Researchers have mapped active and inactive genes in specialized lung immune cells that play a key role in countering bovine tuberculosis (TB) infections, according to an announcement from The Roslin Institute in the U.K.

In order to infect cattle, the scientists found that bovine TB bacteria modify gene activity in cells’ chromosomes, or packages of genetic material.

Studies aiming to improve cattle genetics and resistance to bovine TB could benefit from these findings, made by scientists at University College Dublin (UCD) in collaboration with The Roslin Institute.

The institute said key lung cells called alveolar macrophages are the first immune cells to encounter the bacteria that cause bovine TB during infection.

In order to map which genes in these cells are active or altered during infection, the team investigated all of the chemical changes in the chromosomes of infected macrophages.

"Bovine TB is a complex disease that is a threat to both livestock and humans and has been difficult to control in many countries. We have used epigenomics to map regulatory elements in infected cells," noted Dr. Douglas Vernimmen with Roslin at the University of Edinburgh.

During infection, the bacteria modify gene activity in macrophages to facilitate their survival inside these cells, the researchers said.

Bovine TB is caused by infection with Mycobacterium bovis, which can also cause disease in other mammals, including people. Bovine TB is a threat to livestock and people and causes as much as $3 billion in losses to the agriculture industry each year, Roslin said.

"Our study will help to significantly narrow down the genomic regions of interest for breeding programs to enhance the resilience of cattle to this important disease," UCD professor David MacHugh said.

The research work was funded by Science Foundation Ireland and the European Union through the international Functional Annotation of Animal Genomes Initiative and was published in the journal Frontiers in Genetics.