The thymus gland is an organ in the lymphatic system serves a vital role within the immune system.

In a study published by Science immunology, researchers found a growth protein called BMP4, that is created by the endothelial cells within the inner wall of the thymus and is critical for it’s repair in mice. Scientists also discovered that injecting these cells either into the blood stream or into the thymus itself sped up the recovery of the thymus.

The study’s authors discovered a new axis in the thymus regeneration. Avinash Bhandoola, head of the T-cell biology development unit at the National Cancer Institute’s Centre for Cancer Research, who was not involved in the study stated “ They showed that endothelial cells make the molecule BMP4, and this is actually really important for accelerating the regeneration of the thymus after damage.”

The thymus shrinks as we grow older, is highly sensitive to damage from stress and infection.  Bhandoola states “ We don’t really understand why the thymus shrinks as we get older, or how to make it bigger in patients where it would likely be helpful to have T cells be made.”

Therapies based upon this research would be more likely to isolate BMP4 than an endothelial cell line. Thomas Serwold a Harvard Medical School Immunobiologist who was also not involved in the study stated, “Another future interesting direction would be whether this same pathway could be used in the ageing thymus.” In this scenario, or in damage which is linked to chronic conditions, perhaps boosting BMP4 activity would also drive thymus regeneration, Serworld speculates.

An incredibly interesting study, if you would like to read into this further you can access the full study here:

References
T. Wertheimer et al., “Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration,” Science Immunology, doi:10.1126/sciimmunol.aal2736, 2017. :http://immunology.sciencemag.org/content/3/19/eaal2736