A Novel Adjuvant, Mixture of Alum And Naltrexone, Elicits Humoral Immune Responses for excreted/secreted Antigens of Toxoplasma gondii Tachyzoites Vaccine In Balb/c Murine Model (original) (raw)
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Advanced Pharmaceutical Bulletin, 2021
Purpose: The introduction of novel adjuvants is an important step in attempts to develop a safe and more efficient vaccine. The present study was performed to determine whether the use of a mixed beta-adrenergic receptor antagonist propranolol (PRP) and aluminum (alum), as an adjuvant, have efficacy for Toxoplasma gondii vaccine to induce protective immunity in a mouse model. Methods: Female BALB/c mice divided into five groups were immunized with excretorys-ecretory antigens (ESA) vaccine, alum-ESA vaccine, PRP-ESA vaccine, and alum-PRP ESA vaccine, as well as with phosphate buffered saline (PBS), as a negative control group. The immune responses were evaluated by lymphocyte proliferation assay for measuring delayedtype hypersensitivity (DTH) response and by cytokine assay for evaluating IFN-γ and IL-5 levels. The survival rate of mice in all groups was assessed during a three-week monitoring period after an intraperitoneal challenge with T. gondii tachyzoites. Results: The results...
Vaccine, 2010
The great clinical and economical impact of Toxoplasma gondii infections makes the development of an effective vaccine for controlling toxoplasmosis an extremely important aim. In the presented study, we evaluate the protective and immunogenic properties of three recombinant subunit vaccines composed of rROP2 + rGRA4 + rSAG1, rROP2 + rROP4 + rGRA4 and rROP2 + rROP4 + rSAG1 proteins of T. gondii in an experimental toxoplasmosis model in the C3H/HeJ and C57BL/6 mouse strains. All three recombinant vaccines induced partial protection as measured by the reduction of brain cyst burden following challenge with five tissue cysts of the low virulence DX T. gondii strain. The level of protection was dependent on the antigen composition of the vaccine and the genetic background of the laboratory animals. The strongest protection against chronic toxoplasmosis was induced in both C3H/HeJ and C57BL/6 mice by the mixture of rhoptry proteins rROP2 and rROP4 combined with tachyzoite major protein rSAG1. The average parasite burden in these groups of mice was reduced by 71% and 90%, respectively, compared to non-vaccinated mice. The observed protective effect was related to the vaccine-induced cellular and humoral immune responses, as measured by the antigen-induced release of the Th1 cytokines IFN-␥ and IL-2, the antigenstimulated proliferation of spleen cells of vaccinated animals in comparison to control animals and the development of systemic antigen-specific IgG1 and IgG2a (C3H/HeJ) or IgG2c (C57BL/6) antibodies. Our studies show that recombinant rROP2, rROP4, rGRA4 and rSAG1 antigens may be promising candidates for a subunit vaccine against toxoplasmosis. Additionally, we demonstrate that the ideal composition of vaccine antigens can be equally effective in mice with different genetic backgrounds and variable levels of innate resistance to toxoplasmosis, resulting in strong protection against T. gondii invasion.
Immune response after immunization with an experimental Toxoplasma gondii ISCOM vaccine
Vaccine, 1991
Mice were immunized with ISCOM preparations of tachyzoites from two different strains ofToxoplasma gondii. The antibody response and the cellular response, as measured in vitro, were comparable with those found in chronically infected mice. When challenged with virulent T. gondii tachyzoites, all the immunized mice died, whereas all the chronically infected mice survived. However, the immunized mice 9enerally survived longer than non-immunized animals.
Propranolol efficacy as a novel adjuvant for immunization against Toxoplasma gondii tachyzoites
Experimental Parasitology, 2018
Severe or lethal damages, caused by Toxoplasma gondii infection in congenital cases and immunocompromised patients implies the necessity for development of a vaccine and an appropriate adjuvant would be needed to elicit a protective Th1 biased-immune response. The adjuvant activity of propranolol was surveyed and compared with alum by immunization of BALB/c mice with protein components of T. gondii tachyzoites. Five groups of BALB/c mice were immunized with phosphate buffered saline (negative control), Toxoplasma lysate antigen (TLA), alum plus TLA, Propranolol plus TLA, and alum, propranolol and TLA. Immunization efficacy was evaluated by lymphocyte proliferation and DTH tests, challenge with live tachyzoites, IFN-γ production by spleen cells, serum TNF-α concentration and anti-Toxoplasma total IgG, IgG1 and IgG2a measurements. Mice of the PRP-TLA group induced significantly more IFN-γ and TNF-α production and lymphocyte proliferation than other groups. This group of mice also showed more anti-T. gondii IgG2a and DTH responses and showed a significantly increased survival time after challenge. These findings indicate that propranolol as an adjuvant in combination with TLA, may enhance cellular immunity against T. gondii.
Immunizing Effects in Mice of two Toxoplasma gondii Iscom Preparations
Journal of Veterinary Medicine Series B-infectious Diseases and Veterinary Public Health, 1988
SummaryTwo Toxoplasma gondii antigen preparations consisting of extracted T. gondii RH strain tachyzoite cell membrane proteins arranged into submicroscopical particles (iscoms) were prepared from organisms propagated in mouse peritoneal cavities (A) and cell culture (B), respectively, and the preparations used as vaccine at two doses of 10 μg and 5 μg protein with 42 days apart. Eight days after the second vaccination, high dye test titres as well as significant delayed-type hypersensitivity reactions (footpad assay) were recorded in mice vaccinated with both preparations used, and the highest dye test titres (> 1:4,096) seen in mice vaccinated with the iscom A preparation. After intraperitoneal challenge on the same day with 104 or 105T. gondii C56 strain tachyzoites, no control mice survived longer than 18 or 10 days, respectively, whereas 40 days after challenge mice vaccinated with the iscom A preparation had accumulated mortality rates of 11% and 37.5%, respectively, and iscom B mice 17% at both challenge doses employed.Two Toxoplasma gondii antigen preparations consisting of extracted T. gondii RH strain tachyzoite cell membrane proteins arranged into submicroscopical particles (iscoms) were prepared from organisms propagated in mouse peritoneal cavities (A) and cell culture (B), respectively, and the preparations used as vaccine at two doses of 10 μg and 5 μg protein with 42 days apart. Eight days after the second vaccination, high dye test titres as well as significant delayed-type hypersensitivity reactions (footpad assay) were recorded in mice vaccinated with both preparations used, and the highest dye test titres (> 1:4,096) seen in mice vaccinated with the iscom A preparation. After intraperitoneal challenge on the same day with 104 or 105T. gondii C56 strain tachyzoites, no control mice survived longer than 18 or 10 days, respectively, whereas 40 days after challenge mice vaccinated with the iscom A preparation had accumulated mortality rates of 11% and 37.5%, respectively, and iscom B mice 17% at both challenge doses employed.ZusammenfassungDie immunisierende Wirkung in Mäusen von zwei Präparaten, hergestellt aus Toxoplasma Gondii und Immunstimulierendem Komplex (ISCOM)Zwei Toxoplasma gondii (Stamm RH)-Antigenpräparate wurden aus T. gondii-Tachyzoiten-Zellmembranproteinen extrahiert und in submikroskopische Partikel (ISCOMS) arrangiert. Die Toxoplasmen wurden im Mäuseperitoneum (A) und in Zellkulturen (B) vermehrt. Die Präparate wurden in zwei Dosen von 10 μg und 5 μg in einem Abstand von 42 Tagen an Mäusen getestet.Acht Tage nach der zweiten Vakzination konnten hohe Färbungstesttiter sowie signifikante DTH-Reaktionen (footpad assay) bei beiden Präparaten nachgewiesen werden, wobei die maximalen Färbungstesttiter (> 1:4,096) in den mit Iscom A-Präparat geimpften Mäusen festgestellt wurden.Ebenfalls acht Tage nach der 2. Vakzination wurden die Mäuse mit 104 bzw. 105T. gondii (Stamm C56)-Tachyzoiten intraperitoneal infiziert, wonach keine der Kontrollmäuse mehr als 18 bzw. 10 Tage überlebte, während 11% bzw. 37,5% von den mit Iscom A-Präparat geimpften Mäusen sowie 17% der mit Iscom B behandelten Mäuse bei beiden Challenge-Dosen bis zum 40. Tag nach der Belastung starben.Die immunisierende Wirkung in Mäusen von zwei Präparaten, hergestellt aus Toxoplasma Gondii und Immunstimulierendem Komplex (ISCOM)Zwei Toxoplasma gondii (Stamm RH)-Antigenpräparate wurden aus T. gondii-Tachyzoiten-Zellmembranproteinen extrahiert und in submikroskopische Partikel (ISCOMS) arrangiert. Die Toxoplasmen wurden im Mäuseperitoneum (A) und in Zellkulturen (B) vermehrt. Die Präparate wurden in zwei Dosen von 10 μg und 5 μg in einem Abstand von 42 Tagen an Mäusen getestet.Acht Tage nach der zweiten Vakzination konnten hohe Färbungstesttiter sowie signifikante DTH-Reaktionen (footpad assay) bei beiden Präparaten nachgewiesen werden, wobei die maximalen Färbungstesttiter (> 1:4,096) in den mit Iscom A-Präparat geimpften Mäusen festgestellt wurden.Ebenfalls acht Tage nach der 2. Vakzination wurden die Mäuse mit 104 bzw. 105T. gondii (Stamm C56)-Tachyzoiten intraperitoneal infiziert, wonach keine der Kontrollmäuse mehr als 18 bzw. 10 Tage überlebte, während 11% bzw. 37,5% von den mit Iscom A-Präparat geimpften Mäusen sowie 17% der mit Iscom B behandelten Mäuse bei beiden Challenge-Dosen bis zum 40. Tag nach der Belastung starben.
Microbiology and Immunology, 2005
Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems to both humans and livestock and of great economic impact worldwide. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote Th1 responses, an adjuvant activity that is desirable for vaccination against intracellular pathogens. We investigated the feasibility of using CpG as an adjuvant combined with Toxoplasma lysate antigen (TLA) as a vaccine against toxoplasmosis. Genetically susceptible C57BL/6 mice were vaccinated with TLA with or without CpG ODN as an adjuvant and then challenged with 85 cysts of the moderately virulent RRA (Beverley) strain of T. gondii. Prior to challenge infection, immunization with TLA plus CpG ODN directed cellular and humoral immunity toward a Th1 pattern, characterized by enhanced INF␥ production by splenic cells in response to TLA, and enhanced production of toxoplasma-specific IgG and IgG2a antibodies. Consequently, CpG/TLA-treated mice showed prolonged survival and 64% reduction in brain parasite burden compared to non-CpG/TLA treated group. Our results suggest that CpG ODN would provide a stable and effective adjuvant for use in vaccination against toxoplasmosis.
Parasitology Research, 2012
Various methods are available for enhancing the potency of DNA vaccines, including employment of different forms of adjuvant. The current study was carried out to evaluate and compare the effects of genetic and non-genetic adjuvants on the immune response stimulated by DNA vaccine. Thus, two adjuvants, IL-12 (genetic adjuvant) and aluminum hydroxide (alum, non-genetic adjuvant), were used with cocktail DNA vaccine containing plasmids encoding complete rhoptry antigen 2 (ROP-2) and surface major antigen 1 (SAG-1) of Toxoplasma gondii. The efficacy of pcROP2+pcSAG1 in stimulation of the immune response against toxoplasmosis with and without adjuvant was evaluated in female BALB/c mice by measuring the level of total IgG antibody and cytokines. The results obtained indicated that after challenging the mice with the fatal RH strain of T. gondii, the survival rates of mice immunized with pcROP2+pcSAG1 (DNA cocktail), pcSAG1+pcROP2+ alum, and pcSAG1+pcROP2+IL-12 were significantly greater than that of the control groups (p<0.05). Moreover, measurement of total IgG antibody indicated the significant difference between the control and experimental groups (p<0.05). Finally, the results obtained by measurement of cytokines (IFN-γ and IL-4) showed high levels of IFN-γ and low levels of IL-4 in groups vaccinated with pcROP2+pcSAG1 (DNA cocktail), pcSAG1+pcROP2+alum, and pcSAG1+pcROP2+IL-12 as the experiment groups, in comparison with the controls groups (PBS, pc-DNA3, alum+PBS, and pCAGGS-IL-12+pcDNA3). The results of the study showed that use of adjuvants (IL-12 and alum) coincident with DNA cocktail leads to significant change in the survival rates of the experiment groups in comparison with control groups. Also, there is no significant difference between adjuvants to induce immune responses.
2018
Received 05 Mar 2017 Accepted 10 Oct 2017 Abstract Background: Toxoplasma gondii is a widely prevalent intracellular protozoan parasite which causes serious clinical and veterinary problems. Development of an effective vaccine for controlling toxoplasmosis is an extremely important aim. In the present study, the protective efficacy of recombinant multiepitope antigen (USM.TOXO1) expressing nine potential epitopes identified from SAG1, GRA2, and GRA7 of Toxoplasma gondii was evaluated in BALB/c mice. Methods: Mice were immunized subcutaneously with three doses of USM.TOXO1 antigen (10 μg/ml). Following the immunization, the IgG antibody, IgG subclass, IFN-γ and IL-4 production were evaluated using ELISA, the study was conducted at Animal Research and Service Center (ARASC), USM Health Campus in 2016. Results: Mice immunized with USM.TOXO1 significantly induced a mixed Th1/Th2 response polarized toward the IgG1 antibody isotype. While the cytokine analysis revealed a significant relea...
Advanced Pharmaceutical Bulletin
Purpose: Propranolol as a novel adjuvant, was used to evaluate the immunogenic effect of threedoses of recombinant SAG-1 (rSAG-1) antigen of Toxoplasma gondii in BALB/c mice for findingthe optimal dose, and was compared with efficacy of tachyzoite lysate antigen (TLA).Methods: Eight different groups of 15 BALB/c mice received different volumes of theimmunogenic material (three doses of r SAG-1 and one dose of TLA antigens), with or withoutpropranolol adjuvant, subcutaneously. The control group mice received only PBS. Three weeksafter the last immunization, the serum levels of IgG2a, IgG1 and IgG total antibodies againstTLA, splenic interleukin-5 (IL-5) and Interferon-gamma (IFN-γ) (produced against TLA) and thesplenic lymphocyte proliferation after adding TLA were measured to evaluate humoral andcellular immune responses. Challenge test was performed by subcutaneously injection of 1000alive and active tachyzoites in to five mice per each group and survival days for each group ofmice...