Transforming growth factor beta and apoptosis in leprosy skin lesions: possible relationship with the control of the tissue immune response in the Mycobacterium leprae infection

The course of leprosy depends of the host immune response which ranges from the lepromatous pole (LL) to the tuberculoid pole (TT). A comparative study was conducted in 60 patients with the LL and TT The results showed a mean expression of TGF-beta of 339 +/- 99.4 cells/field for TT and of 519.2 +/- 68.2 cells/field for LL. Frequency of apoptosis was 6.3 +/- 1.8 in TT and 14.0 +/- 6.1 in LL. A correlation (p = 0.0251) between TGF-beta and caspase-3 in the LL was found. This finding indicates a role of TGF-beta and apoptosis in the immune response in leprosy. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Naturally acquired antibodies to Plasmodium vivax blood-stage vaccine candidates (PvMSP-1(19) and PvMSP-3 alpha(359-798)) and their relationship with hematological features in malaria patients from the Brazilian Amazon

An important step when designing a vaccine is identifying the antigens that function as targets of naturally acquired antibodies. We investigated specific antibody responses against two Plasmodium vivax vaccine candidates, PvMSP-1(19) and PvMSP-3 alpha(359-798). Moreover, we assessed the relationship between these antibodies and morbidity parameters. PvMSP-1(19) was the most immunogenic antigen and the frequency of responders to this protein tended to increase in P. vivax patients with higher parasitemia. For both antigens, IgG antibody responses tended to be lower in patients who had experienced their first bout of malaria. Furthermore, anemic patients presented higher IgG antibody responses to PvMSP-3 alpha(359-798). Since the humoral response involves a number of antibodies acting simultaneously on different targets, we performed a Principal Component Analysis (PCA). Anemic patients had, on average, higher first principal component scores (IgG1/IgG2/IgG3/IgG4 anti-MSP3 alpha), which were negatively correlated with hemoglobin levels. Since antibodies against PfMSP-3 have been strongly associated with clinical protection, we cannot exclude the possibility of a dual role of PvMSP-3 specific antibodies in both immunity and pathogenesis of vivax malaria. Our results confirm the high immunogenicity of the conserved C terminus of PvMSP-1 and points to the considerable immunogenicity of polymorphic PvMSP-3 alpha(359-798) during natural infection. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Broad and Cross-Clade CD4(+) T-Cell Responses Elicited by a DNA Vaccine Encoding Highly Conserved and Promiscuous HIV-1 M-Group Consensus Peptides

T-cell based vaccine approaches have emerged to counteract HIV-1/AIDS. Broad, polyfunctional and cytotoxic CD4(+) T-cell responses have been associated with control of HIV-1 replication, which supports the inclusion of CD4(+) T-cell epitopes in vaccines. A successful HIV-1 vaccine should also be designed to overcome viral genetic diversity and be able to confer immunity in a high proportion of immunized individuals from a diverse HLA-bearing population. In this study, we rationally designed a multiepitopic DNA vaccine in order to elicit broad and cross-clade CD4(+) T-cell responses against highly conserved and promiscuous peptides from the HIV-1 M-group consensus sequence. We identified 27 conserved, multiple HLA-DR-binding peptides in the HIV-1 M-group consensus sequences of Gag, Pol, Nef, Vif, Vpr, Rev and Vpu using the TEPITOPE algorithm. The peptides bound in vitro to an average of 12 out of the 17 tested HLA-DR molecules and also to several molecules such as HLA-DP, -DQ and murine IA(b) and IA(d). Sixteen out of the 27 peptides were recognized by PBMC from patients infected with different HIV-1 variants and 72% of such patients recognized at least 1 peptide. Immunization with a DNA vaccine (HIVBr27) encoding the identified peptides elicited IFN-gamma secretion against 11 out of the 27 peptides in BALB/c mice; CD4(+) and CD8(+) T-cell proliferation was observed against 8 and 6 peptides, respectively. HIVBr27 immunization elicited cross-clade T-cell responses against several HIV-1 peptide variants. Polyfunctional CD4(+) and CD8(+) T cells, able to simultaneously proliferate and produce IFN-gamma and TNF-alpha, were also observed. This vaccine concept may cope with HIV-1 genetic diversity as well as provide increased population coverage, which are desirable features for an efficacious strategy against HIV-1/AIDS.

Natural infection of triatomines (Hemiptera: Reduviidae) by trypanosomatids in two different environments in the municipality of Ouro Preto do Oeste, State of Rondonia, Brazil

Introduction: This study analyzed the occurrence and the contamination of triatomines by trypanosomatids in Orbignya speciosa (babassu) specimens in the State of Rondonia, Brazil, in two different environments (pasture and woods). Methods: Capture of triatomines on babassus and microscopic search for trypanosomatids in their digestive tube were carried out. Results: Four hundred ninety-four (494) specimens were captured (Rhodnius prolixus and R.robustus), of which 35.6% of the triatomines were positive for trypanosomatids. Conclusions: The high index of natural infection along with the abundance of triatomines points out to the necessity to create an epidemiological surveillance system to monitor vector-borne transmission and deepen the studies on the ecology of such vectors in the Amazon.

Molecular and phylogenetic analyses of human Parvovirus B19 isolated from Brazilian patients with sickle cell disease and beta-thalassemia major and healthy blood donors

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and beta-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with beta-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the Sao Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection. J. Med. Virol. 84:16521665, 2012. (c) 2012 Wiley Periodicals, Inc.

Detection of the Epstein-Barr virus in blood and bone marrow mononuclear cells of patients with aggressive B-cell non-Hodgkin's lymphoma is not associated with prognosis

The Epstein-Barr virus (EBV) is associated with a large spectrum of lymphoproliferative diseases. Traditional methods of EBV detection include the immunohistochemical identification of viral proteins and DNA probes to the viral genome in tumoral tissue. The present study explored the detection of the EBV genome, using the BALF5 gene, in the bone marrow or blood mononuclear cells of patients with diffuse large B-cell lymphomas (DLBCL) and related its presence to the clinical variables and risk factors. The results show that EBV detection in 21.5% of patients is not associated with age, gender, staging, B symptoms, international prognostic index scores or any analytical parameters, including lactate dehydrogenase (LDH) or beta-2 microglobulin (B2M). The majority of patients were treated with R-CHOP-like (rituximab. cyclophosphamide, doxorubicin, vincristine and prednisolone or an equivalent combination) and some with CHOP-like chemotherapy. Response rates [complete response (CR) + partial response (PR)] were not significantly different between EBV-negative and -positive cases, with 93.2 and 88.9%, respectively. The survival rate was also similar in the two groups, with 5-year overall survival (OS) rates of 64.3 and 76.7%, respectively. However, when analyzing the treatment groups separately there was a trend in EBV-positive patients for a worse prognosis in patients treated with CHOP-like regimens that was not identified in patients treated with R-CHOP-like regimens. We conclude that EBV detection in the bone marrow and blood mononuclear cells of DLBC patients has the same frequency of EBV detection on tumoral lymphoma tissue but is not associated with the risk factors, response rate and survival in patients treated mainly with immunochemotherapy plus rituximab. These results also suggest that the addition of rituximab to chemotherapy improves the prognosis associated with EBV detection in DLBCL.

Correlates of human immunodeficiency virus cervicovaginal shedding among postmenopausal and fertile-aged women

Objective: The aims of this study were to compare the intensity of human immunodeficiency virus (HIV)-RNA genital shedding among postmenopausal (PM) and fertile-aged (F) women and to investigate the association between viral shedding and gynecological features, HIV plasma viral loads, and other markers of HIV disease progression. Methods: We interviewed 146 HIV-infected women (73 PM/73 F) in search of gynecological complaints and signs and symptoms of HIV disease and obtained additional information concerning HIV infection by medical chart review. Cervicovaginal lavages (CVLs) were collected for assessment of HIV shedding. Laboratory analyses included CD4(+) cell counts, HIV-RNA quantitation in plasma and CVL, and screening for concurrent genital infections. Results: HIV-RNA genital shedding was detected in 16.4% of PM and 21.9% of F women (P = 0.400), and the intensity of HIV shedding did not differ between both groups (means-PM: 1.4log/mL; F: 1.4log/mL; P = 0.587). Three women (2 PM/1 F) exhibited viral shedding in the absence of detectable viremia. HIV plasma viral loads correlated with HIV shedding in both groups. In multivariable analysis, HIV plasma viral loads were independently associated with HIV shedding in both groups. Moreover, the intensity of shedding was independently associated with vaginal pH, tumor necrosis factor a concentrations in CVL, and HIV plasma viral loads. Conclusions: Despite significant changes that occur in the vaginal mucosa of PM women, HIV cervicovaginal shedding was not significantly influenced by this state in our cohort. In contrast, increased vaginal pH and genital inflammation, evidenced by increased tumor necrosis factor alpha concentrations in CVL and HIV plasma viral loads, were independently associated with the intensity of HIV shedding in PM and F women.

Natural infection of triatomines (Hemiptera: Reduviidae) by trypanosomatids in two different environments in the municipality of Ouro Preto do Oeste, State of Rondônia, Brazil

INTRODUCTION: This study analyzed the occurrence and the contamination of triatomines by trypanosomatids in Orbignya speciosa (babassu) specimens in the State of Rondônia, Brazil, in two different environments (pasture and woods). METHODS: Capture of triatomines on babassus and microscopic search for trypanosomatids in their digestive tube were carried out. RESULTS: Four hundred ninety-four (494) specimens were captured (Rhodnius prolixus and R.robustus), of which 35.6% of the triatomines were positive for trypanosomatids. CONCLUSIONS: The high index of natural infection along with the abundance of triatomines points out to the necessity to create an epidemiological surveillance system to monitor vector-borne transmission and deepen the studies on the ecology of such vectors in the Amazon.

Experimental infection with Neospora caninum in pregnant bitches

In this study, transplacental transmission of Neospora caninum in bitches at different stages of pregnancy was evaluated. Three bitches were inoculated in the 3rd week and three in the 6th week of gestation with 10(8) tachyzoites of N. caninum (Nc-1 strain). All the infected bitches and at least one of their offspring presented anti-N. caninum antibodies according to the indirect fluorescent antibody test (IFAT > 400). The pups and their mothers were sacrificed and tissues from the central nervous system (CNS), popliteal lymph nodes, skeletal muscle, brain, lungs, heart and liver were analyzed for the presence of N. caninum using the nested polymerase chain reaction (nested PCR), restriction fragment length polymorphism (RFLP) and immunohistochemistry (IHC). The parasite was found in the pups in lymph node, CNS, heart and liver tissues using nested PCR. There was no difference in perinatal mortality between the offspring from bitches infected in the 3rd week of gestation (60%) and in the 6th week (53.8%).

Visceral leishmaniasis in Brazil: trends and challenges

The urbanization of visceral leishmaniasis in Brazil has been related to environmental changes, migration, interaction and spread of sylvatic reservoirs and infected dogs to areas with no transmission, and adaptation of the vector Lutzomyia longipalpis to the peridomiciliary environment. From 1980 to 2005, Brazil recorded 59,129 cases of visceral leishmaniasis, 82.5% of which in the Northeast region. Visceral leishmaniasis gradually spread to other regions of the country: in 1998 these other regions reported 15% of all cases, but by 2005 this proportion had increased to 44%. From 1998 to 2005, indigenous cases were reported in 1,904 different municipalities of the country (34.2%). Reservoir and vector control pose major challenges for disease control, since there is a need for better knowledge of vector behavior in urban areas, and control activities involve high operational costs. In recent years the Brazilian Ministry of Health has supported research on the laboratory diagnosis of infection and disease in humans and dogs, treatment of patients, evaluation of the effectiveness of control strategies, and development of new technologies that could contribute to the surveillance and control of visceral leishmaniasis in the country.

Virus a RNA e a DNA: importanza dell’ampliamento dello spettro d’ospite nell’evoluzione virale

L’ampliamento dello spettro d’ospite è strettamente connesso al processo evolutivo a cui i virus sono assoggettati e rappresenta una notevole sfida alla loro capacità di adattarsi. L’attitudine a superare le barriere di specie è conseguente alla costante e relativamente rapida evoluzione che caratterizza i virus; allo stesso tempo, la forza selettiva esercitata dal nuovo ospite rappresenterà un ulteriore stimolo per le capacità adattative del virus. Ad oggi, i meccanismi genetici ed evolutivi responsabili del salto di specie virale, cioè la trasmissione di un virus da un ospite tradizionale ad uno precedentemente resistente all’infezione, sono parzialmente sconosciuti. Nel seguente lavoro verranno presentati gli studi effettuati sulle dinamiche evolutive caratterizzanti virus a RNA e a DNA in cui si sono osservate variazioni dello spettro d’ospite. Gli studi hanno riguardato i coronavirus, con particolare riferimento al ruolo svolto dai pipistrelli nell’evoluzione dei coronavirus SARS-correlati, e l’importanza del gatto nell’evoluzione dei parvovirus dei carnivori. Nella prima sezione saranno mostrate le correlazioni genetiche dei coronavirus identificati in Italia nei pipistrelli appartenenti alla specie Rhinolophus ferrumequinum con i ceppi europei e del resto del mondo, allo scopo di chiarire l’origine evolutiva dei coronavirus dei pipistrelli correlati al virus della SARS (Bat-SARS-like CoV) europei, gli eventi migratori che hanno caratterizzato la loro diffusione nel continente e le potenziali ripercussioni sulla salute pubblica. Nella seconda sezione saranno evidenziate le caratteristiche molecolari dei ceppi di parvovirus circolanti nella popolazione felina, valutandone la diversità di sequenza e la complessità genetica, allo scopo di ottenere importanti informazioni in merito all’evoluzione del virus e alle interazioni tra il parvovirus e l’ospite.

The role of dendritic cells (DC) in Friend retrovirus-induced immunosuppression and immunotherapeutic applications of functionalized nanoparticles

Friend murine leukemia Virus (FV) infection of immunocompetent mice is a well- established model to acquire further knowledge about viral immune suppression mechanisms, with the aim to develop therapeutics against retrovirus-induced diseases. Interestingly, BALB/c mice are infected by low doses of FV and die from FV-induced erythroleukemia, while C57/BL6 mice are infected by FV only at high viral dose, and remain persistently infected for their whole life. Due to the central role of dendritic cells (DC) in the induction of anti-viral responses, we asked for their functional role in the genotype-dependent sensitivity towards FV infection. In my PhD study I showed that bone marrow (BM)-derived DC differentiated from FV-infected BM cells obtained from FV-inoculated BALB/c (FV susceptible) and C57BL/6 (FV resistant) mice showed an increased endocytotic activity and lowered expression of MHCII and of costimulatory receptors as compared with non-infected control BMDC. FV-infected BMDC from either mouse strain were partially resistant towards stimulation-induced upregulation of MHCII and costimulators, and accordingly were poor T cell stimulators in vitro and in vivo. In addition, FV-infected BMDC displayed an altered expression profile of proinflammator cytokines and favoured Th2 polarization. Ongoing work is focussed on elucidating the functional role of proteins identified as differentially expressed in FV-infected DC in a genotype-dependent manner, which therefore may contribute to the differential course of FV infection in vivo in BALB/c versus C57BL/6 mice. So far, more than 300 proteins have been identified which are differently regulated in FV-infected vs. uninfected DC from both mouse strains. One of these proteins, S100A9, was strongly upregulated specifically in BMDC derived from FV-infected C57BL/6 BM cells. S100A9-/- mice were more sensitive towards inoculation with FV than corresponding wild type (WT) mice (both C57BL/6 background), which suggests a decisive role of this factor for anti-viral defense. In addition, FV-infected S100A9-/- BMDC showed lower motility than WT DC. The future work is aimed to further elucidate the functional importance of S100A9 for DC functions. To exploit the potential of DC for immunotherapeutic applications, in another project of this PhD study the usability of different types of functionalized nanoparticles

Evaluation of chronic HCV infection in transplanted livers using a modified histological activity index

The majority of histopathological classifications of primary chronic viral hepatitis and recurrence of HCV infection in liver transplants is based on the histological activity index (HAI) introduced by Knodell et al in 1981; however, correlation between HAI and clinical/laboratory data is poor. Therefore, the aim of this study was to present a modification of HAI (mHAI) adapted to distinct features of graft infection, and to evaluate its usefulness in the description of disease activity.

Virologic failure and second-line antiretroviral therapy in children in South Africa--the IeDEA Southern Africa collaboration

Background: With expanding pediatric antiretroviral therapy (ART) access, children will begin to experience treatment failure and require second-line therapy. We evaluated the probability and determinants of virologic failure and switching in children in South Africa. Methods: Pooled analysis of routine individual data from children who initiated ART in 7 South African treatment programs with 6-monthly viral load and CD4 monitoring produced Kaplan-Meier estimates of probability of virologic failure (2 consecutive unsuppressed viral loads with the second being >1000 copies/mL, after ≥24 weeks of therapy) and switch to second-line. Cox-proportional hazards models stratified by program were used to determine predictors of these outcomes. Results: The 3-year probability of virologic failure among 5485 children was 19.3% (95% confidence interval: 17.6 to 21.1). Use of nevirapine or ritonavir alone in the initial regimen (compared with efavirenz) and exposure to prevention of mother to child transmission regimens were independently associated with failure [adjusted hazard ratios (95% confidence interval): 1.77 (1.11 to 2.83), 2.39 (1.57 to 3.64) and 1.40 (1.02 to 1.92), respectively]. Among 252 children with ≥1 year follow-up after failure, 38% were switched to second-line. Median (interquartile range) months between failure and switch was 5.7 (2.9-11.0). Conclusions: Triple ART based on nevirapine or ritonavir as a single protease inhibitor seems to be associated with a higher risk of virologic failure. A low proportion of virologically failing children were switched.

Investigation of a large community-based outbreak of hepatitis B infection in the United Kingdom

We describe the largest outbreak of hepatitis B virus infection reported to date in the UK. Between July 2001 and December 2005, 237 cases were identified in Avon, South West England. The likely route of transmission was injecting drug use in 44% (104/237) and heterosexual intercourse in 30% (71/237) of cases. A case-control study in injectors showed that injecting crack cocaine [adjusted odds ratio (aOR) 23·8, 95% confidence interval (CI) 3·04-186, P<0·001] and sharing injecting paraphernalia in the year before diagnosis (aOR 16·67, 95% CI 1·78-100, P=0·010) were strongly associated with acute hepatitis B. In non-IDUs number of sexual partners and lack of consistent condom use were high compared to a national sample. We describe the control measures implemented in response to the outbreak. This outbreak has highlighted the problems associated with the low uptake from the national hepatitis B vaccination policy which targets high-risk groups, the difficulties of identifying those at risk of acquiring hepatitis B infection through heterosexual sex, and injecting crack cocaine as a risk factor for hepatitis B.