B cell lines fail to support efficient rhesus enteric calicivirus and human norovirus replication

Area of Science:

• Virology
• Cell Biology
• Immunology

Background:

• Human norovirus (HuNoV) and rhesus enteric caliciviruses (ReCV) are significant human and animal pathogens.
• Previous studies suggested immune cell tropism for HuNoV and ReCV, leading to the development of B cell culture systems.
• Reproducibility issues have raised concerns about the suitability of B cell cultures for HuNoV research.

Purpose of the Study:

• To evaluate the susceptibility of nonhuman primate (NHP) B cell lines and the human BJAB cell line to ReCV-FT285 infection.
• To investigate the role of Coxsackie and adenovirus receptor (CAR) and histo-blood group antigens (HBGA) in ReCV and HuNoV susceptibility in B cells.
• To assess the validity of B cell cultures for studying enteric calicivirus replication.

Main Methods:

• Infection of NHP B cell lines and BJAB cells with ReCV-FT285.
• Analysis of CAR and HBGA expression using Western blots.
• Co-transfection of BJAB cells with CAR and HBGA expression vectors.
• Detection of viral RNA (dsRNA staining) to confirm initial infection.

Main Results:

• NHP B cell lines lacked CAR and HBGA expression and resisted ReCV infection.
• BJAB cells showed inconsistent, low-level ReCV replication with detectable CAR and HBGA expression.
• CAR was predominantly internalized in BJAB cells, and surface expression did not increase ReCV titers.
• Initial ReCV and HuNoV infections in BJAB cells were mostly abortive, with minimal progeny virus release.

Conclusions:

• BJAB cells express necessary molecules at low levels, supporting only initial, abortive enteric calicivirus infections.
• The B cell culture system, due to poor reproducibility and limited replication, is unsuitable for HuNoV and ReCV research.
• Further research into valid and reproducible cell culture systems for norovirus studies is warranted.