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Sex differences in immune responses : Hormonal effects, antagonistic selection, and evolutionary consequences

Roved, Jacob LU ; Westerdahl, Helena LU and Hasselquist, Dennis LU (2017) In Hormones and Behavior 88. p.95-105
Abstract

Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important roles in adaptive immunity, e.g. Th1 cells trigger type 1 responses which are primarily cell-mediated, and Th2 cells trigger type 2 responses which are primarily humoral responses. In our review of the literature, we find that estrogen and progesterone enhance type 2 and suppress type 1 responses in females, whereas testosterone suppresses... (More)

Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important roles in adaptive immunity, e.g. Th1 cells trigger type 1 responses which are primarily cell-mediated, and Th2 cells trigger type 2 responses which are primarily humoral responses. In our review of the literature, we find that estrogen and progesterone enhance type 2 and suppress type 1 responses in females, whereas testosterone suppresses type 2 responses and shows an inconsistent pattern for type 1 responses in males. When we combine these patterns of generally immunosuppressive and immunoenhancing effects of the sex hormones, our results imply that the sex differences in immune responses should be particularly strong in immune functions associated with type 2 responses, and less pronounced with type 1 responses. In general the hormone-mediated sex differences in immune responses may lead to genetic sexual conflicts on immunity. Thus, we propose the novel hypothesis that sexually antagonistic selection may act on immune genes shared by the sexes, and that the strength of this sexually antagonistic selection should be stronger for type 2- as compared with type 1-associated immune genes. Finally, we put the consequences of sex hormone-induced effects on immune responses into behavioral and ecological contexts, considering social mating system, sexual selection, geographical distribution of hosts, and parasite abundance.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Estrogen, ICHH, Immune system, Immunocompetence handicap hypothesis, Mating system, Sex hormones, Sexual selection, Sexually antagonistic selection, Testosterone, Th1, Th2, Type 1 immune response, Type 2 immune response
in
Hormones and Behavior
volume
88
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:85008196626
  • wos:000394561300013
ISSN
0018-506X
DOI
10.1016/j.yhbeh.2016.11.017
language
English
LU publication?
yes
id
edc975f6-1a37-4308-b691-a1c39cb44032
date added to LUP
2017-01-23 13:39:25
date last changed
2018-08-19 04:31:36
@article{edc975f6-1a37-4308-b691-a1c39cb44032,
  abstract     = {<p>Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important roles in adaptive immunity, e.g. Th1 cells trigger type 1 responses which are primarily cell-mediated, and Th2 cells trigger type 2 responses which are primarily humoral responses. In our review of the literature, we find that estrogen and progesterone enhance type 2 and suppress type 1 responses in females, whereas testosterone suppresses type 2 responses and shows an inconsistent pattern for type 1 responses in males. When we combine these patterns of generally immunosuppressive and immunoenhancing effects of the sex hormones, our results imply that the sex differences in immune responses should be particularly strong in immune functions associated with type 2 responses, and less pronounced with type 1 responses. In general the hormone-mediated sex differences in immune responses may lead to genetic sexual conflicts on immunity. Thus, we propose the novel hypothesis that sexually antagonistic selection may act on immune genes shared by the sexes, and that the strength of this sexually antagonistic selection should be stronger for type 2- as compared with type 1-associated immune genes. Finally, we put the consequences of sex hormone-induced effects on immune responses into behavioral and ecological contexts, considering social mating system, sexual selection, geographical distribution of hosts, and parasite abundance.</p>},
  author       = {Roved, Jacob and Westerdahl, Helena and Hasselquist, Dennis},
  issn         = {0018-506X},
  keyword      = {Estrogen,ICHH,Immune system,Immunocompetence handicap hypothesis,Mating system,Sex hormones,Sexual selection,Sexually antagonistic selection,Testosterone,Th1,Th2,Type 1 immune response,Type 2 immune response},
  language     = {eng},
  pages        = {95--105},
  publisher    = {Elsevier},
  series       = {Hormones and Behavior},
  title        = {Sex differences in immune responses : Hormonal effects, antagonistic selection, and evolutionary consequences},
  url          = {http://dx.doi.org/10.1016/j.yhbeh.2016.11.017},
  volume       = {88},
  year         = {2017},
}