Alexandre Reis

Publications (60) View all

• Source

  Available from: Alexandre Reis

  Article: An assessment on epitope prediction methods for protozoa genomes.

  Daniela M Resende, Antônio M Rezende, Nesley Jd Oliveira, Izabella Ca Batista, Rodrigo Corrêa-Oliveira, Alexandre B Reis, Jeronimo C Ruiz
  [show abstract] [hide abstract]
  ABSTRACT: BACKGROUND: Epitope prediction using computational methods represents one of the most promising approaches to vaccine development. Reduction of time, cost, and the availability of completely sequenced genomes are key points and highly motivating regarding the use of reverse vaccinology. Parasites of genus Leishmania are widely spread and they are the etiologic agents of leishmaniasis. Currently, there is no efficient vaccine against this pathogen and the drug treatment is highly toxic. The lack of sufficiently large datasets of experimentally validated parasites epitopes represents a serious limitation, especially for trypanomatids genomes. In this work we highlight the predictive performances of several algorithms that were evaluated through the development of a MySQL database built with the purpose of: a) evaluating individual algorithms prediction performances and their combination for CD8+ T cell epitopes, B-cell epitopes and subcellular localization by means of AUC (Area Under Curve) performance and a threshold dependent method that employs a confusion matrix; b) integrating data from experimentally validated and in silico predicted epitopes; and c) integrating the subcellular localization predictions and experimental data. NetCTL, NetMHC, BepiPred, BCPred12, and AAP12 algorithms were used for in silico epitope prediction and WoLF PSORT, Sigcleave and TargetP for in silico subcellular localization prediction against trypanosomatid genomes. RESULTS: A database-driven epitope prediction method was developed with built-in functions that were capable of: a) removing experimental data redundancy; b) parsing algorithms predictions and storage experimental validated and predict data; and c) evaluating algorithm performances. Results show that a better performance is achieved when the combined prediction is considered. This is particularly true for B cell epitope predictors, where the combined prediction of AAP12 and BCPred12 reached an AUC value of 0.77. For T CD8+ epitope predictors, the combined prediction of NetCTL and NetMHC reached an AUC value of 0.64. Finally, regarding the subcellular localization prediction, the best performance is achieved when the combined prediction of Sigcleave, TargetP and WoLF PSORT is used. CONCLUSIONS: Our study indicates that the combination of B cells epitope predictors is the best tool for predicting epitopes on protozoan parasites proteins. Regarding subcellular localization, the best result was obtained when the three algorithms predictions were combined. The developed pipeline is available upon request to authors.
  BMC Bioinformatics 11/2012; 13(1):309. · 2.75 Impact Factor
• Source

  Available from: Alexandre Reis

  Article: Higher expression of CCL2, CCL4, CCL5, CCL21, and CXCL8 chemokines in the skin associated with parasite density in canine visceral leishmaniasis.

  Daniel Menezes-Souza, Renata Guerra-Sá, Cláudia Martins Carneiro, Juliana Vitoriano-Souza, Rodolfo Cordeiro Giunchetti, Andréa Teixeira-Carvalho, Denise Silveira-Lemos, Guilherme Corrêa Oliveira, Rodrigo Corrêa-Oliveira, Alexandre Barbosa Reis
  [show abstract] [hide abstract]
  ABSTRACT: The immune response in the skin of dogs infected with Leishmania infantum is poorly understood, and limited studies have described the immunopathological profile with regard to distinct levels of tissue parasitism and the clinical progression of canine visceral leishmaniasis (CVL). A detailed analysis of inflammatory cells (neutrophils, eosinophils, mast cells, lymphocytes, and macrophages) as well as the expression of chemokines (CCL2, CCL4, CCL5, CCL13, CCL17, CCL21, CCL24, and CXCL8) was carried out in dermis skin samples from 35 dogs that were naturally infected with L. infantum. The analysis was based on real-time polymerase chain reaction (PCR) in the context of skin parasitism and the clinical status of CVL. We demonstrated increased inflammatory infiltrate composed mainly of mononuclear cells in the skin of animals with severe forms of CVL and high parasite density. Analysis of the inflammatory cell profile of the skin revealed an increase in the number of macrophages and reductions in lymphocytes, eosinophils, and mast cells that correlated with clinical progression of the disease. Additionally, enhanced parasite density was correlated with an increase in macrophages and decreases in eosinophils and mast cells. The chemokine mRNA expression demonstrated that enhanced parasite density was positively correlated with the expression of CCL2, CCL4, CCL5, CCL21, and CXCL8. In contrast, there was a negative correlation between parasite density and CCL24 expression. These findings represent an advance in the knowledge about skin inflammatory infiltrates in CVL and the systemic consequences. Additionally, the findings may contribute to the design of new and more efficient prophylactic tools and immunological therapies against CVL.
  PLoS Neglected Tropical Diseases 04/2012; 6(4):e1566. · 4.69 Impact Factor
• Source

  Available from: Juliana Vitoriano-Souza

  Article: Cell recruitment and cytokines in skin mice sensitized with the vaccine adjuvants: saponin, incomplete Freund's adjuvant, and monophosphoryl lipid A.

  Juliana Vitoriano-Souza, Nádia das Dores Moreira, Andréa Teixeira-Carvalho, Cláudia Martins Carneiro, Fernando Augusto Mathias Siqueira, Paula Melo de Abreu Vieira, Rodolfo Cordeiro Giunchetti, Sandra Aparecida de Lima Moura, Ricardo Toshio Fujiwara, Maria Norma Melo, Alexandre Barbosa Reis
  [show abstract] [hide abstract]
  ABSTRACT: Vaccine adjuvants are substances associated with antigens that are fundamental to the formation of an intense, durable, and fast immune response. In this context, the use of vaccine adjuvants to generate an effective cellular immune response is crucial for the design and development of vaccines against visceral leishmaniasis. The objective of this study was to evaluate innate inflammatory response induced by the vaccine adjuvants saponin (SAP), incomplete Freund's adjuvant (IFA), and monophosphoryl lipid A (MPL). After a single dose of adjuvant was injected into the skin of mice, we analyzed inflammatory reaction, selective cell migration, and cytokine production at the injection site, and inflammatory cell influx in the peripheral blood. We found that all vaccine adjuvants were able to promote cell recruitment to the site without tissue damage. In addition, they induced selective migration of neutrophils, macrophages, and lymphocytes. The influx of neutrophils was notable at 12 h in all groups, but at other time points it was most evident after inoculation with SAP. With regard to cytokines, the SAP led to production of interleukin (IL)-2, IL-6, and IL-4. IFA promoted production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, IL-17, IL-4, and IL-10. We also observed that MPL induced high production of IL-2, TNF-α, and IFN-γ, in addition to IL-6, IL-17, and IL-10. In peripheral blood, values of certain cell populations in the local response changed after stimulation. Our data demonstrate that the three vaccine adjuvants stimulate the early events of innate immune response at the injection site, suggesting their ability to increase the immunogenicity of co-administered antigens. Moreover, this work provides relevant information about elements of innate and acquired immune response induced by vaccine adjuvants administered alone.
  PLoS ONE 01/2012; 7(7):e40745. · 4.09 Impact Factor
• Source

  Available from: Juliana Vitoriano-Souza

  Article: Parasite Burden in Hamsters Infected with Two Different Strains of Leishmania (Leishmania) infantum: "Leishman Donovan Units" versus Real-Time PCR.

  Nádia das Dores Moreira, Juliana Vitoriano-Souza, Bruno Mendes Roatt, Paula Melo de Abreu Vieira, Henrique Gama Ker, Jamille Mirelle de Oliveira Cardoso, Rodolfo Cordeiro Giunchetti, Cláudia Martins Carneiro, Marta de Lana, Alexandre Barbosa Reis
  [show abstract] [hide abstract]
  ABSTRACT: To develop and test new therapeutics and immune prophylaxis strategies for visceral leishmaniasis (VL), understanding tissue parasitism evolution after experimental infection with Leishmania infantum is important. Experimental infection in a hamster model (Mesocricetus auratus) reproduces several typical aspects of canine and human VL that are closely related to the inoculum's route. We quantified the parasitism in the liver and spleen of hamsters experimentally infected by various routes (intradermal, intraperitoneal, and intracardiac [IC]) and different strains of L. infantum (MHOM/BR/74/PP75 and Wild) and compared two different methodologies to evaluate tissue parasitism (Leishman Donovan units [LDU] and real-time qPCR). In addition, the quantification of specific total-IgG in the serum of uninfected and infected hamsters was determined by ELISA. The animals were followed for 1, 3, 6 and 9 months post-infection for survival analysis. We found that infection with the Wild strain by the IC route resulted in higher mortality. Positive antibody (IgG) responses were detected with higher peaks at 6 and 9 months in the IC group inoculated with PP75 strain. However, in animals infected with the Wild strain the IgG levels were elevated in all infected groups during all the time evaluated. We also observed by LDU analysis that the IC route lead to higher parasitism in the liver and spleen with both strains. Furthermore, qPCR showed higher sensitivity for identifying animals with low parasitic burden. In conclusion, qPCR can be useful for assessing parasitism in the spleen and liver of a hamster model infected with L. infantum independent of the route of infection, and this technique may become an essential tool for assessing parasite density in the hamster model after experimental treatment or immunization with potential vaccine candidates.
  PLoS ONE 01/2012; 7(10):e47907. · 4.09 Impact Factor
• Source

  Available from: Alexandre Reis

  Article: Trypanosoma cruzi: Serum levels of nitric oxide and expression of inducible nitric oxide synthase in myocardium and spleen of dogs in the acute stage of infection with metacyclic or blood trypomastigotes.

  Paula Melo de Abreu Vieira, Amanda Fortes Francisco, Sheler Martins de Souza, Luiz Cosme Cotta Malaquias, Alexandre Barbosa Reis, Rodolfo Cordeiro Giunchetti, Vanja Maria Veloso, Marta de Lana, Washington Luiz Tafuri, Cláudia Martins Carneiro
  [show abstract] [hide abstract]
  ABSTRACT: The participation of nitric oxide (NO) in the control of blood parasitemia and parasitism during the acute phase of infection in dogs inoculated with blood trypomastigotes (BT) or metacyclic trypomastigotes (MT group) of Berenice-78 Trypanosoma cruzi strain has been evaluated. Animals of the MT group (n=4) presented increased levels of serum NO throughout the infection when compared with the BT (n=4) or control (n=4) groups, and a delay in parasitemia peak compared with the BT group. In spleen fragments, tissue parasitism was not observed but the MT group presented larger areas associated with inducible NO synthase (iNOS) in relation to BT and control groups. Heart fragments of MT-infected animals exhibited comparatively low tissue parasitism and high iNOS expression, while animals of the BT group presented high inflammatory infiltrate, high tissue parasitism and low iNOS expression. These results indicate that the source of inoculum can interfere with the development of the acute phase of Chagas disease, and may also trigger a distinct parasite-host interaction during this phase.
  Experimental Parasitology 11/2008; 121(1):76-82. · 2.12 Impact Factor