'Hygienic' lymphocytes convey increased cancer risk.

J Anal Oncol
Authors
Abstract

Risk of developing inflammation-associated cancers has increased in industrialized countries during the past 30 years. One possible explanation is societal hygiene practices with use of antibiotics and Caesarian births that provide too few early life exposures of beneficial microbes. Building upon a 'hygiene hypothesis' model whereby prior microbial exposures lead to beneficial changes in CD4(+) lymphocytes, here we use an adoptive cell transfer model and find that too few prior microbe exposures alternatively result in increased inflammation-associated cancer growth in susceptible recipient mice. Specifically, purified CD4(+) lymphocytes collected from 'restricted flora' donors increases multiplicity and features of malignancy in intestinal polyps of recipient Apc(Min/+) mice, coincident with increased inflammatory cell infiltrates and instability of the intestinal microbiota. We conclude that while a competent immune system serves to maintain intestinal homeostasis and good health, under hygienic rearing conditions CD4(+) lymphocytes instead exacerbate inflammation-associated tumorigenesis, subsequently contributing to more frequent cancers in industrialized societies.

Year of Publication
2014
Journal
J Anal Oncol
Volume
3
Issue
3
Pages
113-121
Date Published
2014 Aug 12
DOI
10.6000/1927-7229.2014.03.03.1
PubMed ID
25722756
PubMed Central ID
PMC4338962
Links
Grant list
P30 ES002109 / ES / NIEHS NIH HHS / United States
R01 CA108854 / CA / NCI NIH HHS / United States
U01 CA164337 / CA / NCI NIH HHS / United States