Exercise as a Modulator of Immune Risk Factors for Ischemic Heart Disease

Pre- and post-exercise peripheral blood mononuclear cell (PBMC) preparations are isolated from venous blood, washed three times at 10 degrees C with sterile phosphate buffered saline (pH 7.4, 0.1 M) and suspended at a concentration of 2 million cells/uL in RPMI-1640. Preparations are incubated under 5% CO2 at 37 degrees C for 48 hours with phytohemagglutinin (5 ug/ml). Culture supernatants are rendered cell-free and supernatants assayed for Interleukin (IL)-1α, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ using solid phase enzyme linked immunoassay kits.

Pre- and post-exercise fasting plasma levels of total cholesterol (TC), very low density lipoprotein cholesterol (VLDL), low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) levels are measured using g-Max Quick-Seal tubes and potassium bromide (KBr) (d=1.006 g/mL). Tubes are centrifuged for 120 minutes at 68,000 rpm at 14 degrees C. The top layer (VLDL) is harvested, the bottom 3.7 mL adjusted to a density of 1.063 g/mL with KBr, and the tubes centrifuged for 150 minutes at 68,000 rpm at 14 degrees C to float the LDL-C. The bottom layer contains the HDL-C. TC, VLDL-C, LDL-C, and HDL concentrations are measured colorimetrically. LDL oxidizability is measured by oxidizing LDL-C (0.05 g/L) with 50 ug/mL Cu++ at 30 degrees C and measuring diene levels spectrometrically at 234 nm.

Pre- and post-exercise blood samples are immunophenotyped using lysed whole blood, a FACScan flow cytometer, and fluorescein- and phycoerythrin-labeled murine monoclonal IgG antibodies to measure levels of T lymphocytes (CD3+), T helper lymphocytes (CD4+), T cytotoxic lymphocytes (CD8+), and T lymphocytes displaying MHC class II antigen (DR+), vascular adhesion molecule-4 (VLA-4) (CD49d+), lymphocyte function-associated antigen-1 (LFA-1) (CD11a+), Fas antigen (CD95+), and gamma-delta T cell receptors (TCR gamma-delta+). Also measured are B lymphocytes (CD3-CD19+), B1 lymphocytes (CD3-CD19+CD5+) and natural killer cells (NK cells) (CD3-CD16+CD56+).