Lymphoid tissues are sites of soluble and cell-associated
antigen sampling of peripheral tissues, and they are key compart-
ments for the generation of cellular and humoral immune responses.
Hilar lymph nodes (HiLNs), which drain the lungs, were examined to
understand the effects of simian immunodeficiency virus (SIV) infec-
tion on this compartment of the immune system. Histologic and
messenger RNA (mRNA) expression profiling approaches were used
to determine the numbers, types, and distributions of SIV viral RNA+
cells and to identify differentially expressed genes in HiLNs during
SIV infection. SIV RNA+ cells were found to be primarily CD682 and
localized to paracortical and medullary regions early in infection,
whereas they resided mainly in paracortex during AIDS. As SIV
infection progressed, CXCL9, CXCL10, interferon-g, and Toll-like
receptor 3 levels all increased. In contrast, CCL19 increased early in
infection but decreased during AIDS, whereas CCL21 decreased
progressively throughout infection. Finally, local levels of cellular
activation were increased throughout infection. Taken together, these
findings indicate that SIV infection leads to an inflammatory envi-
ronment in lung-draining lymph nodes that is characterized by type 1
cytokines and chemokines and likely has an impact on the nature and
strength of immune responses to pulmonary pathogens.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83336/1/Fallert_et_al.2008.Virologic_and_Immunologic_Events_in_Hilar_Lymph.2.pd
