Researchers from the University of Cape Town's Institute of Infectious Disease and Molecular Medicine (IDM), along with local and international colleagues, investigated the early life challenges of babies exposed to HIV before birth. Their focus was on the immune system development during the crucial first months of life of babies who did not contract the disease but were born to women living with HIV. Their findings, published in Nature Communications, uncovered some surprising truths.

It has been known for some time that babies exposed to HIV but not infected face a higher risk of infections compared to those who were neither exposed to HIV before birth nor infected. However, this research reveals the reason why their immune system, like many others, was subtly affected even before birth.

Leading this research was IDM Fellow Dr Sonwabile Dzanibe. His team discovered that infants exposed to HIV in the womb had less variety in their T cell receptors (TCRs), which are the very tools their immune systems use to recognise and fight off different pathogens. This means that Sam's immune system isn't as prepared to combat the wide range of germs he will encounter compared to other children who were never exposed to the virus.

The study was overseen by senior author and IDM Adjunct Member, Professor Emeritus Clive Gray, and co-authored by IDM Member Associate Professor Heather Jaspan, along with experts from Stanford University and Stellenbosch University. Their combined efforts revealed that the reduced variety in TCRs among these infants’ naïve T cells (the ones that haven’t yet encountered diseases) leads to slower development of memory T cells. These memory T cells are essential for a quick response to previously encountered infections.

Read more