Sex hormones regulate the sexual dimorphism of the lung resident immune milieu.

A strong sex-bias characterizes many respiratory immune diseases and has been attributed to sexually dimorphic immune responses. However, the role of lung-resident immunity in this context remains elusive. Here, we thoroughly characterized the lung-resident immune landscape in male and female mice, with a special focus on sex hormone effects in this context.

Pregnancy-acquired memory CD4 regulatory T cells improve pregnancy outcome in mice.

Subsequent pregnancies are generally less prone to obstetric complications. A successful pregnancy outcome requires pivotal immunological adaptation to ensure immune tolerance towards the foetus. Thus, the lower risk for pregnancy complication during subsequent pregnancies may be attributable to immune memory mounted during first pregnancies.

High-sensitivity CRP is elevated in pregnant women with overweight and obesity and modulated by gestational weight gain.

Introduction: The global obesity epidemic presents a growing challenge in perinatal medicine and obstetrics, as it is associated with a higher risk of adverse maternal and perinatal outcomes. In addition to metabolic disturbances, obesity contributes to chronic low-grade inflammation. This study aims to investigate the relationship between maternal overweight, obesity, and excessive weight gain during pregnancy and high-sensitivity C-reactive protein (hs-CRP), an acute-phase reactant of inflammation and infection in maternal serum.

The 'communicatome' of pregnancy: spotlight on cellular and extravesicular chimerism.

Communication via biological mediators between mother and fetus are key to reproductive success and offspring's future health. The repertoire of mediators coding signals between mother and fetus is broad and includes soluble factors, membrane-bound particles and immune as well as non-immune cells. Based on the emergence of technological advancements over the last years, considerable progress has been made toward deciphering the "communicatome" between fetus and mother during pregnancy and even after birth.

Pregnancy-induced transfer of pathogen-specific T cells from mother to fetus in mice.

Neonatal health is determined by the transfer of maternal antibodies from the mother to the fetus. Besides antibodies, maternal cells cross the placental barrier and seed into fetal organs. Contrary to maternal antibodies, maternal microchimeric cells (MMc) show a high longevity, as they can persist in the offspring until adulthood.

Expansion-enhanced super-resolution radial fluctuations enable nanoscale molecular profiling of pathology specimens.

Expansion microscopy physically enlarges biological specimens to achieve nanoscale resolution using diffraction-limited microscopy systems. However, optimal performance is usually reached using laser-based systems (for example, confocal microscopy), restricting its broad applicability in clinical pathology, as most centres have access only to light-emitting diode (LED)-based widefield systems. As a possible alternative, a computational method for image resolution enhancement, namely, super-resolution radial fluctuations (SRRF), has recently been developed.

Pregnancy-induced maternal microchimerism shapes neurodevelopment and behavior in mice.

Life-long brain function and mental health are critically determined by developmental processes occurring before birth. During mammalian pregnancy, maternal cells are transferred to the fetus. They are referred to as maternal microchimeric cells (MMc).

Establishment of tissue-resident immune populations in the fetus.

The immune system establishes during the prenatal period from distinct waves of stem and progenitor cells and continuously adapts to the needs and challenges of early postnatal and adult life. Fetal immune development not only lays the foundation for postnatal immunity but establishes functional populations of tissue-resident immune cells that are instrumental for fetal immune responses amidst organ growth and maturation. This review aims to discuss current knowledge about the development and function of tissue-resident immune populations during fetal life, focusing on the brain, lung, and gastrointestinal tract as sites with distinct developmental trajectories.

Vertically transferred maternal immune cells promote neonatal immunity against early life infections.

During mammalian pregnancy, immune cells are vertically transferred from mother to fetus. The functional role of these maternal microchimeric cells (MMc) in the offspring is mostly unknown. Here we show a mouse model in which MMc numbers are either normal or low, which enables functional assessment of MMc.

Inefficient Placental Virus Replication and Absence of Neonatal Cell-Specific Immunity Upon Sars-CoV-2 Infection During Pregnancy.

Pregnant women have been carefully observed during the COVID-19 pandemic, as the pregnancy-specific immune adaptation is known to increase the risk for infections. Recent evidence indicates that even though most pregnant have a mild or asymptomatic course, a severe course of COVID-19 and a higher risk of progression to diseases have also been described, along with a heightened risk for pregnancy complications. Yet, vertical transmission of the virus is rare and the possibility of placental SARS-CoV-2 infection as a prerequisite for vertical transmission requires further studies.