ICMI 2015

T.121 Tissue-resident NK cells in human lung

Thursday, July 16, 2015
Grand Hall and Gallery, Ground Floor & 1st Floor (Maritim Hotel)
Nicole Marquardt, PhD , Karolinska Institutet, Stockholm, Sweden
Eliisa Kekäläinen, MD PhD , Karolinska Institutet, Stockholm, Sweden
Per Bergmann, MD , Karolinska Institutet, Stockholm, Sweden
Mamdoh Al-Ameri, MD , Karolinska Institutet, Stockholm, Sweden
Ann-Charlotte Orre, MD , Karolinska Institutet, Stockholm, Sweden
Susanne Hylander , Karolinska Institutet, Stockholm, Sweden
Sven-Erik Dahlén, MD PhD , Karolinska Institutet, Stockholm, Sweden
Mikael Adner, PhD , Karolinska Institutet, Stockholm, Sweden
Niklas Bjorkstrom, MD PhD , Karolinska Institutet, Stockholm, Sweden
Hans-Gustaf Ljunggren, Prof , Karolinska Institutet, Stockholm, Sweden
Jakob Michaëlsson, PhD , Karolinska Institutet, Stockholm, Sweden
Natural Killer (NK) cells are the predominant innate lymphocyte population in human lung tissue. However, tissue-resident NK cells in the lung remain undescribed, and their role in physiological and pathological conditions is unknown.

Here we characterize tissue-resident NK cell subsets in human lung tissue by multicolor flow cytometry. Tissue-resident NK cells can be identified by CD69, CD103, and CD49a. Whereas on bulk level terminally differentiated NK cells are accumulated in the lung as compared to matched peripheral blood, tissue-resident lung NK cells appear immature. In 10-15% of the donors we found a clonal-like expansion of tissue-resident NK cells, and accumulation of CD69+ NK cells correlated strongly with decreased lung function. Finally, clonal-like expanded tissue-resident NK cells strongly expressed NKG2C, indicating a role for a preceding viral infection in shaping this NK cell population.

Whereas lung NK cells are normally suppressed, activated clonal-like NK cell expansions might exert bystander cytotoxicity against healthy tissue and contribute to pathological conditions. We expect that our data will help in understanding the role of NK cells in the development and progression of lung diseases and improve the diagnosis and treatment strategies.