Wild Mice Have Natural Protection Against Lyme Borreliosis

Source : University of Zurich

Springtime spells tick-time. Lyme borreliosis is the most common tick-borne disease in Switzerland: around 10,000 people a year become infected with the pathogen. The actual hosts for Borrelia, however, are wild mice. Like in humans, the pathogen is also transmitted by ticks in mice. Interestingly, not all mice are equally susceptible to the bacterium and individual animals are immune to the pathogen. Scientists from the universities of Zurich and Lund headed by evolutionary biologist Barbara Tschirren reveal that the difference in vulnerability among the animals is genetic in origin.

Protective gene variant

Tschirren and colleagues examined wild mice for signs of a Borrelia infection in a large-scale field study. Borrelia afzelii – the scientific name for the bacteria – feed on mouse blood. The researchers discovered that mice with a particular variant of the antigen receptor TLR2 were around three times less susceptible to Borrelia. "The immune system of mice with this receptor variant recognizes the pathogen better and can trigger an immune response more quickly to destroy the Borrelia in time," says Tschirren. Infected mice exhibit similar symptoms to humans – especially joint complaints. Consequently, in the wild infected mice probably do not survive for very long and weakened animals soon fall victim to foxes and birds of prey.

Arms race between mice and Borrelia

The protective gene variant is advantageous for its carriers and, according to the researchers, gradually becoming prevalent in the mouse population. Nonetheless, it is unlikely that all mice will one day be resistant to Borrelia. "The increasing resistance in the host is bound to lead to adaptations in Borrelia," predicts Tschirren. "We can observe the evolutionary adaptation through the rearmament in mice and the pathogen."

People also have the antigen receptor TLR2, but not the resistant gene variant observed in mice. Whether the evolutionary arms race between mice and Borrelia will have repercussions for people remains to be seen. According to Tschirren, the bacterium does not necessarily have to become more aggressive for humans.

###

Literatur:

Barbara Tschirren, Martin Andersson, Kristin Scherman, Helena Westerdahl, Peer R. E. Mittl, and Lars Råberg. Polymorphisms at the innate immune receptor TLR2 are associated with Borrelia infection in a wild rodent population. Proceedings of the Royal Society B, 20130364. April 3, 2013. doi: 10.1098/rspb.2013.0364

Contact:

Prof. Barbara Tschirren
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Phone. +41 44 635 47 77
E-mail: barbara.tschirren@ieu.uzh.ch

  • <<
  • >>

Articles List

  • Choosing Serum for Cells in Culture

    Choosing Serum for Cells in Culture

    Serum is a key component for growing and maintaining cells in culture. Containing a mixture of proteins, hormones, minerals and other growth factors, serum is a nutrient boost for cultured cells. It is added to media as a growth supplement, and specialized forms can be used for different experimental conditions. Determining the serum conditions that provide optimal cell growth can be a challenging task. “Selection of sera products is dependent upon the growth requirements of the cell type it’s being used for, with sensitive cell lines often requiring the highest quality serum,” says Brian Douglass, global head of cell-culture product management and marketing in life sciences at GE Healthcare. Many suppliers offer serum, in various formulations and with different purity levels. Fetal bovine serum (FBS), or fetal calf serum (FCS), is the most widely used form, but there are features and options to consider. Here we discuss some key considerations when selecting sera for culturing cells.
  • Point-of-Care Diagnostic Tests Streamline Patient Care

    Point-of-Care Diagnostic Tests Streamline Patient Care

    Point-of-care (POC) tests have evolved from a unique approach for gathering information to an almost routine, more efficient solution for patients to receive care without having to travel to different locations for lab work. Often POC tests can provide faster time to results, which translates into better patient care. Today many POC tests are available; they focus on everything from blood chemistry to HIV infection. Here is a glimpse into common areas of POC testing and the processes involved in developing new POC diagnostic tests.

Disqus Comments