The HLA-B-21 dimorphism impacts on NK cell education and clinical outcome of immunotherapy in acute myeloid leukemia

• Natural killer (NK) cell function is regulated by inhibitory receptors, such as the family of killer immunoglobulin-like receptors (KIRs) and the NKG2A/CD94 heterodimer. These receptors recognize cognate HLA class I molecules on potential target cells, and recent studies imply that an HLA-B dimorphism at position -21 in the gene segment encoding the leader peptide dictates whether NK cell regulation primarily relies on the KIRs or the NKG2A/CD94 receptor. The impact of this HLA-B dimorphism on NK cell-mediated destruction of leukemic cells or on the course of leukemia is largely unknown. In a first part of this study, we compared functions of NK cells in subjects carrying HLA-B -21Mor 21T using interleukin-2 (IL-2)-activated NK cells and leukemic cells from patients with acute myeloid leukemia (AML). Subjects carrying HLA-B -21M harbored better-educated NKG2A1 NK cells and displayed superior capacity to degranulate lytic granules against KIR ligandmatched primary leukemic blasts. Second, we aimed to define the potential impact of HLA-B -21 variation on the course of AML in a phase 4 trial in which patients received IL-2based immunotherapy. In keeping with the hypothesis that 21M may be associated with improved NK cell functionality, we observed superior leukemia-free survival and overall survival in -21M patients than in -21T patients during IL-2based immunotherapy. We propose that genetic variation at HLA-B -21 may determine the antileukemic efficacy of activated NK cells and the clinical benefit of NK cell-activating immunotherapy.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Hematologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Hematology (hsv//eng)

Keyword

mhc class-i

natural-killer-cells

hla-c expression

inhibitory

receptors

activation

relapse

association

cd94/nkg2a

molecules

infection

Publication and Content Type

ref (subject category)

art (subject category)