The human spleen is a major reservoir for long-lived vaccinia virus–specific memory B cells

• Published in: Blood Vol. 111; no. 9; pp. 4653 - 4659
• Main Authors: Mamani-Matsuda, Maria, Cosma, Antonio, Weller, Sandra, Faili, Ahmad, Staib, Caroline, Garçon, Loïc, Hermine, Olivier, Beyne-Rauzy, Odile, Fieschi, Claire, Pers, Jacques-Olivier, Arakelyan, Nina, Varet, Bruno, Sauvanet, Alain, Berger, Anne, Paye, François, Andrieu, Jean-Marie, Michel, Marc, Godeau, Bertrand, Buffet, Pierre, Reynaud, Claude-Agnès, Weill, Jean-Claude
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 01.05.2008; The Americain Society of Hematology
• Subjects: B-Lymphocytes - immunology; B-Lymphocytes - virology; Biological and medical sciences; Case-Control Studies; Fundamental and applied biological sciences. Psychology; Humans; Immunoglobulin G; Immunologic Memory; Microbiology; Replicative cycle, interference, host-virus relations, pathogenicity, miscellaneous strains; Spleen - cytology; Spleen - immunology; Splenectomy; Vaccinia virus - immunology; Virology; Virus; Human; Spleen; Vaccinia virus; Chordopoxvirinae; Immune response; Poxviridae; Orthopoxvirus; B-Lymphocyte; Humoral immunity; Memory lymphocyte
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2007-11-123844

The fact that you can vaccinate a child at 5 years of age and find lymphoid B cells and antibodies specific for this vaccination 70 years later remains an immunologic enigma. It has never been determined how these long-lived memory B cells are maintained and whether they are protected by storage in a special niche. We report that, whereas blood and spleen compartments present similar frequencies of IgG+ cells, antismallpox memory B cells are specifically enriched in the spleen where they account for 0.24% of all IgG+ cells (ie, 10-20 million cells) more than 30 years after vaccination. They represent, in contrast, only 0.07% of circulating IgG+ B cells in blood (ie, 50-100 000 cells). An analysis of patients either splenectomized or rituximab-treated confirmed that the spleen is a major reservoir for long-lived memory B cells. No significant correlation was observed between the abundance of these cells in blood and serum titers of antivaccinia virus antibodies in this study, including in the contrasted cases of B cell– depleting treatments. Altogether, these data provide evidence that in humans, the two arms of B-cell memory—long-lived memory B cells and plasma cells—have specific anatomic distributions—spleen and bone marrow—and homeostatic regulation.