{"id":24822,"date":"2016-04-23T02:32:06","date_gmt":"2016-04-23T02:32:06","guid":{"rendered":"https:\/\/new.igihe.com\/dirty-mice-better-than-lab-raised-mice-for\/"},"modified":"2016-04-23T02:31:54","modified_gmt":"2016-04-23T02:31:54","slug":"dirty-mice-better-than-lab-raised-mice-for","status":"publish","type":"post","link":"https:\/\/new.igihe.com\/english\/dirty-mice-better-than-lab-raised-mice-for\/","title":{"rendered":"\u2018Dirty\u2019 mice better than lab-raised mice for studying human disease"},"content":{"rendered":"

{Immune system behaves differently for rodents kept in sterile environments.}<\/p>\n

Don\u2019t blame lab mice for shortfalls in their ability to mimic human immune systems \u2014 blame their upbringing.<\/p>\n

Mice with more experience fighting pathogens have immune system reactions more like humans\u2019, conclude two studies published online April 20. \u201cDirty\u201d mice bought from pet stores or caught in the wild have more humanlike immune systems than clean lab mice do, researchers report in Nature. And in Cell Host & Microbe, scientists find that infecting lab mice with a series of viruses and parasites alters their immune responses to be similar to those of dirty mice and humans.<\/p>\n

In recent years, scientists have debated whether mice are adequate stand-ins for humans. Some say mice are poor substitutes, and that money should instead be spent on bolstering human studies (SN: 3\/23\/13, p. 10). Others look at the same data and conclude that mice do a pretty good job of representing humans (SN: 9\/20\/14, p. 14). Plus, many important studies could not be done with humans, so mice are a necessity.<\/p>\n

But even mouse fans recognize there is room for improvement. \u201cAll science is an approximation of the real situation,\u201d says immunologist Andrew Macpherson of the University Hospital of Bern, Switzerland, who relies on mice models. \u201cI don\u2019t think anybody doubts that the models don\u2019t always accurately recapitulate what is happening in humans.\u201d The new papers show where mice fall short and suggest ways to improve their ability to mimic people, he says.<\/p>\n

Lab mice\u2019s immune system responses \u201creally do look different\u201d from that of humans\u2019, says immunologist David Masopust, coauthor of both studies. Masopust, of the University of Minnesota in Minneapolis, and colleagues wondered whether those dissimilarities are due to irreconcilable differences in the genetic makeup of mice and humans or if the environment plays a role.<\/p>\n

His group counted immune cells in blood from adult lab mice, adult humans and human umbilical cords. Of special interest were \u201cmemory CD8+ T cells,\u201d which cull body cells that are infected with viruses or bacteria or that have become cancerous. Lab mice and human infants have few of these memory cells, while adult humans have a plethora. That indicates that lab mice have inexperienced immune systems, much like human babies.<\/p>\n

The finding, \u201cis one of those things that once you know it, it\u2019s incredibly obvious,\u201d says E. John Wherry, an immunologist at the University of Pennsylvania. \u201cMice are like humans raised in a bubble.\u201d<\/p>\n

Masopust agrees. \u201cThey live a preposterously hygienic existence.\u201d Even mice with severe immune deficiencies can thrive in immaculately clean labs.<\/p>\n

Ultraclean lab mice can\u2019t emulate the sort of history most human immune systems experience, says Tiffany Reese, a viral immunologist at the University of Texas Southwestern Medical Center in Dallas. Adults carry an average of eight to 12 chronic viruses, such as Epstein-Barr virus (the cause of mononucleosis). Worm parasites infect about 2 billion people worldwide. And by adulthood, people have usually fought off multiple colds, flus and other infections. <\/p>\n

Masopust\u2019s team found that the memory T cell profiles of wild and pet-store mice more closely resembled that of adult humans than lab mice\u2019s did. Housing lab mice next to pet-store mice for a month caused their immune system to change, making the lab mice resemble the dirty mice, the researchers reported in Nature. In discrepancies between studies of lab mice and humans, \u201cthe mouse may not be at fault,\u201d Masopust says. \u201cIt\u2019s the way that they are cared for.\u201d<\/p>\n

An experienced immune system not only looks different, it also works differently from an inexperienced one, Reese and colleagues report in Cell Host & Microbe. Reese infected lab mice with two types of herpesviruses, gave them the flu and inoculated them with an intestinal parasite. She then compared how uninfected mice reacted to a yellow fever vaccine with how chronically infected mice reacted. Uninfected mice made more antibodies against the vaccine. The result might help explain why some vaccines that look promising in animal studies don\u2019t pan out in human trials.<\/p>\n

Controlled infections may increase understanding of how pathogens interact with each other, with friendly microbes that live in the body and with the host\u2019s immune system, says Reese\u2019s coauthor Herbert Virgin, a viral immunologist at Washington University School of Medicine in St. Louis.<\/p>\n

Researchers have a bias that mice are not humans, says Virgin, \u201cBut I think that\u2019s too simplistic a view. We shouldn\u2019t be asking whether the mouse is a perfect model for humans, but whether we can make the mouse emulate more closely the basic nature of human physiology.\u201d<\/p>\n

\"EXPERIENCE<\/figure>\n","protected":false},"excerpt":{"rendered":"

{Immune system behaves differently for rodents kept in sterile environments.} Don\u2019t blame lab mice for shortfalls in their ability to mimic human immune systems \u2014 blame their upbringing. Mice with more experience fighting pathogens have immune system reactions more like humans\u2019, conclude two studies published online April 20. \u201cDirty\u201d mice bought from pet stores or […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[49],"tags":[75],"byline":[2491],"hashtag":[],"class_list":["post-24822","post","type-post","status-publish","format-standard","hentry","category-science-news","tag-homenews","byline-science-daily"],"bylines":[{"id":2491,"name":"SCIENCE DAILY","slug":"science-daily","description":"","image":{"id":0,"url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&f=y&r=g","alt":"Default avatar","title":"Default avatar","caption":"","mime_type":"image\/jpeg","sizes":[]},"user_id":null}],"contributors":[{"id":2491,"name":"SCIENCE DAILY","slug":"science-daily","description":"","image":{"id":0,"url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&f=y&r=g","alt":"Default avatar","title":"Default avatar","caption":"","mime_type":"image\/jpeg","sizes":[]},"user_id":null}],"featured_image":null,"_links":{"self":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts\/24822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/comments?post=24822"}],"version-history":[{"count":0,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/posts\/24822\/revisions"}],"wp:attachment":[{"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/media?parent=24822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/categories?post=24822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/tags?post=24822"},{"taxonomy":"byline","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/byline?post=24822"},{"taxonomy":"hashtag","embeddable":true,"href":"https:\/\/new.igihe.com\/english\/wp-json\/wp\/v2\/hashtag?post=24822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}