Group A Streptococcus-specific CD4+ germinal center T follicular helper cells underrepresented
MONDAY, Feb. 11, 2019 (HealthDay News) — Children with recurrent tonsillitis (RT) have smaller germinal centers, according to a study published in the Feb. 6 issue of Science Translational Medicine.
Jennifer M. Dan, M.D., Ph.D., from La Jolla Institute for Immunology in California, and colleagues performed phenotypic, genotypic, and functional studies on pediatric group A Streptococcus (GAS) RT and non-RT tonsils from two independent cohorts of children aged 5 to 18 years undergoing tonsillectomy.
The researchers identified smaller germinal centers in GAS RT tonsils, which had an underrepresentation of GAS-specific CD4+ germinal center T follicular helper (GC-TFH) cells. Children with RT exhibited reduced antibody responses to streptococcal pyrogenic exotoxin A (SpeA), an important GAS virulence factor. The investigators identified risk and protective human leukocyte antigen class II alleles for RT. SpeA-induced granzyme B production was observed in GC-TFH cells from RT tonsils, which could kill B cells and had the potential to hinder the germinal center response.
“We have 100+ years of experience with this disease but there really wasn’t any good explanation why some kids suffer from recurrent strep throat,” a coauthor said in a statement. “We think that this is the first solid evidence that there is an important immunological component as well as a genetic one which together contribute to recurrent strep throat. Let’s try and build on it.”
Two authors disclosed holding an international patent application: Diagnosis and treatment of infection involving killer T follicular helper cells, methods of preparation, and uses thereof.
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