I am an interdisciplinary and collaborative researcher focused on improving human health and mentoring the next generation of scientists. I have more than 10 years of experience in infectious disease research. I have worked for 9 years on diagnosis and treatment of schistosomiasis following patients in endemic areas in Brazil. As a post-doctorate, my long-term research interests involve the improvement of vaccines with a focus on development of new adjuvant technologies related to infectious diseases (i.e. malaria, influenza, ebola, etc)
Humans make SARS-CoV-2-specific antibodies, CD4+ T cells, and CD8+ T cells in response to infecti... more Humans make SARS-CoV-2-specific antibodies, CD4+ T cells, and CD8+ T cells in response to infection. Neutralizing antibodies are associated with protective immunity against secondary infection and are the mechanism that can provide truly sterilizing immunity. While not necessarily providing sterilizing protection, T cell responses are critical for limiting disease severity and can limit the danger of antibody escape variants by providing for rapid clearance. Thus, studying antibody, memory B cell, CD4+ T cell, and CD8+ T cell memory to SARS-CoV-2 in an integrated manner is important for understanding mechanisms and durability of protective immunity against COVID-19. Here we add SARS-CoV-2-specific memory CD4+ T cells and CD8+ T cells to those efforts with a particular interest in assessing whether pre-existing cross-reactive T cell memory impacts vaccine-generated immunity. We monitored T cell responses in 70 healthy individuals vaccinated with Pfizer–BioNTech mRNA vaccine over 9 mo...
If Schistosoma mansoni infection could be detected in its early stages, especially before the egg... more If Schistosoma mansoni infection could be detected in its early stages, especially before the egg deposition in the host tissues, the development of severe pathologic lesions could be efficiently prevented. We therefore developed an indirect enzyme-linked immunosorbent assay based on the detection of specific IgG against schistosomula antigens (ELISA-SmTeg). The assay was applied in sera samples from non-infected and infected mice collected seven and 15 days post-infection. The results were compared to the number of adult worms obtained by perfusion of the murine hepatic system 50 days post-infection. The sensitivity and specificity of the ELISA-SmTeg were 100% (p = 0.0032 and 0.0048 respectively for seven and 15 days of infection) with a cutoff value of 0.15 (p = 0.0002). Our findings show a novel low-cost serological assay using antigens which are easy to obtain, which was able to detect all the infected mice as early as seven days post-infection.A detecção da infecção pelo helmin...
As of March 2022, there have been over 450 million reported SARS-CoV-2 cases worldwide, and more ... more As of March 2022, there have been over 450 million reported SARS-CoV-2 cases worldwide, and more than 4 billion people have received their primary series of a COVID-19 vaccine. In order to longitudinally track SARS-CoV-2 antibody levels in people after vaccination or infection, a large-scale COVID-19 sero-surveillance progam entitled SPARTA (SeroPrevalence and Respiratory Tract Assessment) was established early in the pandemic. Anti-RBD antibody levels were tracked in more than 1,000 people. There was no significant decrease in antibody levels during the first 14 months after infection in unvaccinated participants, however, significant waning of antibody levels was observed following vaccination, regardless of previous infection status. Moreover, participants who were pre-immune to SARS-CoV-2 prior to vaccination seroconverted to significantly higher antibody levels, and antibodies were maintained at significantly higher levels than in previously infected, unvaccinated participants....
Control constraints of schistosomiasis include the lack of diagnostic methods with high sensitivi... more Control constraints of schistosomiasis include the lack of diagnostic methods with high sensitivity. We develop a prospective study in southeast Brazil to standardize new sensitive diagnostic methods for Schistosoma mansoni infection. Currently, we are investigating 4 endemic areas together with 84 travelers infected in a freshwater pool. Sera, urine and saliva samples from all those patients has been used for the standardization of innovative methods, including acute, chronic, post-treatment and myeloradiculopathy schistosomiasis patients. Comparisons are performed with eggs in feces, IgG titers, encephalomyelitis by NMR and clinical symptoms. We could diagnose acute patients 10 days post-infection and also more than 95% of positive cases from chronic and low endemicity patients. New methods for IgG detection using purified glycoprotein or recombinant protein or peptides of 10 amino acids were superior to conventional ELISA. Best results were seen for recombinant protein with 100% of sensitivity. Finally...
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium... more Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Worldwide Schistosomiasis mansoni continues to be a serious public health problem. Over the past decades, control programmes have made remarkable progress in reducing S. mansoni infections to a relatively low level in Brazil and African countries. Endemic regions are currently circumscribed in certain core areas where reinfection and repeated chemotherapy are frequent and, consequently, are related to residents with low parasite load. At present, diagnosis is predominately a key step for final disease control although low endemicity area residents are hardly detected by most of the available assays. In this paper, we review the current status and efforts made aiming at the improvement of diagnostic tools for S. mansoni in low endemicity infections. The establishment of diagnostic assays—simple, affordable, sensitive, and specific for field ...
Obesity is the largest risk factor for the development of chronic diseases in industrialized coun... more Obesity is the largest risk factor for the development of chronic diseases in industrialized countries. Excessive fat accumulation triggers a state of chronic low-grade inflammation to the detriment of numerous organs. To address this problem, our lab has been examining the anti-inflammatory mechanisms of two human milk oligosaccharides (HMOs), lacto-N-fucopentaose III (LNFPIII) and lacto-N-neotetraose (LNnT). LNFPIII and LNnT are HMOs that differ in structure via presence/absence of an α1,3-linked fucose. We utilize LNFPIII and LNnT in conjugate form, where 10-12 molecules of LNFPIII or LNnT are conjugated to a 40 kDa dextran carrier (P3DEX/NTDEX). Previous studies from our lab have shown that LNFPIII conjugates are anti-inflammatory, act on multiple cell types, and are therapeutic in a wide range of murine inflammatory disease models. The α1,3-linked fucose residue on LNFPIII makes it difficult and more expensive to synthesize. Therefore, we asked if LNnT conjugates induced simila...
BackgroundDespite decades of employment of control programs, schistosomiasis remains a global pub... more BackgroundDespite decades of employment of control programs, schistosomiasis remains a global public health problem. To further reduce prevalence and intensity of infection, or to achieve the goal of elimination in low-endemic areas, there need to be better diagnostic tools to detect low intensity infections in low-endemic areas as Brazil. The rationale for development of new diagnostic tools is because in low-endemic settings, the standard Kato-Katz diagnostic method loses its sensitivity and misses low intensity infections. To develop new diagnostic tools, we employed a proteomics approach search for biomarkers associated with schistosome-specific immune responses to develop sensitive and specific new methods for immunodiagnosis.Methods and findingsImmunoproteomic analysis was performed on an egg extract of Schistosoma mansoni using pooled sera from infected or non-infected individuals from a low-endemic area of Brazil. Cross reactivity with other helminth parasites was determined...
Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most freque... more Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the findings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for specific antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years post-treatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3-6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test ...
Transactions of the Royal Society of Tropical Medicine and Hygiene, Jan 7, 2018
Prior to eliminating schistosomiasis, efforts must address accurate and fast individual diagnosis... more Prior to eliminating schistosomiasis, efforts must address accurate and fast individual diagnosis. Diagnosis is still inaccurate by parasitological and point-of-care circulating cathodic antigen (POC-CCA) in areas of low endemicity. Our group has optimized POC-CCA with a 30 min urine concentration step with no need for specialized technicians or equipment and with high accuracy. We evaluated this new method, called POC-CCA filter (FLT), in two Brazilian endemic areas with distinct profiles. At baseline, POC-CCA had a poor performance with several false results and undefined trace readings, revealing a prevalence rate of 10% against a rate of 23% for POC-CCA FLT, which was similar to the parasitological rates. Accuracy increased from as low as 0.36 to 0.96 after urine concentration in one area. POC-CCA properly diagnosed only half of the cases at three post-treatment time points, while POC-CCA FLT was able to diagnose 96, 83 and 100%, respectively. The improvement of conventional POC...
Revista da Sociedade Brasileira de Medicina Tropical, 2012
INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a ... more INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a tool for the experimental analysis of different phases of the disease. METHODS: Two simple immunological assays for Schistosoma mansoni in mice sera samples based on specific IgG detection for worms soluble antigens and eggs soluble antigens were standardized and evaluated in our laboratory. Fifty mice were used in negative and positive groups and the results obtained by enzyme-linked immunosorbent assays (ELISA) assays were compared with the number of worms counted and the IgG titers at different times of infection. RESULTS: Data showed that ELISA using adult worm antigens (ELISA-SWAP) presented a satisfactory correlation between the absorbance value of IgG titers and the individual number of worms counted after perfusion technique (R²=0.62). In addition, ELISA-SWAP differentially detected positive samples with 30 and 60 days post infection (p=0.011 and 0.003, respectively), whereas ELI...
Revista do Instituto de Medicina Tropical de São Paulo, 2013
If Schistosoma mansoni infection could be detected in its early stages, especially before the egg... more If Schistosoma mansoni infection could be detected in its early stages, especially before the egg deposition in the host tissues, the development of severe pathologic lesions could be efficiently prevented. We therefore developed an indirect enzyme-linked immunosorbent assay based on the detection of specific IgG against schistosomula antigens (ELISA-SmTeg). The assay was applied in sera samples from non-infected and infected mice collected seven and 15 days post-infection. The results were compared to the number of adult worms obtained by perfusion of the murine hepatic system 50 days post-infection. The sensitivity and specificity of the ELISA-SmTeg were 100% (p = 0.0032 and 0.0048 respectively for seven and 15 days of infection) with a cutoff value of 0.15 (p = 0.0002). Our findings show a novel low-cost serological assay using antigens which are easy to obtain, which was able to detect all the infected mice as early as seven days post-infection.
Humans make SARS-CoV-2-specific antibodies, CD4+ T cells, and CD8+ T cells in response to infecti... more Humans make SARS-CoV-2-specific antibodies, CD4+ T cells, and CD8+ T cells in response to infection. Neutralizing antibodies are associated with protective immunity against secondary infection and are the mechanism that can provide truly sterilizing immunity. While not necessarily providing sterilizing protection, T cell responses are critical for limiting disease severity and can limit the danger of antibody escape variants by providing for rapid clearance. Thus, studying antibody, memory B cell, CD4+ T cell, and CD8+ T cell memory to SARS-CoV-2 in an integrated manner is important for understanding mechanisms and durability of protective immunity against COVID-19. Here we add SARS-CoV-2-specific memory CD4+ T cells and CD8+ T cells to those efforts with a particular interest in assessing whether pre-existing cross-reactive T cell memory impacts vaccine-generated immunity. We monitored T cell responses in 70 healthy individuals vaccinated with Pfizer–BioNTech mRNA vaccine over 9 mo...
If Schistosoma mansoni infection could be detected in its early stages, especially before the egg... more If Schistosoma mansoni infection could be detected in its early stages, especially before the egg deposition in the host tissues, the development of severe pathologic lesions could be efficiently prevented. We therefore developed an indirect enzyme-linked immunosorbent assay based on the detection of specific IgG against schistosomula antigens (ELISA-SmTeg). The assay was applied in sera samples from non-infected and infected mice collected seven and 15 days post-infection. The results were compared to the number of adult worms obtained by perfusion of the murine hepatic system 50 days post-infection. The sensitivity and specificity of the ELISA-SmTeg were 100% (p = 0.0032 and 0.0048 respectively for seven and 15 days of infection) with a cutoff value of 0.15 (p = 0.0002). Our findings show a novel low-cost serological assay using antigens which are easy to obtain, which was able to detect all the infected mice as early as seven days post-infection.A detecção da infecção pelo helmin...
As of March 2022, there have been over 450 million reported SARS-CoV-2 cases worldwide, and more ... more As of March 2022, there have been over 450 million reported SARS-CoV-2 cases worldwide, and more than 4 billion people have received their primary series of a COVID-19 vaccine. In order to longitudinally track SARS-CoV-2 antibody levels in people after vaccination or infection, a large-scale COVID-19 sero-surveillance progam entitled SPARTA (SeroPrevalence and Respiratory Tract Assessment) was established early in the pandemic. Anti-RBD antibody levels were tracked in more than 1,000 people. There was no significant decrease in antibody levels during the first 14 months after infection in unvaccinated participants, however, significant waning of antibody levels was observed following vaccination, regardless of previous infection status. Moreover, participants who were pre-immune to SARS-CoV-2 prior to vaccination seroconverted to significantly higher antibody levels, and antibodies were maintained at significantly higher levels than in previously infected, unvaccinated participants....
Control constraints of schistosomiasis include the lack of diagnostic methods with high sensitivi... more Control constraints of schistosomiasis include the lack of diagnostic methods with high sensitivity. We develop a prospective study in southeast Brazil to standardize new sensitive diagnostic methods for Schistosoma mansoni infection. Currently, we are investigating 4 endemic areas together with 84 travelers infected in a freshwater pool. Sera, urine and saliva samples from all those patients has been used for the standardization of innovative methods, including acute, chronic, post-treatment and myeloradiculopathy schistosomiasis patients. Comparisons are performed with eggs in feces, IgG titers, encephalomyelitis by NMR and clinical symptoms. We could diagnose acute patients 10 days post-infection and also more than 95% of positive cases from chronic and low endemicity patients. New methods for IgG detection using purified glycoprotein or recombinant protein or peptides of 10 amino acids were superior to conventional ELISA. Best results were seen for recombinant protein with 100% of sensitivity. Finally...
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium... more Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Worldwide Schistosomiasis mansoni continues to be a serious public health problem. Over the past decades, control programmes have made remarkable progress in reducing S. mansoni infections to a relatively low level in Brazil and African countries. Endemic regions are currently circumscribed in certain core areas where reinfection and repeated chemotherapy are frequent and, consequently, are related to residents with low parasite load. At present, diagnosis is predominately a key step for final disease control although low endemicity area residents are hardly detected by most of the available assays. In this paper, we review the current status and efforts made aiming at the improvement of diagnostic tools for S. mansoni in low endemicity infections. The establishment of diagnostic assays—simple, affordable, sensitive, and specific for field ...
Obesity is the largest risk factor for the development of chronic diseases in industrialized coun... more Obesity is the largest risk factor for the development of chronic diseases in industrialized countries. Excessive fat accumulation triggers a state of chronic low-grade inflammation to the detriment of numerous organs. To address this problem, our lab has been examining the anti-inflammatory mechanisms of two human milk oligosaccharides (HMOs), lacto-N-fucopentaose III (LNFPIII) and lacto-N-neotetraose (LNnT). LNFPIII and LNnT are HMOs that differ in structure via presence/absence of an α1,3-linked fucose. We utilize LNFPIII and LNnT in conjugate form, where 10-12 molecules of LNFPIII or LNnT are conjugated to a 40 kDa dextran carrier (P3DEX/NTDEX). Previous studies from our lab have shown that LNFPIII conjugates are anti-inflammatory, act on multiple cell types, and are therapeutic in a wide range of murine inflammatory disease models. The α1,3-linked fucose residue on LNFPIII makes it difficult and more expensive to synthesize. Therefore, we asked if LNnT conjugates induced simila...
BackgroundDespite decades of employment of control programs, schistosomiasis remains a global pub... more BackgroundDespite decades of employment of control programs, schistosomiasis remains a global public health problem. To further reduce prevalence and intensity of infection, or to achieve the goal of elimination in low-endemic areas, there need to be better diagnostic tools to detect low intensity infections in low-endemic areas as Brazil. The rationale for development of new diagnostic tools is because in low-endemic settings, the standard Kato-Katz diagnostic method loses its sensitivity and misses low intensity infections. To develop new diagnostic tools, we employed a proteomics approach search for biomarkers associated with schistosome-specific immune responses to develop sensitive and specific new methods for immunodiagnosis.Methods and findingsImmunoproteomic analysis was performed on an egg extract of Schistosoma mansoni using pooled sera from infected or non-infected individuals from a low-endemic area of Brazil. Cross reactivity with other helminth parasites was determined...
Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most freque... more Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the findings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for specific antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years post-treatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3-6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test ...
Transactions of the Royal Society of Tropical Medicine and Hygiene, Jan 7, 2018
Prior to eliminating schistosomiasis, efforts must address accurate and fast individual diagnosis... more Prior to eliminating schistosomiasis, efforts must address accurate and fast individual diagnosis. Diagnosis is still inaccurate by parasitological and point-of-care circulating cathodic antigen (POC-CCA) in areas of low endemicity. Our group has optimized POC-CCA with a 30 min urine concentration step with no need for specialized technicians or equipment and with high accuracy. We evaluated this new method, called POC-CCA filter (FLT), in two Brazilian endemic areas with distinct profiles. At baseline, POC-CCA had a poor performance with several false results and undefined trace readings, revealing a prevalence rate of 10% against a rate of 23% for POC-CCA FLT, which was similar to the parasitological rates. Accuracy increased from as low as 0.36 to 0.96 after urine concentration in one area. POC-CCA properly diagnosed only half of the cases at three post-treatment time points, while POC-CCA FLT was able to diagnose 96, 83 and 100%, respectively. The improvement of conventional POC...
Revista da Sociedade Brasileira de Medicina Tropical, 2012
INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a ... more INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a tool for the experimental analysis of different phases of the disease. METHODS: Two simple immunological assays for Schistosoma mansoni in mice sera samples based on specific IgG detection for worms soluble antigens and eggs soluble antigens were standardized and evaluated in our laboratory. Fifty mice were used in negative and positive groups and the results obtained by enzyme-linked immunosorbent assays (ELISA) assays were compared with the number of worms counted and the IgG titers at different times of infection. RESULTS: Data showed that ELISA using adult worm antigens (ELISA-SWAP) presented a satisfactory correlation between the absorbance value of IgG titers and the individual number of worms counted after perfusion technique (R²=0.62). In addition, ELISA-SWAP differentially detected positive samples with 30 and 60 days post infection (p=0.011 and 0.003, respectively), whereas ELI...
Revista do Instituto de Medicina Tropical de São Paulo, 2013
If Schistosoma mansoni infection could be detected in its early stages, especially before the egg... more If Schistosoma mansoni infection could be detected in its early stages, especially before the egg deposition in the host tissues, the development of severe pathologic lesions could be efficiently prevented. We therefore developed an indirect enzyme-linked immunosorbent assay based on the detection of specific IgG against schistosomula antigens (ELISA-SmTeg). The assay was applied in sera samples from non-infected and infected mice collected seven and 15 days post-infection. The results were compared to the number of adult worms obtained by perfusion of the murine hepatic system 50 days post-infection. The sensitivity and specificity of the ELISA-SmTeg were 100% (p = 0.0032 and 0.0048 respectively for seven and 15 days of infection) with a cutoff value of 0.15 (p = 0.0002). Our findings show a novel low-cost serological assay using antigens which are easy to obtain, which was able to detect all the infected mice as early as seven days post-infection.
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