A clinical protocol for a German birth cohort study of the Maturation of Immunity Against respiratory viral Infections (MIAI).

Introduction: Respiratory viral infections (RVIs) are a major global contributor to morbidity and mortality. The susceptibility and outcome of RVIs are strongly age-dependent and show considerable inter-population differences, pointing to genetically and/or environmentally driven developmental variability. The factors determining the age-dependency and shaping the age-related changes of human anti-RVI immunity after birth are still elusive. Methods: We are conducting a prospective birth cohort study aiming at identifying endogenous and environmental factors associated with the susceptibility to RVIs and their impact on cellular and humoral immune responses against the influenza A virus (IAV), respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The MIAI birth cohort enrolls healthy, full-term neonates born at the University Hospital Würzburg, Germany, with follow-up at four defined time-points during the first year of life. At each study visit, clinical metadata including diet, lifestyle, sociodemographic information, and physical examinations, are collected along with extensive biomaterial sampling. Biomaterials are used to generate comprehensive, integrated multi-omics datasets including transcriptomic, epigenomic, proteomic, metabolomic and microbiomic methods. Discussion: The results are expected to capture a holistic picture of the variability of immune trajectories with a focus on cellular and humoral key players involved in the defense of RVIs and the impact of host and environmental factors thereon. Thereby, MIAI aims at providing insights that allow unraveling molecular mechanisms that can be targeted to promote the development of competent anti-RVI immunity in early life and prevent severe RVIs. Clinical trial registration: https://drks.de/search/de/trial/, identifier DRKS00034278.

A novel conditional NPM-ALK-driven model of CD30+ T-cell lymphoma mediated by a translational stop cassette.

Targeted expression of transgenes is essential for the accurate representation of human disease in in vivo models. Current approaches to generate conditional transgenic mouse models are cumbersome and not amenable to high-throughput analysis since they require de novo generation and characterization of genetically modified mice. Here we describe a new system for lineage-restricted expression of transgenes based on a retroviral vector incorporating a translational stop cassette flanked by loxP recombination sites. Conditional transgene expression in chimeric mice is achieved by retroviral infection and transplantation of hematopoietic stem cells (HSC) derived from transgenic mice expressing Cre-recombinase from a lineage-specific promoter. For validation, we directed expression of NPM-ALK, the fusion oncogene driving a subset of anaplastic large cell lymphoma (ALCL), to T-cells by infecting hematopoietic stem cells from Lck-Cre-transgenic mice with a retroviral construct containing the NPM-ALK cDNA preceded by a translational stop cassette. These mice developed T-cell lymphomas within 12-16 weeks, featuring increased expression of the ALCL hallmark antigen CD30 as well as other cytotoxic T-cell markers, similar to the human disease. The new model represents a versatile tool for the rapid analysis of gene function in a defined lineage or in a developmental stage in vivo.