Transforming growth factor-beta 1 and cortisol in differentially reared primates

Area of Science:

• Neuroendocrinology
• Immunology
• Developmental Psychology

Background:

• Adverse early life experiences can cause long-term behavioral, neuroendocrine, and immunological issues in primates.
• The impact of differential rearing on cytokines, which influence immune responses and the HPA axis, remains understudied.

Purpose of the Study:

• To investigate the relationship between circulating transforming growth factor-beta 1 (TGF-beta 1) and cortisol levels in macaques subjected to variable foraging demand (VFD) rearing compared to normal rearing.
• To assess the long-term effects of VFD rearing on the HPA axis and immune function markers.

Main Methods:

• Macaque infants were reared under normal conditions or VFD, where mothers required more effort to obtain food for 4 months.
• Two years post-rearing, a moderate stressor (confinement) was applied to assess serum TGF-beta 1 and plasma cortisol levels.
• Correlations between TGF-beta 1 and cortisol were analyzed in both rearing groups.

Main Results:

• VFD-reared monkeys exhibited elevated serum TGF-beta 1 and plasma cortisol levels after stress exposure compared to controls.
• A stronger correlation between TGF-beta 1 and cortisol was observed in normally reared macaques.
• These findings suggest lasting alterations in HPA axis and immune responses due to early-life stress.

Conclusions:

• Variable foraging demand rearing in early life induces persistent neuroendocrine and immune dysregulation in primates.
• Understanding the interplay between HPA axis activity and immune function is crucial for comprehending the pathophysiology of adverse rearing.
• This study highlights the long-term consequences of early-life stress on stress hormone and cytokine regulation.