| First Author | Adamo L | Year | 2020 |
| Journal | JCI Insight | Volume | 5 |
| Issue | 3 | PubMed ID | 31945014 |
| Mgi Jnum | J:311418 | Mgi Id | MGI:6754260 |
| Doi | 10.1172/jci.insight.134700 | Citation | Adamo L, et al. (2020) Myocardial B cells are a subset of circulating lymphocytes with delayed transit through the heart. JCI Insight 5(3) |
| abstractText | Current models of B lymphocyte biology posit that B cells continuously recirculate between lymphoid organs, without accumulating in peripheral healthy tissues. Nevertheless, B lymphocytes are one of the most prevalent leukocyte populations in the naive murine heart. To investigate this apparent inconsistency in the literature, we conducted a systematic analysis of myocardial B cell ontogeny, trafficking dynamics, histology, and gene expression patterns. We found that myocardial B cells represent a subpopulation of circulating B cells that make close contact with the microvascular endothelium of the heart and arrest their transit as they pass through the heart. The vast majority (>95%) of myocardial B cells remain intravascular, whereas few (<5%) myocardial B cells cross the endothelium into myocardial tissue. Analyses of mice with B cell deficiency or depletion indicated that B cells modulate the myocardial leukocyte pool composition. Analysis of B cell-deficient animals suggested that B cells modulate myocardial growth and contractility. These results transform our current understanding of B cell recirculation in the naive state and reveal a previously unknown relationship between B cells and myocardial physiology. Further work will be needed to assess the relevance of these findings to other organs. |
