Contribution of immune cells to intervertebral disc degeneration and the potential of immunotherapy

ABSTRACT

Substantial evidence supports that chronic low back pain is associated with intervertebral disc degeneration (IDD), which is accompanied by decreased cell activity and matrix degradation. The role of immune cells, especially macrophages, in a variety of diseases has been extensively studied; therefore, their role in IDD has naturally attracted widespread scholarly interest. The IVD is considered to be an immunologically-privileged site given the presence of physical and biological barriers that include an avascular microenvironment, a high proteoglycan concentration, high physical pressure, the presence of apoptosis inducers such as Fas ligand, and the presence of notochordal cells. However, during IDD, immune cells with distinct characteristics appear in the IVD. Some of these immune cells release factors that promote the inflammatory response and angiogenesis in the disc and are, therefore, important drivers of IDD. Although some studies have elucidated the role of immune cells, no specific strategies related to systemic immunotherapy have been proposed. Herein, we summarize current knowledge of the presence and role of immune cells in IDD and consider that immunotherapy targeting immune cells may be a novel strategy for alleviating IDD symptoms.

KEYWORDS:

• Intervertebral disc degeneration
• immune cells
• inflammation
• angiogenesis
• immunotherapy

Acknowledgments

This work was supported by the Natural Science Foundation of Shanghai (21ZR1412300), “Technology Innovation Action Plan” of Shanghai Science and Technology Commission (21S11902700), National Science Foundation of China (82272457), Shanghai Talent Development Fund (2020067), Shanghai “Rising Stars of Medical Talent” Youth Development Program (Youth Medical Talents –Specialist Program, [2020]087).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Compliance with ethics requirements

Our article does not contain any studies with human or animal subjects.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [82272457]; Natural Science Foundation of Shanghai [21ZR1412300]; Shanghai Talent Development Fund [2020067]; “Technology Innovation Action Plan” of Shanghai Science and Technology Commission [21S11902700]