Search results for "IMMUNOSUPPRESSION"

Myeloid-Derived Suppressor Cells in Multiple Myeloma: Pre-Clinical Research and Translational Opportunities

2014

Immunosuppressive cells have been reported to play an important role in tumor-progression mainly because of their capability to promote immune-escape, angiogenesis, and metastasis. Among them, myeloid-derived suppressor cells (MDSCs) have been recently identified as immature myeloid cells, induced by tumor-associated inflammation, able to impair both innate and adaptive immunity. While murine MDSCs are usually identified by the expression of CD11b and Gr1, human MDSCs represent a more heterogeneous population characterized by the expression of CD33 and CD11b, low or no HLA-DR, and variable CD14 and CD15. In particular, the last two may alternatively identify monocyte-like or granulocyte-lik…

Management of patients with chronic lymphocytic leukemia during the SARS‑CoV‑2 pandemic (Review)

2021

Oncohematological patients are prone to develop infections due to immunosuppression caused by the disease and chemo-immunotherapy. The aim of this review was to outline the details of the management of patients with chronic lymphocytic leukemia (CLL) during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Patients with CLL often exhibit inadequate humoral and cellular immune responses to various infections and vaccinations. Patients under the ‘watch and wait’ strategy have a lower risk of infections, including with SARS-CoV-2, compared with those undergoing therapeutic interventions, but they still have a higher risk than age-matched controls. Patients with CLL hav…

Abstract 1631: GPR65 is a critical mediator of low pH induced immunosuppressive signalling in tumor associated macrophages: Human target validation o…

2021

Abstract Tumor-associated macrophages (TAMs) are the major innate immune component in the microenvironment of solid tumors. These cells are highly heterogeneous and plastic but often display a pronounced immunosuppressive phenotype that supports primary tumor growth and metastasis. A recently identified determinant of the immunosuppressive properties of TAMs is the activation of the pH-sensing G protein-coupled receptor, GPR65, on these cells by the acidic microenvironment that is inherent to many advanced solid tumours1. Previous work in mouse macrophages has shown that GPR65 activation leads to an elevation of inducible cAMP early repressor (ICER), an isoform of the CREM gene, which in tu…

2021

IntroductionImmune checkpoint inhibitors (ICI) are increasingly being used to treat numerous cancer types. Together with improved recognition of toxicities, this has led to more frequent identification of rare immune-related adverse events (irAE), for which specific treatment strategies are needed. Neutropenia is a rare hematological irAE that has a potential for a high mortality rate because of its associated risk of sepsis. Prompt recognition and timely treatment of this life-threatening irAE are therefore critical to the outcome of patients with immune-related neutropenia.MethodsThis multicenter international retrospective study was conducted at 17 melanoma centers to evaluate the clinic…

A rare case of sepsis due to Corynebacterium macginleyi from central venous catheter in an elderly woman

2011

Corynebacterium macginleyi is a gram positive rod that causes especially ocular infections: since now only six elderly cases of extraocular infection are described. A 76 years old bedridden woman with a central venous catheter was hospitalized for 10 days of persistent fever. She was treated before with vancomicin and then with imipenem. The clinical conditions improved and the patient was discharged after two weeks of hospitalization. Among recognised risk factors for this infection the advanced age, indwelling devices and immunosuppression seem the most important. On the other hand, the antibiotics of choice are glycopeptides while the association of another antibiotic is recommended in o…

Effects of Zizyphus lotus L. (Desf.) polyphenols on Jurkat cell signaling and proliferation.

2013

We assessed the effects of Zizyphus lotus L. (Desf.) polyphenols (ZLP) on T-cell signaling and proliferation. Our results showed that ZLP exerted no effect on the increases in intracellular free calcium concentrations, [Ca(2+)]i, in human Jurkat T-cells. However, ZLP modulated the thapsigargin-induced increases in [Ca(2+)]i in these cells. ZLP treatment was found to decrease the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). In addition, ZLP induced a rapid (t1/2=33s) and dose-dependent decrease in intracellular pH (pHi) in human Jurkat T-cells. Furthermore, ZLP significantly curtailed T-cell proliferation by diminishing their progression from S to G2/M phase of cell…

Biodistribution, Uptake and Effects Caused by Cancer-derived Extracellular Vesicles

2015

Extracellular vesicles (EVs) have recently emerged as important mediators of intercellular communication. They are released in the extracellular space by a variety of normal and cancerous cell types and have been found in all human body fluids. Cancer-derived EVs have been shown to carry lipids, proteins, mRNAs, non-coding and structural RNAs and even extra-chromosomal DNA, which can be taken up by recipient cells and trigger diverse physiological and pathological responses. An increasing body of evidence suggests that cancer-derived EVs mediate paracrine signalling between cancer cells. This leads to the increased invasiveness, proliferation rate and chemoresistance, as well as the acquisi…

Remission of experimental autoimmune hepatitis is associated with antigen-specific and non-specific immunosuppression.

1993

SUMMARY Experimental autoimmune hepatitis (EAH) is an animal model for autoimmune hepatitis. The disease is T cell-mediated and runs a subacute course, with maximal disease activity around week four after disease induction and a slow ensuing recovery. The aim of the present study was to investigate the immunoregulatory mechanisms that may account for recovery in EAH. It was found that T cell reactivity to liver antigens preceded histological disease, but at the peak of disease activity this T cell response was already suppressed. Active and antigen-specific suppression could be demonstrated, as irradiated splenocytes from animals at the beginning of recovery from EAH were able to suppress i…

Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

2016

Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced …

A continuous infusion of a minor histocompatibility antigen-immunodominant peptide induces a delay of male skin graft rejection.

2009

Abstract We previously reported that an inhibition of antigen-specific Interferon-γ release and cytotoxicity occurs after a continuous infusion of an HY immunodominant peptide although this treatment is not able to cause a significant delay of male skin grafts rejection. In vivo administration of high doses of an HY peptide, through mini-osmotic pumps, in naive female mice was used to study the effects on the male skin grafts rejection. A continuous infusion of 1 mg of an HY peptide induces a significant delay of male skin graft rejection. In vitro HY-specific Interferon-γ release was inhibited adding peptide-specific suppressor cells: the ability to inhibit Interferon-γ release was evident…