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Increased biodiversity in the environment improves the humoral response of rats.

Pi C, Allott EH, Ren D, Poulton S, Lee SY, Perkins S, Everett ML, Holzknecht ZE, Lin SS, Parker W - PLoS ONE (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Duke University Medical Center, Durham, NC, United States of America.

ABSTRACT
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.

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Natural anti-human serum albumin antibody levels in the serum of biome depleted (n = 20) and biome enriched (n = 15) rats.The relative concentration of antibody was determined by ELISA as described in the Methods. Relative levels of (A) IgM and (B) IgG are shown. Binding to human serum albumin (HSA) was used as a measure of reactivity toward a xenogeneic antigen for which the animals lacked previous exposure. The means, standard errors, and the p-values associated with comparing data from biome depleted and biome enriched animals using a t-test are shown. (NS = not significant)
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pone.0120255.g005: Natural anti-human serum albumin antibody levels in the serum of biome depleted (n = 20) and biome enriched (n = 15) rats.The relative concentration of antibody was determined by ELISA as described in the Methods. Relative levels of (A) IgM and (B) IgG are shown. Binding to human serum albumin (HSA) was used as a measure of reactivity toward a xenogeneic antigen for which the animals lacked previous exposure. The means, standard errors, and the p-values associated with comparing data from biome depleted and biome enriched animals using a t-test are shown. (NS = not significant)

Mentions: The levels of natural antibodies, antibodies that are present without a known history of sensitization, were evaluated in biome depleted and biome enriched animals. For this purpose, two antigens were selected, one xenogeneic (human serum albumin; HSA) and one autologous (rat muscle tissue extract). Typically, antibodies in normal (non-diseased) rats which bind to these antigens are polyreactive (broadly reactive) antibodies that are the first line of defense against foreign antigens or damaged tissue, and do not react strongly with intact tissues[10–15]. Levels of both IgM and IgG natural antibodies were evaluated. Differences observed in natural antibody levels as a function of biome enrichment were somewhat dependent on isotype, with levels of anti-HSA IgG but not anti-HSA IgM being significantly affected by biome enrichment (Fig. 5). The decrease in anti-HSA antibodies associated with biome depletion was particularly notable, with those animals having less than 40% of the level of antibody found in biome enriched animals (p = 0.0015; Fig. 5).


Increased biodiversity in the environment improves the humoral response of rats.

Pi C, Allott EH, Ren D, Poulton S, Lee SY, Perkins S, Everett ML, Holzknecht ZE, Lin SS, Parker W - PLoS ONE (2015)

Natural anti-human serum albumin antibody levels in the serum of biome depleted (n = 20) and biome enriched (n = 15) rats.The relative concentration of antibody was determined by ELISA as described in the Methods. Relative levels of (A) IgM and (B) IgG are shown. Binding to human serum albumin (HSA) was used as a measure of reactivity toward a xenogeneic antigen for which the animals lacked previous exposure. The means, standard errors, and the p-values associated with comparing data from biome depleted and biome enriched animals using a t-test are shown. (NS = not significant)
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390306&req=5

pone.0120255.g005: Natural anti-human serum albumin antibody levels in the serum of biome depleted (n = 20) and biome enriched (n = 15) rats.The relative concentration of antibody was determined by ELISA as described in the Methods. Relative levels of (A) IgM and (B) IgG are shown. Binding to human serum albumin (HSA) was used as a measure of reactivity toward a xenogeneic antigen for which the animals lacked previous exposure. The means, standard errors, and the p-values associated with comparing data from biome depleted and biome enriched animals using a t-test are shown. (NS = not significant)
Mentions: The levels of natural antibodies, antibodies that are present without a known history of sensitization, were evaluated in biome depleted and biome enriched animals. For this purpose, two antigens were selected, one xenogeneic (human serum albumin; HSA) and one autologous (rat muscle tissue extract). Typically, antibodies in normal (non-diseased) rats which bind to these antigens are polyreactive (broadly reactive) antibodies that are the first line of defense against foreign antigens or damaged tissue, and do not react strongly with intact tissues[10–15]. Levels of both IgM and IgG natural antibodies were evaluated. Differences observed in natural antibody levels as a function of biome enrichment were somewhat dependent on isotype, with levels of anti-HSA IgG but not anti-HSA IgM being significantly affected by biome enrichment (Fig. 5). The decrease in anti-HSA antibodies associated with biome depletion was particularly notable, with those animals having less than 40% of the level of antibody found in biome enriched animals (p = 0.0015; Fig. 5).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Duke University Medical Center, Durham, NC, United States of America.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus