The process in which immature B cells from the bone marrow acquire the specialized features of T1 stage B cells in the spleen. T1 stage B cells do not express either CD23 or CD21.
Comment:
Note that immunologists typically use the word 'development' to refer to cells of B or T cell lineages undergoing the process that GO describes as 'cell differentiation'.
Synonyms:
exact_synonym:
T1 stage B cell differentiation; transitional one stage B-lymphocyte differentiation