Premium
Testosterone and innate immune function inversely covary in a wild population of breeding Dark‐Eyed Juncos ( Junco hyemalis )
Author(s) -
GREIVES T. J.,
MCGLOTHLIN J. W.,
JAWOR J. M.,
DEMAS G. E.,
KETTERSON E. D.
Publication year - 2006
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1111/j.1365-2435.2006.01167.x
Subject(s) - innate immune system , biology , immune system , immunity , testosterone (patch) , immunology , population , acquired immune system , classical complement pathway , complement system , endocrinology , medicine , environmental health
Summary1 Innate immunity refers to the non‐specific components of the primary immune response, which act broadly to destroy pathogens. Effective innate immune responses may save an individual the energetic costs associated with activating subsequent specific immune responses. 2 Testosterone can suppress immune function in vitro and in vivo . Most studies examining testosterone's effects on immunity have focused on experimentally elevated testosterone and acquired immune responses (e.g. humoral and cell‐mediated responses to foreign antigens). Few studies have investigated the relationship between endogenous levels of testosterone and innate immunity. 3 In a wild breeding population of Dark‐Eyed Juncos ( Junco hyemalis Linnaeus), we asked whether endogenous levels of testosterone measured at several points during the breeding season covaried with two components of innate immunity: total levels of non‐specific immunoglobulin‐G (IgG), and complement levels. 4 Testosterone levels were significantly negatively correlated with both total IgG and complement activity. Both immune measures were also positively correlated with body mass. Taken together with experimental results from the same species, these results suggest that elevated testosterone levels may compromise innate as well as acquired immune function.