image_1_Tumor-Targeting Anti-CD20 Antibodies Mediate In Vitro Expansion of Memory Natural Killer Cells: Impact of CD16 Affinity Ligation Conditions and In Vivo Priming.PDF

<p>Natural killer (NK) cells represent a pivotal player of innate anti-tumor immune responses. The impact of environmental factors in shaping the representativity of different NK cell subsets is increasingly appreciated. Human cytomegalovirus (HCMV) infection profoundly affects NK cell compartment, as documented by the presence of a CD94/NKG2C⁺FcεRIγ^- long-lived “memory” NK cell subset, endowed with enhanced CD16-dependent functional capabilities, in a fraction of HCMV-seropositive subjects. However, the requirements for memory NK cell pool establishment/maintenance and activation have not been fully characterized yet. Here, we describe the capability of anti-CD20 tumor-targeting therapeutic monoclonal antibodies (mAbs) to drive the selective in vitro expansion of memory NK cells and we show the impact of donor’ HCMV serostatus and CD16 affinity ligation conditions on this event. In vitro expanded memory NK cells maintain the phenotypic and functional signature of their freshly isolated counterpart; furthermore, our data demonstrate that CD16 affinity ligation conditions differently affect memory NK cell proliferation and functional activation, as rituximab-mediated low-affinity ligation represents a superior proliferative stimulus, while high-affinity aggregation mediated by glycoengineered obinutuzumab results in improved multifunctional responses. Our work also expands the molecular and functional characterization of memory NK cells, and investigates the possible impact of CD16 functional allelic variants on their in vivo and in vitro expansions. These results reveal new insights in Ab-driven memory NK cell responses in a therapeutic setting and may ultimately inspire new NK cell-based intervention strategies against cancer, in which the enhanced responsiveness to mAb-bound target could significantly impact therapeutic efficacy.</p

Comparison of GENOTATOR and GWAS gene lists.

<p>(<b>A</b>) results at the single-gene level; (<b>B</b>) results in terms of biological function derived from IPA analysis. Boxes describe specific biological functions; (<b>C</b>) signaling pathway comparison, resulting from IPA analysis; (<b>D</b>) comparison performed in terms of metabolic pathways, derived from IPA analysis. Box indicates “GENOTATOR-only” signaling pathways.</p

Results from the analysis of all the molecules directly or indirectly linked to GENOTATOR/GWAS lists of genes.

<p>Histogram chart (<b>center</b>) shows the absolute number of molecules contemporarily targeted by registered drugs or pharmacologically active compounds and also part of complex molecular networks involving GENOTATOR-only, GWAS-only, or common genes; (<b>left</b> and <b>right</b>): most significant molecular networks and related drugs.</p

Study flow diagram.

<p>It summarizes of the methodology we designed and followed to compare the pre- and post-GWAS understanding of the disease by means of single gene analyses, pathway comparisons, and drug target evaluations.</p