Newborns' immune system surprisingly adept
Wednesday September 24th, 2014
A newborn baby's immune system is better able to fight infections than previously thought, researchers say today.
If
they have an infection, newborns cannot use the antibacterial and antiviral
responses of so-called T helper type 1 cells, as adults can.
The researchers, from King's College London, UK, explain that it is generally believed that babies have an immature immune system that does not cause the same inflammatory response as adults.
But the team has now found that newborns are able to use a small number of T helper type 1 cells, which can limit the potential damage from inflammation when fighting an infection, and allow helpful bacteria to colonise the intestines.
For their study, they analysed blood samples from 28 very premature babies over the first few weeks after birth. This allowed them to outline the properties of newborns' T cells. Findings appeared in the journal Nature Medicine on 21 September.
While T cells in newborns are different to those in adults, they make an effective antibacterial molecule called interleukin 8 which triggers neutrophils to attack dangerous bacteria.
The production of interleukin-8 in the face of infection "was readily apparent in preterm babies, particularly those experiencing neonatal infections and severe pathology", they add. Interleukin-8 producing T cells were rare in adult blood samples, they found.
Researcher Dr Deena Gibbons said: "We found that babies have an in-built anti-bacterial defence mechanism that works differently to adults, but nevertheless may be effective in protecting them. This may also be a mechanism by which the baby protects itself in the womb from infections of the mother. The next stage of our work will be to better understand the pathways that result in the immune cells of newborns being so different to those in adults."
Gibbons, D. et al. Interleukin-8 (CXCL8) production is a signatory T cell effector function of human newborn infants. Nature Medicine 21 September 2014 doi:10.1038/nm.3670
Tags: Child Health | Childbirth and Pregnancy | Flu & Viruses | UK News
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