title: Further characterization of the circulating cell in chronic lymphocytic leukemia.
abstract: Peripheral lymphocytes from normal individuals and from patients with chronic lymphocytic leukemia (CLL) were cultured in vitro for 1-7 days. The growth response to phytohemagglutinin (PHA) was quantitated by the incorporation of tritiated uridine into RNA nucleotide during a 2-hr pulse with the radioisotope. While the maximum response in PHA-stimulated normal cultures appeared at 2-3 days, CLL cultures required 5-7 days to develop their maximal response, which was 50%-60% of the normal magnitude. Dilution of the number of normally reactive lymphocytes by culturing them with totally unreactive, mitomycin-treated cells produced a normal 72-hr maximal response, no matter what proportion of unreactive cells was included in the PHA-stimulated cultures. In addition, the response of peripheral lymphocytes from patients with myeloblastic leukemia, where large numbers of unreactive myeloblasts diluted the normal small lymphocytes, a depressed reaction occurred at the anticipated 2-3 days. Nylon fiber-adherent lymphocytes consisting of 85% immunoglobulin (Ig)-bearing cells responded minimally to PHA, but showed no evidence of a delay. When isolated from CLL patients, both fiber-adherent cells (Ig-bearing) as well as non-fiber-adherent (sheep erythrocyterosetting) cells responded to PHA in a delayed fashion. Similarly, a case of CLL, in which 93.5% of the circulating lymphocytes bore sheep red blood cell receptors, showed its peak response to PHA at 7 days. Therefore, using surface marker criteria considered characteristic of normal T cells and B cells, the delayed response to PHA on the part of CLL lymphocytes was independent of thymic or nonthymic origin.
mesh_terms: D000328:Adult; D000368:Aged; D002448:Cell Adhesion; D006801:Humans; D007104:Immune Adherence Reaction; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology; D007945:Leukemia, Lymphoid / Q000276:immunology*; D007951:Leukemia, Myeloid / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008875:Middle Aged; D011947:Receptors, Antigen, B-Cell / Q000032:analysis
chemical_list: D037102:Lectins; D011947:Receptors, Antigen, B-Cell