Filipe Ferreira de Almeida Rego

HTLV Type 1 Molecular Study in Brazilian Villages with African Characteristics Giving Support to the Post-Columbian Introduction Hypothesis

We performed an HTLV epidemiological study of 986 individuals from 17 villages from the same state of Salvador, the city with the highest HTLV-1 prevalence in Brazil. The HTLV-1 prevalence was 3.85%, 1.56%, and 1.23% in three villages. Phylogenetic analysis of the LTR region demonstrated that all positive samples analyzed belonged to the Transcontinental subgroup of the HTLV-1 Cosmopolitan subtype. Three of the new HTLV-1 sequences formed a well-supported clade within one of the Latin American clusters that contain a South African sequence. This Latin American cluster that segregated from the same ancestor as the other clade contained a Central African sequence. This ancestral relationship could support our previous report that suggests that this subgroup was first introduced into South Africa as a result of the migration of the Bantu population from Central Africa to Southern Africa over the past 3000 years, and afterward to Brazil during the slave trade between the sixteenth and nineteenth centuries.

Seroprevalence and Molecular Epidemiology of HTLV-1 Isolates from HIV-1 Co-Infected Women in Feira de Santana, Bahia, Brazil

HTLV-1/HIV-1 co-infection is associated with severe clinical manifestations, marked immunodeficiency, and opportunistic pathogenic infections, as well as risk behavior. Salvador, the capital of the State of Bahia, Brazil, has the highest HTLV-1 prevalence (1.74%) found in Brazil. Few studies exist which describe this co-infection found in Salvador and its surrounding areas, much less investigate how these viruses circulate or assess the relationship between them. To describe the epidemiological and molecular features of HTLV in HIV co-infected women. To investigate the prevalence of HTLV/HIV co-infection in surrounding areas, as well as the molecular epidemiology of HTLV, a cross sectional study was carried out involving 107 women infected with HIV-1 from the STD/HIV/AIDS Reference Center located in the neighboring City of Feira de Santana. Patient samples were submitted to ELISA, and HTLV infection was confirmed using Western Blot and Polymerase Chain Reaction (PCR). Phylogenetic analysis using Neighbor-Joining (NJ) and Maximum Likelihood (ML) was performed on HTLV LTR sequences in order to gain further insights about molecular epidemiology and the origins of this virus in Bahia. Four out of five reactive samples were confirmed to be infected with HTLV-1, and one with HTLV-2. The seroprevalence of HTLV among HIV-1 co-infected women was 4.7%. Phylogenetic analysis of the LTR region from four HTLV-1 sequences showed that all isolates were clustered into the main Latin American group within the Transcontinental subgroup of the Cosmopolitan subtype. The HTLV-2 sequence was classified as the HTLV-2c subtype. It was also observed that four HTLV/HIV-1 co-infected women exhibited risk behavior with two having parenteral exposure, while another two were sex workers. This article describes the characteristics of co-infected patients. This co-infection is known to be severe and further studies should be conducted to confirm the suggestion that HTLV-1 is spreading from Salvador to surrounding areas.

Oral health profile in patients infected with HTLV‐1: Clinical findings, proviral load, and molecular analysis from HTLV‐1 in saliva

Human T‐lymphotropic virus type 1 (HTLV‐1) is associated with adult T‐cell leukemia (ATL) and HTLV‐1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) and has also been implicated in several disorders, including periodontal disease. The proviral load is an important biological marker for understanding HTLV‐1 pathogenesis and elucidating whether or not the virus is related to the clinical manifestation of the disease. This study describes the oral health profile of HTLV‐1 carriers and HAM/TSP patients in order to investigate the association between the proviral load in saliva and the severity of the periodontal disease and to examine virus intra‐host variations from peripheral blood mononuclear cells and saliva cells. It is a cross‐sectional analytical study of 90 individuals carried out from November 2006 to May 2008. Of the patients, 60 were HTLV‐1 positive and 30 were negative. Individuals from the HTLV‐1 positive and negative groups had similar mean age and social‐economic status. Data were analyzed using two available statistical software packages, STATA 8.0 and SPSS 11.0 to conduct frequency analysis. Differences of P < 0.05 were considered statistically significant. HTLV‐1 patients had poorer oral health status when compared to seronegative individuals. A weak positive correlation between blood and saliva proviral loads was observed. The mean values of proviral load in blood and saliva in patients with HAM/TSP was greater than those in HTLV‐1 carriers. The HTLV‐1 molecular analysis from PBMC and saliva specimens suggests that HTLV‐1 in saliva is due to lymphocyte infiltration from peripheral blood. A direct relationship between the proviral load in saliva and oral manifestations was observed. J. Med. Virol. 84:1428–1436, 2012.

Molecular Epidemiology Database for Sequence Management and Data Mining

A central database to aggregate sequence information from a range of epidemiological aspects including HTLV-1 pathogenesis, origin, and evolutionary dynamic would be useful to scientists and physicians worldwide. This Chapter describes two online tools for studies related to HTLV-1, the HTLV-1 Molecular Epidemiology Database and the HTLV-1 Subtyping Tool. The HTLV-1 Molecular Epidemiology Database is a tool for sequence management and data mining which allows researchers to download sequences with clinical and demographic information. The HTLV-1 Subtyping Tool is an online software used for HTLV-1 genotyping, the algorithm consists in the alignment of a query sequence with a carefully selected set of predefined reference strains, followed by phylogenetic analysis.

HTLV-1aA introduction into Brazil and its association with the trans-Atlantic slave trade

INTRODUCTION Human T-lymphotropic virus (HTLV) is an endemic virus in some parts of the world, with Africa being home to most of the viral genetic diversity. In Brazil, HTLV-1 is endemic amongst Japanese and African immigrant populations. Multiple introductions of the virus in Brazil from other epidemic foci were hypothesized. The long terminal repeat (LTR) region of HTLV-1 was used to infer the origin of the virus in Brazil, using phylogenetic analysis. METHODS LTR sequences were obtained from the HTLV-1 database (http://htlv1db.bahia.fiocruz.br). Sequences were aligned and maximum-likelihood and Bayesian tree topologies were inferred. Brazilian specific clusters were identified and molecular-clock and coalescent models were used to estimate each clusters time to the most recent common ancestor (tMRCA). RESULTS Three Brazilian clusters were identified with a posterior probability ranged from 0.61 to 0.99. Molecular clock analysis of these three clusters dated back their respective tMRCAs between the year 1499 and the year 1668. Additional analysis also identified a close association between Brazilian sequences and new sequences from South Africa. CONCLUSION Our results support the hypothesis of a multiple introductions of HTLV-1 into Brazil, with the majority of introductions occurring in the post-Colombian period. Our results further suggest that HTLV-1 introduction into Brazil was facilitated by the trans-Atlantic slave trade from endemic areas of Africa. The close association between southern African and Brazilian sequences also suggested that greater numbers of the southern African Bantu population might also have been part of the slave trade than previously thought.

CD4+ T-cell count may not be a useful strategy to monitor antiretroviral therapy response in HTLV-1/HIV co-infected patients

BACKGROUND HTLV-1/HIV co-infection is known to elevate the CD4+ T-cell counts of treatment-naïve persons. We investigated whether HTLV-1/HIV co-infected patients continued to have elevated CD4+ T-cell counts after developing virologic failure on antiretroviral therapy (ART). METHODS The data is taken from a drug resistance study located in the KwaZulu-Natal province of South Africa. All participants (N=383) presented for repeated CD4+ T-cell count and HIV viral load level testing between January 2006 and March 2014. We used a random-coefficient model to estimate the change in CD4+ T-cell count and HIV viral load level by HTLV-1/HIV co-infection status over time, adjusting for age, sex, and duration of virologic failure. RESULTS HTLV-1/HIV co-infected participants (n=8) had higher CD4+ T-cell counts, with a positive difference of 117.2 cells/μL at the ART initiation date (p-value=0.001), 114.7 cells/μL (pvalue< 0.001) 12 months after this date, and 112.3 cells/μL (p-value=0.005) 24 months after this date, holding all else constant. In contrast, there was no difference in the HIV viral load level by HTLV-1/HIV co-infected status throughout the observation period. CONCLUSION We show that HTLV-1/HIV co-infected participants continued to have elevated CD4+ T-cell counts after developing virologic failure on ART, despite no difference in their HIV viral load levels when compared with HIV mono-infected participants. Our results indicate that CD4+ T-cell count testing may not be a useful strategy to monitor ART response in the presence of HTLV-1/HIV co-infection.

ORFI genetic polymorphisms in geographically distinct HTLV-1 infections

The region known as pX in the 3’ end of the human T-cell leukemia/lymphoma virus type-1 (HTLV-1) genome contains four overlapping open reading frames (ORF) that encode regulatory proteins. The expression of ORF-I produces the protein p12 which can be cleavage resulting in the p8 protein. These proteins interfere with the ability of a biologically active of HTLV-1, influencing at the virus infectivity and persistence. Here, we evaluated whether natural mutations in HTLV-1 ORF-I can influence the proviral load and clinical manifestation of HAM/TSP. For that, we analyzed 1530 HTLV-1 ORF-I sequences from different clones of 156 patients with negative or positive diagnosis for HAM/TSP and demonstrated that some mutations may be associated with the outcome of HAM/TSP (C39R, L40F, P45L, S69G and R88K) or with proviral load (P34L and F61L). We further examined the presence of mutations in motifs of HBZ and observed that P45L mutation is located within the HBZ nuclear localization signal and was found more frequently between patients with HAM/TSP and high proviral load. This results suggest that some HTLV-1 ORF-I mutations may be associated with the development of HAM/TSP and the proviral load levels.

Genetic characterisation of Langerin gene in human immunodeficiency virus-1-infected women from Bahia, Brazil

Studies on human genetic variations are a useful source of knowledge about human immunodeficiency virus (HIV)-1 infection. The Langerin protein, found at the surface of Langerhans cells, has an important protective role in HIV-1 infection. Differences in Langerin function due to host genetic factors could influence susceptibility to HIV-1 infection. To verify the frequency of mutations in the Langerin gene, 118 samples from HIV-1-infected women and 99 samples from HIV-1-uninfected individuals were selected for sequencing of the promoter and carbohydrate recognition domain (CRD)-encoding regions of the Langerin gene. Langerin promoter analysis revealed two single nucleotide polymorphisms (SNPs) and one mutation in both studied groups, which created new binding sites for certain transcription factors, such as NFAT5, HOXB9.01 and STAT6.01, according to MatInspector software analysis. Three SNPs were observed in the CRD-encoding region in HIV-1-infected and uninfected individuals: p.K313I, c.941C>T and c.983C>T. This study shows that mutations in the Langerin gene are present in the analysed populations at different genotypic and allelic frequencies. Further studies should be conducted to verify the role of these mutations in HIV-1 susceptibility.