AI Article Synopsis

  • Tendon injuries are common and understanding both the innate and adaptive immune responses is crucial for developing treatment options.
  • A study on young male mice revealed that immune cells, including CD4 and CD8 T cells and B cells, respond in a coordinated manner following tendon injuries, showing distinct peaks at different time points post-injury.
  • The research highlights the significance of adaptive immune cells in regulating tendon healing, which is less understood compared to the innate immune response.

Article Abstract

Tendon injuries are a common clinical condition with limited treatment options. The cellular components of the innate immune system, such as neutrophils and macrophages, have been studied in tendon injuries. However, the adaptive immune system, comprising specialized lymphocytes, plays an important role in orchestrating the healing of numerous tissues, but less is known about these cells in tendon healing. To gain a greater understanding of the biological processes that regulate tendon healing, we determined how the cellular components of the adaptive and innate immune system respond to a tendon injury using two-month-old male mice. We observed that lymphatic vasculature is present in the epitenon and superficial regions of Achilles tendons, and that the lymphatics drain into the popliteal lymph node. We then created an acute Achilles tenotomy followed by repair, and collected tendons and popliteal lymph nodes 1, 2, and 4 wk after injury. Tendon injury resulted in a robust adaptive immune cell response that followed an initial innate immune cell response in tendons and lymph nodes. Monocytes, neutrophils, and macrophages initially accumulated at 1 wk after injury in tendons, while dendritic cells and CD4 T cells peaked at 2 wk after injury. B cells and CD8 T cells progressively increased over time. In parallel, immune cells of the popliteal lymph node demonstrated a similarly coordinated response to the injury. These results suggest that there is an adaptive immune response to tendon injury, and adaptive immune cells may play a role in regulating tendon healing. While the innate immune system, consisting of macrophages and related hematopoietic cells, has been studied in tendon injury, less is known about the adaptive immune system. Using a mouse model of Achilles tendon tenotomy and repair, we observed an adaptive immune cell response, consisting of CD4 and CD8 T cells, and B cells, which occur through 4 wk after tendon injury. This response appeared to be coordinated by the draining popliteal lymph node.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7099435PMC
http://dx.doi.org/10.1152/japplphysiol.00682.2019DOI Listing

Publication Analysis

Top Keywords

tendon injury
24
adaptive immune
24
innate immune
20
immune system
20
immune cell
16
popliteal lymph
16
immune
12
lymph nodes
12
tendon
12
tendon healing
12

Similar Publications

Aims: This study presents clinical outcomes, functional results, and return to sports after anterior cruciate ligament (ACL) reconstruction using quadruple hamstring tendon autograft or peroneus longus tendon autograft in a randomized controlled trial.

Patients And Methods: Between February 2018 and July 2019, patients who underwent ACL reconstruction were randomly assigned to two groups: hamstring and peroneus longus. Patient related outcome measurements and pain intensity were evaluated using IKDC, Lysholm, and visual analog scores at 3 and 6 months, 1, 2, and 5 years after the surgery.

View Article and Find Full Text PDF

Introduction: Tendon injuries represent an ongoing challenge in clinical practice due to poor regenerative capacity, structure, and biomechanical function recovery of ruptured tendons. This study is focused on the assessment of a novel strategy to repair ruptured Achilles tendons in a Nude rat model using stem cell-seeded biomaterial.

Methods: Specifically, we have used induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) overexpressing the early tendon marker Scleraxis (SCX, iMSC, iTenocytes) in combination with an elastic collagen scaffold.

View Article and Find Full Text PDF

Proximal gracilis tear is a rare sports-related injury that can easily lead to misdiagnosis and underdiagnosis. Clinical manifestations are dominated by localized pain, tenderness, and dysfunction. Here, we report a therapy of proximal segmental tear of the gracilis and demonstrate its treatment process and clinical outcome.

View Article and Find Full Text PDF

Meniscal root tears are recognized as an important pathology. Failure to recognize and to treat this pathology could lead to early-onset osteoarthritis, similar to a total meniscectomy. Surgical treatment is essential to restore meniscal function and to normalize compartment contact pressures, whenever there is joint overload and not severe cartilaginous damage.

View Article and Find Full Text PDF

Anterior cruciate ligament (ACL) injuries and subsequent surgical reconstruction are exceedingly common orthopaedic procedures. Surgical technique and graft preparation techniques continue to evolve as surgeons seek to increase surgical outcomes and decrease recovery time. As such, there is significant interest in identifying tools and techniques that may enhance the surgical process for patients undergoing an ACL reconstruction.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!