94 research outputs found
Gender issues in the therapy with people with eating disorders
openNell’elaborato in questione viene analizzata e approfondita la questione di genere nel contesto della terapia con pazienti affetti da disturbi alimentari, a partire da una contestualizzazione socio-cultural
Arf6: a new player in FcγRIIIA lymphocyte-mediated cytotoxicity
AbstractThe activation of phosphoinositide metabolism represents a critical step in the signaling pathways leading to the activation of cytolytic machinery, but its regulation is partially understood. We report here that the stimulation of the low-affinity receptor for immunoglobulin G (IgG) (FcγRIIIA, CD16) on primary human natural killer (NK) cells induces a phosphatidylinositol 3-kinase (PI3K)–dependent activation of the small G protein Arf6. We first demonstrate a functional role for Arf6-dependent signals in the activation of the antibody-dependent cellular cytotoxicity (ADCC) attributable to the control of secretion of lytic granule content. We also show that Arf6 couples CD16 to the lipid-modifying enzymes phosphatidylinositol4phosphate 5-kinase type I alpha (PI5KIα) and phospholipase D (PLD) that are involved in the control of granule secretion; Arf6, but not Rho family small G proteins RhoA and Rac1, is required for receptor-induced PI5KIα membrane targeting as well as for PI5KIα and PLD activation. Our findings suggest that Arf6 plays a crucial role in the generation of a phosphatidylinositol4,5-bisphosphate (PIP2) plasma membrane pool required for cytolytic granule-mediated target cell killing
MICA-129 dimorphism and soluble MICA are associated with the progression of multiple myeloma
Natural killer (NK) cells are immune innate effectors playing a pivotal role in the immunosurveillance
of multiple myeloma (MM) since they are able to directly recognize
and kill MM cells. In this regard, among activating receptors expressed by NK cells,
NKG2D represents an important receptor for the recognition of MM cells, being its
ligands expressed by tumor cells, and being able to trigger NK cell cytotoxicity. The
MHC class I-related molecule A (MICA) is one of the NKG2D ligands; it is encoded
by highly polymorphic genes and exists as membrane-bound and soluble isoforms.
Soluble MICA (sMICA) is overexpressed in the serum of MM patients, and its levels
correlate with tumor progression. Interestingly, a methionine (Met) to valine (Val)
substitution at position 129 of the α2 heavy chain domain classifies the MICA alleles
into strong (MICA-129Met) and weak (MICA-129Val) binders to NKG2D receptor.
We addressed whether the genetic polymorphisms in the MICA-129 alleles could
affect MICA release during MM progression. The frequencies of Val/Val, Val/Met, and
Met/Met MICA-129 genotypes in a cohort of 137 MM patients were 36, 43, and 22%,
respectively. Interestingly, patients characterized by a Val/Val genotype exhibited the
highest levels of sMICA in the sera. In addition, analysis of the frequencies of MICA-129
genotypes among different MM disease states revealed that Val/Val patients had a
significant higher frequency of relapse. Interestingly, NKG2D was downmodulated in
NK cells derived from MICA-129Met/Met MM patients. Results obtained by structural
modeling analysis suggested that the Met to Val dimorphism could affect the capacity
of MICA to form an optimal template for NKG2D recognition. In conclusion, our findings
indicate that the MICA-129Val/Val variant is associated with significantly higher levels of
sMICA and the progression of MM, strongly suggesting that the usage of soluble MICA
as prognostic marker has to be definitely combined with the patient MICA genotype
Age-dependent NK cell dysfunctions in severe COVID-19 patients
Natural Killer (NK) cells are key innate effectors of antiviral immune response, and their activity changes in ageing and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we investigated the age-related changes of NK cell phenotype and function during SARS-CoV-2 infection, by comparing adult and elderly patients both requiring mechanical ventilation. Adult patients had a reduced number of total NK cells, while elderly showed a peculiar skewing of NK cell subsets towards the CD56lowCD16high and CD56neg phenotypes, expressing activation markers and check-point inhibitory receptors. Although NK cell degranulation ability is significantly compromised in both cohorts, IFN-γ production is impaired only in adult patients in a TGF-β-dependent manner. This inhibitory effect was associated with a shorter hospitalization time of adult patients suggesting a role for TGF-β in preventing an excessive NK cell activation and systemic inflammation. Our data highlight an age-dependent role of NK cells in shaping SARS-CoV-2 infection toward a pathophysiological evolution
Early primary tumor response in metastatic RCC patients treated with immune checkpoint inhibitors-based combinations
Background:
25-30% of renal cell carcinoma presents with metastases (mRCC) at diagnosis.
The activity of immune checkpoint inhibitor (ICI)-combinations on the primary tumor (PT) is debated.
Patients andMethods:
mRCC patients (pts) with PT who received first-line nivolumab plus ipilimumab (N/I) or pembrolizumab plus axitinib (P/A) were included. We investigated the early primary tumor response (EPTR) at the first radiological assessment.
Results:
73 pts were included. The median early reduction of the PT longest diameter was 12.4% with P/A versus 6.2% with N/I (p = 0.42). We evaluated if the type of EPTR could affect the metastases response. Among pts with PT stable disease (SD), 8.3% had metastatic disease progression (PD) with P/A and 34.8% with N/I. Early PT partial response (PR) was associated with no metastatic PD with both N/I and P/A. The 2 pts with PT PD had also metastatic PD to P/A. Of the 3 PT with PD to N/I, 1 had metastatic SD and 2 PD. In the overall population, of the 94.1% without PT progression (PR+SD), 47.5% had metastatic PR, 35.6% SD, 16.9% PD.
Conclusions:
ICIs-combinations achieved an early PT PR in about 10-20%, without any complete responses. Only a small percentage of PT had an early PD, mainly associated with metastatic PD. However, among those PT without an early progression, metastatic PR can be achieved in approximately 50% of cases
Toward highly potent cancer agents by modulating the c-2 group of the arylthioindole class of tubulin polymerization inhibitors
New arylthioindole derivatives having different cyclic substituents at position 2 of the indole were synthesized as anticancer agents. Several compounds inhibited tubulin polymerization at submicromolar concentration and inhibited cell growth at low nanomolar concentrations. Compounds 18 and 57 were superior to the previously synthesized 5. Compound 18 was exceptionally potent as an inhibitor of cell growth: it showed IC50 = 1.0 nM in MCF-7 cells, and it was uniformly active in the whole panel of cancer cells and superior to colchicine and combretastatin A-4. Compounds 18, 20, 55, and 57 were notably more potent than vinorelbine, vinblastine, and paclitaxel in the NCI/ADR-RES and Messa/Dx5 cell lines, which overexpress P-glycoprotein. Compounds 18 and 57 showed initial vascular disrupting effects in a tumor model of liver rhabdomyosarcomas at 15 mg/kg intravenous dosage. Derivative 18 showed water solubility and higher metabolic stability than 5 in human liver microsomes
Improvement of Water Resistance of Vegetable Proteins by the Use of Synthetic Origin Additives: Trials with Resins and Metal Ions
The adhesives industry is increasingly interested in products coming from natural and renewable resources. The aim of the present work was to improve the water resistance of soy-based proteins by using synthetic and formaldehyde-free additives. These include polyamide-amine epichlorohydrin (PAE), different types of isocyanates, and combinations of these cross-linkers between them and with other agents, including metal ions. In addition, the effect of both curing temperature and maturation time was assessed. Performances were evaluated by means of shear strength tests, solubility tests, and spectroscopic analysis. The obtained results showed that while isocyanates reacted completely but with water instead of proteins, tests with PAE were generally successful. In fact, the insoluble residue as well as the shear strength in wet conditions dramatically increased after PAE addition. Moreover, the wet performances of protein/PAE formulations appreciably increased gluing at 60 °C instead of room temperature. Furthermore, the maturation time had a positive effect on the formulations where metal ions were added, both for solubility and wet shear strength. Actually, for the very long conditioning time of 3 months, a significant and substantial increase of wet shear strength was observed for the series protein/PAE/aluminum
Targeting NKG2D and NKp30 ligands shedding to improve NK cell–based immunotherapy
Natural killer (NK) cells are critical immune effector cells capable of mediating antitumor responses. These cytotoxic lymphocytes recognize transformed cells through a mechanism mainly dependent on the engagement of several activating receptors. However, many tumors have developed strategies to evade immunosurveillance and detection by NK cells. A relevant immune escape mechanism is the down regulation of NK cell activating ligands on the surface of tumor cells by proteolytic shedding mediated by different members of metalloproteinase families. Here, we consider two important NK activating receptors, namely NKG2D and NKp30, the ligands (i.e., MICA/B, ULBPs, and B7-H6) of which can be released by cancer cells through proteolytic cleavage. Modulation of ligand shedding in response to cancer therapy is also examined, and we discuss how metalloproteinases implicated in the ligand cleavage could be targeted in novel therapeutic schemes to counteract tumor escape from stress-elicited immune responses
The adaptor protein shc is involved in the negative regulation of NK cell-mediated cytotoxicity
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