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The early expansion of anergic NKG2A^pos/CD56^dim/CD16^neg natural killer represents a therapeutic target in haploidentical hematopoietic stem cell transplantation.

ABSTRACT: Natural killer cells are the first lymphocyte population to reconstitute early after non-myeloablative and T cell-replete haploidentical hematopoietic stem cell transplantation with post-transplant infusion of cyclophosphamide. The study herein characterizes the transient and predominant expansion starting from the second week following haploidentical hematopoietic stem cell transplantation of a donor-derived unconventional subset of NKp46^neg-low/CD56^dim/CD16^neg natural killer cells expressing remarkably high levels of CD94/NKG2A. Both transcription and phenotypic profiles indicated that unconventional NKp46^neg-low/CD56^dim/CD16^neg cells are a distinct natural killer cell subpopulation with features of late stage differentiation, yet retaining proliferative capability and functional plasticity to generate conventional NKp46^pos/CD56^bright/CD16^neg-low cells in response to interleukin-15 plus interleukin-18. While present at low frequency in healthy donors, unconventional NKp46^neg-low/CD56^dim/CD16^neg cells are greatly expanded in the seven weeks following haploidentical hematopoietic stem cell transplantation, and express high levels of the activating receptors NKG2D and NKp30 as well as of the lytic granules Granzyme-B and Perforin. Nonetheless, NKp46^neg-low/CD56^dim/CD16^neg cells displayed a markedly defective cytotoxicity that could be reversed by blocking the inhibitory receptor CD94/NKG2A. These data open new and important perspectives to better understand the ontogenesis/homeostasis of human natural killer cells and to develop a novel immune-therapeutic approach that targets the inhibitory NKG2A check-point, thus unleashing natural killer cell alloreactivity early after haploidentical hematopoietic stem cell transplantation.

SUBMITTER: Roberto A

PROVIDER: S-EPMC6068034 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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The early expansion of anergic NKG2Apos/CD56dim/CD16neg natural killer represents a therapeutic target in haploidentical hematopoietic stem cell transplantation.

Roberto Alessandra A Di Vito Clara C Zaghi Elisa E Mazza Emilia Maria Cristina EMC Capucetti Arianna A Calvi Michela M Tentorio Paolo P Zanon Veronica V Sarina Barbara B Mariotti Jacopo J Bramanti Stefania S Tenedini Elena E Tagliafico Enrico E Bicciato Silvio S Santoro Armando A Roederer Mario M Marcenaro Emanuela E Castagna Luca L Lugli Enrico E Mavilio Domenico D

Haematologica 20180426 8

Natural killer cells are the first lymphocyte population to reconstitute early after non-myeloablative and T cell-replete haploidentical hematopoietic stem cell transplantation with post-transplant infusion of cyclophosphamide. The study herein characterizes the transient and predominant expansion starting from the second week following haploidentical hematopoietic stem cell transplantation of a donor-derived unconventional subset of NKp46neg-low/CD56dim/CD16neg ...[more]

PMID: 29700172

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Project description:BackgroundEvidence on the changes in the absolute counts of monocyte subpopulations in sepsis is missing.MethodsFirstly, absolute counts of circulating CD14pos/HLA-DRpos/CD45pos monocytes were measured by flow cytometry in 70 patients with Gram-negative sepsis and in 10 healthy volunteers. In the second phase, immunophenotyping was performed and the absolute count of circulating inflammatory monocytes and of circulating CD14dim/CD16pos/CD45pos patrolling monocytes were measured in another 55 patients and 10 healthy volunteers. Measurements were repeated on days 3, 7, and 10. Results were correlated with survival after 28 days.ResultsGreater numbers of CD14pos/HLA-DRpos/CD45pos monocytes were found on day 1 in survivors compared to nonsurvivors (p = 0.030). Receiver operating characteristic (ROC) analysis showed that a cutoff higher than 337 cells/mm3 on day 1 could discriminate between survivors and nonsurvivors with a positive predictive value (PPV) of 91.1%. Logistic regression including Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation (APACHE) II score showed that an absolute count greater than 337 cells/mm3 was independently associated with unfavorable outcome (odds ratio (OR) 0.19, p = 0.050). The absolute counts of inflammatory and of CD14dim/CD16pos/CD45pos monocytes were greater in patients than healthy controls during the entire 10 days of follow-up. The absolute counts on day 3 of CD14dim/CD16pos/CD45pos monocytes were greater in survivors than nonsurvivors (p = 0.027). ROC analysis revealed that the cutoff at 27 cells/mm3 could discriminate between survivors and nonsurvivors with PPV of 94.1%. Logistic regression including age, SOFA score, and APACHE II score showed that an absolute count greater than 27 cells/mm3 was independently associated with unfavorable outcome (OR 0.06, p = 0.033). Logistic regression analysis showed that intra-abdominal infection on day 1 was predictive of low CD14dim/ CD16pos/CD45pos count on day 3.ConclusionCirculating counts of inflammatory and patrolling monocytes are greatly increased in Gram-negative sepsis. Absolute counts of CD14pos/HLA-DRpos/CD45pos monocytes on day 1 and CD14dim/CD16pos/CD45pos monocytes on day 3 are independently associated with final outcome.Trial registrationClinicalTrials.gov, NCT01223690 . Registered retrospectively on 18 October 2010.

Project description:Natural killer (NK) cells are innate cytotoxic and immunoregulatory lymphocytes that have a central role in anti-tumor immunity and play a critical role in mediating cellular immunity in advanced cancer immunotherapies, such as dendritic cell (DC) vaccines. Our group recently tested a novel recombinant adenovirus-transduced autologous DC-based vaccine that simultaneously induces T cell responses against three melanoma-associated antigens for advanced melanoma patients. Here, we examine the impact of this vaccine as well as the subsequent systemic delivery of high-dose interferon-α2b (HDI) on the circulatory NK cell profile in melanoma patients. At baseline, patient NK cells, particularly those isolated from high-risk patients with no measurable disease, showed altered distribution of CD56dim CD16+ and CD56dim CD16- NK cell subsets, as well as elevated serum levels of immune suppressive MICA, TN5E/CD73 and tactile/CD96, and perforin. Surprisingly, patient NK cells displayed a higher level of activation than those from healthy donors as measured by elevated CD69, NKp44 and CCR7 levels, and enhanced K562 killing. Elevated cytolytic ability strongly correlated with increased representation of CD56dim CD16+ NK cells and amplified CD69 expression on CD56dim CD16+ NK cells. While intradermal DC immunizations did not significantly impact circulatory NK cell activation and distribution profiles, subsequent HDI injections enhanced CD56bright CD16- NK cell numbers when compared to patients that did not receive HDI. Phenotypic analysis of tumor-infiltrating NK cells showed that CD56dim CD16- NK cells are the dominant subset in melanoma tumors. NanoString transcriptomic analysis of melanomas resected at baseline indicated that there was a trend of increased CD56dim NK cell gene signature expression in patients with better clinical response. These data indicate that melanoma patient blood NK cells display elevated activation levels, that intra-dermal DC immunizations did not effectively promote systemic NK cell responses, that systemic HDI administration can modulate NK cell subset distributions and suggest that CD56dim CD16- NK cells are a unique non-cytolytic subset in melanoma patients that may associate with better patient outcome.

Project description:Conventional CD4pos regulatory T (Treg) cells characterized by expression of the key transcription factor forkhead box P3 (FoxP3) are crucial to control immune responses, thereby maintaining homeostasis and self-tolerance. Within the substantial population of non-conventional T cell receptor (TCR)αβpos CD4negCD8αneg double-negative (dn) T cells of dogs, a novel FoxP3pos Treg-like subset was described that, similar to conventional CD4pos Treg cells, is characterized by high expression of CD25. Noteworthy, human and murine TCRαβpos regulatory dn T cells lack FoxP3. Immunosuppressive capacity of canine dn T cells was hypothesized based on expression of inhibitory molecules (interleukin (IL)-10, cytotoxic T-lymphocyte associated protein 4, CTLA4). Here, to verify their regulatory function, the dnCD25pos (enriched for FoxP3pos Treg-like cells) and the dnCD25neg fraction, were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells (PBMC) of Beagle dogs and analyzed in an in vitro suppression assay in comparison to conventional CD4posCD25pos Treg cells (positive control) and CD4posCD25neg T cells (negative control). Canine dnCD25pos T cells suppressed the Concanavalin A-driven proliferation of responder PBMC to a similar extent as conventional CD4posCD25pos Treg cells. Albeit to a lesser extent than FoxP3-enriched dn and CD4posCD25pos populations, even dnCD25neg T cells reduced the proliferation of responder cells. This is remarkable, as dnCD25neg T cells have a FoxP3neg phenotype comparable to non-suppressive CD4posCD25neg T cells. Both, CD25pos and CD25neg dn T cells, can mediate suppression independent of cell-cell contact and do not require additional signals from CD4posCD25neg T cells to secrete inhibitory factors in contrast to CD4posCD25pos T cells. Neutralization of IL-10 completely abrogated the suppression by dnCD25pos and CD4posCD25pos Treg cells in a Transwell™ system, while it only partially reduced suppression by dnCD25neg T cells. Taken together, unique canine non-conventional dnCD25pos FoxP3pos Treg-like cells are potent suppressor cells in vitro. Moreover, inhibition of proliferation of responder T cells by the dnCD25neg fraction indicates suppressive function of a subset of dn T cells even in the absence of FoxP3. The identification of unique immunoregulatory non-conventional dn T cell subpopulations of the dog in vitro is of high relevance, given the immunotherapeutic potential of manipulating regulatory T cell responses in vivo.

Dataset Information

The early expansion of anergic NKG2A^pos/CD56^dim/CD16^neg natural killer represents a therapeutic target in haploidentical hematopoietic stem cell transplantation.

Publications

The early expansion of anergic NKG2A<sup>pos</sup>/CD56<sup>dim</sup>/CD16<sup>neg</sup> natural killer represents a therapeutic target in haploidentical hematopoietic stem cell transplantation.

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