Human colonic adenocarcinoma cells. I. Establishment and description of a new line.

A series of human colonic epithelial cell lines have been cultured from a single patient: LS-180 the original adenocarcinoma, LS-174T a trypsinized variant, and normal colonic tissue. The malignant cells, 20 to 40, mum in diameter and oval to polygonal, exhibited characteristics of normal colonic mucosal cells, namely, abundant microvilli prominent in secretory cells, and the presence of intracytoplasmic mucin vacuoles. The cultured adenocarcinoma cells, but not normal, demonstrated neoplastic properties by producing high levels of carcinoembryonic antigen (CEA) and by the ability to be propagated in hamster cheek pouches and in immunodeprived mice. The CEA production by the newly established line LS-180 released 900 times more CEA per cell into the culture medium and bore 30 times more cell-associated material than the established line, HT-29. These cell lines may permit detection of distinctive chemical, physiological, pharmacologic, and immunologic characteristics of neoplastic colonic cells.

Characteristics of the leucocyte-aggregation assay for cell-mediated immunity.

The leucocyte aggregation assay detects cell-mediated immunity by the specific adherence of sensitized lymphocytes onto target cell monolayers. Leucocyte aggregates appear to develop by instruction of non-immune cells by sensitized T lymphocytes. B cells may function in a secondary capacity to amplify aggregate formation. The reactions are sensitive to low temperatures and to metabolic inhibitors of protein and RNA synthesis and function. Serum factors alternatively enhanced or blocked the phenomenon, depending upon the immune status of the patient. This assay may prove useful for the dissection of allograft rejection and tumor resistance due to its brevity, reflection of T-cell immunity, and sensitivity to host humoral factors.