Primary Antibody Response Induced in vitro Among Cells from Normal Animals

Since early in the history of immunology, many workers have searched for a system to duplicate in vitro most, if not all of the steps of antibody formation observed in the intact animal (Carrel and Ingebritsen, 1912; Liidke, 1912). Some workers have reported successful experiments, but their results have always been barely significant due to the difficulty of ascertaining true de novo synthesis of antibody arising from the low sensitivity of the methods employed to detect the antibody pro-duced. During the last ten years new attempts to find such a system have been made as a result of the development of new techniques for the detection of minute amounts of antibody, and new easy methods for the cultivation of tissues. Various laboratories have succeeded in main-taining tissues and cells actively producing an-tibody in culture for various lengths of time (Hannoun and Bussard, 1966), while others have been able to bring about antibody production in quiescent issues and cells previously stimulated in vivo by in vitro contact with specific antigen i.e., a "secondary reponse " in vitro (Michaelides and Coons, 1963; Harris, 1965). In some investiga-tions, uncommitted cells have been stimulated in vitro before transferring them to incompetent recipients whose presumed role would be to sustain the life of the "grafted " antibody producing cells ("immunocytes") (Harris and Harris, 1965; Harris and Harris, 1958). A closer approach to the com-plete in vitro conditions was achieved by using peritoneal chambers in recipients that played the role of "living incubator " for the immunocytes (Capalbo, Albright, and Bennett, 1964; Bussard and Anderson, 1966). In recent years, some authors have been able to initiate antibody production in a completely in vitro system by stimulation of tissue fragments (Globerson and Auerbach, 1966