B Cell Production in Adult Rats

Abstract

The sequence of B cell development during ontogeny has been investigated by a number of groups (1,2). However, these studies mainly concentrate on events before the full development of secondary lymphoid organs. B cells continue to be produced throughout life in the bone marrow of rodents (3,4). Recent experience with bone marrow transplantation confirms this ability for adult B cell production in humans. We have set out to study the sequence and rate of B cell entry from primary to secondary lymphoid organs in adult rats. This has been achieved by suppressing the development of B cells by administration from birth for 6 weeks rabbit-anti-rat-IgM and IgD. The technique used has been described previously (5). The rats received their last injection of anti-rat-IgM and IgD at 43 days of age and suppression was stopped two days later by injection of 4.5 mg each of rat IgM and IgD. At the time of stopping suppression and at intervals thereafter rats were killed and the extent of B cell and plasma cell population of spleen, lymph nodes and gut-associated lymphoid tissue was assessed by immunohistology.