Non-infected Individuals Research Articles

Dysregulated Immune Activation in Second-Line HAART HIV+ Patients Is Similar to That of Untreated Patients.

BackgroundSuccessful highly active antiretroviral therapy (HAART) has changed the outcome of AIDS patients worldwide because the complete suppression of viremia improves health and prolongs life expectancy of HIV-1+ patients. However, little attention has been given to the immunological profile of patients under distinct HAART regimens. This work aimed to investigate the differences in the immunological pattern of HIV-1+ patients under the first- or second-line HAART in Brazil.MethodsCD4+ T cell counts, Viral load, and plasma concentration of sCD14, sCD163, MCP-1, RANTES, IP-10, IL-1β, IL-6, TNF-α, IL-12, IFN-α, IFN-γ, IL-4, IL-5, and IL-10 were assessed for immunological characterization of the following clinical groups: Non-infected individuals (NI; n = 66), HIV-1+ untreated (HIV; n = 46), HIV-1+ treated with first-line HAART (HAART 1; n = 15); and HIV-1+ treated with second-line HAART (HAART 2; n = 15).ResultsWe found that the immunological biosignature pattern of HAART 1 is similar to that of NI individuals, especially in patients presenting slow progression of the disease, while patients under HAART 2 remain in a moderate inflammatory state, which is similar to that of untreated HIV patients pattern. Network correlations revealed that differences in IP-10, TNF-α, IL-6, IFN-α, and IL-10 interactions were primordial in HIV disease and treatment. Heat map and decision tree analysis identified that IP-10>TNF-α>IFN-α were the best respective HAART segregation biomarkers.ConclusionHIV patients in different HAART regimens develop distinct immunological biosignature, introducing a novel perspective into disease outcome and potential new therapies that consider HAART patients as a heterogeneous group.

Impulsive vaccination and dispersal on dynamics of an SIR epidemic model with restricting infected individuals boarding transports

To understand the effect of impulsive vaccination and restricting infected individuals boarding transports on disease spread, we establish an SIR model with impulsive vaccination, impulsive dispersal and restricting infected individuals boarding transports. This SIR epidemic model for two regions, which are connected by transportation of non-infected individuals, portrays the evolvement of diseases. We prove that all solutions of the investigated system are uniformly ultimately bounded. We also prove that there exists globally asymptotically stable infection-free boundary periodic solution. The condition for permanence is discussed. It is concluded that the approach of impulsive vaccination and restricting infected individuals boarding transports provides reliable tactic basis for preventing disease spread.

Torque Teno Midi Virus/Small Anellovirus in Sera of Healthy, HIV/HCV and HIV Infected Individuals in Lorestan Province, Iran

Background:Torque Teno Midi Virus/Small Anellovirus (TTMDV/SAV) is a member of the Gammatorquevirus genus within the family Anelloviridae. It is detected in healthy, Hepatitis B Virus, Hepatitis C Virus and HIV infected individuals and also patients with acute respiratory disease in different countries, but its role in clinical diseases and its full geographical distribution is still unclear.Objectives:The current study aimed to detect the frequency of infection with TTMDV/SAV in the sera of healthy blood donors, hepatitis C infected and HIV positive individuals in Lorestan province, Iran; and also investigate the possible role of TTMDV/SAV virus in liver diseases.Materials and Methods:Fifty two, 36, 4, and 110 serum samples from HIV positive, patients with HIV/HCV and HIV/HCV/HBV co-infections, and healthy individuals were collected in Khorramabad city, respectively. Nested-polymerase chain reaction was performed using SMAs/SMAr primers to detect TTMDV/SAV DNA. Serum aminotransferases were measured.Results:In the HIV/HCV, HIV/HCV/HBV, HIV, and control cases, 29 (80.5%), 3 (75%), 43 (82.7%), and 16 (14.5%) were positive for DNA of TTMDV/SAV, respectively. In the HIV/HCV infected cases and HIV positive cases the level of Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) were not significantly different in TTMDV/SAV infected and non-infected individuals (P > 0.05).Conclusions:Although significant differences (P < 0.01) were observed in the frequency of TTMDV/SAV between healthy controls and each of the HIV positive and HIV/HCV co-infected individuals, no significant difference was observed between HIV positive and HIV/HCV co-infected cases, which may be due to HIV associated immunodeficiency. This is the first time that TTMDV/SAV is reported in HIV infected individuals worldwide. Interpretation of the high frequency of the virus (82.7%) in HIV cases needs more detailed studies.

Transmission of the Ebola virus in the wild

Introduction : The Ebola virus has been found in several non-human and unrelated mammalian species which has made it even more difficult to determine transmission routes. The bats are serve as a vector in the transmission to wild mammals and humans. Hypotheses connecting among wildlife species and humans are generally lacking. Ebola transmission is via bodily fluids of infected animals. Result and discussion : I propose a fruit-saliva connection as a major pathway among Ebola transmission. Bats do not eat large fruits whole ingesting the juices but ejecting the fibrous pulp, they also urinate and defecate during foraging bouts producing a near constant nightly “rain” Ebola virus fluids. Close contact among infected individual in a social group would likely spread the virus from infected to non-infected individuals rapidly. Under our “fruit rain” hypothesis, Ebola transmission to humans can occur by direct human consumption of infected fruit, through contaminated animals, and via water saliva infected.

Dynamics of an SIR model with vertical transmission and impulsive dispersal

To understand the effect of vertical transmission, impulsive dispersal and restricting infected individuals boarding transports on disease spread, we establish an SIR model with vertical transmission and impulsive dispersal. This SIR epidemic model for two regions, which are connected by transportation of non-infected individuals, portrays the evolvement of diseases. We prove that all solutions of the investigated system are uniformly ultimately bounded. We also prove that there exists globally asymptotically stable infection-free boundary periodic solution. The condition for permanence is discussed. It is concluded that the approach of restricting infected individuals boarding transports provides reliable tactic basis for preventing disease spread.

Increased extrafollicular expression of the B-cell stimulatory molecule CD70 in HIV-1-infected individuals.

CD70 molecules expressed by activated T cells provide potent B cell stimulatory signals. We hypothesized that an altered CD70 expression might contribute to B cell abnormalities during HIV-1 infection. CD70 expression and the functional and migratory properties of the CD4CD70 T lymphocytes were analyzed in HIV-1-infected patients and in humanized mice. Correlations were tested between CD70 expression and features of B-cell activation, apoptosis sensitivity and functional exhaustion. CD4CD70 T cells were analyzed in cohorts of CD4 T-cell lymphopenic, viremic or nonlymphopenic, nonviremic HIV-1-infected patients and in noninfected individuals. CD70 upregulation was also followed in HIV-1-infected humanized mice. CD38, CD95, LAIR1 and PD-1 expressions were monitored on B-cell subpopulations, Ki67 was assessed to estimate B-cell proliferation and antibody levels were measured in plasma. Blood CD4CD70 T-cell frequencies increased in response to CD4 T-cell depletion or high viremia levels as a possible consequence of increased activation and proliferation in this subset. CD4CD70 T cells produced T-helper 1-type cytokines and expressed chemokine receptors mobilizing toward sites of inflammation but not to lymphoid follicles. High CD70 expression was observed in HIV-1-infected humanized mice at extrafollicular sites (peritoneum, bone-marrow). CD4CD70 T-cell frequencies correlated with the expression of the activation marker CD38 and the death receptor CD95 on various memory B-cell subsets, with B-cell proliferation and with plasma IgG levels. CD4CD70 T cells may contribute to B cell hyperactivation and accelerated memory B-cell turnover during HIV-1 infection.

Spatio-temporal analysis of tuberculous infection risk among clients of a homeless shelter during an outbreak.

British Columbia (BC) has a low incidence of tuberculosis (TB), with the burden of endogenously acquired disease concentrated among vulnerable populations, including the homeless. In May 2008, a TB outbreak began in a BC homeless shelter, with a single index case seeding multiple secondary cases within the shelter. To use nightly shelter records to quantify the risk of latent tuberculous infection (LTBI) among shelter clients as a function of their sleeping distance from and duration of exposure to the index case. Distance and duration of exposure were visualised and assessed using logistic regression with LTBI status as outcome. We used a novel machine learning approach to establish exposure thresholds that optimally separated infected and non-infected individuals. Of 161 exposed shelter clients, 58 had a recorded outcome of infected (n = 39) or non-infected (n = 19). Only duration of exposure to the index was associated with increased odds of infection (OR 1.26); stays of ⩾ 5 nights put shelter clients at higher odds of infection (OR 4.97). The unique data set and analytical approach suggested that, in a shelter environment, long-term clients are at highest risk of LTBI and should be prioritised for screening during an outbreak investigation.

Electrocardiogram and Chagas disease: a large population database of primary care patients.

Chagas disease (ChD) used to be a disease restricted to Latin America, but has become a worldwide problem due to migration of infected individuals to developed countries. Electrocardiography has been considered an essential exam to evaluate ChD patients. This study sought to identify prevalent electrocardiographic abnormalities in a large sample of ChD patients evaluated in the primary care setting. This retrospective observational study assessed all consecutive digital 12-lead electrocardiograms (ECG) performed by the Telehealth Network of Minas Gerais, Brazil, from January 1 to December 31, 2011. In that time, the service attended primary care patients in 660 cities in the Minas Gerais province. ChD was self-reported, and the individuals who did not report having ChD were considered noninfected. The prevalence of electrocardiographic abnormalities was assessed. Self-reported ChD patients comprised 7,590 (2.9%) of 264,324 patients who underwent ECG during the study period. The mean age for ChD patients was 57.0 ± 13.7 years, and 64.1% of patients were women. The most common comorbidities were hypertension (61.3%), diabetes (9.1%), and dyslipidemia (6.9%), and 10.7% were smokers. The most frequent electrocardiographic abnormalities were nonspecific repolarization abnormalities (34.6%), right bundle branch block (RBBB) (22.7%), left anterior hemiblock (LAH) (22.5%), ventricular premature beats (5.4%), and atrial fibrillation (5.4%). Only 31.5% of the patients had no electrocardiographic abnormality versus 61.2% in noninfected individuals (p < 0.001). The prevalence of normal ECG decreased with aging and was significantly lower than for noninfected individuals in all age groups. Pacemaker rhythm (odds ratio [OR]: 13.3, 95% confidence intervals [CI]: 11.5 to 15.4), RBBB (OR: 10.7, 95% CI: 10.1 to 11.4), especially in association with LAH (OR: 12.1, 95% CI: 11.2 to 13.0), second atrioventricular block (OR: 4.1, 95% CI: 2.5 to 6.6), and third atrioventricular block (OR: 13.3, 95% CI: 11.5 to 15.4) were strongly related to ChD. In this large sample of primary care patients with ChD, there was a high prevalence of electrocardiographic abnormalities. Pacemaker rhythm, RBBB, especially in association with LAH, and second and third atrioventricular block were strongly related to ChD.

Reduction in Size and Number of Plantar Verrucae in Human Immunodeficiency Virus-Infected Individuals After the Implementation of Highly Active Antiretroviral Therapy.

Implementation of highly active antiretroviral therapy (HAART) significantly increased the life expectancy of those living with human immunodeficiency virus (HIV). Except for prevalence, scientific reports regarding clinical manifestations of plantar verrucae in the post-HAART era are lacking. The objective of this study was to compare clinical manifestations of plantar verrucae between HIV-infected and noninfected individuals and then to compare these findings with those observed before the implementation of HAART. Nineteen patients with plantar verrucae (ten with HIV and nine without HIV) were examined to determine the size, number, and clinical type of verrucae present. The two groups were first compared with each other and then with previously collected data from a similar analysis conducted in 1995, before the implementation of HAART. Statistical significance was determined using the Fisher exact test or the Wilcoxon rank sum test. No significant differences were observed in the size, number, or clinical type of verrucae between HIV-negative and HIV-positive patients. Compared with the 1995 data, there was a significant decrease in the number of verrucae lesions per individual and a nonsignificant decrease in the average size of verrucae in HIV-positive patients. Study results indicate that the implementation of HAART has impacted the clinical manifestations of plantar verrucae in HIV-positive individuals. Further analyses with a larger number of patients are required to confirm and substantiate these findings.

NK cell modulation by JAK inhibition.

NK cells are innate immune effector cells recognizing and killing virus-infected or malignant cells [1]. NK cell function is tightly regulated by a complex balance between various activating and inhibitory NK cell receptors. In addition, several cytokines (IL-2, IL-12, IL-15 and IL-18) mediated via the JAK/STAT pathway are critical for NK cell development and activation. Thus it is tempting to speculate that the novel class of immune-modulatory compounds (i.e. the JAK inhibitors) are able to modify NK cell biology in vitro and in vivo. We recently support this idea by demonstrating that the first approved JAK1/2/(3) inhibitor ruxolitinib dramatically impacts NK cell biology in vivo in patients suffering from myeleloproliferative neoplasia (MPN)[2]. Ruxolitinib-treated MPN patients have drastically reduced circulating NK cell numbers. Individuals deficient in NK cells due to an inherited genetic disposition (i.e. JAK3 and/or STAT5B mutations that cause severe combined immunodeficiency (SCID) syndrome in humans) are prone to severe infections. Therefore, it is not surprising to see that patients with MPN exposed to the JAK inhibitor, who develop infections, have lower NK cell counts compared to non-infected individuals. However, we also clearly state that severe infections (tuberculosis, progressive multifocal encephalopathy, toxoplasmosis), even though described during ruxolitinib therapy, are relatively infrequent[3]. The most prevalent types of infections during ruxolitinib therapy are urinary tract infection and herpes zoster reactivation, which is known to be linked to NK cell deficiency. However, there are huge differences between patients with inherited disruption of the JAK/STAT pathway as opposed to patients treated with ruxolitinib. Firstly, we could show that the drug-related effect is reversible. In patients who had to stop the therapy due to side effects, NK cell levels rose back to normal values. Furthermore, the main difference is that in patients exposed to the drug, JAK/STAT inhibition lasts only for several hours (3–4) due to the pharmacokinetic properties of the drug. As a consequence of the bi-daily intake of the drug, the total number of JAK/STAT inhibition may last a maximum of 6–8 hours[4]. In between the JAK/STAT pathway is active and allows residual cells to be activated relatively normal. In contrast, for limiting the hyper-inflammation going along with the MPN, this inhibition time appears to be sufficient to drastically reduce symptom burden and shrink the spleen[5]. Furthermore, it also suffices to clearly deplete NK cells in MPN patients. But why is this the case? The increased ratio of immature to mature NK cells during ruxolitinib therapy provides some hints, that the development of mature NK cells is affected, which could be explained by the inhibition of various important cytokine signals essential for NK maturation (i.e. IL-2 and IL-15). Reduced NK cell numbers in ruxolitinib-exposed patients may at least in part be due to defective NK cell maturation, which results in the time-dependent NK cell drop. In line with this idea, data demonstrated that NK cell precursors lacking IL-15Rβ also exhibit a NK cell differentiation defect leading to severe immunodeficiency. Moreover, IL-15R integrates signals via its common γ-chain in committed NK cell precursors and fosters immature to mature NK cell differentiation as well as the cytokine supports mature NK cell survival. Thus, it is tempting to speculate that ruxolitinib interferes with essential cytokine signals for terminal NK cells maturation and explaining the shift to the more immature NK cell phenotype. Strikingly, ruxolitinib not only affects NK cell biology in vivo, but also impairs NK cell function in vitro. Mainly, cytokine-mediated activation is blocked by the drug and most importantly it inhibits NK killing activity, as it interferes amongst others also with the lytic synapse formation process. We are currently investigating in detail the impact of the drug on the migration process of immune cells and early data clearly highlight the effects of the compound on cytoskeletal rearrangement. This may at least in part also affect the potential of NK cells to go into stable contact with target cells, thereby limiting their killing activity. These data may be of particular relevance when considering the application of the drug as cancer-inflammation reverting compound (e.g. in pancreatic cancer[6]) or when applying the drug as immune-suppressant after allogeneic stem cell transplantation[7], as it may also interfere with cancer immune-surveillance or the graft-versus-disease effect in patients thereby fostering disease recurrence. Considering our data, an important question that arises is how long-term ruxolitinib therapy shapes the immune system after years or even decades. The figure depicts the major effects of the JAK inhibitor ruxolitinib on NK cells in vivo (in MPN patients) and in vitro. Figure 1 The figure depicts the major effects of the JAK inhibitor ruxolitinib on NK cells in vivo (in MPN patients) and in vitro

Tuberculosis (TB) incidence in a cohort of individuals infected with human T-lymphotropic virus type 1 (HTLV-1) in Salvador, Brazil

Few reports evaluate the association between HTLV-1 and TB in countries where both infections are endemic. The incidence and relative risk of TB in a cohort of HTLV-1-infected individuals was estimated from 22 to 2012. Using records from the CHTLV database, the Information System on Diseases of Compulsory Declaration (Sinan) database was searched for TB cases matching each patients’ full name, date of birth and mother's full name. Structured Query Language for use in relational databases was used to cross match both registries by employing a “linkage” strategy. TB incidence density (ID) in both seropositive and seronegative HTLV-1 subjects was calculated as the number of new-TB-cases per 1,0 person-years of follow-up. From a cohort of 6,495 patients, 1,711 were infected with HTLV-1. 73 TB cases occurred during the 11-year study period: 33 in HTLV-1-infected patients and 40 in uninfected individuals. The ID for the HTLV-1/TB group was 3.3 per 1,0 person-years and 1.1 per 1,0 person-years in the non-infected individuals. The relative risk for TB in HTLV-1+ group was 2.3 (CI 95% 1.46 - 3.65). In addition, HTLV-1-infected individuals aged 31 to 50 presented the highest ID (3.4). In this group, the relative risk for TB was 2.6 (CI 95% 1.2-5.5). HTLV-1 patients with TB were older (p = 0. 5), had lower educational levels (p=0.02) and presented higher recurrence rates of TB (p=0.09) than non-HTLV-infected individuals with TB. HIV serology was positive for 6.0% of individuals infected with HTLV-1 versus 12.5% of individuals with isolated TB (p= 0.45). Patients infected with HTLV-1 are more susceptible to TB. The populations of HTLV/TB co-infected patients and HTLV-1-infected individuals share similar epidemiological features, highlighting the neglected nature of both diseases.

Hepatology highlights

Hepatology highlights

Study of Latent Toxoplasma gondii Role in Level of Testosterone, DHEA, Cortisol and Prolactin Hormones of Young Persons

Toxoplasmosis influences the behavior and personality of infected persons. Possible mechanisms for these psychic disorders include its effect on dopamine and on hormone levels. In the present research, the effect of latent toxoplasmosis on testosterone, DHEA, cortisol and prolactin hormones in the infected and noninfected individuals was examined. A total of 215 plasma sample were examined for IgG and IgM anti-Toxoplasma antibody, testosterone, DHEA, cortisol and prolactin levels. In addition the prevalence of hirsutism, acne and alopecia also evaluated in individuals. Serological analysis confirmed that 61 men (28.37%) and 58 women (26.97%) were sero-positive. A statistically significant correlation between toxoplasmosis and testosterone and cortisol increase were observed but there were no significant differences between infected and noninfected individuals in level of prolactin and DHEA. There were significant differences in frequency of allopcy, acne and hirsutism between two groups. Because of these hormones have though helps in management of stress and human behavior and personality so the direct correlation between toxoplasmosis and psychological disorders is suggested due to effect of Toxoplasma on host’s hormone levels

Application of salivary antibody immunoassays for the detection of incident infections with Norwalk virus in a group of volunteers

Norovirus infection is the most common cause of acute gastroenteritis in developed countries. Developing an assay based on a non-invasive biomarker for detecting incident norovirus infections could improve disease surveillance and epidemiological investigations. This project involved analysis of IgA and IgG norovirus-specific antibody responses in saliva samples from a Norwalk virus (Genogroup I, genotype 1 norovirus) challenge study involving infected and symptomatic, and non-infected asymptomatic individuals. Saliva was collected at the challenge, and two weeks and 40days post-challenge. Samples were analyzed using the Luminex fluorometric and Meso Scale Discovery (MSD) electrochemiluminescence immunoassays. Recombinant P domains of Norwalk virus capsid protein, as well as similar recombinant proteins of two genogroup II noroviruses (VA387 and VA207) were used as antigens. Immunoconversions were defined as >4-fold increase in antibody responses to the norovirus antigens. Various sample pre-treatment options, buffers, saliva dilution ratios, and data adjustment approaches to control for sample-to-sample variability in saliva composition were compared using the Luminex assay. The results suggest that adjusting responses to the norovirus antigens for responses to the protein purification tag, glutathione-S-transferase (GST), significantly improved the odds of producing a correct immunoconversion test result. IgG-based tests were more accurate compared to IgA-based tests. At optimal conditions, both Luminex and MSD assays for Norwalk-specific IgG antibodies correctly identified all infected and non-infected individuals. There was no evidence of cross-reactivity of anti-Norwalk virus antibodies with genogroup II noroviruses. These results suggest that salivary antibody responses can be used for the detection of incident infections with Norwalk virus in prospective surveys.

Human Platelet Polymorphism can be a genetic marker associated with HIV/HCV coinfection.

To evaluate the associations of HPA polymorphisms -1, -3, and -5 with HIV/HCV coinfection were included in this study 60 HIV/HCV-coinfected patients from the Sao Paulo State health service centers. Data reported by Verdichio-Moraes et al. (2009: J. Med Virol 81:757-759) were used as the non-infected and HCV monoinfected groups. Human Platelet Polymorphism genotyping was performed in 60 Patients co-infected with HIV/HCV by PCR-SSP or PCR-RFLP. HIV subtyping and HCV genotyping was performed by RT-PCR followed sequencing. The data analyses were performed using the χ2 test or Fisher's Exact Test and the logistic regression model. Patients coinfected with HIV/HCV presented HCV either genotype 1 (78.3%) or non-1 (21.7%) and HIV either subtype B (85.0%) or non-B (15%). The Human Platelet Polymorphism-1a/1b genotype was more frequent (P < 0.05) in HIV/HCV coinfection than in HCV monoinfection and the allelic frequency of Human Platelet Polymorphism-5b in the Patients coinfected with HIV/HCV was higher (P < 0.05) than in HCV monoinfected cases and non-infected individuals. These data suggest that the presence of specific HPA allele on platelets could favor the existence of coinfection. On the other hand, Human Platelet Polymorphism-5a/5b was more frequent (P < 0.05) in HIV/HCV coinfected and HCV monoinfected groups than in the non-infected individuals, suggesting that this platelet genotype is related to HCV infection, regardless of HIV presence. Results suggest that the Human Platelet Polymorphism profile in HIV/HCV coinfected individuals differs from the one of both HCV monoinfected and non-infected population. So, the Human Platelet Polymorphism can be a genetic marker associated with HIV/HCV coinfection.

Periportal fibrosis, liver and spleen sizes among S. mansoni mono or co-infected individuals with human immunodeficiency virus-1 in fishing villages along Lake Victoria shores, North-Western, Tanzania.

BackgroundThe pathogenesis of S. mansoni infection involves chronic inflammatory responses to parasite eggs which can be associated with a characteristic periportal fibrosis (PPF) and the progression to severe hepatosplenic disease. The effects of HIV-1 co-infection and the influence of CD4+ cell numbers on these clinical manifestations of chronic S. mansoni are not known. To understand the effects of HIV-1 co-infection on these morbidities, we examined S. mansoni ultrasound-detectable morbidities in relation to HIV-1 infection and CD4+ cell counts, and other factors in fishing communities where the two infections are present.MethodsUltrasonographical examination was conducted during a cross-sectional study of 1,671 (aged 21–55 years) individuals in North-Western Tanzania. Blood samples were obtained for HIV-1 screening and CD4+ cell quantification. A single stool sample was examined for S. mansoni eggs using the Kato-Katz technique. A questionnaire was used to collect socio-demographic-economic information.ResultsThe prevalence of PPF (grade C-F) was 13.79% and 15.01% for the HIV-1 infected and non-infected individuals (P = 0.72). Male gender (P< 0.001), age group 21–30 years (P< 0.028) and, residential time of 11–20 (P< 0.01) and ≥21 years (P< 0.01) were associated with PPF in S. mansoni infected individuals. The height-adjusted measurements of the left liver lobe were significantly larger in HIV-1/S. mansoni co-infected compared to S. mansoni only-infected individuals (t = −2.0702, P< 0.039). Predictors of the height-adjusted measurements of the left liver lobe and spleen were age, male gender, malaria infection, fishing occupation, village of residence and heavy intensity of S. mansoni infection. After accounting for these factors, neither HIV-1 infection nor CD4+ cell counts predicted PPF, hepatosplenomegaly, measurements of the liver or spleen. Height-adjusted ultrasound measurements of the left liver lobe did not correlate with the CD4+ cells counts in co-infected individuals (r = −0.16, P = 0.084).ConclusionS. mansoni-related PPF, liver and spleen enlargement are prevalent in the study population. The intensity of S. mansoni infection was associated with the enlargement of liver, spleen and hepatosplenomegaly. The PPF grades observed were similar in both HIV-1/S. mansoni co-infected and in those only infected with S. mansoni. There was no evidence that HIV-1 infection or CD4+ cells counts were associated with these S. mansoni morbidities.

Abstract 151: Lysine Residues at Positions 4 and 7 on Nef are Critical for Interaction with Calnexin and Drive Inhibition of Cholesterol Transporter: ATP-Binding Cassette A1

HIV patients are at a greater risk of developing atherosclerosis than non-infected individuals, partly due to the impairment of the ATP-Binding Cassette A1 (ABCA1) cholesterol transporter by the HIV-1 viral protein Nef leading to accumulation of cholesterol inside the cell. While studying the possible mechanism of Nef-mediated disruption of cholesterol efflux, we found that ABCA1 interacts with Nef, but a direct interaction with Nef is dispensable for the inactivation of ABCA1. Using mass spectroscopy we identified calnexin as a protein that associates with both ABCA1 and Nef and provided evidence to show that in the presence of Nef, ABCA1-calnexin interaction is disrupted leading to ABCA1 retention in the ER, subsequent degradation and impairment of cholesterol efflux. However, the molecular interactions taking place remained unknown as Nef is not known to enter the ER lumen and the domain of calnexin involved in binding to substrate proteins is located within the ER lumen. We hypothesized that Nef interacts with the C-terminal cytoplasmic domain of calnexin and that inhibiting this interaction would rescue ABCA1 function and expression. Using calnexin mutants lacking a luminal or cytoplasmic domain, we identified that the C-terminal cytoplasmic domain is responsible for Nef interaction. Using structural models of Nef and calnexin, possible Nef-calnexin interaction models were built using docking servers. Interacting residues in Nef were identified by calculating intermolecular contacts in the resulting complexes. Identified residues were mutated to confirm loss of interaction and this loss of interaction was found to associate with rescue of ABCA1 expression and restoration of cholesterol efflux. In conclusion, lysine residues at positions 4 and 7 on Nef were found to be indispensable for interacting with calnexin and inactivation of ABCA1. As cardiovascular diseases like atherosclerosis have emerged as an important cause of morbidity and mortality in HIV-infected individuals, there is a great need for targeted therapeutic strategies. This study identifies important targets that can be manipulated to inhibit the pathogenic effect of HIV on cholesterol metabolism.

Molecular examinations of Babesia microti in rodents and rodent-attached ticks from urban and sylvatic habitats in Germany

Small mammals serve as reservoir hosts for tick-borne pathogens, especially for those which are not transmitted transovarially in ticks – such as Babesia microti. Molecular investigations on the prevalence of B. microti in wild small mammals and on attached ticks from differently structured areas may provide information on the circulation of B. microti in different ecological niches. In 2012 and 2013, 622 rodents (396 Myodes glareolus, 178 Apodemus flavicollis, 36 Apodemus sylvaticus, 4 Apodemus agrarius, 7 Microtus arvalis, 1 Microtus agrestis) were captured from three differently structured habitats (urban, sylvatic, recultivated) in Germany. Attached ticks were collected from 449 small mammals (3250 Ixodes ricinus, 7 Ixodes trianguliceps, 133 Dermacentor reticulatus). A representative selection of a maximum of 5 ticks per developmental stage and species per 30 rodents of each species, location and year resulting in 965 ticks was further investigated. DNA was extracted from tick, blood and spleen samples, and tested by PCR for the partial 18S rRNA gene of B. microti with subsequent sequencing. The prevalence was significantly higher in rodents from the sylvatic site (4.6%) than in rodents captured at both other sites (–0.6%) (χ2=11.95; p=0.00125). Body and spleen weight of infected M. glareolus from the sylvatic site were significantly higher compared to those from non-infected individuals from that site (p=0.00288 and p=0.00017, respectively). Babesia microti DNA was detected in 3 out of 965 attached ticks (0.3%; 95%CI: 0–1) from all sites, but they derived exclusively from rodents captured at the sylvatic site. At the same site, I. ricinus nymphs (7.7%; 95%CI: 1–25.3) were significantly more often infected than I. ricinus larvae (0%; 95%CI: 0–1.3)(χ2=26.72; p<0.0001). The majority of positive rodents was also found at that site. I. trianguliceps occurred exclusively and the majority of M. glareolus at that site. Thus, it may be assumed that the circulation of B. microti is more efficient where this tick species and voles exist sympatrically than in areas with a predominant occurrence of Apodemus species.

Parasites and personality in periwinkles (Littorina littorea): Infection status is associated with mean-level boldness but not repeatability

We demonstrate the presence of animal personality in an inter-tidal gastropod, Littorina littorea, both in a sample of individuals infected by the trematode Cryptocotyle lingua and in an uninfected sample. On average infected individuals behaved more cautiously than individuals free of infection, but the parasite did not affect repeatability. Although the parasite is not associated with greater diversity of behaviour amongst infected individuals, infection might be associated with state-dependent personality differences between infected and non-infected individuals.

Plaque burden in HIV-infected patients is associated with serum intestinal microbiota-generated trimethylamine.

Some intestinal microbiota-generated metabolites of phosphatidylcholine are recognized to be proatherogenic. As the HIV population is vulnerable to cardiovascular disease and can develop intestinal dysbiosis associated with systemic inflammation, we investigated the novel relationship between microbiota-derived metabolites of phosphatidylcholine and coronary atherosclerosis in HIV. One hundred and fifty-five HIV-infected and 67 non-HIV-infected individuals without known history of cardiovascular disease were previously recruited to assess coronary plaque by computed tomography angiography. In the current study, we evaluate whether serum choline, trimethylamine (TMA), or trimethylamine-N-oxide (TMAO) levels are associated with plaque features. Young, asymptomatic HIV-infected patients (age 47 ± 7 years) demonstrated significantly higher prevalence of plaque (53 vs. 35%, P = 0.01) and number of total plaque segments (1.8 ± 2.5 vs. 1.2 ± 2.2, P = 0.03) when compared with well matched noninfected individuals with similar comorbidities. TMA was significantly associated with calcium score (r = 0.22, P = 0.006), number of total (r = 0.20, P = 0.02) and calcified (r = 0.18, P = 0.03) plaque segments, and calcium plaque volume (r = 0.19, P = 0.02) and mass (r = 0.22, P = 0.009) in the HIV cohort only. In multivariate modeling among HIV-infected patients, TMA remained significantly associated with calcium score (P = 0.008), number of total (P = 0.005) and calcified (P = 0.02) plaque segments, and calcium plaque volume (P = 0.01) and mass (P = 0.007), independent of Framingham risk score. In contrast, there was no association of TMAO to coronary plaque features in either cohort. A link between TMA and atherosclerosis has not previously been established. The current study suggests that TMA may be a nontraditional risk factor related to the number of plaque segments and severity of calcified plaque burden in HIV.