Elevated expansion of follicular helper T cells in peripheral blood from children with acute measles infection

Abstract

Background: Measles outbreaks have threatened the global elimination and eradication of measles in recent years. Measles virus (MeV)-specific antibodies are successful in clearing MeV infection. Follicular helper T (Tfh) cells play a crucial role in promoting antibody production. This study investigated the potential role of Tfh cells in peripheral blood mononuclear cells (PBMCs) from children with acute MeV infection.

Results: The frequencies of CXCR5⁺CD4⁺ Tfh, ICOS^high Tfh, and PD-1^high Tfh cells in PBMCs and levels of IL-6 and IL-21 in plasma were significantly elevated in patients with acute MeV infection. Moreover, a positive correlation was discovered among the frequency of ICOS^high Tfh cells, plasma levels of IL-21 and optical density (OD) values of MeV-specific IgM antibodies in the patients with acute MeV infection. However, elevated plasma MeV-specific NAb titres were not associated with the frequency of Tfh, ICOS^high Tfh, or PD-1^high Tfh cells in the patients with acute MeV infection.

Conclusion: These results suggest that an elevated Tfh cell frequency and associated molecules possibly play a key role in children with acute MeV infection, which contributes to the prevention and treatment of MeV infection in children.

Keywords: Bcl-6; Follicular helper T cells; IL-21; Measles virus; Neutralizing antibody.