EMPHYSEMA

EMPHYSEMA

Cigarette Smoke Induction of Osteopontin (SPP1) Mediates T_H17 Inflammation in Human and Experimental Emphysema

1. Ming Shan¹,², 
2. Xiaoyi Yuan¹,², 
3. Li-zhen Song¹, 
4. Luz Roberts¹, 
5. Nazanin Zarinkamar¹,
6. Alexander Seryshev¹, 
7. Yiqun Zhang³, 
8. Susan Hilsenbeck³, 
9. Seon-Hee Chang⁴, 
10. Chen Dong⁴,
11. David B. Corry¹,²,⁵,* and 
12. Farrah Kheradmand¹,²,⁵,* 
¹Department of Medicine, Section of Pulmonary and Critical Care, Baylor College of Medicine, Houston, TX 77030, USA

ABSTRACT

Smoking-related lung diseases are among the leading causes of death worldwide, underscoring the need to understand their pathogenesis and develop new effective therapies. We have shown that CD1a⁺ antigen-presenting cells (APCs) from lungs of patients with emphysema can induce autoreactive T helper 1 (T_H1) and T_H17 cells. Similarly, the canonical cytokines interferon-γ (IFN-γ) and interleukin-17A (IL-17A) are specifically linked to lung destruction in smokers, but how smoke activates APCs to mediate emphysema remains unknown. Here, we show that, in addition to increasing IFN-γ expression, cigarette smoke increased the expression of IL-17A in both CD4⁺ and γδ T cells from mouse lung. IL-17A deficiency resulted in attenuation of, whereas lack of γδ T cells exacerbated, smoke-induced emphysema in mice. Adoptive transfer of lung APCs isolated from mice with emphysema revealed that this cell population was capable of transferring disease even in the absence of active smoke exposure, a process that was dependent on IL-17A expression. Spp1 (the gene for osteopontin) was highly expressed in the pathogenic lung APCs of smoke-exposed mice and was required for the T_H17 responses and emphysema in vivo, in part through its inhibition of the expression of the transcription factor Irf7. Thus, the Spp1-Irf7 axis is critical for induction of pathological T_H17 responses, revealing a major mechanism by which smoke activates lung APCs to induce emphysema and identifying a pathway that could be targeted for therapeutic purposes.

• Copyright © 2012, American Association for the Advancement of Science

Citation: M. Shan, X. Yuan, L.-z. Song, L. Roberts, N. Zarinkamar, A. Seryshev, Y. Zhang, S. Hilsenbeck, S.-H. Chang, C. Dong, D. B. Corry, F. Kheradmand, Cigarette Smoke Induction of Osteopontin (SPP1) Mediates T_H17 Inflammation in Human and Experimental Emphysema. Sci. Transl. Med. 4, 117ra9 (2012).