Idiopathic pulmonary fibrosis (IPF) is a fibroproliferative disease with irreversible lung function loss and poor survival. Myeloid-derived suppressor cells (MDSC) are associated with poor prognosis in cancer, facilitating immune evasion. The abundance and function of MDSC in IPF is currently unknown.Fluorescence-activated cell sorting was performed in 170 patients (IPF: n=69; non-IPF interstitial lung disease (ILD): n=56; chronic obstructive pulmonary disease (COPD): n=23; healthy controls: n=22) to quantify blood MDSC and lymphocyte subtypes. MDSC abundance was correlated with lung function, MDSC localisation was performed by immunofluorescence. Peripheral blood mononuclear cell (PBMC) mRNA levels were analysed by qRT-PCR.We detected increased MDSC in IPF and non-IPF ILD compared with controls (30.99+/-15.61% versus 18.96+/-8.17%, p=0.01). Circulating MDSC inversely correlated with maximum vital capacity (r= -0.48, p=0.0001) in IPF, but not in COPD or non-IPF ILD. MDSC suppressed autologous T-cells. The mRNA levels of co-stimulatory T-cell signals were significantly downregulated in IPF PBMC. Importantly, CD33(+)CD11b(+) cells, suggestive of MDSC, were detected in fibrotic niches of IPF lungs.We identified increased MDSC in IPF and non-IPF ILD, suggesting that elevated MDSC may cause a blunted immune response. MDSC inversely correlate with lung function only in IPF, identifying them as potent biomarkers for disease progression. Controlling expansion and accumulation of MDSC, or blocking their T-cell suppression, represents a promising therapy in IPF.
- Fernandez, I. E.
- Greiffo, F. R.
- Frankenberger, M.
- Bandres, J.
- Heinzelmann, K.
- Neurohr, C.
- Hatz, R.
- Hartl, D.
- Behr, J.
- Eickelberg, O.
Keywords
- Aged
- Biomarkers/blood
- Case-Control Studies
- Cell Separation
- Coculture Techniques
- Disease Progression
- Female
- Flow Cytometry
- Humans
- Idiopathic Pulmonary Fibrosis/*immunology/physiopathology
- Immune System
- Leukocytes, Mononuclear/*immunology
- Lung/pathology
- Lung Diseases, Interstitial/blood
- Male
- Middle Aged
- Myeloid-Derived Suppressor Cells/*cytology
- Prognosis
- Prospective Studies
- Pulmonary Disease, Chronic Obstructive/blood
- RNA, Messenger/metabolism