Gene Literature Dashboard

In order to investigate some characteristics of Millipore diffusion chamber cultures (DCC) and their potential for the quantitation of tumor cell growth kinetics, HeLa S-3-cells were grown in diffusion chambers implanted i.p. in mice. HeLa cells grew pseudologarithmically in DCC with a population-doubling time of approximately 2.8 days when 9.2 to 12.0 X 10(5) cells were placed in the chambers initially. The population-doubling time varied as a function of the initial innocula size but was always longer than the in vitro population-doubling time of 1.2 days. Comparable harvests of cells from experiment to experiment varied quantitatively by no more than a factor 1.8. This variaton somewhat limits the use of DCC for the quantitation of subtle effects. The fate and morphology of HeLa cells in DCC were determined from scanning electron microscopy. DCC might be exploited in clinical studies of the growth of patients' tumors and the effects of various therapies in a host-mediated system.

Earlier studies from our laboratory demonstrated that the terpolymer of L-glutamic acid, L-alanine, and L-tyrpsine (GAT) stimulated the development of T cells capable of specifically suppressing the antibody responses in vivo and in vitro of nonresponder strains (bearing the H-2(s), H-2(q), and H-2(p) haplotypes) to GAT complexed with an immunogenic carrier, methylated bovine serum albumin, MBSA (1,2). We then extended these findings to another antigen, the copolymer of L-glutamic acid and L-tyrosine (GT). None of 19 inbred or congenic resistant mouse strains developed antibody responses to GT after immunization with this synthetic polypeptide in adjuvants. All the strains investigated, however, developed IgG plaque-forming cells (PFC) primary responses to GT complexed with MBSA (3). This permitted us to determine that: (a) preimmunization with GT suppressed the response to GT-MBSA in certain but not in all strains; (b) the suppression could be transferred by thymocytes and spleen cells from GT-primed animals; (c) the development of GT-specific suppressor cells is under dominant control of H-2- linked gene(s) which have been designated specific immune suppressor genes (Is genes); (d) the Is genes are antigen specific since GAT-MBSA responses are suppressed by GAT in strains carrying the H-2(q) haplotype, while GT-MBSA responses are not suppressed by the related polymer GT in these same strains (3,4). The experiments reported in this study map the Is genes responsible for GT-specific suppression within the H-2 complex. The data indicate that the K and D loci are not concerned with GT-specific suppression, and that this phenomenon is controlled by complementing or interacting genes which map on either side of cross-over events between the IB and IC subregions.