Increased biodiversity in the environment improves the humoral response of rats

PLoS One. 2015 Apr 8;10(4):e0120255. doi: 10.1371/journal.pone.0120255. eCollection 2015.


Previous studies have compared the immune systems of wild and of laboratory rodents in an effort to determine how laboratory rodents differ from their naturally occurring relatives. This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors. However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals. In this study, the humoral immune responses of laboratory rats in a traditional laboratory environment and in an environment with enriched biodiversity were examined following immunization with a panel of antigens. Biodiversity enrichment included colonization of the laboratory animals with helminths and co-housing the laboratory animals with wild-caught rats. Increased biodiversity did not apparently affect the IgE response to peanut antigens following immunization with those antigens. However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of "natural" antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens / immunology
  • Biodiversity*
  • Body Weight / immunology
  • Female
  • Immunity, Humoral*
  • Immunization
  • Immunoglobulins / blood
  • Immunoglobulins / immunology
  • Male
  • Rats
  • T-Lymphocytes / immunology


  • Antigens
  • Immunoglobulins

Grant support

This work was supported in part by the Coalition for SafeMinds ( to WP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.