Increased expression of interferon-inducible genes in macaque lung tissues during simian immunodeficiency virus infection

Abstract

Pulmonary infections and dysfunction are frequent outcomes during the development of immunodeficiency associated with human immunodeficiency virus type 1 (HIV-1) infection, and obtaining a better understanding of the immunologic changes that occur in lungs following HIV-1 infection will provide a foundation for the development of further intervention strategies. We sought here to identify changes in the pulmonary immune environment that arise during simian immunodeficiency virus (SIV) infection of rhesus macaques, which serves as an excellent model system for HIV-1 infection and disease. To examine the gene expression profiles of macaque lung tissues following infection with the pathogenic SIV/DeltaB670 isolate, we performed cDNA microarray hybridizations with lung total RNAs using two commercially available cDNA arrays and a custom-fabricated, immunologically focused macaque cDNA microarray. In situ hybridization and real-time RT-PCR were performed to provide additional analyses of gene expression. Among the genes exhibiting the highest level of induction in lung tissues were the IFN-gamma-inducible chemokines, CXCL10/IP-10 and CXCL9/Mig. In situ hybridization and real-time RT-PCR strongly supported these findings. Correlation analyses revealed that the levels of expression of IFN-gamma, CXCL9/Mig, and CXCL10/IP-10 mRNAs were all strongly positively correlated, and that CXCL10/IP-10 mRNA and Pneumocystis carinii rRNA were positively correlated. Taken together, these findings demonstrate that inflammatory chemokines are among the most differentially expressed mRNAs in macaque lung tissues during systemic SIV infection of rhesus macaques, and provide insight into the complicated events occurring in the lung tissues during HIV-1 infection in humans.

Nonpathogenesis of Simian Immunodeficiency Virus Infection Is Associated with Reduced Inflammation and Recruitment of Plasmacytoid Dendritic Cells to Lymph Nodes, Not to Lack of an Interferon Type I Response, during the Acute Phase

“…Higher recruitment of pDCs within LNs is observed in monkeys progressing more rapidly to AIDS and associated with greater inflammatory response (as measured by the presence of circulating IL-8). Recently, the examination of global gene expression changes of pathogenic (pigtail monkeys) and nonpathogenic (AGMs) SIV infections (23) has revealed in LNs that the greatest differential regulation of genes is related to (i) genes associated with cell death, which is consistent with the extent of apoptosis detected by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) method in the tissues of SIV-infected monkeys (9, 14, 33, 43, 49); (ii) inflammatory and chemotaxis genes, which is consistent with the detection of IL-8 and other reports (1,25,40,42); (iii) higher levels of immune activation consistent with previous studies showing that in NCs the extent of CD8 activation is greater than in CS RMs of Chinese origin (34,36); and (iv) genes associated with the IFN response (1,21,41). Consistent with our data, Milush et al (32) found that expression of type I IFN expression in LNs was more highly expressed in NC-RMs than in C-RMs.…”

Simian Immunodeficiency Virus Infection Alters Chemokine Networks in Lung Tissues of Cynomolgus Macaques

“…52 Similarly, CXCL9 and CXCL10 were found by us through microarray analyses to be up-regulated in rhesus macaque lung tissues. 13 Taken altogether, our data strongly suggest that P. carinii is involved in induction of these chemokines. These increased chemokines would recruit more inflammatory cells to infected sites and thus contribute to damaging inflammation in the infected lung tissue.…”

“…9,12,13 Autoradiographic exposure times, following ISH with antisense and control sense 35 S-labeled riboprobes specific for SIV, P. carinii, interferon (IFN)-␥, and chemokine RNAs were 7 to 10 days.…”

“…RNA extraction, template preparation, and real-time RT-PCR were performed by using a two-step protocol as described, 13,14 with RT-negative controls always performed in parallel. PCR amplification was performed by using 2.5 l of each cDNA in TaqMan Universal PCR Master Mix with TaqMan primer/probe combinations in a total volume of 25 l. Primer and probe sequences for real-time RT-PCR were either purchased as gene-specific sets (Applied Biosystems, Foster City, CA) or designed by using the Primer Express Software package (Applied Biosystems).…”

Antiviral Therapy during Primary Simian Immunodeficiency Virus Infection Fails To Prevent Acute Loss of CD4 + T Cells in Gut Mucosa but Enhances Their Rapid Restoration through Central Memory T Cells

“…To determine the magnitude of difference in gene expression levels between the PSI and CSI groups, the data are presented as a ratio of the CSI to PSI. The PSI sample was used as the calibrator in this analysis (1,62).…”