Antibody formation by cells isolated from donors of different ages after transfer to young rabbits and to x-irradiated adult rabbits.

Abstract

To study the first phase of antibody formation by isolated cells, a method was developed for transferring isolated lymphoid cells stiinulated by antigen in vitro. Antibody formation by spleen cells isolated from adult, nonimmunized donors and mixed with Brucella suis antigen was compared after transfer to young rabbits and to adult recipients irradiated with 450 r. It was found that this dose did not produce complete inhibition and that the recipients still responded actively to the antigen. Therefore, only young animals are a suitable experimental model in which to study antibody formation by transferred isolated cells. Development of antibody in young rabbits was studied by transferring cells isolated from the spleen of animals aged 8-30 days and mixed with antigen in vitro. Antibodies were formed after the transfer of these cells to x-irradiated recipients, but by the active response of the latter to the antigen. Antibody formation by cells of donors of different ages can be determined after transfer to young animals. The youngest donors whose cells formed antibodies after transfer were 3-week-old rabbits, but demonstration of antibodies required the transfer of large numbers of cells. It is clear from these results that cells from adult donors which have contactedmore » antigen in vitro form antibodies when transferred to homologous newborn recipients. However, newborn rabbits are functionally too active to be altogether ideal and suitable recipients. The newborn destroy transferred cells within a few days, thus abolish their immunological activity. The discrepancy between the finding that antibodies can be obtained in young animals immunized soon after birth and failure of their isolated cells to perform the same function may be due to several factors. It is suggested that direct immunization experiments, using different antigens, may provide a more accurate answer. (H.H.D.)« less