CYTOKINE EFFECTS ON MITOCHONDRIAL MEMBRANE POTENTIAL AND POSSIBLE MITOCHONDRIAL DYSFUNCTION 1N CHRONIC FATIGUE AND IMMUNE DYSFUNCTION SYNDROME.
B. Chazotte and M. Pettengill, Univ. of
N. Carolina School of Medicine, Chapel Hill. N.C. 27599
Laser scanning confocal microscopy was
used to image membrane potentials in individual living human cells to quantitatively
assess cellular and mitochondrial energy metabolism. Graylevel cell images
were histogrammed using in-house software, and a lookup table divas selected
to convert pixels to millivolt (mV) membrane potentials. These potentials
are binned as extracellular, cellular, cytoplasmic and mitochondrial. The
relative mV probability densities for areas, "integrated optical densities",
and average density for each bin are then determined to assess energy transduction.
This also permits the quantitative comparison among individual cells and
cell populations. Our preliminary data compared human mononuclear leukocytes
from a small population of CFIDS patients to healthy controls and suggests
possible mitochondrial dysfunction as reported by
lower cellular and mitochondrial membrane potentials and smaller areas
of cells at mitochondrial potentials. More detailed studies on CFIDS patients'
cells are warranted and are in progress. In related studies, interferon-alfa
added to cultured human fibroblasts was found to decrease the mitochondrial
membrane potentials and areas at mitochondrial potentials. Interleukin-2
decreases mitochondrial potentials and may induce an unexplained photosensitivity
as reported by the membrane potentials. Supported in part by grants te
B.C. from CFIDS Assoc. of America, UNC Ctr. for Res. on Chronic Illness
NIH 5P30 NR03962-02, and UNC Univ. Res. Council.