0000000000195246
AUTHOR
Emanuela Marcenaro
Cognate HLA absence in trans diminishes human NK cell education
NK cells are innate lymphocytes with protective functions against viral infections and tumor formation. Human NK cells carry inhibitory killer cell Ig-like receptors (KIRs), which recognize distinct HLAs. NK cells with KIRs for self-HLA molecules acquire superior cytotoxicity against HLA– tumor cells during education for improved missing-self recognition. Here, we reconstituted mice with human hematopoietic cells from donors with homozygous KIR ligands or with a mix of hematopoietic cells from these homozygous donors, allowing assessment of the resulting KIR repertoire and NK cell education. We found that co-reconstitution with 2 KIR ligand–mismatched compartments did not alter the frequenc…
NKp46-expressing human gut-resident intraepithelial Vδ1 T cell subpopulation exhibits high antitumor activity against colorectal cancer
γδ T cells account for a large fraction of human intestinal intraepithelial lymphocytes (IELs) endowed with potent anti-tumor activities. However, little is known about their origin, phenotype and clinical relevance in colorectal cancer (CRC). To determine γδ IEL gut-specificity, homing and functions, γδ T cells were purified from human healthy blood, lymph nodes, liver, skin, intestine either disease-free or affected by CRC or generated from thymic precursors. The constitutive expression of NKp46 specifically identifies a new subset of cytotoxic Vδ1 T cells representing the largest fraction of gut-resident IELs. The ontogeny and gut-tropism of NKp46pos/Vδ1 IELs depends both on distinctive …
Accumulation of Circulating CCR7+ Natural Killer Cells Marks Melanoma Evolution and Reveals a CCL19-Dependent Metastatic Pathway
Abstract Immune checkpoint blockade therapy has changed prognoses for many melanoma patients. However, immune responses that correlate with clinical progression of the disease are still poorly understood. To identify immune responses correlating with melanoma clinical evolution, we analyzed serum cytokines as well as circulating NK and T-cell subpopulations from melanoma patients. The patients' immune profiles suggested that melanoma progression leads to changes in peripheral blood NK and T-cell subsets. Stage IV melanoma was characterized by an increased frequency of CCR7+CD56bright NK cells as well as high serum concentrations of the CCR7 ligand CCL19. CCR7 expression and CCL19 secretion …