Sarcoidosis is a chronic inflammatory disease that often results in progressive, untreatable pathology. It likely results from complex interactions between unidentified genetic, infectious, and/or environmental factors that combine to induce ongoing granuloma formation in affected tissues. These granulomas contain increased numbers of monocytes and CD4+ T cells and are accompanied by increased proinflammatory cytokines and chemokines, as well as by abnormalities in regulatory T cells (Tregs) which normally function to control inflammation. Little is known about how these factors lead to phenotypic differences in disease activity. Thus, while many patients with sarcoidosis will stabilize and in some cases even remit, approximately 20% of patients will develop progressive disease that in some cases results in death. Until we understand this disease better, there is little hope for predicting the clinical course and finding new therapies. We have recently found that the blood of patients with sarcoidosis contains several unique cell populations with potential import in disease pathogenesis. We have found that sarcoid patients show increased numbers of circulating fibrocytes, and that (unlike normal controls) these cells secrete increased quantities of proinflammatory cytokines. We have also found that the blood of sarcoid patients contains a unique Treg population that expresses Semaphorin 7a, and that these cells appear to stimulate exaggerated fibrocyte outgrowth and cytokine secretion. Curiously, both fibrocytes and Sema 7a+ Tregs are most elevated in those sarcoid patients with severe or progressive disease and as such may be related to disease phenotype. This grant tests the hypothesis that fibrocytes and/or Sema 7a+ Tregs function as biomarkers of disease progression in patients with newly diagnosed pulmonary sarcoidosis.
In aim 1 we will recruit and characterize a cohort of sarcoid patients (and controls) to create a biorepository for the proposed studies.
In aims 2 and 3 we will quantify circulating fibrocytes and Sema 7a+ Tregs and assess their ability to predict disease progression in the subjects recruited in aim 1. Mechanistic studies will be performed to determine the nature of the fibrocyte-Treg interactions. It is hoped that these studies will deepen our understanding of disease progression in patients with sarcoidosis and lead to new insight that could lead to novel therapeutic options.

Public Health Relevance

The purpose of this grant is to recruit and characterize a cohort of subjects with pulmonary sarcoidosis, as well two additional cohorts (one with no known lung disease, and one with Alpha-1 Antitrypsin Deficiency, another form of genetic lung disease) that will serve as controls. We will then determine whether disease progression can be predicted in sarcoid patients by measurements of peripheral blood fibrocytes or by regulatory T cells that express the neuronal guidance protein Semaphorin 7a.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project--Cooperative Agreements (U01)
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Special Emphasis Panel (ZHL1-CSR-S (F3))
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Punturieri, Antonello
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Yale University
Internal Medicine/Medicine
Schools of Medicine
New Haven
United States
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Ryu, Changwan; Sun, Huanxing; Gulati, Mridu et al. (2017) Extracellular Mitochondrial DNA Is Generated by Fibroblasts and Predicts Death in Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med 196:1571-1581
Ryu, Changwan; Herzog, Erica L; Pan, Hongyi et al. (2017) Upper Airway Obstruction Requiring Emergent Tracheostomy Secondary to Laryngeal Sarcoidosis: A Case Report. Am J Case Rep 18:157-159
Peng, Xueyan; Moore, Meagan; Mathur, Aditi et al. (2016) Plexin C1 deficiency permits synaptotagmin 7-mediated macrophage migration and enhances mammalian lung fibrosis. FASEB J 30:4056-4070
Ryu, Changwan; Homer, Robert J; Herzog, Erica L (2016) The Airway in Idiopathic Pulmonary Fibrosis: Protecting the Lung or Promoting Disease? Am J Respir Crit Care Med 193:1081-2
Gulati, Mridu; Redlich, Carrie A (2015) Asbestosis and environmental causes of usual interstitial pneumonia. Curr Opin Pulm Med 21:193-200
Hu, Xinyuan; DeBiasi, Erin M; Herzog, Erica L (2015) Flow Cytometric Identification of Fibrocytes in the Human Circulation. Methods Mol Biol 1343:19-33
Strange, Charlie; Senior, Robert M; Sciurba, Frank et al. (2015) Rationale and Design of the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis Study. Alpha-1 Protocol. Ann Am Thorac Soc 12:1551-60
Moller, David R; Koth, Laura L; Maier, Lisa A et al. (2015) Rationale and Design of the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) Study. Sarcoidosis Protocol. Ann Am Thorac Soc 12:1561-71
Zhou, Yang; Peng, Hong; Sun, Huanxing et al. (2014) Chitinase 3-like 1 suppresses injury and promotes fibroproliferative responses in Mammalian lung fibrosis. Sci Transl Med 6:240ra76
Gan, Ye; Herzog, Erica L (2014) MMP28 and macrophage polarization: orchestrating the attack of the mac. J Leukoc Biol 95:1-3

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