Transcriptional responses of PBMC in psychosocially stressed animals indicate an alerting of the immune system in female but not in castrated male pigs.
BACKGROUND
Brain and immune system are linked in a bi-directional manner. To date, it remained largely unknown why immune components become suppressed, enhanced, or remain unaffected in relation to psychosocial stress. Therefore, we mixed unfamiliar pigs with different levels of aggressiveness. We separated castrated male and female pigs into psychosocially high- and low- stressed animals by skin lesions, plasma cortisol level, and creatine kinase activity obtained from agonistic behaviour associated with regrouping. Peripheral blood mononuclear cells (PBMC) were collected post-mortem and differential gene expression was assessed using the Affymetrix platform (n = 16).


RESULTS
Relevant stress-dependent alterations were found only between female samples, but not between castrated male samples. Molecular routes related to TREM 1 signalling, dendritic cell maturation, IL-6 signalling, Toll-like receptor signalling, and IL-8 signalling were increased in high stressed females compared to low stressed females. This indicates a launch of immune effector molecules as a direct response. According to the shifts of transcripts encoding cell surface receptors (e.g. CD14, TLR2, TLR4, TREM1) the study highlights processes acting on pattern recognition, inflammation, and cell-cell communication.


CONCLUSIONS
The transcriptional response partly affected the degree of 'stress responsiveness', indicating that the high stressed females altered their signal transduction due to potential infections and injuries while fighting.
Michael
M
Oster
Eduard
E
Muráni
Siriluck
S
Ponsuksili
Richard B
RB
D'Eath
Simon P
SP
Turner
Gary
G
Evans
Ludger
L
Thölking
Esra
E
Kurt
Ronald
R
Klont
Aline
A
Foury
Pierre
P
Mormède
Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany. wimmers@fbn-dummerstorf.de.
Klaus
K
Wimmers
D000818:Animals; D016000:Cluster Analysis; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007109:Immunity / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology; D012737:Sex Factors; D015398:Signal Transduction; D013315:Stress, Psychological / Q000235:genetics*; D013552:Swine; D014158:Transcription, Genetic; D059467:Transcriptome
D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic