Mouse Cytomegalovirus Infection in BALB/c Mice Resembles Virus-Associated Secondary Hemophagocytic Lymphohistiocytosis and Shows a Pathogenesis Distinct from Primary Hemophagocytic Lymphohistiocytosis

Ellen Brisse, Maya Imbrechts, Karen Put, Anneleen Avau, Tania Mitera, Nele Berghmans, Omer Rutgeerts, Mark Waer, Marisa Ninivaggi, Hilde Kelchtermans, Louis Boon, Robert Snoeck, Carine H. Wouters, Graciela Andrei, Patrick Matthys*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

26 Citations (Web of Science)

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immunological disorder that is characterized by systemic inflammation, widespread organ damage, and hypercytokinemia. Primary HLH is caused by mutations in granule-mediated cytotoxicity, whereas secondary HLH occurs, without a known genetic background, in a context of infections, malignancies, or autoimmune and autoinflammatory disorders. Clinical manifestations of both HLH subtypes are often precipitated by a viral infection, predominantly with Herpesviridae. Exploiting this knowledge, we established an animal model of virus-associated secondary HLH by infecting immunocompetent wild-type mice with the beta-herpesvirus murine CMV.C57BL/6 mice developed a mild inflammatory phenotype, whereas BALB/c mice displayed the clinicopathologic features of HLH, as set forth in the Histiocyte Society diagnostic guidelines: fever, cytopenia, hemophagocytosis, hyperferritinemia, and elevated serum levels of soluble CD25. BALB/c mice also developed lymphadenopathy, liver dysfunction, and decreased NK cell numbers. Lymphoid and myeloid cells were in a hyper-activated state. Nonetheless, depletion of CD8(+) T cells could not inhibit or cure the HLH-like syndrome, highlighting a first dissimilarity from mouse models of primary HLH. Immune cell hyperactivation in BALB/c mice was accompanied by a cytokine storm. Notably, plasma levels of IFN-gamma, a key pathogenic cytokine in models of primary HLH, were the highest. Nevertheless, murine CMV-infected IFN-gamma-deficient mice still developed the aforementioned HLH-like symptoms. In fact, IFN-gamma-deficient mice displayed a more complete spectrum of HLH, including splenomegaly, coagulopathy, and decreased NK cell cytotoxicity, indicating a regulatory role for IFN-gamma in the pathogenesis of virus-associated secondary HLH as opposed to its central pathogenic role in primary HLH.
Original languageEnglish
Pages (from-to)3124-3134
JournalJournal of Immunology
Volume196
Issue number7
DOIs
Publication statusPublished - 1 Apr 2016

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