Persistence of Human Bocavirus 1 in Tonsillar Germinal Centers and Antibody-Dependent Enhancement of Infection
Man Xu, Maria F. Perdomo, Salla Mattola, Lari Pyöriä, Mari Toppinen, Jianming Qiu, Maija Vihinen‐Ranta, Klaus Hedman, Johanna Nokso‐Koivisto, Leena‐Maija Aaltonen, Maria Söderlund‐Venermo
Abstract
Human bocavirus 1 (HBoV1), a common pediatric respiratory pathogen, can persist in airway secretions for months hampering diagnosis. It also persists in tonsils, providing potential reservoirs for airway shedding, with the exact location, host cell types, and virus activity unknown. Our study provides new insights into tonsillar HBoV1 persistence. We observed HBoV1 persistence exclusively in germinal centers where immune maturation occurs, and the main host cells were B cells and monocytes. In cultured cell lines and primary tonsillar B cells, we showed the virus uptake to be significantly enhanced by HBoV1-specific antibodies, mediated by the cellular IgG receptor, leading to viral mRNA synthesis, but without detectable productive replication. Possible implications of such active viral persistence could be tonsillar inflammation, disturbances in immune maturation, reactivation, or cell death with release of virus DNA, explaining the long-lasting HBoV1 airway shedding.