Comparison of protein and DNA synthesis assays of guinea pig spleen lymphocytes after stimulation with influenza virus antigen and phytohemagglutinin

Two in vitro-methods for demonstration of cell-mediated immune response are compared: Protein and DNA synthesis for detection of in vitro influenza virus antigen- and mitogen-induced lymphocyte stimulation. Guinea pig spleen lymphocytes sensitized with influenza virus antigen were tested in a microadaptation of the lymphocyte transformation test using ¹⁴C- or ³H-leucine and ³H-thymidme. As a positive control for T-cell stimulation PHA-induced lymphocyte stimulation was measured.

The following results were obtained:

• 1.

  Kinetics of the incorporation of ¹⁴C-leucine and ³H-thymidine in lymphocytes incubated with optimal and suboptimal PHA-doses respectively are quantitatively similar but different in time.

• 2.

  The results of the protein- and DNA-synthesis stimulation assays were correlated against influenza virus antigens, this could not be described by the comparison of cellular and single humoral parameters.

• 3.

  The administration of influenza virus antigens in CFA induced a more intensive cell-mediated reaction than injections of antigens in aqueous suspensions, but the results of both methods of CMI were correlated.

• 4.

  The optimal CMI under the exeprimental conditions described is induced by an administration of 30 to 50 μg virus protein per animal and by a combined intramuscular — intraperitoneal immunization procedure.

• 5.

  The measurement of the early stimulation of protein synthesis in the PSS-test is substantially more rapid than for the classical LTT.