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Conserved protective mechanisms in radiation and genetically attenuated uis3(-) and uis4(-) Plasmodium sporozoites.

Kumar KA, Baxter P, Tarun AS, Kappe SH, Nussenzweig V - PLoS ONE (2009)

Bottom Line: Immunization with radiation attenuated Plasmodium sporozoites (RAS) elicits sterile protective immunity against sporozoite challenge in murine models and in humans.There were no differences in the immune responses to the circumsporozoite protein (CSP) generated by RAS and GAPs.We conclude that CSP is a powerful protective antigen in both RAS and GAPs viz., uis3(-) and uis4(-) and that the protective mechanisms are similar independently of the method of sporozoite attenuation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Micheal Hidelberg Division of Immunology, New York University School of Medicine, New York, New York, United States of America. kaksl@uohyd.ernet.in

ABSTRACT
Immunization with radiation attenuated Plasmodium sporozoites (RAS) elicits sterile protective immunity against sporozoite challenge in murine models and in humans. Similarly to RAS, the genetically attenuated sporozoites (GAPs) named uis3(-), uis4(-) and P36p(-) have arrested growth during the liver stage development, and generate a powerful protective immune response in mice. We compared the protective mechanisms in P. yoelii RAS, uis3(-) and uis4(-) in BALB/c mice. In RAS and GAPs, sterile immunity is only achieved after one or more booster injections. There were no differences in the immune responses to the circumsporozoite protein (CSP) generated by RAS and GAPs. To evaluate the role of non-CSP T-cell antigens we immunized antibody deficient, CSP-transgenic BALB/c mice, that are T cell tolerant to CSP, with P. yoelii RAS or with uis3(-) or uis4(-) GAPs, and challenged them with wild type sporozoites. In every instance the parasite liver stage burden was approximately 3 logs higher in antibody deficient CSP transgenic mice as compared to antibody deficient mice alone. We conclude that CSP is a powerful protective antigen in both RAS and GAPs viz., uis3(-) and uis4(-) and that the protective mechanisms are similar independently of the method of sporozoite attenuation.

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Protective immune responses are conserved in P. yoelli RAS and uis3(-), uis4(-) GAPs.Comparative analysis of protective immune response in BALB/cAnN mice following priming and boosting with 1×105 P. yoelli RAS or with uis3(-) or with uis4(-) GAPs. All mice were challenged with 1×104 wild type infectious sporozoites and infected livers were isolated 42 hours post infection. (A) Liver stage burden in indicated groups of immunized mice were assessed by measuring the parasite specific 18S rRNA copy numbers by q-RT PCR. (B) CS-specific antibody response in indicated groups of immunized mice. (C) Liver stage burden in mice that received wild type P. yoelli sporozoites following neutralization with sera obtained from naïve or indicated groups of immunized mice. (D) IFN-gamma ELISPOT assay to quantify CS specific T cells from indicated groups of immunized mice. Results are expressed as mean±s.d of CS-specific CD8+ T cells obtained from 5 immunised mice per group. In (A) and (C) results are expressed as mean±s.d of 18S r RNA copy numbers from 5 mice per group.
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pone-0004480-g001: Protective immune responses are conserved in P. yoelli RAS and uis3(-), uis4(-) GAPs.Comparative analysis of protective immune response in BALB/cAnN mice following priming and boosting with 1×105 P. yoelli RAS or with uis3(-) or with uis4(-) GAPs. All mice were challenged with 1×104 wild type infectious sporozoites and infected livers were isolated 42 hours post infection. (A) Liver stage burden in indicated groups of immunized mice were assessed by measuring the parasite specific 18S rRNA copy numbers by q-RT PCR. (B) CS-specific antibody response in indicated groups of immunized mice. (C) Liver stage burden in mice that received wild type P. yoelli sporozoites following neutralization with sera obtained from naïve or indicated groups of immunized mice. (D) IFN-gamma ELISPOT assay to quantify CS specific T cells from indicated groups of immunized mice. Results are expressed as mean±s.d of CS-specific CD8+ T cells obtained from 5 immunised mice per group. In (A) and (C) results are expressed as mean±s.d of 18S r RNA copy numbers from 5 mice per group.

Mentions: Groups of BALB /c mice were primed and boosted 14 days later with 105 P. yoelii RAS, or with 105 P. yoelii uis3(-) or with uis4(-) GAPs. All animals were challenged a week later with 1×104 wild type infectious sporozoites. The liver stage burdens were evaluated by q-RT PCR at 42 hours post infection when the EEFs are mature. We found that the levels of protection elicited by RAS or GAP vaccination were greater than 95% in all groups (Fig 1A). The anti-CSP antibody titers measured by ELISA against the repeat domain of the P. yoelii CSP ranged between 12,500 and 50,000 in all immunized mice (Fig 1B). To compare the neutralizing activity of the antibodies, P. yoelii salivary gland sporozoites were incubated with pooled immune sera from the respective immunized groups and injected into naïve mice and the liver stage burden was evaluated. In every instance the liver stage burdens were 8–9 fold lower than that of sporozoites inoculated with normal mouse serum (Fig 1C). The abundance of interferon-γ producing CD8+ T cells against the H2-Kd CTL epitope of CSP was evaluated by ex-vivo ELISPOT assay. The T cell responses amongst different groups of immunized mice were indistinguishable (Fig 1D). Therefore, irrespective of how the sporozoites were attenuated, the overall immune response of BALB/c mice directed against epitopes in CSP was very similar.


Conserved protective mechanisms in radiation and genetically attenuated uis3(-) and uis4(-) Plasmodium sporozoites.

Kumar KA, Baxter P, Tarun AS, Kappe SH, Nussenzweig V - PLoS ONE (2009)

Protective immune responses are conserved in P. yoelli RAS and uis3(-), uis4(-) GAPs.Comparative analysis of protective immune response in BALB/cAnN mice following priming and boosting with 1×105 P. yoelli RAS or with uis3(-) or with uis4(-) GAPs. All mice were challenged with 1×104 wild type infectious sporozoites and infected livers were isolated 42 hours post infection. (A) Liver stage burden in indicated groups of immunized mice were assessed by measuring the parasite specific 18S rRNA copy numbers by q-RT PCR. (B) CS-specific antibody response in indicated groups of immunized mice. (C) Liver stage burden in mice that received wild type P. yoelli sporozoites following neutralization with sera obtained from naïve or indicated groups of immunized mice. (D) IFN-gamma ELISPOT assay to quantify CS specific T cells from indicated groups of immunized mice. Results are expressed as mean±s.d of CS-specific CD8+ T cells obtained from 5 immunised mice per group. In (A) and (C) results are expressed as mean±s.d of 18S r RNA copy numbers from 5 mice per group.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2637429&req=5

pone-0004480-g001: Protective immune responses are conserved in P. yoelli RAS and uis3(-), uis4(-) GAPs.Comparative analysis of protective immune response in BALB/cAnN mice following priming and boosting with 1×105 P. yoelli RAS or with uis3(-) or with uis4(-) GAPs. All mice were challenged with 1×104 wild type infectious sporozoites and infected livers were isolated 42 hours post infection. (A) Liver stage burden in indicated groups of immunized mice were assessed by measuring the parasite specific 18S rRNA copy numbers by q-RT PCR. (B) CS-specific antibody response in indicated groups of immunized mice. (C) Liver stage burden in mice that received wild type P. yoelli sporozoites following neutralization with sera obtained from naïve or indicated groups of immunized mice. (D) IFN-gamma ELISPOT assay to quantify CS specific T cells from indicated groups of immunized mice. Results are expressed as mean±s.d of CS-specific CD8+ T cells obtained from 5 immunised mice per group. In (A) and (C) results are expressed as mean±s.d of 18S r RNA copy numbers from 5 mice per group.
Mentions: Groups of BALB /c mice were primed and boosted 14 days later with 105 P. yoelii RAS, or with 105 P. yoelii uis3(-) or with uis4(-) GAPs. All animals were challenged a week later with 1×104 wild type infectious sporozoites. The liver stage burdens were evaluated by q-RT PCR at 42 hours post infection when the EEFs are mature. We found that the levels of protection elicited by RAS or GAP vaccination were greater than 95% in all groups (Fig 1A). The anti-CSP antibody titers measured by ELISA against the repeat domain of the P. yoelii CSP ranged between 12,500 and 50,000 in all immunized mice (Fig 1B). To compare the neutralizing activity of the antibodies, P. yoelii salivary gland sporozoites were incubated with pooled immune sera from the respective immunized groups and injected into naïve mice and the liver stage burden was evaluated. In every instance the liver stage burdens were 8–9 fold lower than that of sporozoites inoculated with normal mouse serum (Fig 1C). The abundance of interferon-γ producing CD8+ T cells against the H2-Kd CTL epitope of CSP was evaluated by ex-vivo ELISPOT assay. The T cell responses amongst different groups of immunized mice were indistinguishable (Fig 1D). Therefore, irrespective of how the sporozoites were attenuated, the overall immune response of BALB/c mice directed against epitopes in CSP was very similar.

Bottom Line: Immunization with radiation attenuated Plasmodium sporozoites (RAS) elicits sterile protective immunity against sporozoite challenge in murine models and in humans.There were no differences in the immune responses to the circumsporozoite protein (CSP) generated by RAS and GAPs.We conclude that CSP is a powerful protective antigen in both RAS and GAPs viz., uis3(-) and uis4(-) and that the protective mechanisms are similar independently of the method of sporozoite attenuation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Micheal Hidelberg Division of Immunology, New York University School of Medicine, New York, New York, United States of America. kaksl@uohyd.ernet.in

ABSTRACT
Immunization with radiation attenuated Plasmodium sporozoites (RAS) elicits sterile protective immunity against sporozoite challenge in murine models and in humans. Similarly to RAS, the genetically attenuated sporozoites (GAPs) named uis3(-), uis4(-) and P36p(-) have arrested growth during the liver stage development, and generate a powerful protective immune response in mice. We compared the protective mechanisms in P. yoelii RAS, uis3(-) and uis4(-) in BALB/c mice. In RAS and GAPs, sterile immunity is only achieved after one or more booster injections. There were no differences in the immune responses to the circumsporozoite protein (CSP) generated by RAS and GAPs. To evaluate the role of non-CSP T-cell antigens we immunized antibody deficient, CSP-transgenic BALB/c mice, that are T cell tolerant to CSP, with P. yoelii RAS or with uis3(-) or uis4(-) GAPs, and challenged them with wild type sporozoites. In every instance the parasite liver stage burden was approximately 3 logs higher in antibody deficient CSP transgenic mice as compared to antibody deficient mice alone. We conclude that CSP is a powerful protective antigen in both RAS and GAPs viz., uis3(-) and uis4(-) and that the protective mechanisms are similar independently of the method of sporozoite attenuation.

Show MeSH
Related in: MedlinePlus