Quirin Hammer team – Innate Immune Regulation

The team investigates molecular mechanisms that regulate innate immune cell responses.

Illustration of innate immune cells.
Illustration of the team's work on recognition of aberrant or virus-infected cells by innate immune cells. By: Quirin Hammer

About our research

The Quirin Hammer team is part of the Karl-Johan Malmberg group at the Center for Infectious Medicine. The team explores signals that regulate the activation of immune cells with a focus on cytotoxic effector cells of the innate immune system.

Innate immune cells with cytolytic properties such as natural killer (NK) cells represent the first line of defense against virus infections and developing cancers. NK cells respond to a broad range of viruses and tumor cells using partly overlapping and partly very distinct pathways.

Central aspects of our research are to delineate the molecular signals that allow NK cells to recognize virus-infected cells and to study by which means NK cells discriminate between healthy and tumor-transformed cells. For this, we employ a broad range of in silico, cellular, as well as molecular biology techniques and study samples from patients with ongoing disease.

In parallel to understanding the signals that initiate and restrict NK cell activation, we aim at exploiting such recognition pathways for cell therapy against cancer.

The team

Quirin and Pouria. Photo: Tyler Sandberg

Team leader

Quirin Hammer

PhD, Team Leader

Quirin completed his PhD at the German Rheumatism Research Centre and the Humboldt University of Berlin in 2018. During his PhD, he studied host-pathogen interactions between human natural killer cells and cytomegalovirus. His work focuses on developing next-generation NK cell immunotherapy against cancer. When not at work, Quirin enjoys learning chess, having coffee, and socializing.

Team member

Pouria Momayyezi

PhD Student

Pouria received his medical degree from Karolinska Institutet in 2015 and is currently a resident in Hematology at the Karolinska University hospital. His PhD studies concern next-generation NK-cell immunotherapy, specifically prolonging the survival of transferred NK cells in patients receiving immunotherapy. In his spare time, he enjoys cooking, reading, watching football and experiencing different forms of art, preferably with friends and family.


Chiara Romagnani, Berlin, Germany

Amir Horowitz, New York City, United States of America

Mattia Mori, Siena, Italy

Francesco Spallotta, Rome, Italy

Research support

  • Marie Skłodowska-Curie Actions (EU)
  • Hedlungs Stiftelse
  • Groschinksy Minnesfond
  • Karolinska Institutet Foundation for Virus Reserach
  • Region Stockholm
  • Stiftelsen Lars Hiertas Minne
  • Petrus och Augusta Hedlunds Stiftelse


Extent of Cytomegalovirus Replication in the Human Host Depends on Variations of the HLA-E/UL40 Axis.
Vietzen H, Rückert T, Hartenberger S, Honsig C, Jaksch P, Geleff S, Hammer Q, Romagnani C, Segura-Wang M, Puchhammer-Stöckl E
mBio 2021 03;12(2):

Natural killer cell immunotypes related to COVID-19 disease severity.
Maucourant C, Filipovic I, Ponzetta A, Aleman S, Cornillet M, Hertwig L, Strunz B, Lentini A, Reinius B, Brownlie D, Cuapio A, Ask EH, Hull RM, Haroun-Izquierdo A, Schaffer M, Klingström J, Folkesson E, Buggert M, Sandberg JK, Eriksson LI, Rooyackers O, Ljunggren HG, Malmberg KJ, Michaëlsson J, Marquardt N, Hammer Q, Strålin K, Björkström NK,
Sci Immunol 2020 08;5(50):

TOX is expressed by exhausted and polyfunctional human effector memory CD8+ T cells.
Sekine T, Perez-Potti A, Nguyen S, Gorin JB, Wu VH, Gostick E, Llewellyn-Lacey S, Hammer Q, Falck-Jones S, Vangeti S, Yu M, Smed-Sörensen A, Gaballa A, Uhlin M, Sandberg JK, Brander C, Nowak P, Goepfert PA, Price DA, Betts MR, Buggert M
Sci Immunol 2020 07;5(49):

NK cell receptor NKG2D enforces proinflammatory features and pathogenicity of Th1 and Th17 cells.
Babic M, Dimitropoulos C, Hammer Q, Stehle C, Heinrich F, Sarsenbayeva A, Eisele A, Durek P, Mashreghi MF, Lisnic B, Van Snick J, Löhning M, Fillatreau S, Withers DR, Gagliani N, Huber S, Flavell RA, Polic B, Romagnani C
J Exp Med 2020 08;217(8):

Remodeling of secretory lysosomes during education tunes functional potential in NK cells.
Goodridge JP, Jacobs B, Saetersmoen ML, Clement D, Hammer Q, Clancy T, Skarpen E, Brech A, Landskron J, Grimm C, Pfefferle A, Meza-Zepeda L, Lorenz S, Wiiger MT, Louch WE, Ask EH, Liu LL, Oei VYS, Kjällquist U, Linnarsson S, Patel S, Taskén K, Stenmark H, Malmberg KJ
Nat Commun 2019 01;10(1):514

Off-the-shelf cell therapy with induced pluripotent stem cell-derived natural killer cells.
Saetersmoen ML, Hammer Q, Valamehr B, Kaufman DS, Malmberg KJ
Semin Immunopathol 2019 01;41(1):59-68

Natural killer cell specificity for viral infections.
Hammer Q, Rückert T, Romagnani C
Nat Immunol 2018 08;19(8):800-808

Peptide-specific recognition of human cytomegalovirus strains controls adaptive natural killer cells.
Hammer Q, Rückert T, Borst EM, Dunst J, Haubner A, Durek P, Heinrich F, Gasparoni G, Babic M, Tomic A, Pietra G, Nienen M, Blau IW, Hofmann J, Na IK, Prinz I, Koenecke C, Hemmati P, Babel N, Arnold R, Walter J, Thurley K, Mashreghi MF, Messerle M, Romagnani C
Nat Immunol 2018 05;19(5):453-463

Adaptive Natural Killer Cells Integrate Interleukin-18 during Target-Cell Encounter.
Hammer Q, Rückert T, Dunst J, Romagnani C
Front Immunol 2017 ;8():1976

About Training and Memory: NK-Cell Adaptation to Viral Infections.
Hammer Q, Romagnani C
Adv Immunol 2017 ;133():171-207