The role of cell death in the pathogenesis of autoimmune disease: HMGB1 and microparticles as intercellular mediators of inflammation

Cell death is critical to normal homeostasis, although this process, when increased aberrantly, can lead to the production of pro-inflammatory mediators promoting autoimmunity. Two novel intercellular mediators of inflammation generated during cell death are high mobility group box 1 (HMGB1) protein and microparticles (MPs). HMGB1 is a nuclear protein that functions in transcription when inside the nucleus but takes on pro-inflammatory properties when released during cell death. Microparticles are small, membrane-bound structures that extrude from cells when they die and contain cell surface proteins and nuclear material from their parent cells. MPs circulate widely throughout the vasculature and mediate long-distance communication between cells. Both MPs and HMGB1 have been implicated in the pathogenesis of a broad spectrum of inflammatory diseases, including the prototypic autoimmune conditions systemic lupus erythematosus and rheumatoid arthritis. Given their range of activity and association with active disease, both structures may prove to be targets for effective therapy in these and other disorders

Genital tract infections, the vaginal microbiome and gestational age at birth among pregnant women in South Africa : a cohort study protocol

DATA STATEMENT : The research team will prepare datasets used in analyses, in accordance with data sharing requirements of open access journals in which manuscripts are published and in compliance with local Protection of Personal Information Act requirements. These data files will be archived with codebooks as .csv documents or R datasets and stored in REDCap. The final data files will not contain any personal identifying information of participants.INTRODUCTION : Preterm birth complications are the most common cause of death in children under 5 years. The presence of multiple microorganisms and genital tract inflammation could be the common mechanism driving early onset of labour. South Africa has high levels of preterm birth, genital tract infections and HIV infection among pregnant women. We plan to investigate associations between the presence of multiple lower genital tract microorganisms in pregnancy and gestational age at birth. METHODS AND ANALYSIS : This cohort study enrols around 600 pregnant women at one public healthcare facility in East London, South Africa. Eligible women are ≥18 years and at <27 weeks of gestation, confirmed by ultrasound. At enrolment and 30–34 weeks of pregnancy, participants receive on-site tests for Chlamydia trachomatis and Neisseria gonorrhoeae, with treatment if test results are positive. At these visits, additional vaginal specimens are taken for: PCR detection and quantification of Trichomonas vaginalis, Candida spp., Mycoplasma genitalium, M. hominis, Ureaplasma urealyticum and U. parvum; microscopy and Nugent scoring; and for 16S ribosomal RNA gene sequencing and quantification. Pregnancy outcomes are collected from a postnatal visit and birth registers. The primary outcome is gestational age at birth. Statistical analyses will explore associations between specific microorganisms and gestational age at birth. To explore the association with the quantity of microorganisms, we will construct an index of microorganism load and use mixed-effects regression models and classification and regression tree analysis to examine which combinations of microorganisms contribute to earlier gestational age at birth. ETHICS AND DISSEMINATION : This protocol has approvals from the University of Cape Town Research Ethics Committee and the Canton of Bern Ethics Committee. Results from this study will be uploaded to preprint servers, submitted to open access peer-reviewed journals and presented at regional and international conferences. TRIAL REGISTRATION NUMBER : NCT06131749; Pre-results.An MD-PhD scholarship from the Swiss National Science Foundation, the Swiss National Science Foundation and the US National Institutes of Health.http://bmjopen.bmj.comam2024Medical MicrobiologySDG-03:Good heatlh and well-bein

Comparison of Kaposi Sarcoma risk in human immunodeficiency virus-positive adults across 5 continents: A multiregional multicohort study

Background: We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America. Methods: We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs). Results: We included 208 140 patients from 57 countries. Over a period of 1 066 572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100 000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts 65700 cells/\u3bcL with those whose counts were &lt;50 cells/\u3bcL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by 6595% in other regions. Conclusions. Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa

Complete In Vitro Life Cycle of Trypanosoma congolense: Development of Genetic Tools

Trypanosoma congolense is a parasite responsible for severe disease of African livestock. Its life cycle is complex and divided into two phases, one in the tsetse fly vector and one in the bloodstream of the mammalian host. Molecular tools for gene function analyses in parasitic organisms are essential. Previous studies described the possibility of completing the entire T. congolense life cycle in vitro. However, the model showed major flaws including the absence of stable long-term culture of the infectious bloodstream forms, a laborious time-consuming period to perform the cycle and a lack of genetic tools. We therefore aimed to develop a standardized model convenient for genetic engineering. We succeeded in producing long-term cultures of all the developmental stages on long-term, to define all the differentiation steps and to finally complete the whole cycle in vitro. This improved model offers the opportunity to conduct phenotype analyses of genetically modified strains throughout the in vitro cycle and also during experimental infections

Infections with Immunogenic Trypanosomes Reduce Tsetse Reproductive Fitness: Potential Impact of Different Parasite Strains on Vector Population Structure

The parasite Trypanosoma brucei rhodesiense and its insect vector Glossina morsitans morsitans were used to evaluate the effect of parasite clearance (resistance) as well as the cost of midgut infections on tsetse host fitness. Tsetse flies are viviparous and have a low reproductive capacity, giving birth to only 6–8 progeny during their lifetime. Thus, small perturbations to their reproductive fitness can have a major impact on population densities. We measured the fecundity (number of larval progeny deposited) and mortality in parasite-resistant tsetse females and untreated controls and found no differences. There was, however, a typanosome-specific impact on midgut infections. Infections with an immunogenic parasite line that resulted in prolonged activation of the tsetse immune system delayed intrauterine larval development resulting in the production of fewer progeny over the fly's lifetime. In contrast, parasitism with a second line that failed to activate the immune system did not impose a fecundity cost. Coinfections favored the establishment of the immunogenic parasites in the midgut. We show that a decrease in the synthesis of Glossina Milk gland protein (GmmMgp), a major female accessory gland protein associated with larvagenesis, likely contributed to the reproductive lag observed in infected flies. Mathematical analysis of our empirical results indicated that infection with the immunogenic trypanosomes reduced tsetse fecundity by 30% relative to infections with the non-immunogenic strain. We estimate that a moderate infection prevalence of about 26% with immunogenic parasites has the potential to reduce tsetse populations. Potential repercussions for vector population growth, parasite–host coevolution, and disease prevalence are discussed

The origins of the trypanosome genome strains Trypanosoma brucei brucei TREU 927, T. b. gambiense DAL 972, T. vivax Y486 and T. congolense IL3000

The genomes of several tsetse-transmitted African trypanosomes (Trypanosoma brucei brucei, T. b. gambiense, T. vivax, T. congolense) have been sequenced and are available to search online. The trypanosome strains chosen for the genome sequencing projects were selected because they had been well characterised in the laboratory, but all were isolated several decades ago. The purpose of this short review is to provide some background information on the origins and biological characterisation of these strains as a source of reference for future users of the genome data. With high throughput sequencing of many more trypanosome genomes in prospect, it is important to understand the phylogenetic relationships of the genome strains

Differential Trypanosome Surface Coat Regulation by a CCCH Protein That Co-Associates with procyclin mRNA cis-Elements

The genome of Trypanosoma brucei is unusual in being regulated almost entirely at the post-transcriptional level. In terms of regulation, the best-studied genes are procyclins, which encode a family of major surface GPI-anchored glycoproteins (EP1, EP2, EP3, GPEET) that show differential expression in the parasite's tsetse-fly vector. Although procyclin mRNA cis-regulatory sequences have provided the paradigm for post-transcriptional control in kinetoplastid parasites, trans-acting regulators of procyclin mRNAs are unidentified, despite intensive effort over 15 years. Here we identify the developmental regulator, TbZFP3, a CCCH-class predicted RNA binding protein, as an isoform-specific regulator of Procyclin surface coat expression in trypanosomes. We demonstrate (i) that endogenous TbZFP3 shows sequence-specific co-precipitation of EP1 and GPEET, but not EP2 and EP3, procyclin mRNA isoforms, (ii) that ectopic overexpression of TbZFP3 does not perturb the mRNA abundance of procyclin transcripts, but rather that (iii) their protein expression is regulated in an isoform-specific manner, as evidenced by mass spectrometric analysis of the Procyclin expression signature in the transgenic cell lines. The TbZFP3 mRNA-protein complex (TbZFP3mRNP) is identified as a trans-regulator of differential surface protein expression in trypanosomes. Moreover, its sequence-specific interactions with procyclin mRNAs are compatible with long-established predictions for Procyclin regulation. Combined with the known association of TbZFP3 with the translational apparatus, this study provides a long-sought missing link between surface protein cis-regulatory signals and the gene expression machinery in trypanosomes. © 2009 Walrad et al

A Collective Household Labour Supply Model with Disability: Evidence from Iraq

In this study we explored the determinants of the women’s labour supply and we attempted to identify the sharing rules for married couples. The analysis relied on data derived by the Iraqi Household Socio-Economic Survey (IHSES) in 2012–2013. The study considered the housework contributed by both spouses and we also included the wife’s disability status as a distribution factor. Moreover, we estimated the sharing rules accounting for female non-participation in the labour market. The household collective model was preferred over the unitary model as the results supported that changes on wages, non-labour income, age, education, number of children, and disability as a distribution factor affect the bargaining power and the share of spouses. The findings showed that for a one percent increase on female’s daily wage rate, her share on full income was increased by 1320 Iraqi Dinar (ID) corresponding to $1.12, while reached 1470 ID ($1.25) when the domestic labour was considered. Similarly, increases on the male’s wage increased her share by 630 ID ($0.50), while increases of 1 ID in the non-labour income increased female’s share by 0.43. The estimates showed that the disabled women decreased the share by 1275 ID ($1.08). Furthermore, the findings illustrated that considering the non-participation of the wife in the labour market, her share and therefore her bargaining power was lower than their earner counterparts