Falling in love is associated with immune system gene regulation

Abstract

Although falling in love is one of the most important and psychologically potent events in human life, the somatic implications of new romantic love remain poorly understood. Psychological, immunological, and reproductive perspectives offer competing predictions of the specific transcriptional regulatory shifts that might accompany the experience of falling in love. To characterize the impact of romantic love on human genome function, we conducted genome-wide transcriptome profiling of 115 circulating immune cell samples collected from 47 young women over the course of a 2-year longitudinal study. Analyses revealed a selective alteration in immune cell gene regulation characterized by up-regulation of Type I interferon response genes associated with CD1C+/BDCA-1+ dendritic cells (DCs) and CLEC4C+/BDCA-2+ DCs, and a reciprocal down-regulation of α-defensin-related transcripts associated with neutrophil granulocytes. These effects emerged above and beyond the effects of changes in illness, perceived social isolation, and sexual contact. These findings are consistent with a selective up-regulation of innate immune responses to viral infections (e.g., Type I interferons and DC) and with DC facilitation of sexual reproduction, and provide insight into the immunoregulatory correlates of one of the keystone experiences in human life.

Keywords: Health; Immune system regulation; Romantic love; Social genomics.

Conflict of interest statement

Competing Interests

Declarations of interest: None

Competing Interests/Conflict of Interest

We have no competing interests.

Copyright © 2018 Elsevier Ltd. All rights reserved.

Figures

Fig 1 –. Gene transcriptional correlates of falling in love.

(A.) Representative examples of 61 gene transcripts showing > 15% differential change from baseline to follow-up in 94 longitudinal PBMC samples from 47 women who fell in love (n=17) vs. did not (n=30). Boxes span 25th-75th percentiles, internal bar = median, and dashes indicate the no-change reference point. Transcript Origin Analysis (TOA) mapped the cellular origins of the 20 up-regulated and 41 down-regulated genes (listed in Table S1) over major leukocyte subsets (B.) and a more refined fractionation of myeloid lineage immune cells (C.). Data represent mean ± SE TOA cell diagnostic z-score; * indicates p

Fig 2 –. Transcription control pathways in love-related gene regulation.

TELiS bioinformatics analysis analyzed the prevalence of transcription factor-binding motifs (TFBMs) for representative transcription factors involved in myeloid immune cell development and effector function and neuroendocrine regulation. Data represent the average (± SE) log2 ratio of TFBM frequency in promoters of 20 genes up-regulated in association with falling in love vs. 41 genes down-regulated (genes listed in Table S1). * indicates p