Surgery, trauma and immune suppression. Evolving the mechanism.

Area of Science:

• Immunology
• Surgical Medicine

Background:

• Major surgical procedures can lead to significant immune suppression.
• This suppression is linked to increased suppressor cell activity affecting immune responses.
• The exact mechanisms underlying post-surgical immune dysfunction require further elucidation.

Purpose of the Study:

• To investigate the cellular mechanisms behind immune suppression following major surgery.
• To identify specific cell types and serum factors involved in post-operative immune impairment.
• To propose a unifying hypothesis for "paradoxical" immune suppression after major trauma.

Main Methods:

• Utilized third-party mixed leukocyte culture to analyze cell interactions.
• Investigated the roles of nonadherent and plastic-adherent cells in immune responses.
• Conducted adoptive transfer experiments to assess the effects of serum factors.

Main Results:

• A T cell-macrophage interaction was identified as crucial for immune impairment.
• Serum factors in operated mice were found to inhibit mixed leukocyte culture reactivity.
• These serum factors also enhanced primary tumor growth in adoptive transfer studies.

Conclusions:

• Post-surgical immune suppression involves a complex interplay of T cells and macrophages.
• Serum factors play a significant role in mediating immune dysfunction after major trauma.
• A unifying hypothesis is proposed to explain "paradoxical" immune suppression in trauma patients.