SIV DNA can be detected in lymphoid tissue–resident macrophages of chronically SIV-infected Asian macaques. These macrophages also contain evidence of recently phagocytosed SIV-infected CD4+ T cells. Here, we examine whether these macrophages contain replication-competent virus, whether viral DNA can be detected in tissue-resident macrophages from antiretroviral (ARV) therapy–treated animals and humans, and how the viral sequences amplified from macrophages and contemporaneous CD4+ T cells compare. In ARV-naive animals, we find that lymphoid tissue–resident macrophages contain replication-competent virus if they also contain viral DNA in ARV-naive Asian macaques. The genetic sequence of the virus within these macrophages is similar to those within CD4+ T cells from the same anatomic sites. In ARV-treated animals, we find that viral DNA can be amplified from lymphoid tissue–resident macrophages of SIV-infected Asian macaques that were treated with ARVs for at least 5 months, but we could not detect replication-competent virus from macrophages of animals treated with ARVs. Finally, we could not detect viral DNA in alveolar macrophages from HIV-infected individuals who received ARVs for 3 years and had undetectable viral loads. These data demonstrate that macrophages can contain replication-competent virus, but may not represent a significant reservoir for HIV in vivo.
Abstract Rationale: Despite the availability of multi-“omics” strategies, insights into the etiology and pathogenesis of sarcoidosis have been elusive. This is partly due to the lack of reliable preclinical models and a paucity of validated biomarkers. As granulomas are a key feature of sarcoidosis, we speculate that direct genomic interrogation of sarcoid tissues, may lead to identification of dysregulated gene pathways or biomarker signatures. Objective: To facilitate the development sarcoidosis genomic biomarkers by gene expression profiling of sarcoidosis granulomas in lung and lymph node tissues (most commonly affected organs) and comparison to infectious granulomas (coccidiodomycosis and tuberculosis). Methods: Transcriptomic profiles of immune-related gene from micro-dissected lungs and mediastinal lymph nodes sarcoidosis granulomas was compared to infectious granulomas. Differentially-expressed genes (DEGs) were profiled, compared among the three granulomatous diseases and analyzed for functional enrichment pathways. Results: Despite histologic similarities, DEGs and pathway enrichment markedly differed in sarcoidosis granulomas from lymph nodes and lung. Lymph nodes showed a clear immunological response, whereas a structural regenerative response was observed in lung. Sarcoidosis granuloma gene expression data corroborated previously reported genomic biomarkers, excluded others and identified new genomic markers present in lung and lymph nodes, ADAMTS1, CXCL2, FABP4 . Comparisons between sarcoidosis and pathogen granulomas identified pathway divergences and commonalities at gene expression level. Conclusion : These findings suggest the importance of tissue and disease-specificity evaluation when exploring sarcoidosis genomic markers. This relevant translational information in two commonly affected tissue in sarcoidosis and other two histopathological similar infections provides meaningful specific genomic-derived biomarkers for sarcoidosis diagnosis and prognosis.
Researchers over the past 40 years have utilized bronchoalveolar lavage (BAL) as a tool to help expand our knowledge of pulmonary medicine. Many reports have documented BAL as a safe procedure for research subjects. New technologies, such as flow cytometry, have provided much needed insight into the mechanisms behind several pulmonary diseases. The concept of the lung as an easily accessible mucosal site to monitor local immune responses and treatment effects is evolving. Future BAL research with human subjects, aided by new technology, will undoubtedly yield clinically relevant information regarding biomarkers of disease and new therapeutic targets.
