Individuals vary their immune response according to age, sex and the costs

September 10, 2008
The sexes face differential immune investment costs as they mature from nest-bound juveniles to independent adults. Credit: Oliver P. Love

Is it always good to respond maximally when pathogens or disease strike, or should individuals vary their immune response to balance immediate and future costs? This is the question evolutionary physiologists Oliver Love, Katrina Salvante, James Dale, and Tony Williams asked when they examined how a simple immune response varied at different life stages across the life-span of individual zebra finches (Taeniopygia guttata), in a study published in the September issue of the American Naturalist.

When transitioning from nest-bound juveniles to adults, female immune responses matured slowly whereas males showed dramatic variation potentially due to the costs of molting into their colorful sexually dimorphic plumage. Adult males showed little variation in immune response despite changes in resource quality.

Likewise, when females laid eggs under high-quality resource conditions, immune responses were also consistent with those during non-breeding and similar to male responses. However, when laying on reduced resources females reduced their immune response and their reproductive output consistent with a facultative (resource-driven) effect of reproductive effort on immunity.

Moreover, even under high-resource conditions during the chick-rearing stage mothers showed reduced immune responses compared to fathers suggesting a residual energetic cost of egg-laying. Perhaps most importantly, immune responses of juveniles of both sexes did not predict their subsequent adult responses.

Immune responses of adult females were only predictable when the quality of the environment remained constant; as soon as conditions deteriorated, individual females required flexibility in both the immune and reproductive systems. However, the degree of flexibility came at a cost as only individuals with high immune responses as non-breeders had the capacity to reduce responses when times became tough.

These results underlie the fact that immunity is a highly plastic trait that can be modulated in a sex- and context-dependent manner. Given the need for individual flexibility in the immune system, this suggests that an immune response at one stage may provide limited information about immune response at future stages.

Citation: Oliver P. Love, Katrina G. Salvante, James Dale, and Tony D. Williams, "Sex-specific variability in the immune system across life-history stages." American Naturalist (2008) 172: E99–E112

Source: University of Chicago

Explore further: Colorful potatoes may pack powerful cancer prevention punch

Related Stories

How plant sensors detect pathogens

August 25, 2015

In the mid-20th century, an American scientist named Harold Henry Flor helped explain how certain varieties of plants can fight off some plant killers (pathogens), but not others, with a model called the "gene-for-gene" hypothesis. ...

Biophysicists take small step in quest for 'robot scientist'

August 25, 2015

Biophysicists have taken another small step forward in the quest for an automated method to infer models describing a system's dynamics - a so-called robot scientist. Nature Communications published the finding - a practical ...

Clever feedback system regulates immune responses

August 17, 2015

A newly discovered feedback mechanism in the body is responsible for keeping immune responses from getting out of hand. It works at the level of certain genes, linking the inactivation of those genes to the progress made ...

Recommended for you

New material science research may advance tech tools

August 31, 2015

Hard, complex materials with many components are used to fabricate some of today's most advanced technology tools. However, little is still known about how the properties of these materials change under specific temperatures, ...

An engineered surface unsticks sticky water droplets

August 31, 2015

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.