Hammond Emma, Monari Patrick, Kilponen Lila, Chen Yiru, Auger Anthony, Marler Catherine
University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
Psychoneuroendocrinology. 2025 Jun;176:107445. doi: 10.1016/j.psyneuen.2025.107445. Epub 2025 Mar 23.
Social isolation hampers immune system function, and the biological mechanisms driving this effect remain understudied. We hypothesized that oxytocin (OT), a key neuropeptide involved in social cognition, is a critical mediator of social context on immune function. In the California mouse (Peromyscus californicus), we examined how female and male immune function is influenced by (1) social isolation from same-sex peers, (2) social peer affiliation, and (3) exogenous OT. We evaluated immune function through wound size progression following a skin biopsy and proinflammatory cytokines in the wound fluid. Unexpectedly, social isolation alone did not influence wound healing, but isolation + OT increased wound size in a dose dependent manner. Wound size progression interacted with sex and OT in socially-housed mice, suggesting that OT increases inflammation in females, while decreasing inflammation in males in a social context-dependent manner. Inflammatory biomarker interleukin-6 (IL-6) mRNA expression correlated with wound size overall, supporting wound healing as an index of inflammatory response. However, isolation + OT mice did not have higher levels of IL-6, suggesting that the mechanism through which isolation + OT influences wound size is not through IL-6 activity. Behaviorally, higher levels of affiliation were negatively associated with wound size, and this effect was diminished by OT treatment. Our results highlight that the anti-inflammatory effects of OT are likely highly dependent on social context.
社会隔离会妨碍免疫系统功能，而驱动这种效应的生物学机制仍未得到充分研究。我们推测，催产素（OT）作为一种参与社会认知的关键神经肽，是社会环境对免疫功能影响的关键调节因子。在加州小鼠（加州林鼠）中，我们研究了（1）与同性同伴的社会隔离、（2）社会同伴关系以及（3）外源性OT如何影响雌性和雄性的免疫功能。我们通过皮肤活检后的伤口大小变化以及伤口液中的促炎细胞因子来评估免疫功能。出乎意料的是，单独的社会隔离并未影响伤口愈合，但隔离 + OT会以剂量依赖的方式增加伤口大小。在群居小鼠中，伤口大小变化与性别和OT存在相互作用，这表明在社会环境依赖的方式下，OT会增加雌性的炎症反应，同时减少雄性的炎症反应。炎症生物标志物白细胞介素-6（IL-6）的mRNA表达总体上与伤口大小相关，支持将伤口愈合作为炎症反应的指标。然而，隔离 + OT组小鼠的IL-6水平并未升高，这表明隔离 + OT影响伤口大小的机制并非通过IL-6的活性。在行为方面，更高水平的同伴关系与伤口大小呈负相关，而OT处理会减弱这种效应。我们的研究结果表明，OT的抗炎作用可能高度依赖于社会环境。
