Background: Depression of the immune system can result in poor or delayed w
ound healing.
Methods: Thymectomized rats were depleted of CD4(+) and CD8(+) lymphocytes
by intraperitoneal injection of Medical Research Council Oxford (MRC OX)38
antibodies and MRC OX8. Significant depletion was demonstrated throughout t
he wound healing process by immunofluorescence studies of peripheral blood.
Following depletion the rats underwent laparotomy incisions which were all
owed to heal for 10 weeks. Differences in healing were demonstrated by anal
ysing the wounds biomechanically by tensiometry to obtain values of ultimat
e strength, resilience, toughness, maximum extension and elastic constant.
Results: Wounds of animals depleted of CD4(+) lymphocytes showed a signific
ant decrease in ultimate strength, resilience and toughness. Wounds of anim
als depleted of CD8(+) lymphocytes showed a significant increase in ultimat
e strength, resilience and toughness.
Conclusion: Wounds healed in the absence of T lymphocytes. However, the sub
sets have an opposing regulatory role, with CD4(+) lymphocytes upregulating
and CD8(+) lymphocytes downregulating wound healing.