Permanent alteration of the murine Ly‐1 B repertoire due to selective depletion of Ly‐1 B cells in neonatal animals

摘要

AbstractStudies presented here demonstrate that paternal allotype Ly‐1 B cells are permanently depleted following neonatal treatment with antibodies to the paternal IgM allotype. Paternal allotype conventional B cells, in contrast, are temporarily depleted by treatment with either anti‐IgM or anti‐IgD allotype antibodies and return rapidly to normal frequencies once the antibody treatment disappears. These differences are explained by basic developmental differences between Ly‐1 B and conventional lineage B cells. That is, the conventional B cell population is replenished from Ig‐precursors throughout life and, therefore, is only temporarily affected when depleted in neonates. The Ly‐1 B cell population, in contrast, develops from Ig‐progenitors during the prenatal and neonatal life but survives because it is exclusively self‐replenishing in adults. Therefore, elimination of a population of Ly‐1 B cells from neonates is tantamount to removing it forever.These findings suggest that while conventional B cells turn over rapidly and have an effectively unlimited repertoire, Ly‐1 B cells express a repertoire whose composition is strongly influenced by neonatal conditions that favor or select against the retention of cells producing certain antibody molecules. Thus, Ly‐1 B cells play a unique role in the immune system in that they retain indefinitely the history of the neonatal animal's imm