Enhanced proliferation and il-2 secretion by lung lymphocytes from
hiv-infected subjects.
Spain, Blake A., Diaa M. Soliman, Richard A. Sidner, and Homer L.
Twigg.
Department of Medicine, Division of Pulmonary and Critical Care,
and Department of Surgery, Indiana University Medical Center,
Indianapolis, IN 46202
APStracts 2:0090L, 1995.
HIV-positive patients frequently develop a CD3+/CD8+ cytotoxic T cell
lymphocytic alveolitis. This could occur through in situ expansion of
lung lymphocytes. We evaluated lung and blood lymphocyte
proliferation in asymptomatic HIV-infected individuals by measuring
spontaneous and cytokine-induced tritiated thymidine incorporation.
IL-2 and IL-4 secretion was determined using ELISA, western blotting,
and immunoprecipitation techniques. Spontaneous proliferation by lung
lymphocytes from HIV-positive patients was significantly greater than
that of normal volunteers. Proliferation was confined to the CD8+
lymphocyte subset. Over time spontaneous proliferation declined
unless autologous alveolar macrophages (AM) were added, suggesting AM
were providing additional stimulatory signals to lung lymphocytes.
Lung and blood lymphocytes proliferated in response to IL-2, but not
IL-4. HIV lung lymphocytes spontaneously produced and secreted more
IL-2 than either normal lung lymphocytes or autologous blood
lymphocytes. IL-4 production was not detectable in either group.
These findings support the hypothesis that lymphocytic alveolitis in
asymptomatic HIV-positive patients results from IL-2 dependent in
situ proliferation of CD3+/CD8+ cytotoxic T cells.
Received 14 February 1995; accepted in final form 15 May 1995.
APS Manuscript Number L46-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 26 May 1995.