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Rosa Sorrentino

Publications and source records attributed to Rosa Sorrentino.

10 recordsLinked to original sources
PubMed2025

An Immunosenescent CD8+ T Cell Subset in Patients with Axial Spondyloarthritis and Psoriatic Arthritis Links Spontaneous Motility to Telomere Shortening and Dysfunction.

OBJECTIVE: A pathogenetic role of CD8+ T lymphocytes in radiographic axial spondyloarthritis (r-axSpA) and other spondyloarthritis (SpA) is sustained by genome-wide association studies and by the expansion of public T cell clonotypes in the target tissues. This study investigates the migration of CD8+ T cells along with their phenotype and functions in patients with r-axSpA and psoriatic arthritis (PsA). METHODS: Peripheral blood CD8+ and CD4+ T cells were isolated from patients with r-axSpA (n = 128), PsA (n = 60), and rheumatoid arthritis (RA) (n = 74) and healthy donors (HDs) (n = 79). Transwell migration assay was performed in the presence of different chemokines. CD8+ T cell immunoprofiling and effector functions were assessed by multiparametric flow cytometry. Transcriptome signature was evaluated by RNA sequencing analysis, whereas telomere length and dysfunction were measured by reverse transcriptase-polymerase chain reaction and immunofluorescence-fluorescence in situ hybridization, respectively. RESULTS: A significantly higher number of CD8+ T cells migrating in the absence of chemokine stimuli was found in patients with SpA compared with HDs and patients with RA. This subset, producing cytotoxic (granzyme B, perforin, granulysin) and proinflammatory molecules (tumor necrosis factor), was significantly enriched in terminally differentiated (CCR7-CD45RA+) and senescent (CD28-CD57+) cells having a gene expression profile characterized by cytolytic signature and natural killer markers. Remarkably, these spontaneously migrating CD8+ T cells showed DNA damage response activation, telomere shortening, and dysfunction. CONCLUSION: These data describe a terminally differentiated CD8+ T cell subset with a senescent and cytotoxic/proinflammatory profile and an intrinsic invasive potential enriched in patients with SpA that represents a possible player in disease pathogenesis.

Humans↗
PubMed2006

Characterization of CD8+ T cell repertoire in identical twins discordant and concordant for multiple sclerosis.

Autoreactive CD4+ and CD8+ T cells directed against CNS autoantigens may play a role in the development of multiple sclerosis (MS). Identical twins share the same genetic background but not the TCR repertoire that is shaped by the encounter with self or foreign antigens. To gain insights into the interplay between MS and T cell repertoire, peripheral blood CD4+ and CD8+ T lymphocytes and their CCR7+/CCR7- subsets from five pairs of identical twins (four discordant and one concordant for MS; none of which had taken disease-modifying therapy) were compared by TCR beta-chain (TCRB) complementary-determining region 3 (CDR3) spectratyping. CD4+ T cells generally showed a Gaussian distribution, whereas CD8+ T cells exhibited subject-specific, widely skewed TCR spectratypes. There was no correlation between CD8+ T cell oligoclonality and disease. Sequencing of predominant spectratype expansions revealed shared TCRB-CDR3 motifs when comparing inter- and/or intrapair twin members. In many cases, these sequences were homologous to published TCRs, specific for viruses implicated in MS pathogenesis, CNS autoantigens, or copaxone [glatiramer acetate (GA)], implying the occurrence of naturally GA-responding CD8+ T cells. It is notable that these expanded T cell clones with putative pathogenic or regulatory properties were present in the affected as well as in the healthy subject, thus suggesting the existence of a "MS predisposing trait" shared by co-twins discordant for MS.

Adult↗
PubMed2005

Conformational dimorphism of self-peptides and molecular mimicry in a disease-associated HLA-B27 subtype.

An interesting property of certain peptides presented by major histocompatibility complex (MHC) molecules is their acquisition of a dual binding mode within the peptide binding groove. Using x-ray crystallography at 1.4 A resolution, we show here that the glucagon receptor-derived self-peptide pGR ((412)RRRWHRWRL(420)) is presented by the disease-associated human MHC class I subtype HLA-B*2705 in a dual conformation as well, with the middle of the peptide bent toward the floor of the peptide binding groove of the molecule in both binding modes. The conformations of pGR are compared here with those of another self-peptide (pVIPR, RRKWRRWHL) that is also displayed in two binding modes by HLA-B*2705 antigens and with that of the viral peptide pLMP2 (RRRWRRLTV). Conserved structural features suggest that the N-terminal halves of the peptides are crucial in allowing cytotoxic T lymphocyte (CTL) cross-reactivity. In addition, an analysis of T cell receptors (TCRs) from pGR- or pVIPR-directed, HLA-B27-restricted CTL clones demonstrates that TCR from distinct clones but with comparable reactivity may share CDR3alpha but not CDR3beta regions. Therefore, the cross-reactivity of these CTLs depends on TCR-CDR3alpha, is modulated by TCR-CDR3beta sequences, and is ultimately a consequence of the conformational dimorphism that characterizes binding of the self-peptides to HLA-B*2705. These results lend support to the concept that conformational dimorphisms of MHC class I-bound peptides might be connected with the occurrence of self-reactive CTL.

Antigens↗
PubMed2005

The C terminus of the nucleoprotein of influenza A virus delivers antigens transduced by Tat to the trans-golgi network and promotes an efficient presentation through HLA class I.

Cytotoxic T lymphocytes (CTLs) are the most powerful weapon of the immune system to eliminate cells infected by intracellular parasites or tumors. However, very often, escape mechanisms overcome CTL immune surveillance by impairing the classical HLA class I antigen-processing pathway. Here, we describe a strategy for CTL activation based on the ability of Tat to mediate transcellular delivery of viral proteins encompassing HLA class I-restricted epitopes. In this system, the recombinant protein TAT-NpFlu containing the transduction domain of Tat of human immunodeficiency virus type 1 fused to the amino acid region 301 to 498 of the nucleoprotein of influenza A virus is proven to sensitize different human cells to lysis by HLA-B27-restricted, Flu 383-391-specific CTL lines. The fusion protein is processed very effectively, since a comparable biological effect is obtained with an amount of protein between 1 and 2 orders of magnitude lower than that of the synthetic peptide. Interestingly, while part of TAT-NpFlu undergoes fast and productive cleavage, a large amount of it remains intact for up to 24 h. Confocal microscopy shows that TAT-NpFlu accumulates in the trans-Golgi network (TGN), where it starts to be detectable 1 h after transduction. Using TAT-NpFlu mutants and hybrid constructs, we demonstrate that enrichment in the TGN occurs only when the carboxy-terminal region of NpFlu (amino acids 400 to 498) is present. These data disclose an unconventional route for presentation of epitopes restricted for HLA class I molecules.

Antigen Presentation↗
PubMed2004

Allele-dependent similarity between viral and self-peptide presentation by HLA-B27 subtypes.

Molecular mimicry is discussed as a possible mechanism that may contribute to the development of autoimmune diseases. It could also be involved in the differential association of the human major histocompatibility subtypes HLA-B(*)2705 and HLA-B(*)2709 with ankylosing spondylitis. These two subtypes differ only in residue 116 of the heavy chain (Asp in B(*)2705 and His in B(*)2709), but the reason for the differential disease association is not understood. Using x-ray crystallography, we show here that the viral peptide pLMP2 (RRRWRRLTV, derived from latent membrane protein 2 (residues 236-244) of Epstein-Barr virus) is presented by the B(*)2705 and B(*)2709 molecules in two drastically deviating conformations. Extensive structural similarity between pLMP2 and the self-peptide pVIPR (RRKWRRWHL, derived from vasoactive intestinal peptide type 1 receptor (residues 400-408)) is observed only when the peptides are presented by B(*)2705 because of a salt bridge between Arg(5) of both peptides and the subtype-specific heavy chain residue Asp(116). Combined with functional studies using pLMP2/pVIPR-cross-reactive cytotoxic T cell lines and clones, together with target cells presenting these peptides or a modified peptide analogue, our results reveal that a pathogen-derived peptide can exhibit major histocompatibility complex class I subtype-dependent, drastically distinct binding modes. Furthermore, the results demonstrate that molecular mimicry between pLMP2 and pVIPR in the HLA-B27 context is an allele-dependent property.

Alleles↗
PubMed2004

Dual, HLA-B27 subtype-dependent conformation of a self-peptide.

The products of the human leukocyte antigen subtypes HLA-B*2705 and HLA-B*2709 differ only in residue 116 (Asp vs. His) within the peptide binding groove but are differentially associated with the autoimmune disease ankylosing spondylitis (AS); HLA-B*2705 occurs in AS-patients, whereas HLA-B*2709 does not. The subtypes also generate differential T cell repertoires as exemplified by distinct T cell responses against the self-peptide pVIPR (RRKWRRWHL). The crystal structures described here show that pVIPR binds in an unprecedented dual conformation only to HLA-B*2705 molecules. In one binding mode, peptide pArg5 forms a salt bridge to Asp116, connected with drastically different interactions between peptide and heavy chain, contrasting with the second, conventional conformation, which is exclusively found in the case of B*2709. These subtype-dependent differences in pVIPR binding link the emergence of dissimilar T cell repertoires in individuals with HLA-B*2705 or HLA-B*2709 to the buried Asp116/His116 polymorphism and provide novel insights into peptide presentation by major histocompatibility antigens.

Amino Acid Sequence↗
PubMed2003

Two distinctive HLA haplotypes harbor the B27 alleles negatively or positively associated with ankylosing spondylitis in Sardinia: implications for disease pathogenesis.

OBJECTIVE: To compare haplotype distribution in HLA-B27-positive patients with ankylosing spondylitis (AS) and healthy control subjects possessing either AS-associated HLA-B27 alleles or the non-AS-associated HLA-B*2709 allele. METHODS: DNA samples from 47 HLA-B27-positive patients with AS and 76 HLA-B27-positive healthy controls (19 positive and 57 negative for B*2709) living in different areas of Sardinia were collected and typed for HLA class I and class II alleles. The third exon of the B27 gene was analyzed for the presence of Asp(116) or His(116), which differentiates B*2709 from the other two B27 subtypes (B*2705 and B*2702) that are mostly found in Sardinia. The parents of 6 subjects positive for B*2709 were also typed for HLA class I and class II alleles. Statistical analysis was performed by Fisher's exact test. RESULTS: In Sardinia, the B27 alleles conferring susceptibility to AS appear to be more frequently carried by a haplotype (A2;B27;Cw2;DR16) that reaches its highest frequency in patients with AS (A2 80.8%, B27 100%, Cw2 83%, and DR16 74.5%). Conversely, the non-AS-associated B*2709 allele is more frequently found together with other HLA alleles whose frequencies are inversely correlated with the disease (A32 or A30, Cw1, and DR12). Familial analysis of 6 subjects positive for HLA-B*2709 confirmed the existence of a "Sardinian" haplotype that is not associated with AS (A32;B*2709;Cw1;DR12). CONCLUSION: In Sardinia, 2 distinct haplotypes harbor the non-AS-associated HLA-B*2709 allele or the AS-associated B27 alleles. Our findings are compatible with the hypothesis that other genes within the HLA region besides HLA-B27 may play some role in conferring susceptibility to AS.

Adult↗