Proliferation of Human Lymphoid Cells Lymphocytopoiesis and Cell Cycle Parameters in Isolated Perfused Human Spleens

Abstract

Parameters of the cell cycle of lymphoid cells and the rate of production of small lymphocytes and mature plasma cells were estimated in human spleens. 12 normal and 1 enlarged spleen with lymphatic hyperplasia were labelled either by a pulse or continuously with 3H-TdRthymidine during normothermic perfusion of the isolated spleens. Biopsies of splenic tissue were taken at different intervals and evaluated autoradiographically. The mean initial labelling index of immunoblasts was 73 % and for plasmoblasts 52 %. The labelling index for small lymphocytes and mature plasma cells increased initially from 0 % to 1 %, and up to 25 % respectively after 14 h. The duration of the S-phase, as determined by double labelling, was 8.26 h for lymphoid blasts. Data from the percentage labelled mitosis curve resulted in a minimal tG2 of about 1 h and tG2 + tM of about 4 h. The estimated generation time was about 11.5 h. The results found on the hyperplastic spleen were comparable to those on the normal spleen.

The pig as a model for immunology research

“…Thus, the proliferation in the normal microenvironment was characterized in contrast to many in vitro techniques (Pabst and Trepel 1975a, b). These data obtained in pigs was the base for the perfusion of isolated human spleens, and the cell cycle length, G2 and S phase, could be determined (Pabst and Reinecke 1981) and documenting the production of the coagulation factor VIII by the spleen (Pabst et al 1977a). All nucleated cells in the spleen were labelled by selective perfusion of the pig spleen with an RNA precursor (H3-cytidine) and the emigrated lymphocytes identified in other organs and quantified (Pabst et al 1978).…”