Duke-NUS study links NKT cells to dengue defense

This can potentially reduce the severity of subsequent infections.

The Duke-NUS Medical School researchers discovered that natural killer T (NKT) cells influence the immune response to initial dengue infection, whether the response generates protective antibodies that neutralise the virus or harmful ones that may worsen future infections.

Dengue fever is caused by serotypes, and an initial infection with one serotype does not provide immunity against the others; however, secondary infections are a well-known risk factor for developing severe disease. 

When NKT cells are active during the initial dengue infection, they help establish a strong immune memory that protects against subsequent infections. 

NKT cells also help to establish a supportive immune environment in nearby lymph nodes, which facilitates the production of effective antibodies.

The researchers also discovered that NKT cells drive dengue-specific Th1 responses, which focus on destroying threats once they have infected cells, leading to the production of “good” antibodies that neutralise the virus.

In a pre-clinical model, patients with primary dengue infections who developed Th1-associated antibodies had better outcomes.

Meanwhile, those with secondary infections who produced high levels of Th2-associated antibodies, which combat pathogens like bacteria, parasites, and toxins outside cells, were more likely to experience severe disease.