BOSTON, Sept. 26 (UPI) -- Differences in the way antibodies operate in the bodies of patients with active tuberculosis infections, as compared to those with latent, inactive infections, may help researchers treat patients more effectively and eventually develop a vaccine.
Patients with latent infections generally have lower overall levels of antibodies than people with active infections, but unique sugar groups that boost these people's immune systems against the bacteria causing tuberculosis may help drive new research.
About one-third of people around the world carry the mycobacterium tuberculosis, or Mtb, bacteria, which causes tuberculosis, but many do not have active infections, which researchers have not fully understood.
The differences in antibodies -- which help activate the immune system and cause Mtb-infected cells to kill the bacteria -- could help researchers understand how to instigate the immune system to react and prevent the bug from infecting people.
"One of the long-standing challenges in generating a TB vaccine is that we don't really know how to build a vaccine that generates a robust T-cell response," Dr. Sarah Fortune, a professor of immunology and infectious diseases at the Harvard Chan School of Public Health, said in a press release. "But now, with our findings suggesting an important role for antibodies, it casts light on a path toward TB vaccine development that is much more straightforward. That's incredibly exciting."
For the study, published in the journal Cell, researchers analyzed antibody samples from two groups of tuberculosis patients, one with active infections and one with latent infections.
In addition to finding people with latent Mtb infection had lower levels of antibodies, the researchers also found antibodies of those with latent infection carried something actively infected people did not -- sugar groups called digalactose, which signal the immune system to kill the bacteria in infected cells.
The finding could allow for better diagnosis of tuberculosis, the researchers say. The study's finding will also help better inform how the body fights off tuberculosis infection in some people and not in others, and may lead to a long-sought vaccine for the infections.
"Our work shatters some long-standing paradigms on TB," Fortune said. "That means we'll need to think differently about how the body develops natural immunity to the infection and how effective vaccines should be engineered."