Title

Immunology and cartilage regeneration

Publication Date

2015

Journal Title

Immunol Res

Abstract

The intrinsic regenerative capacity of avascular cartilage is limited. Cartilage injuries result in chronic, non-healing lesions requiring surgical management. Frequently, these surgical techniques make use of allogeneic cells and tissues. This review discusses the immune status of these materials. Cartilage allografts, often used in orthopedic and plastic surgeries, have rarely provoked a significant immune response. In whole cartilage transplants, the dense matrix produced by chondrocytes inhibits lymphocyte migration, preventing immune detection rendering them "antigen sequestered." It is unclear whether isolated chondrocytes are immune-privileged; chondrocytes express immune inhibitory B7 molecules, indicating that they have some ability to modulate immune reactions. Allogeneic cartilage grafts often involve a bony portion often retaining immunogenic cells and proteins-to facilitate good surgical attachment and concern that this may enhance inflammation and immune rejection. However, studies of failed cartilage grafts have not found immune responses to be a contributing factor. Meniscus allografts, which also retain a bony portion, raise similar concerns as cartilage allografts. Despite this, the plugs improved patient outcomes, indicating that the immunological effects were not clinically significant. Finally, allogeneic mesenchymal stromal cells (MSCs) also are being investigated as a treatment for cartilage damage. MSCs have been demonstrated to have unique immunomodulatory properties including their ability to reduce immune cell infiltration and to modulate inflammation. In summary, the immunogenic properties of cartilage vary with the type of allograft used: Cartilage allografts demonstrate active immune-suppressive mechanisms as evidenced by lack of allograft rejection, while MSC allografts appear to be safe for transplantation.

Volume Number

63

Issue Number

1-3

Pages

181-6

Document Type

Article

EPub Date

2015/10/21

Status

Faculty

Facility

School of Medicine

Primary Department

Molecular Medicine

Additional Departments

Orthopedic Surgery

PMID

26481914

DOI

10.1007/s12026-015-8720-7