Immunoinformatic analysis of immunogenic B- and T-cell epitopes of MIC4 protein to designing a vaccine candidate against Toxoplasma gondii through an in-silico approach

Purpose@#Toxoplasmosis, transmitted by Toxoplasma gondii, is a worldwide parasitic disease that affects approximately one-third of the world’s inhabitants. Today, there are no appropriate drugs to deter tissue cysts from developing in infected hosts. So, developing an effective vaccine would be valuable to avoid from toxoplasmosis. Considering the role of microneme antigens such as microneme protein 4 (MIC4) in T. gondii pathogenesis, it can be used as potential candidates for vaccine against T. gondii. @*Materials and Methods@#In this study several bioinformatics methods were used to assess the different aspects of MIC4 protein such as secondary and tertiary structure, physicochemical characteristics, the transmembrane domains, subcellular localization, B-cell, helper-T lymphocyte, cytotoxic-T lymphocyte epitopes, and other notable characteristic of this protein design a suitable vaccine against T. gondii. @*Results@#The studies revealed that MIC4 protein includes 59 potential post-translational modification sites without any transmembrane domains. Moreover, several probable epitopes of Band T-cells were detected for MIC4. The secondary structure comprised 55.69% random coil, 5.86% beta-turn, 19.31% extended strand, and 19.14% alpha helix. According to the Ramachandran plot results, 87.42% of the amino acid residues were located in the favored, 9.44% in allowed, and 3.14% in outlier regions. The protein allergenicity and antigenicity revealed that it was non-allergenic and antigenic. @*Conclusion@#This study gives vital basic on MIC4 protein for further research and also established an effective vaccine with different techniques against acute and chronic toxoplasmosis.

Antigenic properties of dense granule antigen 12 protein using bioinformatics tools in order to improve vaccine design against Toxoplasma gondii

Purpose@#Toxoplasma gondii is an opportunistic parasite infecting all warm-blooded animals including humans. The dense granule antigens (GRAs) play an important role in parasite survival and virulence and in forming the parasitophorous vacuole. Identification of protein characteristics increases our knowledge about them and leads to develop the vaccine and diagnostic studies. @*Materials and Methods@#This paper gave a comprehensive definition of the important aspects of GRA12 protein, including physico-chemical features, a transmembrane domain, subcellular position, secondary and tertiary structure, potential epitopes of B-cells and T-cells, and other important features of this protein using different and reliable bioinformatics methods to determine potential epitopes for designing of a high-efficient vaccine. @*Results@#The findings showed that GRA12 protein had 53 potential post-translational modification sites. Also, only one transmembrane domain was recognized for this protein. The secondary structure of GRA12 protein comprises 35.55% alpha-helix, 19.50% extended strand, and 44.95% random coil. Moreover, several potential B- and T-cell epitopes were identified for GRA12. Based on the results of the Ramachandran plot, 79.26% of amino acid residues were located in favored, 11.85% in allowed and 8.89% in outlier regions. Furthermore, the results of the antigenicity and allergenicity assessment noted that GRA12 is immunogenic and nonallergenic. @*Conclusion@#This research provided important basic and conceptual data on GRA12 to develop an effective vaccine against acute and chronic toxoplasmosis for further in vivo investigations. More studies are required on vaccine development using the GRA12 alone or combined with other antigens in the future.

Antigenic properties of dense granule antigen 12 protein using bioinformatics tools in order to improve vaccine design against Toxoplasma gondii

Purpose@#Toxoplasma gondii is an opportunistic parasite infecting all warm-blooded animals including humans. The dense granule antigens (GRAs) play an important role in parasite survival and virulence and in forming the parasitophorous vacuole. Identification of protein characteristics increases our knowledge about them and leads to develop the vaccine and diagnostic studies. @*Materials and Methods@#This paper gave a comprehensive definition of the important aspects of GRA12 protein, including physico-chemical features, a transmembrane domain, subcellular position, secondary and tertiary structure, potential epitopes of B-cells and T-cells, and other important features of this protein using different and reliable bioinformatics methods to determine potential epitopes for designing of a high-efficient vaccine. @*Results@#The findings showed that GRA12 protein had 53 potential post-translational modification sites. Also, only one transmembrane domain was recognized for this protein. The secondary structure of GRA12 protein comprises 35.55% alpha-helix, 19.50% extended strand, and 44.95% random coil. Moreover, several potential B- and T-cell epitopes were identified for GRA12. Based on the results of the Ramachandran plot, 79.26% of amino acid residues were located in favored, 11.85% in allowed and 8.89% in outlier regions. Furthermore, the results of the antigenicity and allergenicity assessment noted that GRA12 is immunogenic and nonallergenic. @*Conclusion@#This research provided important basic and conceptual data on GRA12 to develop an effective vaccine against acute and chronic toxoplasmosis for further in vivo investigations. More studies are required on vaccine development using the GRA12 alone or combined with other antigens in the future.

Rhoptry antigens as Toxoplasma gondii vaccine target

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii that belongs to the phylum Apicomplexa. It is estimated that over one-third of the world's population has been exposed and are latently infected with the parasite. In humans, toxoplasmosis is predominantly asymptomatic in immunocompetent persons, while among immunocompromised individuals may be cause severe and progressive complications with poor prognosis. Moreover, seronegative pregnant mothers are other risk groups for acquiring the infection. The life cycle of T. gondii is very complex, indicating the presence of a plurality of antigenic epitopes. Despite of great advances, recognize and construct novel vaccines for prevent and control of toxoplasmosis in both humans and animals is still remains a great challenge for researchers to select potential protein sequences as the ideal antigens. Notably, in several past years, constant efforts of researchers have made considerable advances to elucidate the different aspects of the cell and molecular biology of T. gondii mainly on microneme antigens, dense granule antigens, surface antigens, and rhoptry proteins (ROP). These attempts thereby provided great impetus to the present focus on vaccine development, according to the defined subcellular components of the parasite. Although, currently there is no commercial vaccine for use in humans. Among the main identified T. gondii antigens, ROPs appear as a putative vaccine candidate that are vital for invasion procedure as well as survival within host cells. Overall, it is estimated that they occupy about 1%–30% of the total parasite cell volume. In this review, we have summarized the recent progress of ROP-based vaccine development through various strategies from DNA vaccines, epitope or multi epitope-based vaccines, recombinant protein vaccines to vaccines based on live-attenuated vectors and prime-boost strategies in different mouse models.

Calcium-dependent protein kinases are potential targets for Toxoplasma gondii vaccine

Toxoplasma gondii belongs to the Apicomplexa phylum that caused a widespread zoonotic infection in wide range of intermediate hosts. Over one-third of the world's population are latently infected with T. gondii and carry it. The complex life cycle of T. gondii indicates the presence of a plurality of antigenic epitopes. During the recent years, continuous efforts of scientists have made precious advances to elucidate the different aspects of the cell and molecular biology of T. gondii. Despite of great progresses, the development of vaccine candidates for preventing of T. gondii infection in men and animals is still remains a challenge. The calcium-dependent protein kinases (CDPKs) belongs to the superfamily of kinases, which restricted to the apicomplexans, ciliates, and plants. It has been documented that they contribute several functions in the life cycle of T. gondii such as gliding motility, cell invasion, and egress as well as some other critical developmental processes. In current paper, we reviewed the recent progress concerning the development of CDPK-based vaccines against acute and chronic T. gondii.

Recent progress in microneme-based vaccines development against Toxoplasma gondii

Toxoplasmosis is a cosmopolitan zoonotic disease, which infect several warm-blooded mammals. More than one-third of the human population are seropositive worldwide. Due to the high seroprevalence of Toxoplasma gondii infection worldwide, the resulting clinical, mental, and economical complications, as well as incapability of current drugs in the elimination of parasites within tissue cysts, the development of a vaccine against T. gondii would be critical. In the past decades, valuable advances have been achieved in order to identification of vaccine candidates against T. gondii infection. Microneme proteins (MICs) secreted by the micronemes play a critical role in the initial stages of host cell invasion by parasites. In this review, we have summarized the recent progress for MIC-based vaccines development, such as DNA vaccines, recombinant protein vaccines, vaccines based on live-attenuated vectors, and prime-boost strategy in different mouse models. In conclusion, the use of live-attenuated vectors as vehicles to deliver and express the target gene and prime-boost regimens showed excellent outcomes in the development of vaccines against toxoplasmosis, which need more attention in the future studies.

Lack gene's immune response induced by cocktail dna vaccine with il-12 gene against cutaneous leishmaniasis in balb/c mice

Background: Leishmaniasis is caused by parasitic protozoa of the genus Leishmania which is an obligate intracellular parasite in the infected host. Individuals who have been recovered from clinical leishmaniasis develop strong immunity against reinfection. DNA vaccines are the new type of vaccines that induce expression of protein eukaryotic cells. DNA vaccines can be stimulated by the cellular and humoral immune responses using one or several genes

Methods: A DNA vaccine containing plasmids encoding the pcLACK+pcTSA genes of Leishmania major [L. major] [MHRO/IR/75/ER] in the vicinity of IL-12 gene expression was made and then its protective efficacy in comparison with single-gene of LACK was evaluated. Also, BALB/c mice were immunized intramuscularly three times. The humoral and cellular immune responses were evaluated after immunization with pcLACK, pcLACK+pcTSA+pCAGGS-IL12, and then challenged with L. major

Results: Humoral response and IFN-Gamma values were significantly higher than control groups after immunization with pcLACK, pcLACK+pcTSA+pCAGGS-IL12 and challenge with L. major [p

Conclusion: The survival time of the immunized mice with pcLACK, pcLACK+pcTSA+ pCAGGS-IL12 groups was higher than the control groups. Then, DNA vaccine of pcLACK appeared to be likely able to induce more protection against infection with L. major in mice. Therefore, cocktail DNA is effective to enhance specific immunity

DNA vaccination with a plasmid encoding LACK-TSA fusion against Leishmania major infection in BALB/c mice

Vaccination would be the most important strategy for the prevention and elimination of leishmaniasis.The aim of the present study was to compare the immune responses induced following DNA vaccinationwith LACK (Leishmania analogue of the receptor kinase C), TSA (Thiol-specific-antioxidant) genesalone or LACK-TSA fusion against cutaneous leishmaniasis (CL). Cellular and humoral immuneresponses were evaluated before and after challenge with Leishmania major (L. major). In addition,the mean lesion size was also measured from 3th week post-infection. All immunized mice showed apartial immunity characterized by higher interferon (IFN)-γ and Immunoglobulin G (IgG2a) levelscompared to control groups (p<0.05). IFN-γ/ Interleukin (IL)-4 and IgG2a/IgG1 ratios demonstratedthe highest IFN-γ and IgG2a levels in the group receiving LACK–TSA fusion. Mean lesion sizesreduced significantly in all immunized mice compared with control groups at 7th week post-infection(p<0.05). In addition, there was a significant reduction in mean lesion size of LACK-TSA andTSA groups than LACK group after challenge (p<0.05). In the present study, DNA immunizationpromoted Th1 immune response and confirmed the previous observations on immunogenicity ofLACK and TSA antigens against CL. Furthermore, this study demonstrated that a bivalent vaccinecan induce stronger immune responses and protection against infectious challenge with L. major.

Molecular detection and genotypic characterization of toxoplasma gondii in paraffin-embedded fetoplacental tissues of women with recurrent spontaneous abortion

Background: Congenital toxoplasmosis is an important cause of spontaneous abortion worldwide. However, there is limited information on detection and genotypic characterization of Toxoplasma gondii [T. gondii] in women with recurrent spontaneous abortion [RSA]. The aim of this study is the molecular detection and genotypic characterization of T. gondii in formalin-fixed, paraffin-embedded fetoplacental tissues [FFPTs] of women with RSA that have referred to the Avicenna Research Institute in Tehran, Iran

Materials and Methods: This experimental research was undertaken on 210 FFPTs of women with RSA. The information of the patients was collected from the archives of Avicenna Research Institute in Tehran, Iran. After DNA extraction, the presence of T. gondii was examined by nested polymerase chain reaction targeting the GRA6 gene. Genotyping was performed on positive samples using polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP] that targeted the GRA6 and SAG3 genes. Sequencing was conducted on two GRA6 positive samples

Results: T. gondii DNA was detected in 3.8% [8/210] of the samples. Genotyping showed that all positive samples belonged to type III of the T. gondii genotype. Sequencing two genomic DNAs of the GRA6 gene revealed 99% similarity with each other and 99-100% similarity with T. gondii sequences deposited in GenBank. There were six patients with histories of more than three abortions; one patient had a healthy girl and another patient had two previous abortions. Abortions occurred in the first trimester of pregnancy in seven patients and in the second trimester of pregnancy in one patient

Conclusion: The results of this study have indicated that genotype III is the predominant type of T. gondii in women with RSA in Tehran, Iran. Also, our findings suggest that toxoplasmosis may play a role in the pathogenesis of RSA. However, further studies are needed to elucidate a clear relationship between T. gondii infection and RSA

[ killing effect of silver nanoparticles and direct electric current induction on leishmania major promastigotes in vitro]

Objective: Worldwide, Leishmania major is one of the major causes of cutaneous leishmaniasis, including Iran. In the present study we investigate the effect of a direct electricity current in combination with silver nanoparticle on the killing of Leishmania major in vitro

Methods: We evaluated the effects of different concentrations of silver nanoparticles against Leishmania major promastigotes in vitro, then the half maximal inhibitory concentration [IC50] of the nanoparticles was determined. In the second step, the killing effect of silver nanoparticles alone or in combination with 3mA of direct electric current was assessed in promastigote cultures for 10 minutes. Next, we evaluated the survival rate of treated promastigotes with the MTT assay

Results: The parasite count showed that the various concentrations of silver nanoparticles significantly decreased the numbers of live promastigotes over time compared with the control group after 24, 48 and 72 hours of culture. The IC50 of the nanoparticles was 39.8 microg/ml after 48 hours of cultivation. Promastigote mortality occurred in 33.5% with the use of silver nanoparticles alone at concentrations of 160 microg/ml and 100% when combined with 3 mA direct current electricity after 10 minutes

Conclusion: Silver nanoparticles alone did not completely kill Leishmania major promastigotes. However, the combined use of both direct current electricity and silver nanoparticles had a significant synergistic effect on promastigote mortality

Evaluation of protective effect of IL-22 and IL-12 on cutaneous leishmaniasis in BALB/c mice

OBJECTIVE@#To investigate the protective effect of IL-22 and IL-12 on cutaneous leishmaniasisin BALB/c mice.@*METHODS@#The protective effect of IL-22 and IL-12 on cutaneous leishmanias in BALB/c mice was evaluated by measurement of IL-4, INF-γ, total IgG, IgG1 and IgG2a after challenge with Leishamania major. Clinical evaluations were performed by measurement of lesion diameter, and survival rate of the mice.@*RESULTS@#In week 27 post infection, the mortality rates for control groups were 100%. While the survival rates for the IL-12, IL-12 + IL-22, and IL-22(5 ng/g) groups were 100%. The size of lesions decreased in the presence IL-22 (5 ng/g) of mice weight, which was statistically significant in comparison with other groups (P<0.05). Mean of total IgG, IgG1 and IgG2a for IL-22 (5 ng/g) group was more than other groups. In IL-22 group (5 ng/g), INF-γ production was significantly higher than other groups and IL-4 was significantly lower than other groups.@*CONCLUSIONS@#The results obtained indicate the effectiveness of IL-22 and its effect on IL-12 in protection of cutaneous leishmaniasis.

vitro study on cytotoxic effects of zno nanoparticles on promastigote and amastigote forms of leishmanta major

Although pentavalent antimony compounds are used as antileish-manial drugs but they are associated with limitations and several adverse complications. Therefore, always effort to find a new and effective treatment is desired. In this study, the effect of ZnO nanoparticles with mean particle size of 20 nanometers [nm] on Leishmania major promastigotes and amastigotes was evaluated. Viability percentage of promastigotes after adding different concentrations of ZnO nanoparticles [30, 60, 90 and 120 microg/ml] to the parasite culture was evaluated by MTT assay. In the flow cytometry study, Annexin V-FITC Apoptosis detection Kit was used to study the induced apoptosis and necrotic effects. IC50 after 24 hours of incubation was 37.8 microg/ml. ZnO nanoparticles exert cytotoxic effects on promastigotes of L major through the induction of apoptosis. A concentration of 120 microg/ml of ZnO nanoparticles induced 93.76% apoptosis in L major after 72 hours. ZnO NPs can induce apoptosis in L major by dose and time-depended manner in vitro condition

[ identification of human cryptosporidium species in Tehran by PCR/RFLP]

Cryptosporidiosis is one of the most important parasitic infections in Iran which causes diarrhea in humans and animals. The identification of the Cryptosporidium species among humans is necessary. This study aims to identify species of Cryptosporidium isolated from patients that referred to three hospitals in Tehran based on the 18s rRNA gene by nested PCR-RFLP assay. In the first step of the present descriptive cross-sectional study, 1128 human fecal samples were collected from patients that referred to three hospitals [Ali Asgar, Mofid and Imam Khomeini] in Tehran. The samples were examined for Cryptosporidium by modified acid fast staining. In the second step, DNA of the positive samples were extracted, then gene of 18s rRNA was amplified by nested PCR in order to differentiate between species. The PCR products were subsequently digested by Vsp1 restriction enzyme and their sequences determined. The modified acid fast method detected 12 [1.06%] positive samples which was confirmed by a molecular technique. The 845bp fragment of 18s rRNA was digested by restriction enzymes. There were 10 samples identified as Cryptosporidium parvum that showed similar patterns on 2.5% agarose gel; 2 other samples were identified as Cryptosporidium homonis and Cryptosporidium andersoni based on the different patterns and sequence results. Although Cryptosporidium parvum is introduced as the major agent for cryptosporidiosis in humans, Cryptosporidium hominis and Cryptosporidium andersoni may also infect humans

Evaluation of protective effect of IL-22 and IL-12 on cutaneous leishmaniasis in BALB/c mice

Objective: To investigate the protective effect of IL-22 and IL-12 on cutaneous leishmaniasisin BALB/c mice. Methods: The protective effect of IL-22 and IL-12 on cutaneous leishmanias in BALB/c mice was evaluated by measurement of IL-4, INF-γ, total IgG, IgG1 and IgG2a after challenge with Leishamania major. Clinical evaluations were performed by measurement of lesion diameter, and survival rate of the mice. Results: In week 27 post infection, the mortality rates for control groups were 100%. While the survival rates for the IL-12, IL-12 + IL-22, and IL-22(5 ng/g) groups were 100%. The size of lesions decreased in the presence IL-22 (5 ng/g) of mice weight, which was statistically significant in comparison with other groups (. P<0.05). Mean of total IgG, IgG1 and IgG2a for IL-22 (5 ng/g) group was more than other groups. In IL-22 group (5 ng/g), INF-γ production was significantly higher than other groups and IL-4 was significantly lower than other groups. Conclusions: The results obtained indicate the effectiveness of IL-22 and its effect on IL-12 in protection of cutaneous leishmaniasis.

In-vitro evaluation of antileishmanial activity and toxicity of artemether with focus on its apoptotic effect

Artemisinin and its derivatives are very important new class of antimalarial drugs. One of the most important artemisinin derivatives is artemether. The antiparasitic activity of artemether as a derivative of artemisinin is related to endoperoxide bridge in its structure. The aim of this study was the evaluation of antileishmanial effect of artemether, with more focus on its apoptotic effect. In this study we used artemether in concentration of 5, 10, 25, 50 and 100 microg/mL for promastigote assay, promastigote proliferation measurements by MTT assay, detection of apoptotic cells by Flow cytometry analysis and DNA ladder assay. The application of artemether, promastigote IC[50] was measured as 25 microg/mL. The percentage of apoptotic promastigotes by using 25 microg/mL of artemether was 42.28. The results of present study showed that artemether has inhibition effect on intracellular and extracellular growth of Leishmania major. Promastigotes of Leishmania major undergo apoptosis after exposure to artemether

Cloning of a Recombinant Plasmid Encoding Thiol-Specific Antioxidant Antigen (TSA) Gene of Leishmania major and Expression in the Chinese Hamster Ovary Cell Line

Background: TSA (thiol-specific antioxidant antigen) is the immune-dominant antigen of Leishmania major and is considered to be the most promising candidate molecule for a recombinant or DNA vaccine against leishmaniasis. The aim of the present work was to express a plasmid containing the TSA gene in eukaryotic cells. Methods: Genomic DNA was extracted, and the TSA gene was amplified by polymerase chain reaction (PCR). The PCR product was cloned into the pTZ57R/T vector, followed by subcloning into the eukaryotic expression vector pcDNA3 (EcoRI and HindIII sites). The recombinant plasmid was characterised by restriction digest and PCR. Eukaryotic Chinese hamster ovary cells were transfected with the plasmid containing the TSA gene. Expression of the L. major TSA gene was confirmed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and Western blotting. Results: The plasmid containing the TSA gene was successfully expressed, as demonstrated by a band of 22.1 kDa on Western blots. Conclusion: The plasmid containing the TSA gene can be expressed in a eukaryotic cell line. Thus, the recombinant plasmid may potentially be used as a DNA vaccine in animal models.

effect of artemether-induced apoptosis in promastigotes of leishmania major [MRHO/IR/75/ER] under in-vitro conditions

Leishmaniasis is one of the significant causes of morbidity and mortality in several countries. It is an important problem in endemic areas such as Iran. The goal in treatment of leishmaniasis is to reduce the disease period and leave no evidence of any remaining scars or lesions. A derivative of artemisinin is artemether. Scientists believe that the strong action of artemether against parasites is due to the presence of an endoperoxide bridge. Due to problems in the treatment of Leishmania major, in this research we have studied the effect of artemether on Leishmania major under in vitro conditions. Parasites were cultured in NNN and RPMI, after which artemether at concentrations of 5, 10, 25, 50 and 100 microg/ml were used for the promastigote assay. Apoptosis was detected by flow cytometry and DNA ladder assay. The inhibitory concentration [IC50] of artemether was determined to be 25 microg/ml. The percentage of apoptotic promastigotes at 25 imcrog/ml of artemether was 42.28. The results of DNA fragmentation show that exposure of Leishmania major promastigote cells to 25 microg/ml of artemether lead to DNA fragmentation. We have proven the effect of artemether on apoptosis of Leishmania major by flow cytometry and the DNA ladder assay

Identification of live toxoplasma gondii by the nasba method in rat

Toxoplasmosis is a worldwide disease, for which different detection methods have been used. The nucleic acid sequence-based amplification [NASBA] method is shown to be highly efficient for diagnosis of live microorganisms. The present research evaluates the molecular isothermal method of NASBA to identify live Toxoplasma gondii [T. gondii] in rat. Tachyzoites of T. gondii were inoculated in the peritoneal cavities of mice [Mus musculus] and their RNA was extracted. The NASBA method was then used to amplify the tachyzoite B1 rRNA gene. Next, we examined blood samples from 30 experimentally infected case and control rats [Rattus norvegicus] by NASBA. Finally, the resultant band was investigated on an agarose gel. The B1 genes extracted from both the tachyzoites and blood samples were successfully amplified by the NASBA method. This amplified gene yielded an amplicon of approximately 116 bp on gel agarose. NASBA is highly efficient for the identification of live T. gondii. This method can be applied for early diagnosis of active toxoplasmosis in both newborns and immunocompromised individuals

In vitro study of the effect of artimisinin on promastigotes and amastigotes of leishmania major

Cutaneous leishmaniasis is an endemic infectious disease considered to be a crucial health problem in many countries, including Iran. As such, there is a need for new medications with few side effects. In the present research we have studied the effect of artimisinin on Leishmania major [L. major] and cell death in vitro. A specific number of promastigotes of L. major were grown in the presence of different concentration of artimisinin to achieve IC[50] of the drug. The MTT method was applied to evaluate the cytotoxic effect of the artiminisinin on L. major. Various densities of this drug were applied to study the induction of apoptosis by flow cytometry on L. major promastigotes. We calculated the IC[580] of artimisinin to be 25 microg/ml by promastigote assay. Promastigotes were incubated at 72 hours incubation with various doses of artimisinin [10, 25, 50 and 100 microg/ml]. The dose 100 ?g/ml showed the most apoptosis [68.16%] by Annexin-V FITC. Whereas the 10 microg/ml dose had the least apoptosis [12.78%]. There was no change in the control group. According to MTT, the toxic effect of artiminisinin on L. major promastigotes increased with increasing drug concentration. This study revealed that artimisinin has a little toxic effect on macrophages. According to the flow cytometry and MTT results, artimisinin can be suggested as an appropriate drug for in vivo antileishmanial study

[Evaluation of two aluminum adjuvant on DNA vaccine containing ROP1 gene of toxoplasma gondii [RH strain] for immunity and survival assay in animal model]

Toxoplasmosis can lead to severe pathological effects in both infected humans and animals. The various DNA vaccines against Toxoplasma compose of single or cocktail antigens have been investigated but they have partial protective against disease. In this study, we used pcROP1 as a DNA vaccine and aluminium phosphate and aluminium hydroxide to compare their efficacy as mineral adjuvants. BALB/c mice immunized with pcROP1 alone or with co-administration of Alpo4 or Alum and the effectiveness of these two adjuvants were compared using lymphocyte proliferation assay, cytokine and antibody assay and survival time. The group co-administered alum elicited stronger humoral and Th1-type cellular immune responses than the group co-administered Alpo4, while immune response in group administered with pcROP1 alone is higher than them. When challenged with Toxoplasma gondii RH strain, mice immunized with or without alum had significantly higher survival rates, whereas there was no notable enhancement of survival rate in Alpo4 group [P