Superresolution imaging of human cytomegalovirus vMIA localization in sub-mitochondrial compartments

The human cytomegalovirus (HCMV) viral mitochondria-localized inhibitor of apoptosis (vMIA) protein, traffics to mitochondria-associated membranes (MAM), where the endoplasmic reticulum (ER) contacts the outer mitochondrial membrane (OMM). vMIA association with the MAM has not been visualized by imaging. Here, we have visualized this by using a combination of confocal and superresolution imaging. Deconvolution of confocal microscopy images shows vMIA localizes away from mitochondrial matrix at the Mitochondria-ER interface. By gated stimulated emission depletion (GSTED) imaging, we show that along this interface vMIA is distributed in clusters. Through multicolor, multifocal structured illumination microscopy (MSIM), we find vMIA clusters localize away from MitoTracker Red, indicating its OMM localization. GSTED and MSIM imaging show vMIA exists in clusters of ~100–150 nm, which is consistent with the cluster size determined by Photoactivated Localization Microscopy (PALM). With these diverse superresolution approaches, we have imaged the clustered distribution of vMIA at the OMM adjacent to the ER. Our findings directly compare the relative advantages of each of these superresolution imaging modalities for imaging components of the MAM and sub-mitochondrial compartments. These studies establish the ability of superresolution imaging to provide valuable insight into viral protein location, particularly in the sub-mitochondrial compartments, and into their clustered organization

Household food security is associated with infant feeding practices in rural Bangladesh.

Although household food security (HHFS) has been shown to affect diet, nutrition, and health of adults and also learning in children, no study has examined associations with infant feeding practices (IFP). We studied 1343 infants born between May 2002 and December 2003 in the Maternal and Infant Nutrition Intervention in Matlab study to investigate the effect of HHFS on IFP in rural Bangladesh. We measured HHFS using a previously developed 11-item scale. Cumulative and current infant feeding scales were created from monthly infant feeding data for the age groups of 1-3, 1-6, 1-9, and 1-12 mo based on comparison to infant feeding recommendations. We used lagged, dynamic, and difference longitudinal regression models adjusting for various infant and maternal variables to examine the association between HHFS and changes in IFP, and Cox proportional hazards models to examine the influence of HHFS on the duration of breast-feeding and the time of introduction of complementary foods. Better HHFS status was associated with poor IFP during 3-6 mo but was associated with better IFP during 6-9 and 9-12 mo of age. Although better HHFS was not associated with the time of introduction of complementary foods, it was associated with the type of complementary foods given to the infants. Intervention programs to support proper IFP should target mothers in food-secure households when their babies are 3-6 mo old and also mothers in food-insecure households during the 2nd half of infancy. Our results provide strong evidence that HHFS influences IFP in rural Bangladesh

Reaching the poor with health interventions: Programme-incidence analysis of seven randomised trials of women's groups to reduce newborn mortality in Asia and Africa

Background Efforts to end preventable newborn deaths will fail if the poor are not reached with effective interventions. To understand what works to reach vulnerable groups, we describe and explain the uptake of a highly effective community-based newborn health intervention across social strata in Asia and Africa. Methods We conducted a secondary analysis of seven randomised trials of participatory women's groups to reduce newborn mortality in India, Bangladesh, Nepal and Malawi. We analysed data on 70 574 pregnancies. Socioeconomic and sociodemographic differences in group attendance were tested using logistic regression. Qualitative data were collected at each trial site (225 focus groups, 20 interviews) to understand our results. Results Socioeconomic differences in women's group attendance were small, except for occasional lower attendance by elites. Sociodemographic differences were large, with lower attendance by young primigravid women in African as well as in South Asian sites. The intervention was considered relevant and interesting to all socioeconomic groups. Local facilitators ensured inclusion of poorer women. Embarrassment and family constraints on movement outside the home restricted attendance among primigravid women. Reproductive health discussions were perceived as inappropriate for them. Conclusions Community-based women's groups can help to reach every newborn with effective interventions. Equitable intervention uptake is enhanced when facilitators actively encourage all women to attend, organise meetings at the participants' convenience and use approaches that are easily understandable for the less educated. Focused efforts to include primigravid women are necessary, working with families and communities to decrease social taboos

TCF1 Is Required for the T Follicular Helper Cell Response to Viral Infection

T follicular helper (TFH) and T helper 1 (Th1) cells generated after viral infections are critical for the control of infection and the development of immunological memory. However, the mechanisms that govern the differentiation and maintenance of these two distinct lineages during viral infection remain unclear. We found that viral-specific TFH and Th1 cells showed reciprocal expression of the transcriptions factors TCF1 and Blimp1 early after infection, even before the differential expression of the canonical TFH marker CXCR5. Furthermore, TCF1 was intrinsically required for the TFH cell response to viral infection; in the absence of TCF1, the TFH cell response was severely compromised, and the remaining TCF1-deficient TFH cells failed to maintain TFH-associated transcriptional and metabolic signatures, which were distinct from those in Th1 cells. Mechanistically, TCF1 functioned through forming negative feedback loops with IL-2 and Blimp1. Our findings demonstrate an essential role of TCF1 in TFH cell responses to viral infection

Deletion of β-catenin impairs T cell development

T cells encounter two main checkpoints during development in the thymus. These checkpoints are critically dependent on signals derived from the thymic microenvironment as well as from the pre-T cell receptor (pre-TCR) and the {alpha}{beta} TCR. Here we show that T cell-specific deletion of {beta}-catenin impaired T cell development at the {beta}-selection checkpoint, leading to a substantial decrease in splenic T cells. In addition, {beta}-catenin also seemed to be a target of TCR-CD3 signals in thymocytes and mature T cells. These data indicate that {beta}-catenin-mediated signals are required for normal T cell development

Upfront Xpert MTB/RIF for diagnosis of pediatric TB-Does it work? Experience from India.

BackgroundDiagnosis of TB in pediatric population poses several challenges. A novel initiative was implemented in several major cities of India aimed at providing upfront access to free-of-cost Xpert MTB/RIF to presumptive pediatric TB cases. This paper aims to describe the experience of implementing this large initiative and assess feasibility of the intervention in high TB burden settings.MethodsData were drawn from the pediatric TB project implemented in 10 major cities of India between April 2014 and March 2018. In each city, providers, both public and private, were engaged and linked with a high throughput Xpert MTB/RIF lab (established in that city) through rapid specimen transportation and electronic reporting system. Rates and proportions were estimated to describe the characteristics of this cohort.ResultsOf the total 94,415 presumptive pediatric TB cases tested in the project, 6,270 were diagnosed positive for MTB (6.6%) on Xpert MTB/RIF (vs 2% on smear microscopy). Among MTB positives, 545 cases were rifampicin resistant (8.7%). The median duration between collection of specimens and reporting of results was 0 days (same day) and >89% cases were initiated on treatment. Approximately 50% of the specimens tested were non-sputum. The number of providers/facilities engaged under the project increased >10-fold (from 124 in Q2'14 to 1416 in Q1'18).ConclusionThis project, which was one of the largest initiatives globally among pediatric population, demonstrated the feasibility of sustaining rapid and upfront access to free-of-cost Xpert MTB/RIF testing. The project underscores the efficiency of this rapid diagnostic assay in tackling several challenges in pediatric TB diagnosis, identifies opportunities for further interventions as well as brings to light scope for effective engagement with healthcare providers. The findings have facilitated a policy decision by National TB Programme mandating the use of Xpert MTB/RIF as a primary diagnostic tool for TB diagnosis in children, which is being scaled-up