Science Editorial, Feb 23 (EFE).- The immune system of a newborn is not an immature version of that of adults, as had been believed. In fact, their white blood cells (T cells), which protect once morest disease, outperform those of adults in fighting some infections.
These findings, published today by Science Immunology, help clarify why adults and infants respond differently to infections and pave the way for controlling T cell behavior for therapeutic purposes.
Adult T cells outperform newborn T cells in tasks such as antigen recognition, immunological memory formation and response to repeated infections, which has led to the belief that childhood T cells were just a weaker version of them.
A team led by Cornell University (USA) describes their discovery in a study carried out with mice and observations corroborated by fetal, neonatal and adult human data.
The pandemic gave the first clue
During the Covid-19 pandemic, many were surprised by the apparent absence of disease in infants, which called into question this long-held belief regarding the immune system of babies, and the team was interested in understanding these differences related to age.
The researchers focused on innate-type CD8+ T cells, which are more common in neonates and can fight pathogens before immune memory exists.
Adult T cells use adaptive immunity, which recognizes specific germs to fight them later if necessary.
However, those of newborns are activated by proteins associated with innate immunity, the part of the immune system that offers rapid but nonspecific protection once morest microbes that the body has never encountered, the university explained in a statement.
Different functions
Neonatal T cells “are simply different” from adult ones, and these differences “probably reflect the type of functions that are most useful to the host at different stages of life,” according to one of the signatories Brian Rudd of the University of Cornell.
These cells in newborns can participate in the innate arm of the immune system, that is, the “general” defenses that we are born with and that are not adapted to any particular disease.
This allows them to do something that most adults cannot do: respond during the early phases of an infection and defend themselves once morest a wide variety of unknown bacteria, parasites and viruses.
“We know that neonatal T cells do not protect as well as adult T cells once morest repeated infections with the same pathogen, but in fact, neonatal T cells have a greater capacity to protect the host once morest the early phases of an initial infection,” Rudd explained.
Therefore, the researcher defended that “it cannot be said that adult T cells are better than neonatal ones or that neonatal ones are better than adult ones. “They just have different functions.”
The researcher now wants to study neonatal T cells that persist into adulthood in humans and how changes in the relative number of those cells in adults contribute to variation in susceptibility to infection and disease outcomes.
By: EFE
2024-02-23 19:17:26
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