PRISCILLA RAMOS COSTA
Projetos de Pesquisa
Unidades Organizacionais
LIM/60 - Laboratório de Imunologia Clínica e Alergia, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- Low-Cost Ultra-Wide Genotyping Using Roche/454 Pyrosequencing for Surveillance of HIV Drug Resistance(2012) DUDLEY, Dawn M.; CHIN, Emily N.; BIMBER, Benjamin N.; SANABANI, Sabri S.; TAROSSO, Leandro F.; COSTA, Priscilla R.; SAUER, Mariana M.; KALLAS, Esper G.; O'CONNOR, David H.Background: Great efforts have been made to increase accessibility of HIV antiretroviral therapy (ART) in low and middle-income countries. The threat of wide-scale emergence of drug resistance could severely hamper ART scale-up efforts. Population-based surveillance of transmitted HIV drug resistance ensures the use of appropriate first-line regimens to maximize efficacy of ART programs where drug options are limited. However, traditional HIV genotyping is extremely expensive, providing a cost barrier to wide-scale and frequent HIV drug resistance surveillance. Methods/Results: We have developed a low-cost laboratory-scale next-generation sequencing-based genotyping method to monitor drug resistance. We designed primers specifically to amplify protease and reverse transcriptase from Brazilian HIV subtypes and developed a multiplexing scheme using multiplex identifier tags to minimize cost while providing more robust data than traditional genotyping techniques. Using this approach, we characterized drug resistance from plasma in 81 HIV infected individuals collected in Sao Paulo, Brazil. We describe the complexities of analyzing next-generation sequencing data and present a simplified open-source workflow to analyze drug resistance data. From this data, we identified drug resistance mutations in 20% of treatment naive individuals in our cohort, which is similar to frequencies identified using traditional genotyping in Brazilian patient samples. Conclusion: The developed ultra-wide sequencing approach described here allows multiplexing of at least 48 patient samples per sequencing run, 4 times more than the current genotyping method. This method is also 4-fold more sensitive (5% minimal detection frequency vs. 20%) at a cost 3-5 x less than the traditional Sanger-based genotyping method. Lastly, by using a benchtop next-generation sequencer (Roche/454 GS Junior), this approach can be more easily implemented in low-resource settings. This data provides proof-of-concept that next-generation HIV drug resistance genotyping is a feasible and low-cost alternative to current genotyping methods and may be particularly beneficial for in-country surveillance of transmitted drug resistance.
- Frequency of subtype B and F1 dual infection in HIV-1 positive, Brazilian men who have sex with men(2012) OLIVEIRA, Ana Carolina Soares de; FARIAS, Rodrigo Pessoa de; COSTA, Antonio Charlys da; SAUER, Mariana Melillo; BASSICHETTO, Katia Cristina; OLIVEIRA, Solange Maria Santos; COSTA, Priscilla Ramos; TOMIYAMA, Claudia; TOMIYAMA, Helena Tomoko Iwashita; SABINO, Ester Cerdeira; KALLAS, Esper Georges; SANABANI, Sabri SaeedBackground: Because various HIV vaccination studies are in progress, it is important to understand how often inter- and intra-subtype co/superinfection occurs in different HIV-infected high-risk groups. This knowledge would aid in the development of future prevention programs. In this cross-sectional study, we report the frequency of subtype B and F1 co-infection in a clinical group of 41 recently HIV-1 infected men who have sex with men (MSM) in Sao Paulo, Brazil. Methodology: Proviral HIV-1 DNA was isolated from subject's peripheral blood polymorphonuclear leukocytes that were obtained at the time of enrollment. Each subject was known to be infected with a subtype B virus as determined in a previous study. A small fragment of the integrase gene (nucleotide 4255-4478 of HXB2) was amplified by nested polymerase chain reaction (PCR) using subclade F1 specific primers. The PCR results were further confirmed by phylogenetic analysis. Viral load (VL) data were extrapolated from the medical records of each patient. Results: For the 41 samples from MSM who were recently infected with subtype B virus, it was possible to detect subclade F1 proviral DNA in five patients, which represents a co-infection rate of 12.2%. In subjects with dual infection, the median VL was 5.3 x 10(4) copies/ML, whereas in MSM that were infected with only subtype B virus the median VL was 3.8 x 10(4) copies/ML (p > 0.8). Conclusions: This study indicated that subtype B and F1 co-infection occurs frequently within the HIV-positive MSM population as suggested by large number of BF1 recombinant viruses reported in Brazil. This finding will help us track the epidemic and provide support for the development of immunization strategies against the HIV.
- Frequency of subtype B and F1 dual infection in HIV-1 positive, Brazilian men who have sex with men(2012) SANABANI, Sabri Saeed; OLIVEIRA, Ana Carolina Soares de; COSTA, Antonio Charlys da; MELILLO, Mariana; SOLANGE, Sauer Katia Cristina Bassichetto; OLIVEIRA, Maria Santos; COSTA, Priscilla Ramos; TOMIYAMA, Claudia; TOMIYAMA, Helena Tomoko Iwashita; CERDEIRA, Ester; ESPER, Sabino; KAL, Georges
conferenceObject Altered Circulating Follicular Helper T Cell Phenotype and Subset Composition Are Associated with Disease Activity in Patients with Systemic Lupus Erythematosus(2012) HO, Hsi-en; CHOI, Jin Young; BUNIN, Viviane M.; PASOTO, Sandra G.; CARRASCO, Solange; BORBA, Eduardo F.; GONCALVES, Celio R.; COSTA, Priscila R.; KALLAS, Esper G.; BONFA, Eloisa; CRAFT, Joseph E.Background/Purpose: Autoreactive B cells in SLE undergo autoantigen selection, suggesting a requirement for germinal center follicular helper T (Tfh) cells in their maturation. However, evidence for dysregulation of Tfh cells in SLE and their potential contribution to disease remains unclear. Recently, blood CXCR5 CD4 T cells, a heterogeneous pool consisting of functionally distinct Th1-, Th2-, and Th17-like subsets, have been proposed to be the circulating counterpart of Tfh (cTfh) cells. We now ask if changes in cTfh markers or subset composition within blood CXCR5 cells are found in SLE patients, and the extent to which such alterations are associated with B cell and disease activity. Methods: Blood samples from 49 clinically well-characterized SLE patients, 28 Behc ̧et’s disease (BD) patients, and 16 healthy controls were included. Expression of Tfh surface markers (CXCR5; ICOS, inducible T-cell costimulator; PD-1, programmed cell death protein-1), composition of blood CXCR5 subsets, and frequency of plasmablasts were enumerated by flow cytometry. The phenotype of blood CXCR5 subsets was correlated with disease activity, clinical history, and plasmablast expansion. Results: SLE patients had significant expansion of CXCR5 ICOS PD-1 CD4 T cells compared to controls (p 0.001). PD-1, but not ICOS or CXCR5, expression was markedly elevated in CD4 T cells of SLE patients compared to BD patients and healthy controls (p 0.001). PD-1 MFI in CXCR5 cells correlated with SLE disease activity index (SLEDAI; Spearman r 0.43, p 0.03). PD-1 MFI also correlated with expansion of plasmablasts (Spearman r 0.34, p 0.02). In SLE patients with high anti-dsDNA antibody titers, PD-1 expression in CXCR5cells was also significantly elevated compared to patients with no detectable titers (p 0.004). Enhanced PD-1 expression was neither a function of disease duration nor past activity; rather, it reflected current disease activity. Compared to BD patients, SLE patients also had an increase in the CXCR5 Th2 (p 0.05) and a decrease in the Th17 (p 0.001) subsets. Concurrently, PD-1 expression in SLE patients was significantly higher in CXCR5 Th2 cells compared to Th17 cells (p 0.01). The expansion of the CXCR5 Th2 subset was also positively associated with SLEDAI scores. Conclusion: Our results demonstrate that dysregulation of cTfh cells is strongly correlated with disease activity in SLE, supporting a potential causal relationship. The altered composition of blood CXCR5 cells also appeared to be a fundamental cellular defect in SLE, with our results revealing a novel dimension of Tfh dysregulation that may be central to disease pathogenesis.