SARS-CoV-2 induces robust germinal center CD4 T follicular helper cell responses in rhesus macaques

CD4 T follicular helper (T-fh) cells are important for the generation of durable and specific humoral protection against viral infections. The degree to which SARS-CoV-2 infection generates T-fh cells and stimulates the germinal center (GC) response is an important question as we investigate vaccine induced immunity against COVID-19. Here, we report that SARS-CoV-2 infection in rhesus macaques, either infused with convalescent plasma, normal plasma, or receiving no infusion, resulted in transient accumulation of pro-inflammatory monocytes and proliferating T-fh cells with a T(h)1 profile in peripheral blood. CD4 helper cell responses skewed predominantly toward a T(h)1 response in blood, lung, and lymph nodes. SARS-CoV-2 Infection induced GC T-fh cells specific for the SARS-CoV-2 spike and nucleocapsid proteins, and a corresponding early appearance of antiviral serum IgG antibodies. Collectively, the data show induction of GC responses in a rhesus model of mild COVID-19. Induction of CD4 T follicular helper (Tfh) cells is important for antibody responses to viral infections. Here, the authors show in a rhesus macaque model of mild COVID-19 that SARS-CoV-2 infection results in transient accumulation of proliferating Tfh cells with a Th1 profile in peripheral blood and generation of germinal center Tfh cells specific for viral proteins.

Automated summary

Induction of CD4 T follicular helper (Tfh) cells is crucial for antibody responses to viral infections, as shown in a rhesus macaque model of mild COVID-19 where SARS-CoV-2 infection resulted in transient accumulation of proliferating Tfh cells with a Th1 profile in peripheral blood and the generation of germinal center Tfh cells specific for viral proteins.