PMID- 35404121 OWN - NLM STAT- MEDLINE DCOM- 20220428 LR - 20240214 IS - 2150-7511 (Electronic) VI - 13 IP - 2 DP - 2022 Apr 26 TI - Human Norovirus Triggers Primary B Cell Immune Activation In Vitro. PG - e0017522 LID - 10.1128/mbio.00175-22 [doi] LID - e00175-22 AB - Human norovirus (HNoV) is a global health and socioeconomic burden, estimated to infect every individual at least five times during their lifetime. The underlying mechanism for the potential lack of long-term immune protection from HNoV infections is not understood and prompted us to investigate HNoV susceptibility of primary human B cells and its functional impact. Primary B cells isolated from whole blood were infected with HNoV-positive stool samples and harvested at 3 days postinfection (dpi) to assess the viral RNA yield by reverse transcriptase quantitative PCR (RT-qPCR). A 3- to 18-fold increase in the HNoV RNA yield was observed in 50 to 60% of donors. Infection was further confirmed in B cells derived from splenic and lymph node biopsy specimens. Next, we characterized infection of whole-blood-derived B cells by flow cytometry in specific functional B cell subsets (naive CD27(-) IgD(+), memory-switched CD27(+) IgD(-), memory-unswitched CD27(+) IgD(+), and double-negative CD27(-) IgD(-) cells). While the susceptibilities of the subsets were similar, changes in the B cell subset distribution upon infection were observed, which were also noted after treatment with HNoV virus-like particles and the predicted recombinant NS1 protein. Importantly, primary B cell stimulation with the predicted recombinant NS1 protein triggered B cell activation and induced metabolic changes. These data demonstrate that primary B cells are susceptible to HNoV infection and suggest that the NS1 protein can alter B cell activation and metabolism in vitro, which could have implications for viral pathogenesis and immune responses in vivo. IMPORTANCE Human norovirus (HNoV) is the most prevalent causative agent of gastroenteritis worldwide. Infection results in a self-limiting disease that can become chronic and severe in the immunocompromised, the elderly, and infants. There are currently no approved therapeutic and preventative strategies to limit the health and socioeconomic burdens associated with HNoV infections. Moreover, HNoV does not elicit lifelong immunity as repeat infections are common, presenting a challenge for vaccine development. Given the importance of B cells for humoral immunity, we investigated the susceptibility and impact of HNoV infection on human B cells. We found that HNoV replicates in human primary B cells derived from blood, spleen, and lymph node specimens, while the nonstructural protein NS1 can activate B cells. Because of the secreted nature of NS1, we put forward the hypothesis that HNoV infection can modulate bystander B cell function with potential impacts on systemic immune responses. FAU - Mirabelli, Carmen AU - Mirabelli C AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Jones, Melissa K AU - Jones MK AD - Department of Molecular Genetics and Microbiology, College of Medicine, University of Floridagrid.15276.37, Gainesville, Florida, USA. AD - Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA. FAU - Young, Vivienne L AU - Young VL AD - Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otagogrid.29980.3a, Dunedin, New Zealand. FAU - Kolawole, Abimbola O AU - Kolawole AO AUID- ORCID: 0000-0001-8520-865X AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Owusu, Irene AU - Owusu I AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. AD - West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Accra, Ghana. FAU - Shan, Mengrou AU - Shan M AD - Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Abuaita, Basel AU - Abuaita B AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Turula, Holly AU - Turula H AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. AD - Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Trevino, Jose G AU - Trevino JG AD - Division of Surgical Oncology, Department of Surgery, Virginia Commonwealth University, Richmond, Virginia, USA. FAU - Grigorova, Irina AU - Grigorova I AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Lundy, Steven K AU - Lundy SK AD - Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical Schoolgrid.471406.0, Ann Arbor, Michigan, USA. FAU - Lyssiotis, Costas A AU - Lyssiotis CA AUID- ORCID: 0000-0001-9309-6141 AD - Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA. FAU - Ward, Vernon K AU - Ward VK AD - Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otagogrid.29980.3a, Dunedin, New Zealand. FAU - Karst, Stephanie M AU - Karst SM AD - Department of Molecular Genetics and Microbiology, College of Medicine, University of Floridagrid.15276.37, Gainesville, Florida, USA. FAU - Wobus, Christiane E AU - Wobus CE AUID- ORCID: 0000-0001-5286-0924 AD - Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. LA - eng GR - R01 AI141478/AI/NIAID NIH HHS/United States GR - R01 AI123144/AI/NIAID NIH HHS/United States GR - DK097153/NH/NIH HHS/United States GR - R21 AI142032/AI/NIAID NIH HHS/United States GR - U24 DK097153/DK/NIDDK NIH HHS/United States GR - R37 CA237421/CA/NCI NIH HHS/United States GR - R21 AI130328/AI/NIAID NIH HHS/United States GR - R01 CA242003/CA/NCI NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20220411 PL - United States TA - mBio JT - mBio JID - 101519231 RN - 0 (Immunoglobulin D) SB - IM MH - Aged MH - *Caliciviridae Infections MH - *Gastroenteritis MH - Humans MH - Immunoglobulin D MH - Lymphocyte Activation MH - *Norovirus/physiology PMC - PMC9040803 OTO - NOTNLM OT - B cells OT - calicivirus OT - immune cell activation OT - nonstructural protein OT - noroviruses COIS- The authors declare a conflict of interest. C.A.L. has received consulting fees from Astellas Pharmaceuticals and is an inventor on patents pertaining to Kras regulated metabolic pathways, redox control pathways in pancreatic cancer, and targeting the GOT1-pathway as a therapeutic approach. EDAT- 2022/04/12 06:00 MHDA- 2022/04/29 06:00 PMCR- 2022/04/11 CRDT- 2022/04/11 12:13 PHST- 2022/04/12 06:00 [pubmed] PHST- 2022/04/29 06:00 [medline] PHST- 2022/04/11 12:13 [entrez] PHST- 2022/04/11 00:00 [pmc-release] AID - 00175-22 [pii] AID - mbio.00175-22 [pii] AID - 10.1128/mbio.00175-22 [doi] PST - ppublish SO - mBio. 2022 Apr 26;13(2):e0017522. doi: 10.1128/mbio.00175-22. Epub 2022 Apr 11.