species, even in combination with human and mouse genomic DNA. Conventional kDNA-PCR could not properly discriminate L. tropica from L. infantum. CONCLUSION: PCR-HRM analysis of kDNA proved to be fast and accurate for discrimination of L. major, L. tropica, and L. infantum.

Cutaneous leishmaniasis in Iran: A systematic review and meta-analysis.

Cutaneous leishmaniasis as a public health concern that attracts many attentions in endemic area. There is no exact estimation of cutaneous leishmaniasis in Iran. This study aimed to assess the exact prevalence of disease and carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Magiran, Iran doc, Barakatkns and Scientific Information Database (SID) from 2000 to 2019. Totally 84 studies were eligible to be included in this systematic review and Meta-analysis study. Based on a random effect model the pooled prevalence of leishmaniasis was estimated 45% (95% CI: 39%-51%; I^2 = 99.8%P < 0.001). The highest prevalence of CL was related to Isfahan 66% (53%-78%), Golestan 64% (62%-65%) and Fars province 63% (38%-84%) and the lowest prevalence was estimated in Kermanshah province 4% (4%-5%), Hormozgan 10% (8%-11%), Bushehr 12% (1%-35%) and Kerman 15% (9%-22%) provinces respectively. The lowest prevalence was associated with L. trapica spices 23% (11%-38%) and the highest was associated with L. major spices 32% (21%-45%). The prevalence with both L. trapica and L. major spices was achieved 60% (48%-71%). It is essential for health authorities to take steps to control and prevent the epidemic by rapid treatment of patients, destroying gerbils and promotion of general and health education for the local population.

The effects of natural disasters on leishmaniases frequency: A global systematic review and meta-analysis.

OBJECTIVES: Natural disasters (NDs) may increase the outbreaks and transmissions of vector-borne diseases such as cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). However, the relationship between leishmaniases and NDs has not yet been clearly established. Here, we systematically reviewed all reported articles in this field to answer whether NDs increase the frequency of leishmaniases. METHODS: All the related articles published during January 2000 till January 2020 were reviewed. Moreover, all NDs and the associated leishmaniases frequencies reports in 17 leishmaniases endemic countries were searched to find any ND-leishmaniases relationship. RESULTS: After the initial screening, 39 articles on ND-leishmaniases were selected and systematically reviewed. These articles showed different frequencies of CL in the endemic areas before and after NDs in some regions of Pakistan and Iran and in case of VL in Brazil, Ethiopia, and Sudan. After thorough deliberation, four studies for CL-ND and five studies for VL-ND relationships were selected for meta-analysis. The results showed increases in the leishmaniases incidences after NDs, although not robustly. CONCLUSION: The lack of a strong leishmaniases-ND relationship could be attributed to the local compilations of such data in scattered regions of the endemic countries. Therefore, currently a substantial knowledge gap on leishmaniases-ND relationship is apparent.

Computational evaluation of a fusion protein consisted of pertussis toxin and filamentous hemagglutinin from Bordetella pertussis to target Claudin-4 using C-terminal fragment of Clostridium perfringens enterotoxin.

Pertussis, caused by Bordetella pertussis is still one of the controversial diseases worldwide due to its high prevalence in both the developed and the developing countries, especially among young children. As currently approved vaccines are not protective enough and provide Th2-type immune responses, there is an urgent need to develop new vaccines. In the current study, we applied the C-terminal fragment of Clostridium perferingens enterotoxin (C-CPE) as a delivery system and F1S1 fragment (Filamentous hemagglutinin (F1) and subunit 1 of pertussis toxin (S1) of B. pertussis to design a novel chimeric protein in silico, to target Claudin-4 receptors in mice lung cells. To achieve this goal, the primary, secondary and tertiary structures of the fusion protein were evaluated and the interaction of this protein with Claudin-4 receptors was studied. Molecular dynamic (MD) simulation analysis was performed to investigate the physical movement of atoms in a fixed period. According to the results; the full-length fusion protein has consisted of 807 amino acid residues which could be classified as a stable protein. There was a convenient consistency between the 3D predicted structure and the secondary structure prediction. An acceptable percentage of the residues were also detected in the most favored and allowed regions for the model. Based on HADDOCK results, there were no considerable differences between the interactions and MD simulation analysis, indicating that the predicted structures were stable during the simulation. Altogether, the data reported in this study represents the first step toward developing a nasal vaccine candidate against B. pertussis infection. Communicated by Ramaswamy H. Sarma.

Naloxone Diminishes the Virulence and Modifies the Cellular Immune Responses of BALB/c Mice Infected with Leishmania major.

PURPOSE: Leishmania major-infected BALB/c mice display strong susceptibility to the infection due to the induction of Th2 response. The aim of this study was to assess the effects of naloxone on virulence of L. major in BALB/c mice and the ensued cellular immune response. METHODS: The effects of injection of a single dose of naloxone in the footpad of L. major-infected BALB/c mice were investigated by evaluating the lesion sizes, the parasite burden, cell proliferation, secreted cytokines (IFN-γ, IL-4, IL-10 and IL-12) and their genes expressions due to naloxone treatment while the untreated mice were used as a control. RESULTS: Significantly lower lesion sizes and less parasite burden were measured in the treated mice. Significantly decreased productions of IFN-γ, IL-12, IL-4, and IL-10 were also observed in the treated mice at week 4 post-infection while the production IL-10 remained significantly hindered till 8 weeks post-infection. CONCLUSION: Our data indicated that although the treatment of L. major-infected BALB/c mice with a single dose of naloxone was unable to improve the cellular immune response, it led to lower virulence, confirmed by significantly reduced lesions and parasite load.

Cloning, Expression and Purification of Espc, Espb and Espc/Espb Proteins of Mycobacterium tuberculosis ESX-1 Secretion System.

BACKGROUND: It is estimated that one third of the world's population is infected with Mycobacterium tuberculosis (Mtb), the causative agent of Tuberculosis (TB). The BCG vaccine is widely used to fight against TB; however, many question its ability to provide complete protection from Mtb. Recently, the "Region of Difference 1" (RD1) set of genes were shown to be involved in the pathogenesis of Mtb. Downstream of RD1 transcription region, two proteins are encoded, known as EspB and EspC, which were found to contribute to Mtb virulence.In this study these two proteins are targeted as potential vaccine candidates against TB. METHODS: The EspB and EspC Mtb genes were codon-optimized for expression and synthesis in Escherichia coli (E. coli). The amplicons were cloned into a pET21a expression vector and transformed into E. coli BL21(DE3). The expression and purity of the expressed proteins (i.e. rEspC, rEspB and rEspC/EspB) were confirmed by SDS-PAGE and Western blotting. Moreover, BALB/c mice were immunized against Mtb using the recombinant proteins. Finally, the mice sera were analyzed via Western blotting. RESULTS: EspC, EspB, and EspC/EspB fusion genes were cloned and expressed in E. coli. Both SDS-PAGE and Western blots confirmed the presence and successful purification of the desired proteins. Moreover, antisera produced against the purified recombinant proteins reacted with Mtb proteins. CONCLUSION: rEspC, rEspB, and rEspC/EspB could be expressed and purified using an E. coli expression system. The recombinant proteins induced the production of antibodies in BALB/c mice that reacted with Mtb proteins.

Immuno-proteomics analysis between OMV of vaccine and dominant wild type strains of Bordetella pertussis in Iran.

BACKGROUND AND OBJECTIVES: Despite widespread vaccination programs against pertussis, there has been a worldwide resurgence of the disease in recent years. We aimed to investigate protein composition of outer membrane vesicles (OMV) of Bordetella pertussis (Bp) and to evaluate the immunogenicity of OMV antigens both in the vaccine and the dominant wild type strains in Iran. MATERIALS AND METHODS: The OMV were purified from both vaccine and wild type strains. The immunoreactivity of the OMVs was investigated by exposing sera taken from the patients and the vaccinated infants. The protein profiles of OMVs were compared using two-dimensional electrophoresis. The LC-MS/MS was used to analyse and identify differentially expressed protein spots. RESULTS: The two type strains showed differences in their 2D gel protein profile. Further analysis of selected proteins from the dominant Iranian strains using LC-MS/MS demonstrated that the identified proteins fell into different functional categories including (i) metabolism, (ii) membrane transport and secretion system, (iii) biosynthesis and degradation, (iv) adaption, adhesion, pathogenicity, conserved hypothetical and protection responses. Moreover, a number of immunogenic proteins were identified including Bp 2434 (serine protease) and Bp 1616 (putative DNA binding protein) from the vaccine and the wild type strains, respectively which could be considered as potential antigens for an OMV vaccine. CONCLUSION: OMV Bp could be considered as an alternative vaccine against pertussis, containing the bacterium's protein antigens that can confer equal efficacy compared to a whole bacterial cell vaccine with advantages such as less side effects and lower costs than acellular pertussis vaccines.

Lactococcus lactis expressing sand fly PpSP15 salivary protein confers long-term protection against Leishmania major in BALB/c mice.

Cutaneous leishmaniasisis a vector-borne disease transmitted by Leishmania infected sand flies. PpSP15 is an immunogenic salivary protein from the sand fly Phlebotomus papatasi. Immunization with PpSP15 was shown to protect against Leishmania major infection. Lactococcus lactis is a safe non-pathogenic delivery system that can be used to express antigens in situ. Here, the codon-optimized Ppsp15-egfp gene was cloned in pNZ8121 vector downstream of the PrtP signal peptide that is responsible for expression and secretion of the protein on the cell wall. Expression of PpSP15-EGFP recombinant protein was monitored by immunofluorescence, flow cytometry and Western blot. Also, expression of protein in cell wall compartment was verified using whole cell ELISA, Western blot and TEM microscopy. BALB/c mice were immunized three times with recombinant L. lactis-PpSP15-EGFPcwa, and the immune responses were followed up, at short-term (ST, 2 weeks) and long-term (LT, 6 months) periods. BALB/c mice were challenged with L. major plus P. papatasi Salivary Gland Homogenate. Evaluation of footpad thickness and parasite burden showed a delay in the development of the disease and significantly decreased parasite numbers in PpSP15 vaccinated animals as compared to control group. In addition, immunized mice showed Th1 type immune responses. Importantly, immunization with L. lactis-PpSP15-EGFPcwa stimulated the long-term memory in mice which lasted for at least 6 months.

Seroconversion after three doses of intramuscular rabies vaccine as a post-exposure treatment.

Rabies is still threatening half of the world's population with the global burden of canine rabies being estimated as 59,000 human deaths, annually. With no cure existing for clinical rabies, post-exposure prophylaxis (PEP) is the only certain means to save lives of the exposed people. In Iran, bite incidences exceed 180,000 per year, where all victims receive 5 vaccine doses for PEP, conforming to the Essen regimen. More than two-thirds of the exposed individuals stop receiving treatments after day 7, for the reason of being exposed to a non-rabid dog or cat. According to the national standard protocols, these individuals should re-start a complete 5-dose PEP course upon the re-exposure. New WHO recommendations based on scientific data is encouraging revisions to the existing prophylaxis programs. In order to know if an incomplete Essen regimen can provide adequate immunity, in the present study, 5 groups of individuals who had only received 3 first doses of the Essen regimen within the previous 1, 3, 6, 12 and 24 months were examined for immunity against rabies. Our results indicated sufficient anti-rabies neutralizing antibody in all individuals, before and after receiving two standard booster doses (i.e. days 0 and 3). This might also suggest the adequacy of the 3 first doses of vaccination, as a one-week long post-exposure vaccination program.