Mariolina Salio - Academia.edu (original) (raw)

Papers by Mariolina Salio

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature, Jun 28, 2022

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature, Jan 30, 2023

Journal of Experimental Medicine, Jan 8, 2021

Juvenile myelomonocytic leukemia (JMML) is a poor-prognosis childhood leukemia usually caused by ... more Juvenile myelomonocytic leukemia (JMML) is a poor-prognosis childhood leukemia usually caused by RAS-pathway mutations. The cellular hierarchy in JMML is poorly characterized, including the identity of leukemia stem cells (LSCs). FACS and single-cell RNA sequencing reveal marked heterogeneity of JMML hematopoietic stem/progenitor cells (HSPCs), including an aberrant Lin − CD34 + CD38 − CD90 + CD45RA + population. Single-cell HSPC index-sorting and clonogenic assays show that (1) all somatic mutations can be backtracked to the phenotypic HSC compartment, with RAS-pathway mutations as a "first hit," (2) mutations are acquired with both linear and branching patterns of clonal evolution, and (3) mutant HSPCs are present after allogeneic HSC transplant before molecular/clinical evidence of relapse. Stem cell assays reveal interpatient heterogeneity of JMML LSCs, which are present in, but not confined to, the phenotypic HSC compartment. RNA sequencing of JMML LSC reveals upregulation of stem cell and fetal genes (HLF, MEIS1, CNN3, VNN2, and HMGA2) and candidate therapeutic targets/biomarkers (MTOR, SLC2A1, and CD96), paving the way for LSC-directed disease monitoring and therapy in this disease.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature, Sep 7, 2020

Gut, Sep 1, 2005

Background: Current understanding of T cell epitopes in coeliac disease (CD) largely derives from... more Background: Current understanding of T cell epitopes in coeliac disease (CD) largely derives from intestinal T cell clones in vitro. T cell clones allow identification of gluten peptides that stimulate T cells but do not quantify their contribution to the overall gluten specific T cell response in individuals with CD when exposed to gluten in vivo. Aims: To determine the contribution of a putative dominant T cell epitope to the overall gliadin T cell response in HLA-DQ2 CD in vivo. Patients: HLA-DQ2+ individuals with CD and healthy controls. Methods: Subjects consumed 20 g of gluten daily for three days. Interferon c (IFN-c) ELISPOT was performed using peripheral blood mononuclear cells (PBMC) to enumerate and characterise peptide and gliadin specific T cells before and after gluten challenge. Results: In 50/59 CD subjects, irrespective of homo-or heterozygosity for HLA-DQ2, IFN-c ELISPOT responses for an optimal concentration of A-gliadin 57-73 Q-E65 were between 10 and 1500 per million PBMC, equivalent to a median 51% of the response for a ''near optimal'' concentration of deamidated gliadin. Whole deamidated gliadin and gliadin epitope specific T cells induced in peripheral blood expressed an intestinal homing integrin (a4b7) and were HLA-DQ2 restricted. Peripheral blood T cells specific for A-gliadin 57-73 Q-E65 are rare in untreated CD but can be predictably induced two weeks after gluten exclusion. Conclusion: In vivo gluten challenge is a simple safe method that allows relevant T cells to be analysed and quantified in peripheral blood by ELISPOT, and should permit comprehensive high throughput mapping of gluten T cell epitopes in large numbers of individuals with CD.

International Immunology, Dec 1, 1998

The TCR-associated CD3 complex consists of four subunits, i.e. CD3γ, δ, ε and ζ, which are expres... more The TCR-associated CD3 complex consists of four subunits, i.e. CD3γ, δ, ε and ζ, which are expressed very early in T cell development prior to the expression of the TCR and the pre-TCR α chain. It is unclear whether the expression of each CD3 protein is independent of, or is influenced by, other CD3 subunits. To study whether CD3ε regulates expression of CD3γ and δ genes, we generated a strain of CD3ε-deficient mice termed CD3ε ∆P/∆P (ε ∆P), in which the promoter of CD3ε was disrupted, and subsequently reconstituted these mice with a CD3ε transgene. In the ε ∆P mice, T cell development is arrested at the double-negative stage and targeting the CD3ε gene caused severe inhibition of CD3γ and δ gene expression. Introduction of the CD3ε transgene did not restore CD3γ and δ expression. However, a very small fraction of prothymocytes that expressed CD3γ and δ was rescued upon reconstitution of the CD3ε transgene. Remarkably, this rescue led to a very efficient differentiation and maturation of thymocytes, resulting in a significant T cell population in the periphery. These results demonstrate that CD3ε does not regulate expression of CD3γ and δ genes, and underscore the capacity of each prothymocyte to give rise to a large number of mature peripheral T cells.

Seminars in Immunology, Nov 1, 2022

Frontiers in Immunology, Jul 28, 2015

Regulation of lipid specific and vitamin specific non-MHC restricted T cells by antigen presentin... more Regulation of lipid specific and vitamin specific non-MHC restricted T cells by antigen presenting cells and their therapeutic potentials.

European Journal of Immunology, Mar 1, 2008

The glycolipid a-galactosylceramide (a-GalCer) is a potent activator of invariant natural killer ... more The glycolipid a-galactosylceramide (a-GalCer) is a potent activator of invariant natural killer T (iNKT) cells and has been shown to be an effective agent against cancer, infections and autoimmune diseases. The effectiveness of a-GalCer and its alkyl chain analogues depends on efficient loading and presentation by the antigen-presenting molecule CD1d. To monitor the ability of CD1d to present the glycolipids, we have used a phage display strategy to generate recombinant antibodies with T cell receptor-like (TCRL) specificity against the human CD1d (hCD1d)-a-GalCer complex. These Fab fragments were able to detect specifically hCD1d-a-GalCer complexes in cell-free systems such as surface plasmon resonance and ELISA, as well as on the surface of hCD1d + antigen-presenting cells (APC) by flow cytometry and immunofluorescence microscopy, the latter of which could also detect intracellular complexes. We show that our TCRL antibodies can stain dendritic cells from CD11c-hCD1d-transgenic mice administered in vivo with a-GalCer and its analogues. Furthermore, the antibody was also able to detect the presentation by hCD1d molecules of analogues of a-GalCer with the same polar head structure. Using this reagent, we were able to confirm directly that the a-GalCer analogue C20:2 preferentially loads onto cell surface CD1d rapidly without the need for internalization, while the loading of a-GalCer is improved with longer incubation times on professional APC. This reagent will be essential for assessing the loading and presenting capabilities of hCD1d of a-GalCer and its analogues.

Journal of Biological Chemistry, May 1, 2011

Invariant natural killer T (iNKT) cells are a population of T lymphocytes that play an important ... more Invariant natural killer T (iNKT) cells are a population of T lymphocytes that play an important role in regulating immunity to infection and tumors by recognizing endogenous and exogenous CD1d-bound lipid molecules. Using soluble iNKT T cell receptor (TCR) molecules, we applied single molecule force spectroscopy for the investigation of the iNKT TCR affinity for human CD1d molecules loaded with glycolipids differing in the length of the phytosphingosine chain using either recombinant CD1d molecules or lipid-pulsed THP1 cells. In both settings, the dissociation of the iNKT TCR from human CD1d molecules loaded with the lipid containing the longer phytosphingosine chain required higher unbinding forces compared with the shorter phytosphingosine lipid. Our findings are discussed in the context of previous results obtained by surface plasmon resonance measurements. We present new insights into the energy landscape and the kinetic rate constants of the iNKT TCR/human CD1d-glycosphingolipid interaction and emphasize the unique potential of single molecule force spectroscopy on living cells.

Frontiers in Immunology, Oct 22, 2020

Adaptive immune recognition is mediated by specific interactions between heterodimeric T cell rec... more Adaptive immune recognition is mediated by specific interactions between heterodimeric T cell receptors (TCRs) and their cognate peptide-MHC (pMHC) ligands, and the methods to accurately predict TCR:pMHC interaction would have profound clinical, therapeutic and pharmaceutical applications. Herein, we review recent developments in predicting cross-reactivity and antigen specificity of TCR recognition. We discuss current experimental and computational approaches to investigate cross-reactivity and antigen-specificity of TCRs and highlight how integrating kinetic, biophysical and structural features may offer valuable insights in modeling immunogenicity. We further underscore the close interrelationship of these two interconnected notions and the need to investigate each in the light of the other for a better understanding of T cell responsiveness for the effective clinical applications.

Current Opinion in Immunology, Feb 1, 2010

It is well established that different populations of ab T lymphocytes can recognize not only pept... more It is well established that different populations of ab T lymphocytes can recognize not only peptides in the context of MHC class I and class II molecules, but also foreign and selflipids in association with CD1 proteins, which share structural similarities with MHC class I molecules. CD1 molecules are comprised of five isoforms, known as group 1 (CD1a, b, c, e) and group 2 (CD1d) CD1, presenting lipid antigens to conventional T lymphocytes or innate-like T cells bearing an invariant T cell receptor (TCR) and known as invariant NKT (iNKT) cells. During the last couple of years, several papers have been published describing important aspects of the mechanisms controlling the processing and presentation of endogenous and exogenous CD1 lipid antigens, which will be the main focus of this review.

Journal of Immunological Methods, Feb 1, 2004

Assessment of cell-mediated toxicity has traditionally been achieved by measuring the specific ac... more Assessment of cell-mediated toxicity has traditionally been achieved by measuring the specific activity of enriched effector cell populations against antigen-loaded target cells labeled with radioactive isotopes in vitro. Fluorometric techniques are viewed as a promising alternative to the use of radioactive isotopes for these analyses. Direct assessment of cytotoxicity in vivo can be achieved by monitoring survival of injected fluorescent targets relative to a differentially labeled internal control population without specific antigen. We have developed this approach, incorporating the use of multiple target cell populations labeled with different dyes so that cytotoxicity can be assessed against titrated doses of a given antigen, or against a range of different antigens, simultaneously. We show that this assay, referred to as the VITAL assay, can be used to assess cytotoxic activity of CTL and iNKT cells in vivo and in vitro. CTL responses measured in vivo could be correlated with antigen doses used in immunization strategies, and also with the size of specific CTL populations enumerated in the blood with fluorescent MHC/ peptide tetramers. The VITAL assay is, therefore, a sensitive technique allowing analysis of complex multi-epitope responses.

Methods in molecular biology, Dec 3, 2019

Mucosal-associated invariant T (MAIT) cells recognize intermediates of the vitamin B2 biosyntheti... more Mucosal-associated invariant T (MAIT) cells recognize intermediates of the vitamin B2 biosynthetic pathway present in a variety of bacteria, presented by the monomorphic MR1 molecules. Because of their central role in shaping adaptive immunity through interaction with dendritic cells (DCs) and B cells, their manipulation can be of translational relevance. We describe a method to routinely isolate and maintain MAIT cells from peripheral blood and to investigate their activity using DC as targets.

British Journal of Dermatology, 2014

British Journal of Dermatology, 2015

Biophysical Journal, 2014

PLOS Biology, Oct 27, 2009

Trends in Immunology, Oct 1, 2007

Recent findings have highlighted the ability of invariant natural killer T (iNKT) cells to recogn... more Recent findings have highlighted the ability of invariant natural killer T (iNKT) cells to recognize microbe-derived glycolipids and have demonstrated the role of these cells in several disease states, from autoimmune disease to cancer. It has also become clear that iNKT cells can rapidly mature dendritic cells and licence them to prime antigen-specific T-and B-cell responses. The use of CD1d tetramers to monitor iNKT cell frequency and phenotype has moved the field forward at a fast pace. To harness iNKT cells for therapeutic purposes and to understand their role in vivo, it is essential to characterize the molecular events that contribute to iNKT cell activation. Here we review new reagents and novel protocols that are facilitating a closer look at lipid presentation by CD1d molecules and their recognition by iNKT cells.

Frontiers in Immunology, Aug 13, 2020

Mucosal-associated invariant T (MAIT) cells are unconventional T lymphocytes that express a semi-... more Mucosal-associated invariant T (MAIT) cells are unconventional T lymphocytes that express a semi-invariant T cell receptor (TCR) recognizing microbial vitamin B metabolites presented by the highly conserved major histocompatibility complex (MHC) class I like molecule, MR1. The vitamin B metabolites are produced by several commensal and pathogenic bacteria and yeast, but not viruses. Nevertheless, viral infections can trigger MAIT cell activation in a TCR-independent manner, through the release of pro-inflammatory cytokines by antigen-presenting cells (APCs). MAIT cells belong to the innate like T family of cells with a memory phenotype, which allows them to rapidly release Interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and in some circumstances Interleukin (IL)-17 and IL-10, exerting an immunomodulatory role on the ensuing immune response, akin to iNKT cells and γδ T cells. Recent studies implicate MAIT cells in a variety of inflammatory, autoimmune diseases, and in cancer. In addition, through the analysis of the transcriptome of MAIT cells activated in different experimental conditions, an important function in tissue repair and control of immune homeostasis has emerged, shared with other innate-like T cells. In this review, we discuss these recent findings, focussing on the understanding of the molecular mechanisms underpinning MAIT cell activation and effector function in health and disease, which ultimately will aid in clinically harnessing this unique, not donor-restricted cell subtype.