title: Rapid expansion and long-term persistence of elevated NK cell numbers in humans infected with hantavirus.
abstract: Natural killer (NK) cells are known to mount a rapid response to several virus infections. In experimental models of acute viral infection, this response has been characterized by prompt NK cell activation and expansion followed by rapid contraction. In contrast to experimental model systems, much less is known about NK cell responses to acute viral infections in humans. We demonstrate that NK cells can rapidly expand and persist at highly elevated levels for >60 d after human hantavirus infection. A large part of the expanding NK cells expressed the activating receptor NKG2C and were functional in terms of expressing a licensing inhibitory killer cell immunoglobulin-like receptor (KIR) and ability to respond to target cell stimulation. These results demonstrate that NK cells can expand and remain elevated in numbers for a prolonged period of time in humans after a virus infection. In time, this response extends far beyond what is considered normal for an innate immune response.
authors.affiliation: Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
authors.forename: Niklas K
authors.initials: NK
authors.lastname: Björkström
authors.forename: Therese
authors.initials: T
authors.lastname: Lindgren
authors.forename: Malin
authors.initials: M
authors.lastname: Stoltz
authors.forename: Cyril
authors.initials: C
authors.lastname: Fauriat
authors.forename: Monika
authors.initials: M
authors.lastname: Braun
authors.forename: Magnus
authors.initials: M
authors.lastname: Evander
authors.forename: Jakob
authors.initials: J
authors.lastname: Michaëlsson
authors.forename: Karl-Johan
authors.initials: KJ
authors.lastname: Malmberg
authors.forename: Jonas
authors.initials: J
authors.lastname: Klingström
authors.forename: Clas
authors.initials: C
authors.lastname: Ahlm
authors.forename: Hans-Gustaf
authors.initials: HG
authors.lastname: Ljunggren
mesh_terms: D049109:Cell Proliferation; D042783:Endothelial Cells / Q000276:immunology; D018778:Hantavirus Infections / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D008024:Ligands; D055654:NK Cell Lectin-Like Receptor Subfamily C / Q000276:immunology; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D008024:Ligands; D055654:NK Cell Lectin-Like Receptor Subfamily C