Toxoplasma Proteins Recognized by Protective T Lymphocytes

Fischer, Hans; Reichmann, Gaby; Hadding, U.

doi:10.1007/978-3-642-51014-4_16

Cited by 7 publications

(8 citation statements)

References 20 publications

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“…Herein, ROP2 protein was chosen because it is the major protein involved in the biogenesis and maintenance of rhoptry structure, parasite invasion, replication and host cell interaction (NAKAAR et al, 2003); it has been observed in all subgroups (I, II, and III) and stages of the life of the parasite (FISCHER et al, 1996). Additionally, ROP2 was recognized by a human T-cell clone isolated from an immune donor specifically for the parasite and produced high levels of IFN-γ (SAAVEDRA et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats

Zulpo

Igarashi

Sammi

et al. 2017

Rev. Bras. Parasitol. Vet.

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The aim of the present study was to evaluate oocyst shedding in cats immunized by nasal route with T. gondii proteins ROP2. Twelve short hair cats (Felis catus) were divided in three groups G1, G2 and G3 (n=4). Animals from G1 received 100 μg of rROP2 proteins plus 20 μg of Quil-A, G2 received 100 μg of BSA plus 20 μg of Quil-A, and the G3 only saline solution (control group). All treatments were done by intranasal route at days 0, 21, 42, and 63. The challenge was performed in all groups on day 70 with ≅ 800 tissue cysts of ME-49 strain by oral route. Animals from G1 shed less oocysts (86.7%) than control groups. ELISA was used to detect anti-rROP2 IgG and IgA, however, there were no correlation between number of oocyst shedding by either IgG or IgA antibody levels. In the present work, in spite of lesser oocysts production in immunized group than control groups, it was not possible to associate the use of rROP2 via nostrils with protection against oocyst shedding. For the future, the use of either other recombinant proteins or DNA vaccine, in combination with rROP2 could be tested to try improving the efficacy of this kind of vaccine.

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Section: Discussionmentioning

confidence: 99%

rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats

Zulpo

Igarashi

Sammi

et al. 2017

Rev. Bras. Parasitol. Vet.

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“…In our laboratory a panel of T. gondii-specific murine CD4 + T cell clones has been established to analyse target molecules in different intraspecies subgroups and parasite stages (Fischer et al 1996). Two clones were found to detect antigens/epitopes of restricted expression patterns: while clone 3Tx11 reacts only with strains belonging to group I (Fischer et al 1996), the present study demonstrates clone 3Tx9 to be stimulated only by tachyzoites irrespective of their intraspecies origin. Detailed analyses of the corresponding antigen provide evidence for a new tachyzoite marker of 60 kD defined by clone 3Tx9.…”

Section: Introductionmentioning

confidence: 57%

“…Isolated T cells have been used as tools to determine relevant parasite antigens. So far, five Toxoplasma proteins-the major surface antigen SAG1, the rhoptry protein ROP2, and the dense granule antigens GRA1, GRA2, and GRA4-have been identified as T cell-stimulatory antigens (for review see Fischer, Reichmann & Hadding 1996). These antigens have been originally prepared from Toxoplasma strains of the first intraspecies subgroup comprising mouse-virulent isolates.…”

Section: Introductionmentioning

confidence: 99%

Murine Th1 clone defines a 60 kD tachyzoite antigen of Toxoplasma gondii

Reichmann

Długońska

Fischer

1997

Parasite Immunology

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Toxoplasma gondii-specific murine CD4+ T cell clone 3Tx9 belongs to the Th1 subtype by virtue of secreting high levels of interleukin(IL)-2, interferon-gamma and tumor necrosis factor without producing IL4 and IL10. To characterize the clonal antigen, Toxoplasma lysate-was separated by SDS-PAGE and probed in T cell blot analysis with 3Tx9 T cells, revealing a fraction of about 60 kD molecular weight. This fraction proved highly stimulatory also for CD4+ splenocytes isolated from infected mice. The expression pattern of the relevant 60 kD antigen was determined by challenge of clone 3Tx9 with T. gondii strains from all three intraspecies subgroups and tachyzoites versus bradyzoites isolated from two strains as a source of antigen. While the T cell clone reacted with tachyzoites of all strains tested, bradyzoites lacked antigenic activity. Parallel T cell blot and ELISA confirmed co-migration of the T cell-stimulatory antigen p60 and rhoptry proteins ROP1, ROP2,3,4, and ROP5 among which ROP1 is a molecule of similar size and has only been shown on tachyzoites. However, a ROP1 knock-out Toxoplasma mutant still had antigen activity for 3Tx9 T cells. Since the two known tachyzoite-specific proteins, surface antigens SAG1/p30 and SAG2/p22, have a much lower molecular weight, we suggest that p60 represents a new T. gondii tachyzoite marker which is defined by clone 3Tx9.

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“…The toxoplasma antigens GRA1/p23 and GRA2/p28 have been shown to be recognized by T lymphocytes from infected rodents. The third immunodominant molecular mass range (36 -40 kDa) contains p40, a new T cell-stimulatory T. gondii excretory protein recently described (for review [6]). …”

Section: Discussionmentioning

confidence: 99%

“…Each result represents more than 95% cells staining positive. Data for clones 3TxS, 3Tx11 and 3Tx14 are derived from [6] CD4 T cell clones analyzed exhibit a typical Th1 profile, secreting high activities of IFN-γ and TNF without producing IL-4 or IL-10. Except for clone 4Tx12, which lacked IL-2 production, these Th1 clones also released reasonable activities of IL-2.…”

Section: Usage Of Tcr Vα and Vβ Chains By T Gondii-reactive Cd4 + T mentioning

confidence: 99%

T cell receptor specificities of Toxoplasma gondii-reactive mouse CD4 + T lymphocytes and Th1 clones

Reichmann

Długońska²,

Fischer³

1997

Medical Microbiology and Immunology

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The Toxoplasma gondii-directed CD4+ T cell response in chronically infected mice was studied with respect to both T cell receptor diversity and antigen specificities. T cell receptor chains V beta 4, 6, 8, 10, and 14 were predominantly found on toxoplasma-reactive CD4+ splenocytes. This repertoire was also detected among T. gondii-specific CD4+ T cell clones. Analysis of clonotypic cytokine profiles revealed typical Th1 clones secreting interleukin-2, interferon-gamma and tumour necrosis factor activity and Th2 clones producing interleukin-4 and interleukin-10. Five distinct toxoplasma antigens (p26, p40, p55, p58 and p60) were detected in electrophoretically separated toxoplasma lysate by five individual Th1 clones. Parallel testing of CD4+ T lymphocytes from infected mice confirmed that these specificities constitute the peak immunogenic fractions of toxoplasma lysate. The expression patterns of two clonotypic, T cell-stimulatory parasite antigens were studied in detail. While p55 was expressed by mouse-virulent and avirulent T. gondii isolates and in both the tachyzoite and bradyzoite stages, p58 was detected only in virulent strains from intraspecies subgroup I. Thus, we describe the heterogeneity of toxoplasmic immunodominant T cell antigens including a 58-kDa group I-restricted molecule which may provide a marker for virulent isolates.

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Toxoplasma Proteins Recognized by Protective T Lymphocytes

Cited by 7 publications

References 20 publications

rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats

rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats

Murine Th1 clone defines a 60 kD tachyzoite antigen of Toxoplasma gondii

T cell receptor specificities of Toxoplasma gondii-reactive mouse CD4 + T lymphocytes and Th1 clones

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