Adaptive immune responses to SARS-CoV-2 persist in the pharyngeal lymphoid tissue of children
Most studies of adaptive immunity to SARS-CoV-2 infection focus on peripheral blood, which may not fully reflect immune responses at the site of infection. Using samples from 110 children undergoing tonsillectomy and adenoidectomy during the COVID-19 pandemic, we identified 24 samples with evidence of previous SARS-CoV-2 infection, including neutralizing antibodies in serum and SARS-CoV-2-specific germinal center and memory B cells in the tonsils and adenoids. Single-cell B cell receptor (BCR) sequencing indicated virus-specific BCRs were class-switched and somatically hypermutated, with overlapping clones in the two tissues. Expanded T cell clonotypes were found in tonsils, adenoids and blood post-COVID-19, some with CDR3 sequences identical to previously reported SARS-CoV-2-reactive T cell receptors (TCRs). Pharyngeal tissues from COVID-19-convalescent children showed persistent expansion of germinal center and antiviral lymphocyte populations associated with interferon (IFN)-γ-type responses, particularly in the adenoids, and viral RNA in both tissues. Our results provide evidence for persistent tissue-specific immunity to SARS-CoV-2 in the upper respiratory tract of children after infection.
Xu, Qin; Milanez-Almeida, Pedro; Martins, Andrew J.; Radtke, Andrea J.; Hoehn, Kenneth B.; Oguz, Cihan; Chen, Jinguo; Liu, Can; Tang, Juanjie; Grubbs, Gabrielle; Stein, Sydney; Ramelli, Sabrina; Kabat, Juraj; Behzadpour, Hengameh; Karkanitsa, Maria; Spathies, Jacquelyn; Kalish, Heather; Kardava, Lela; Kirby, Martha; Cheung, Foo; Preite, Silvia; Duncker, Patrick C.; Kitakule, Moses M.; Romero, Nahir; Preciado, Diego; Gitman, Lyuba; Koroleva, Galina; Smith, Grace; Shaffer, Arthur; McBain, Ian T.; McGuire, Peter J.; and Pittaluga, Stefania, "Adaptive immune responses to SARS-CoV-2 persist in the pharyngeal lymphoid tissue of children" (2022). GW Authored Works. Paper 2077.