RAPID ADSORPTION OF A FETAL CALF SERUM COMPONENT BY MAMMALIAN-CELLS IN CULTURE - POTENTIAL SOURCE OF ARTIFACTS IN STUDIES OF ANTISERA TO CELL-SPECIFIC ANTIGENS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 31  (6) , 881-891
Abstract
Injection of CBA mice with mitogen-stimulated (LPS [lipopolysaccharide] [Escherichia coli] or con A [concanavalin A]) CBA lymphocytes which were cultured for 3 days in the presence of fetal calf serum (FCS) led to the production of antisera which reacted strongly with virtually all types of mammalian cells, including human [colonic carcinoma cells, lymphoblastoid K562 cells, diploid fibroblast cells], whether normal or malignant, provided they were cultured in FCS-containing media. Reactivity was detected by sensitive immunological assays such as complement-dependent cytotoxicity using rabbit complement (but not using guinea pig complement), or EA[sheep erythrocyte, antibody]-rosette inhibition of Fc receptor-bearing cells. The antisera did not react with fresh normal lymphoid cells or ascites tumor cells; these same cell populations became fully susceptible to the cytotoxic effects of the antisera after as little as 4 h incubation at 37.degree. in the presence of FCS. Cells incubated without FCS or with FCS at 0.degree. were not affected. The antisera reacted with FCS to form a single band on Ouchterlony double-diffusion plates. On immunoelectrophoresis the reactive antigen appeared to migrate in the .alpha.-globulin region of serum proteins. FCS may be a source of potentially serious misinterpretations in immunological studies of cell-associated antigens using antisera produced by the injection of cells grown in FCS-containing cultures. Examples of artifacts arising from the use of FCS in certain systems, e.g., the preparation of alloantisera using cultured tumor cells vs. fresh non-cultured lymphoid cells, are described.