Newborns have a stronger immune system than previously thought

Newborn immune T-cells – specialist cells that help to defend the body against infection – may have the ability to trigger an inflammatory response to bacteria, something that we didn't previously think was possible, finds a study led by King’s College London and involving teams at Great Ormond Street Hospital (GOSH).

This discovery, published in the journal Nature Medicine, suggests that although a newborn’s immune system works very differently to that of adults, babies may still be able to mount a strong immune defence to protect them from viruses and harmful microbes. 

Up to now, it was believed that babies have an immature immune system that doesn't trigger the same inflammatory response normally seen in adults. Although babies need to protect themselves from things that cause infection from birth, it was thought that their T-cells were suppressed to some extent to prevent inflammatory damage to the developing child.

Researchers have now found that might not be the case. The team examined small samples of blood in twenty-eight highly premature babies who had early exposure to infection, in order to look for patterns that may reveal alternative immune responses occur in the first few weeks of life.

The team discovered that whilst T-cells in newborn babies are largely different to those in adults, it is not because they are immunosuppressed. Instead, the T-cells create a potent anti-bacterial molecule that activates immune cells, known as neutrophils, that attack the body’s foreign invaders.

Neil Sebire, Consultant Paediatric Pathologist at GOSH who was involved in the study, says: "This work provides important new information about how newborn babies may respond to infection and with further research could lead to novel treatments that boost the immune system of children on the neonatal intensive care unit."