Recombinant canine adenovirus type-2 expressing TgROP16 provides partial protection against acute Toxoplasma gondii infection in mice

Li, Xiuzhen; Lv, Lin; Anchang, Kenneth Yongabi; Abdullahi, A. Y.; Tu, Liqing; Wang, Xiaohu; Xia, Lijun; Zhang, Xiu‐Xiang; Feng, Weili; Lu, Chong‐Dao; Li, Shoujun; Yuan, Zihao

doi:10.1016/j.meegid.2016.10.006

Cited by 11 publications

(13 citation statements)

References 42 publications

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“…Since Toxoplasma is an obligatory intracellular protozoa, the use of live, attenuated vectors (bacteria or viruses) as vehicles to deliver and express the parasite antigen, can mimic the intracellular niche of T. gondii [1983]. It has been shown that this immunization strategy against T. gondii infection capable to provoke a strong humoral and cell mediated immune responses lead to high protection or complete protection in some studies, because of its intrinsic adjuvant properties and/or mimicry of a natural infection [147150151152153154]. These vaccine types can also be administered intramuscularly, intraoral, intranasal, subcutaneous, and intravenous and induce effective immune responses and protection in terms of enhancing the survival time and/or reduce the brain cyst burden [146147].…”

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

“…For example, it has been reported that adenoviral vectors are safe and efficient for transgene expression in vivo as well as having intrinsic adjuvant properties which lead to activation the innate immune response through TLRs and nod-like receptors [160161]. Adenoviruses (Ad) are considered as popular vaccine vectors and have been used extensively, because of their powerful capability to provokation the T-cell mediated immunity [151152]. Since, there is frequently pre-existing immunity against the classically human adenovirus type 5 (AdHu5), alternatively canine adenovirus type 2 (CAV-2) has been suggested as vectors for human gene transfer [162].…”

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

“…Besides, the use of CAV-2 has the following advantages: well-characterized biology of CAV-2, ease of genetic manipulation, suitable for gene transfer into the central nervous system, able to induce strong protective immunity of humoral and cellular immune responses [152163]. Thus, currently CAV-2 is appointed as one of the most applicable non-human adenoviruses for vaccine vector purposes [151152]. In this case, Li et al (2016) [151] constructed a novel recombinant CAV-2 carrying TgROP16 (CAV-2-ROP16) and then evaluated the immune response and survival status of BALB/c mice.…”

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

“…Thus, currently CAV-2 is appointed as one of the most applicable non-human adenoviruses for vaccine vector purposes [151152]. In this case, Li et al (2016) [151] constructed a novel recombinant CAV-2 carrying TgROP16 (CAV-2-ROP16) and then evaluated the immune response and survival status of BALB/c mice. CAV-2-ROP16 was able to elicit significantly both humoral and cell mediated responses (mixed IgG1 and IgG2a levels with the predominance of IgG2a titers, p<0.05) and increased production of IFN-γ, IL-2, and IL-4 (p<0.05).…”

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

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Rhoptry antigens asToxoplasma gondiivaccine target

Foroutan

Ghaffarifar

Sharifi

et al. 2019

Clin Exp Vaccine Res

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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.

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Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

Section: Vaccines Based On Live-attenuated Vectorsmentioning

confidence: 99%

See 2 more Smart Citations

Rhoptry antigens asToxoplasma gondiivaccine target

Foroutan

Ghaffarifar

Sharifi

et al. 2019

Clin Exp Vaccine Res

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show abstract

“…Adenovirus, which can penetrate host cells delivering vaccine antigen to antigen-presenting cells (APCs) and elicit vigorous and sustained T-cell responses, is a promising T. gondii vaccine vector and can be used effectively to transport immunogens [27]. Recent studies have also found that recombinant canine adenovirus type-2 expressing TgROP16 and TgROP18 provides partial protection against acute T. gondii infection in mice, and indicate that adenovirus vectors may be potentially useful in the development of an effective vaccine against T. gondii infection [21,22]. The mucosal immune system consisting of specialized epithelial cells can trigger both humoral and cell immune responses when antigens are administered with appropriate adjuvants or attenuated live vaccines via mucosal routes (oral, nasal, sublingual, ocular, genital, or rectal) [18,23].…”

Section: Introductionmentioning

confidence: 99%

Vaccination with recombinant adenovirus expressing multi-stage antigens ofToxoplasma gondiiby the mucosal route induces higher systemic cellular and local mucosal immune responses than with other vaccination routes

Wang

Yin

et al. 2017

Parasite

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Toxoplasmosis caused by Toxoplasma gondii, an obligate intracellular protozoan, is a cause of congenital disease and abortion in humans and animals. Various vaccination strategies against toxoplasmosis in rodent models have been used in the past few decades; however, effective vaccines remain a challenge. A recombinant adenovirus vaccine expressing ubiquitin-conjugated multi-stage antigen segments (Ad-UMAS) derived from different life-cycle stages of T. gondii was constructed previously. Here, we compared the immune responses and protection effects in vaccination of mice with Ad-UMAS by five vaccination routes including intramuscular (i.m.), intravenous (i.v.), subcutaneous (s.c.), intraoral (i.o.), and intranasal (i.n.). Much higher levels of T. gondii-specific IgG and IgA antibodies were detected in the sera of the intraoral and intranasal vaccination groups on day 49 compared with controls (p < 0.05). The percentages of CD8+ T-cells in mice immunized intranasally and intraorally were larger than in mice immunized intramuscularly (p < 0.05). The highest level of IL-2 and IFN-γ was detected in the group with nasal immunization, and splenocyte proliferation activity was significantly enhanced in mice immunized via the oral and nasal routes. Furthermore, the higher survival rate (50%) and lower cyst numbers observed in the intraoral and intranasal groups all indicate that Ad-UMAS is far more effective in protecting mice against T. gondii infection via the mucosal route. Ad-UMAS could be an effective and safe mucosal candidate vaccine to protect animals and humans against T. gondii infection.

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