Biology Reference
In-Depth Information
10
Alveolar Macrophages
Jianmin Zhang and Henry Koziel
Harvard Medical School, Boston, MA, USA
INTRODUCTION
The lungs remain an important target for human immunode®ciency virus
( HIV ) infection. In the absence of chemoprophylaxis or speci®c antiretroviral
therapy, the majority of HIV-infected persons experience pulmonary compli-
cations. At this anatomical locus, alveolar macrophages (AM) represent the
most abundant and principal resident immune cells. AM are critical for the
initiation and maintenance of normal immune and in¯ammatory responses in
the lower respiratory tract and are poised to serve as a ®rst-line host defense
against invading pathogens. However, whether AM function is altered in the
lungs of HIV-infected persons remains somewhat controversial.
Most published studies examining the e¨ects of HIV-1 on macrophage
function have been performed on monocytes or mono-derived macrophages,
with few studies speci®cally examining AM. For comprehensive overviews of
macrophage function in HIV infection, the reader is referred to a number of
excellent reviews (Agostini et al., 1993a; Twigg, 1997, 1998). As the alveolar
compartment represents a unique environment in which macrophages function,
extrapolation from studies performed on other cells of monocyte-macrophage
lineage must be made with caution. In this regard, this chapter will focus on
AM (especially human AM), highlighting data that illustrate important funda-
mental observations in the study of AM in the context of HIV infection, and
feature data derived by ¯ow cytometry.
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