New publication on flow cytometric characterization of memory B cells directed against SARS-CoV-2 spike proteins.
Memory B cells (MBCs), part of the immune response elicited by infection or vaccination, can persist in lymphoid organs and peripheral blood and are capable of rapid reactivation upon secondary antigen exposure. Here, we describe a flow cytometric assay to identify SARS-CoV-2 spike-specific MBCs from peripheral blood mononuclear cells and characterize their isotypes and activation status.
Leonie M. Weskamm, Christine Dahlke, Marylyn M. Addo. Flow cytometric protocol to characterize human memory B cells directed against SARS-CoV-2 spike protein antigens. STAR Protocols 2022 Dec 16; 4(3):101902. doi: 10.1016/j.xpro.2022.101902
Prof. Dr. Addo honored for HIV research
Prof. Dr. Marylyn Addo, Director of the Institute for Infection Research and Vaccine Development, has been awarded the Heinz Ansmann Prize for AIDS Research 2022. The Heinz Ansmann foundation honored her work on immune control of HIV infection and transfer of knowledge to other viral diseases with pandemic potential. Prof. Dr. Addo accepted the 10,000 euro prize on July 13, 2022 at Schloss Mickeln in Düsseldorf.
New publication on the MVA-MERS-S vaccine candidate
Weskamm et al. longitudinally describe B and T cell responses as well as antibody subclasses and neutralization capacity induced by three homologous immunizations with the MVA-MERS-S vaccine candidate.
The Middle East Respiratory Syndrome (MERS) is a respiratory disease caused by MERS coronavirus (MERS-CoV). In follow-up to a phase 1 trial, we perform a longitudinal analysis of immune responses following immunization with the Modified Vaccinia virus Ankara (MVA)-based vaccine MVA-MERS-S encoding the MERS-CoV-spike protein. Three homologous immunizations were administered on days 0 and 28 with a late booster vaccination at 12±4 months. Antibody isotypes, subclasses and neutralization capacity as well as T and B cell responses were monitored over a period of three years using standard and bead-based ELISA, PRNT50, ELISpot and flowcytometry. The late booster immunization significantly increases frequency and persistence of spike-specific B cells, binding IgG1 and neutralizing antibodies, but not T cell responses. Our data highlight the potential of a late boost to enhance long-term antibody and B cell immunity against MERS-CoV. Our findings on the MVA-MERS-S vaccine may be of relevance for COVID-19 vaccination strategies.
Weskamm LM, Fathi A, Raadsen MP, Mykytyn AZ, Koch T, Spohn M, Friedrich M, MVA-MERS-S Study Group, Haagmans BL, Becker S, Sutter G, Dahlke C, Addo MM. Persistence of MERS-CoV-spike-specific B cells and antibodies after late third immunization with the MVA-MERS-S vaccine. Cell Rep Med. 2022 in press