Longitudinal single-cell analysis of SARS-CoV-2-reactive B cells uncovers persistence of early-formed, antigen-specific clones.

Understanding persistence and evolution of B cell clones after COVID-19 infection and vaccination is crucial for predicting responses against emerging viral variants and optimizing vaccines. Here, we collected longitudinal samples from patients with severe COVID-19 every third to seventh day during hospitalization and every third month after recovery. We profiled their antigen-specific immune cell dynamics by combining single-cell RNA-Seq, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq), and B cell receptor-Seq (BCR-Seq) with oligo-tagged antigen baits. While the proportion of Spike receptor binding domain-specific memory B cells (MBC) increased from 3 months after infection, the other Spike- and Nucleocapsid-specific B cells remained constant. All patients showed ongoing class switching and sustained affinity maturation of antigen-specific cells, and affinity maturation was not significantly increased early after vaccine. B cell analysis revealed a polyclonal response with limited clonal expansion; nevertheless, some clones detected during hospitalization, as plasmablasts, persisted for up to 1 year, as MBC. Monoclonal antibodies derived from persistent B cell families increased their binding and neutralization breadth and started recognizing viral variants by 3 months after infection. Overall, our findings provide important insights into the clonal evolution and dynamics of antigen-specific B cell responses in longitudinally sampled patients infected with COVID-19.

Prediction of preeclampsia based on maternal serum endoglin level in women with pregestational diabetes mellitus.

PURPOSE: To evaluate the level of soluble endoglin (sEng) in pregnant women with pregestational diabetes mellitus (DM) and to assess its predictive value for preeclampsia development. METHODS: Ninety pregnant women were enrolled in the study forming five comparison groups: type 1 DM (not planned, n = 20; planned, n = 20), type 2 DM (diet, n = 15; insulin therapy, n = 20), and the control group (n = 15). The primary outcome was clinically confirmed preeclampsia. Maternal serum concentrations of sEng were measured at 11+0-13+6 and 30+0-33+6 weeks. RESULTS: sEng level was elevated in all patients with pregestational DM compared to the control group. Its plasma concentration increased with gestational age and in case of preeclampsia development. In patients with type 1 DM, serum sEng level did not depend on the presence of preeclampsia. This is evidence of severe metabolic disorder and endothelial dysfunction in these patients. The addition of sEng level to logistic models considering established risk factors (body mass index + age + HbA1c level) in the first and third trimesters significantly improved their performance for preeclampsia prediction. CONCLUSIONS: Eng level may become an important marker for early prediction of preeclampsia in women with pregestational DM.

Single-cell BCR and transcriptome analysis after influenza infection reveals spatiotemporal dynamics of antigen-specific B cells.

B cell responses are critical for antiviral immunity. However, a comprehensive picture of antigen-specific B cell differentiation, clonal proliferation, and dynamics in different organs after infection is lacking. Here, by combining single-cell RNA and B cell receptor (BCR) sequencing of antigen-specific cells in lymph nodes, spleen, and lungs after influenza infection in mice, we identify several germinal center (GC) B cell subpopulations and organ-specific differences that persist over the course of the response. We discover transcriptional differences between memory cells in lungs and lymphoid organs and organ-restricted clonal expansion. Remarkably, we find significant clonal overlap between GC-derived memory and plasma cells. By combining BCR-mutational analyses with monoclonal antibody (mAb) expression and affinity measurements, we find that memory B cells are highly diverse and can be selected from both low- and high-affinity precursors. By linking antigen recognition with transcriptional programming, clonal proliferation, and differentiation, these finding provide important advances in our understanding of antiviral immunity.

The presence of polymorphisms in genes controlling neurotransmitter metabolism and disease prognosis in patients with prostate cancer: a possible link with schizophrenia.

Polymorphisms of neurotransmitter metabolism genes were studied in patients with prostate cancer (PC) characterized by either reduced or extended serum prostate-specific antigen doubling time (PSADT) corresponding to unfavorable and favorable disease prognosis respectively. The 'unfavorable prognosis' group (40 cases) was defined by PSADT ≤ 2 months, whereas patients in the 'favorable prognosis' group (67 cases) had PSADT ≥ 30 months. The following gene polymorphisms known to be associated with neuropsychiatric disorders were investigated: a) the STin2 VNTR in the serotonin transporter SLC6A4 gene; b) the 30-bp VNTR in the monoamine oxidase A MAOA gene; c) the Val158Met polymorphism in the catechol-ortho-methyltransferase COMT gene; d) the promoter region C-521T polymorphism and the 48 VNTR in the third exon of the dopamine receptor DRD4 gene. The STin2 12R/10R variant of the SLC6A4 gene (OR = 2.278; 95% CI = 0.953-5.444) and the -521T/T homozygosity of the DRD4 gene (OR = 1.579; 95% CI = 0.663-3.761) tended to be overrepresented in PC patients with unfavorable disease prognosis. These gene variants are regarded as protective against schizophrenia, and the observed trend may be directly related to a reduced PC risk described for schizophrenia patients. These results warrant further investigation of the potential role of neurotransmitter metabolism gene polymorphisms in PC pathogenesis.