Human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are endowed with the ability of establishing lifelong latency in human hosts and reactivating in immunocompromised subjects, including patients suffering from ulcerative colitis (UC). We, therefore, aimed to investigate virus-specific immunity in UC patients. A cohort of 24 UC patients (14 responders and 10 refractory to therapy) and 26 control subjects was prospectively enrolled to undergo virus-specific serology (by ELISA assay) and assessment of both CD4+ and CD8+ virus-specific T-cell response (by interferon-γ enzyme-linked immunospotanalysis). In parallel, mucosal viral load was determined by quantitative real-time PCR and the values were correlated with both clinical and endoscopic indexes of activity. For statistics, the t-test, Mann-Withney test, Fisher's exact test and Spearman rank correlation test were applied; p < 0.05 was considered significant. EBV-specific CD4+ and CD8+ T-cell responses were significantly lower in UC patients compared to controls (p < 0.0001 and p = 0.0006, respectively), whereas no difference was found for HCMV-specific T-cell response. When dividing the UC group according to response to therapy, both responders and refractory UC patients showed a deficient EBV-specific CD4+ T-cell response with respect to controls (p < 0.04 and p = 0.0003, respectively). Moreover, both EBV and HCMV mucosal loads were significantly higher in refractory UC than in responders and controls (p = 0.007 and 0.003; and p = 0.02 and 0.001, respectively), and correlated with activity indexes. Steroid therapy seemed the main risk factor for triggering EBV colitis. Finally, no cases of IgM positivity were found in the study population. An impaired EBV-specific immunity was clearly evident in UC patients, mostly in those refractory to therapy. The ELISPOT assay may serve as new tool for quantifying and monitoring virus-specific T-cell immunity in UC.

• Klíčová slova
• Adaptive immunity, Epstein-Barr virus, Human Cytomegalovirus, Therapy, Ulcerative colitis,
• MeSH
• CD4-pozitivní T-lymfocyty metabolismus   MeSH
• CD8-pozitivní T-lymfocyty metabolismus   MeSH
• cytomegalovirové infekce farmakoterapie   imunologie   MeSH
• Cytomegalovirus imunologie   fyziologie   MeSH
• DNA virů genetika   MeSH
• infekce virem Epsteina-Barrové farmakoterapie   imunologie   MeSH
• lidé MeSH
• prospektivní studie MeSH
• steroidy škodlivé účinky   terapeutické užití   MeSH
• studie případů a kontrol MeSH
• ulcerózní kolitida farmakoterapie   imunologie   virologie   MeSH
• virová nálož MeSH
• virus Epsteinův-Barrové imunologie   fyziologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA virů MeSH
• steroidy MeSH

Cytomegalovirus (CMV) infection is associated with allograft rejection but the mechanisms behind are poorly defined yet. Although cross-reactivity of T cells to alloantigen and CMV has been hypothesized, direct evidence in patients is lacking. In this observational cohort study, we tested the pre-transplant effector/memory T cell response to CMV peptide pools and alloantigen in 78 living donor/recipient pairs using the interferon-gamma Enzyme-Linked ImmunoSpot (ELISPOT) assay. To prove the hypothesis of cross-reactivity, we analyzed by applying next-generation sequencing the T cell receptor ß (TCR- ß) repertoire of CMV- and alloantigen-reactive T cells enriched from peripheral pre-transplant blood of 11 CMV-seropositive and HLA class I mismatched patients. Moreover, the TCR-repertoire was also analyzed in the allograft biopsies of those patients. There was a significant association between the presence of pre-transplant CMV immediate-early protein 1 (IE-1)-specific effector/memory T cells and acute renal allograft rejection and function (p = 0.01). Most importantly, we revealed shared TCR-ß sequences between CMV-IE1 and donor alloantigen-reactive T cells in all pre-transplant peripheral blood samples analyzed in CMV-seropositive patients who received HLA class I mismatched grafts. Identical TCR sequences were also found in particular in post-transplant allograft biopsies of patients with concomitant CMV infection and rejection. Our data show the presence of functional, cross-reactive T cells and their clonotypes in peripheral blood and in kidney allograft tissue. It is therefore likely that CMV-donor cross-reactivity as well as CMV specific T cell elicited inflammation is involved in the processes that affect allograft outcomes.

• Klíčová slova
• ELISPOT, TCR repertoire, cross-reactivity, cytomegalovirus, heterologous immunity, kidney transplantation, rejection,
• MeSH
• alografty MeSH
• biopsie MeSH
• cytomegalovirové infekce * etiologie   genetika   imunologie   patologie   MeSH
• Cytomegalovirus imunologie   MeSH
• dospělí MeSH
• imunologická paměť * MeSH
• isoantigeny genetika   imunologie   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• receptory antigenů T-buněk alfa-beta * imunologie   MeSH
• T-lymfocyty * mikrobiologie   patologie   MeSH
• transplantace ledvin * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• pozorovací studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• isoantigeny MeSH
• receptory antigenů T-buněk alfa-beta * MeSH