10 research outputs found
ER-Alpha-cDNA As Part of a Bicistronic Transcript Gives Rise to High Frequency, Long Term, Receptor Expressing Cell Clones
Within the large group of Estrogen Receptor alpha (ERĪ±)-negative breast cancer patients, there is a subgroup carrying the phenotype ERĪ±ā, PRā, and Her2ā, named accordingly āTriple-Negativeā (TN). Using cell lines derived from this TN group, we wished to establish cell clones, in which ERĪ± is ectopically expressed, forming part of a synthetic lethality screening system. Initially, we generated cell transfectants expressing a mono-cistronic ERĪ± transcription unit, adjacent to a separate dominant selectable marker transcription unit. However, the yield of ERĪ± expressing colonies was rather low (5ā12.5%), and only about half of these displayed stable ectopic ERĪ± expression over time. Generation and maintenance of such cell clones under minimal exposure to the ERĪ± ligand, did not improve yield or expression stability. Indeed, other groups have also reported grave difficulties in obtaining ectopic expression of ERĪ± in ERĪ±-deficient breast carcinoma cells. We therefore switched to transfecting these cell lines with pERĪ±-IRES, a plasmid vector encoding a bicistronic translation mRNA template: ERĪ± Open Reading Frame (ORF) being upstream followed by a dominant-positive selectable marker (hygroR) ORF, directed for translation from an Internal Ribosome Entry Site (IRES). Through usage of this bicistronic vector linkage system, it was possible to generate a very high yield of ERĪ± expressing cell clones (50ā100%). The stability over time of these clones was also somewhat improved, though variations between individual cell clones were evident. Our successful experience with ERĪ± in this system may serve as a paradigm for other genes where ectopic expression meets similar hardships
Tixagevimabācilgavimab for treatment of patients hospitalised with COVID-19: a randomised, double-blind, phase 3 trial
Background: Tixagevimabācilgavimab is a neutralising monoclonal antibody combination hypothesised to improve outcomes for patients hospitalised with COVID-19. We aimed to compare tixagevimabācilgavimab versus placebo, in patients receiving remdesivir and other standard care. Methods: In a randomised, double-blind, phase 3, placebo-controlled trial, adults with symptoms for up to 12 days and hospitalised for COVID-19 at 81 sites in the USA, Europe, Uganda, and Singapore were randomly assigned in a 1:1 ratio to receive intravenous tixagevimab 300 mgācilgavimab 300 mg or placebo, in addition to remdesivir and other standard care. Patients were excluded if they had acute organ failure including receipt of invasive mechanical ventilation, extracorporeal membrane oxygenation, vasopressor therapy, mechanical circulatory support, or new renal replacement therapy. The study drug was prepared by an unmasked pharmacist; study participants, site study staff, investigators, and clinical providers were masked to study assignment. The primary outcome was time to sustained recovery up to day 90, defined as 14 consecutive days at home after hospital discharge, with co-primary analyses for the full cohort and for participants who were neutralising antibody-negative at baseline. Efficacy and safety analyses were done in the modified intention-to-treat population, defined as participants who received a complete or partial infusion of tixagevimabācilgavimab or placebo. This study is registered with ClinicalTrials.gov, NCT04501978 and the participant follow-up is ongoing. Findings: From Feb 10 to Sept 30, 2021, 1455 patients were randomly assigned and 1417 in the primary modified intention-to-treat population were infused with tixagevimabācilgavimab (n=710) or placebo (n=707). The estimated cumulative incidence of sustained recovery was 89% for tixagevimabācilgavimab and 86% for placebo group participants at day 90 in the full cohort (recovery rate ratio [RRR] 1Ā·08 [95% CI 0Ā·97ā1Ā·20]; p=0Ā·21). Results were similar in the seronegative subgroup (RRR 1Ā·14 [0Ā·97ā1Ā·34]; p=0Ā·13). Mortality was lower in the tixagevimabācilgavimab group (61 [9%]) versus placebo group (86 [12%]; hazard ratio [HR] 0Ā·70 [95% CI 0Ā·50ā0Ā·97]; p=0Ā·032). The composite safety outcome occurred in 178 (25%) tixagevimabācilgavimab and 212 (30%) placebo group participants (HR 0Ā·83 [0Ā·68ā1Ā·01]; p=0Ā·059). Serious adverse events occurred in 34 (5%) participants in the tixagevimabācilgavimab group and 38 (5%) in the placebo group. Interpretation: Among patients hospitalised with COVID-19 receiving remdesivir and other standard care, tixagevimabācilgavimab did not improve the primary outcome of time to sustained recovery but was safe and mortality was lower. Funding: US National Institutes of Health (NIH) and Operation Warp Speed
Ovarian steroid hormones: Effects on immune responses and Chlamydia trachomatis infections of the female genital tract
Female sex hormones are known to regulate the adaptive and innate immune functions of the female reproductive tract. This review aims to update our current knowledge of the effects of the sex hormones estradiol and progesterone in the female reproductive tract on innate immunity, antigen presentation, specific immune responses, antibody secretion, genital tract infections caused by Chlamydia trachomatis, and vaccine-induced immunity