A Plasmodium promiscuous T cell epitope delivered within the Ad5 hexon protein enhances the protective efficacy of a protein based malaria vaccine

A malaria vaccine is a public health priority. In order to produce an effective vaccine, a multistage approach targeting both the blood and the liver stage infection is desirable. The vaccine candidates also need to induce balanced immune responses including antibodies, CD4+ and CD8+ T cells. Protein-based subunit vaccines like RTS,S are able to induce strong antibody response but poor cellular reactivity. Adenoviral vectors have been effective inducing protective CD8+ T cell responses in several models including malaria; nonetheless this vaccine platform exhibits a limited induction of humoral immune responses. Two approaches have been used to improve the humoral immunogenicity of recombinant adenovirus vectors, the use of heterologous prime-boost regimens with recombinant proteins or the genetic modification of the hypervariable regions (HVR) of the capsid protein hexon to express B cell epitopes of interest. In this study, we describe the development of capsid modified Ad5 vectors that express a promiscuous Plasmodium yoelii T helper epitope denominated PyT53 within the hexon HVR2 region. Several regimens were tested in mice to determine the relevance of the hexon modification in enhancing protective immune responses induced by the previously described protein-based multi-stage experimental vaccine PyCMP. A heterologous prime-boost immunization regime that combines a hexon modified vector with transgenic expression of PyCMP followed by protein immunizations resulted in the induction of robust antibody and cellular immune responses in comparison to a similar regimen that includes a vector with unmodified hexon. These differences in immunogenicity translated into a better protective efficacy against both the hepatic and red blood cell stages of P. yoelii. To our knowledge, this is the first time that a hexon modification is used to deliver a promiscuous T cell epitope. Our data support the use of such modification to enhance the immunogenicity and protective efficacy of adenoviral based malaria vaccines

XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot

Induction of Multifunctional Broadly Reactive T Cell Responses by a Plasmodium vivax Circumsporozoite Protein Recombinant Chimera

Submitted by sandra infurna ([email protected]) on 2016-04-07T16:04:21Z No. of bitstreams: 1 joseli_ferreira_etal_IOC_2015.pdf: 1757003 bytes, checksum: 01e448357359440dc4ab90e0cf154025 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-04-07T16:19:25Z (GMT) No. of bitstreams: 1 joseli_ferreira_etal_IOC_2015.pdf: 1757003 bytes, checksum: 01e448357359440dc4ab90e0cf154025 (MD5)Made available in DSpace on 2016-04-07T16:19:25Z (GMT). No. of bitstreams: 1 joseli_ferreira_etal_IOC_2015.pdf: 1757003 bytes, checksum: 01e448357359440dc4ab90e0cf154025 (MD5) Previous issue date: 2015Emory University. Yerkes National Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA.Emory University. Yerkes National Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA.Emory University. Yerkes National Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.University of Massachusetts Medical School. Department of Pathology. Massachusetts, USA.Emory University. Yerkes National Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA / Emory University. Department of Medicine. Division of Infectious Disease. Atlanta, GA, USA.Plasmodium vivax is the most widespread species of Plasmodium, causing up to 50% of the malaria cases occurring outside subSaharan Africa. An effective vaccine is essential for successful control and potential eradication. A well-characterized vaccine candidate is the circumsporozoite protein (CSP). Preclinical and clinical trials have shown that both antibodies and cellular immune responses have been correlated with protection induced by immunization with CSP. On the basis of our reported approach of developing chimeric Plasmodium yoelii proteins to enhance protective efficacy, we designed PvRMC-CSP, a recombinant chimeric protein based on the P. vivax CSP (PvCSP). In this engineered protein, regions of the PvCSP predicted to contain human T cell epitopes were genetically fused to an immunodominant B cell epitope derived from the N-terminal region I and to repeat sequences representing the two types of PvCSP repeats. The chimeric protein was expressed in soluble form with high yield. As the immune response to PvCSP has been reported to be genetically restricted in the murine model, we tested the immunogenicity of PvRMC-CSP in groups of six inbred strains of mice. PvRMC-CSP was able to induce robust antibody responses in all the mouse strains tested. Synthetic peptides representing the allelic forms of the P. vivax CSP were also recognized to a similar extent regardless of the mouse strain. Furthermore, the immunization regimen induced high frequencies of multifunctional CD4 and CD8 PvRMC-CSP-specific T cells. The depth and breadth of the immune responses elicited suggest that immunization with PvRMC-CSP can circumvent the genetic restriction of the immune response to P. vivax CSP. Interestingly, PvRMCCSP was also recognized by naturally acquired antibodies from individuals living in areas where malaria is endemic. These features make PvRMC-CSP a promising vaccine candidate for further development

A chimeric protein-based malaria vaccine candidate induces robust T cell responses against Plasmodium vivax MSP119

Submitted by Sandra Infurna ([email protected]) on 2017-02-15T11:52:59Z No. of bitstreams: 1 joseli_ferreira_etal_IOC_2016.pdf: 1481275 bytes, checksum: 02e9a8a4d01eed2ae485bc039d32a797 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-02-15T12:04:18Z (GMT) No. of bitstreams: 1 joseli_ferreira_etal_IOC_2016.pdf: 1481275 bytes, checksum: 02e9a8a4d01eed2ae485bc039d32a797 (MD5)Made available in DSpace on 2017-02-15T12:04:18Z (GMT). No. of bitstreams: 1 joseli_ferreira_etal_IOC_2016.pdf: 1481275 bytes, checksum: 02e9a8a4d01eed2ae485bc039d32a797 (MD5) Previous issue date: 2016Emory University. YerkesNational Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA / Emory University. Department of Medicine. Division of Infectious Diseases. Atlanta, GA, USA.Emory University. YerkesNational Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA.Emory University. YerkesNational Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ. Brasil.University of Massachusetts Medical School. Department of Pathology. Worcester, MA, USA.Universidad Nacional de Colombia. Department of Pharmacy. Molecular Mimetism of Infectious Agents Unit. Bogotá, Colombia.Emory University. YerkesNational Primate Research Center. Emory Vaccine Center. Atlanta, GA, USA / Emory University. Department of Medicine. Division of Infectious Diseases. Atlanta, GA, USA.The most widespread Plasmodium species, Plasmodium vivax, poses a significant public health threat. An effective vaccine is needed to reduce global malaria burden. Of the erythrocytic stage vaccine candidates, the 19 kDa fragment of the P. vivax Merozoite Surface Protein 1 (PvMSP119) is one of the most promising. Our group has previously defined several promiscuous T helper epitopes within the PvMSP1 protein, with features that allow them to bind multiple MHC class II alleles. We describe here a P. vivax recombinant modular chimera based on MSP1 (PvRMC-MSP1) that includes defined T cell epitopes genetically fused to PvMSP119. This vaccine candidate preserved structural elements of the native PvMSP119 and elicited cytophilic antibody responses, and CD4+ and CD8+ T cells capable of recognizing PvMSP119. Although CD8+ T cells that recognize blood stage antigens have been reported to control blood infection, CD8+ T cell responses induced by P. falciparum or P. vivax vaccine candidates based on MSP119 have not been reported. To our knowledge, this is the first time a protein based subunit vaccine has been able to induce CD8+ T cell against PvMSP119. The PvRMC-MSP1 protein was also recognized by naturally acquired antibodies from individuals living in malaria endemic areas with an antibody profile associated with protection from infection. These features make PvRMC-MSP1 a promising vaccine candidate

Cytokine production in splenocytes induced by the vaccination regimens including Ad5HVR2 modified vectors.

<p>CB6F1/J (n = 5 per group) mice received the regimens described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154819#pone.0154819.g002" target="_blank">Fig 2</a>. Splenocytes were obtained 5 days after the final immunization and were incubated with the PyT53 epitope present in the vector capsid, the PyCMP protein, or peptide pools (15 amino acids long, overlapping be 10 amino acids) representing the PyCMP sequence. After stimulation, cells were intracellularly stained and acquired by flow cytometry, <b>Top.</b> CD8+ T cells able to produce IL-2 <b>(A)</b> IFN-γ <b>(B)</b> and TNF-α <b>(C)</b> after stimulation. <b>Bottom.</b> CD4+ T cells able to produce IL-2 <b>(D)</b> IFN-γ <b>(E)</b> and TNF-α <b>(F)</b> after stimulation. Results were analyzed after background subtraction. Statistical analysis was performed using the Kruskal–Wallis test with Dunn’s post-test, differences between the vaccination groups and the control group are presented *(p<0.05) **(p<0.01) ***(p<0.001).</p

Protection induced by the vaccination regimens including Ad5HVR2 modified vectors.

<p>CB6F1/J (n = 10 per group) mice received the regimens described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154819#pone.0154819.g002" target="_blank">Fig 2</a>. Twenty days after the last immunizations mice were challenged with <i>Plasmodium yoelii</i> sporozoites and the kinetic of parasitemia expressed as an AUC <b>(A)</b> and the pre-patency period <b>(B)</b> were analyzed by Kruskal-Wallis test with Dunns post-test significant statistical differences between the groups are denoted by *(p<0.05) **(p<0.01).</p

Protection induced by the vaccination regimens based on the Ad5HVRT53PyCMP vector.

<p>CB6F1/J (n = 10 per group) mice received the immunization regimens described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154819#pone.0154819.g006" target="_blank">Fig 6</a>. Twenty days after the last immunizations mice were challenged with <i>Plasmodium yoelii</i> sporozoites, the kinetics of parasitemia expressed as an AUC <b>(A)</b> and the pre-patency period <b>(B)</b> were analyzed by Kruskal-Wallis test with Dunns post-test, significant statistical differences between the groups are denoted by *(p<0.05), **(p<0.01).</p

Cytokine production in splenocytes induced by the vaccination regimens based on Ad5HVR2T53PyCMP vectors.

<p>CB6F1/J (n = 5 per group) mice received the regimens described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154819#pone.0154819.g006" target="_blank">Fig 6</a>. Splenocytes were obtained 5 days after the final immunization and were incubated with recombinant <i>P yoelii</i> MSP1 (Black Bars) or CSP (White Bars) proteins or 15 AA overlapping peptide pools representing the PyCMP structure (Grey and Pattern Bars). After stimulation cells were intracellularly stained and acquired by flow cytometry, Results are presented after background subtraction. Top. CD8+ T cells able to produce IL-2 (A) IFN-γ (B) and TNF-α (C) after stimulation. Bottom. CD4+ T cells able to produce IL-2 (D) IFN-γ (E) and TNF-α (F) after stimulation. Differences between the immunization regimens were analyzed by the Mann-Whitney test, significant statistical differences between the groups are denoted by *(p<0.05) **(p<0.01).</p

Immunization regimens tested with hexon modified vectors.

<p>Immunization regimens tested with hexon modified vectors.</p