B cell-derived cfDNA after primary BNT162b2 mRNA vaccination anticipates memory B cells and SARS-CoV-2 neutralizing antibodies.

BACKGROUND: Much remains unknown regarding the response of the immune system to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination. METHODS: We employed circulating cell-free DNA (cfDNA) to assess the turnover of specific immune cell types following administration of the Pfizer/BioNTech vaccine. FINDINGS: The levels of B cell cfDNA after the primary dose correlated with development of neutralizing antibodies and memory B cells after the booster, revealing a link between early B cell turnover-potentially reflecting affinity maturation-and later development of effective humoral response. We also observed co-elevation of B cell, T cell, and monocyte cfDNA after the booster, underscoring the involvement of innate immune cell turnover in the development of humoral and cellular adaptive immunity. Actual cell counts remained largely stable following vaccination, other than a previously demonstrated temporary reduction in neutrophil and lymphocyte counts. CONCLUSIONS: Immune cfDNA dynamics reveal the crucial role of the primary SARS-CoV-2 vaccine in shaping responses of the immune system following the booster vaccine. FUNDING: This work was supported by a generous gift from Shlomo Kramer. Supported by grants from Human Islet Research Network (HIRN UC4DK116274 and UC4DK104216 to R.S. and Y.D.), Ernest and Bonnie Beutler Research Program of Excellence in Genomic Medicine, The Alex U Soyka Pancreatic Cancer Fund, The Israel Science Foundation, the Waldholtz/Pakula family, the Robert M. and Marilyn Sternberg Family Charitable Foundation, the Helmsley Charitable Trust, Grail, and the DON Foundation (to Y.D.). Y.D. holds the Walter and Greta Stiel Chair and Research Grant in Heart Studies. I.F.-F. received a fellowship from the Glassman Hebrew University Diabetes Center.

Safety and clinical outcome of tamoxifen in Duchenne muscular dystrophy.

Patients having Duchenne muscular dystrophy (DMD) are currently being treated with corticosteroids, which slow down disease progression at the expense of serious adverse effects. Tamoxifen is a pro-drug some of whose metabolites interact with the nuclear estrogen receptor, leading to anti-fibrotic and muscle-protective effects as has been demonstrated in a murine model of DMD. Here we report the results from a monocentric single arm prospective study in 13 ambulant boys aged 6-14 years with genetically confirmed DMD, aimed to assess the safety of tamoxifen and its impact on disease progression. Boys were treated for up to 3 years with 20 mg/day of oral tamoxifen, in addition to their ongoing corticosteroid treatment. For 8 of these patients, outcome was compared to an age- and performance-matched 12-month natural history dataset. The primary end point was the 6-minute walk test. Secondary end points were the NorthStar assessment, timed function tests, pulmonary function, the biomarker creatine phosphokinase and adverse effects. No adverse effects were noticed other than mild gynecomastia in 4 boys. Tamoxifen-treated patients retained motor and respiratory function, compared with a significant deterioration of age-matched historical control patients receiving corticosteroids only. These encouraging findings warrant a larger clinical trial to substantiate the use of tamoxifen in Duchenne muscular dystrophy.

Aging-Dependent Demethylation of Regulatory Elements Correlates with Chromatin State and Improved ß Cell Function.

Aging is driven by changes of the epigenetic state that are only partially understood. We performed a comprehensive epigenomic analysis of the pancreatic ß cell, key player in glucose homeostasis, in adolescent and very old mice. We observe a global methylation drift resulting in an overall more leveled methylome in old ß cells. Importantly, we discover targeted changes in the methylation status of ß cell proliferation and function genes that go against the global methylation drift, are specific to ß cells, and correlate with repression of the proliferation program and activation of metabolic regulators. These targeted alterations are associated with specific chromatin marks and transcription factor occupancy in young ß cells. Strikingly, we find ß cell function improved in aged mice, as predicted by the changes in methylome and transcriptome. Thus, aging of terminally differentiated cells in mammals is not always coupled to functional decline.