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Gerna G.,Laboratori Sperimentali Of Ricerca | Lilleri D.,Laboratori Sperimentali Of Ricerca | Lilleri D.,Institute for Research in Biomedicine | Fornara C.,Laboratori Sperimentali Of Ricerca | And 5 more authors.
Journal of General Virology | Year: 2015

The comparative long-term kinetics of human cytomegalovirus (HCMV) load and HCMV-specific antibody responses in the immunocompetent and immunocompromised solid-organ transplanted host during primary HCMV infection was investigated. In total, 40 immunocompetent subjects and 17 transplanted patients were examined for viral load as well as for IgG antibody responses to HCMV glycoproteins gH/gL/pUL128L, gH/gL and gB, and neutralizing antibodies in ARPE-19 epithelial cells and human fibroblasts. In parallel, the CD4+ and CD8+ HCMV-specific T-cell responses were determined by cytokine flow cytometry. Transplanted patients reached significantly higher viral DNA peaks, which persisted longer than in immunocompetent subjects. The ELISA-IgG responses to the pentamer, gH/gL and gB were significantly higher in primary infections of the immunocompetent until six months after onset, with the two antibody levels then overlapping from six to 12 months. Antibody levels neutralizing infection of epithelial cells were significantly higher in transplanted patients after six months, persisting for up to a year after transplantation. This trend was not observed for antibodies neutralizing infection of human fibroblasts, which showed higher titres in the immunocompetent over the entire one-year followup. In conclusion, in immunocompromised patients the viral load peak was much higher, while the neutralizing antibody response exceeded that detected in the immunocompetent host starting six months after onset of follow-up, often concomitantly with a lack of specific CD4+ T cells. In this setting, the elevated antibody response occurred in the presence of differentiated follicular helper T cells in the blood, which decreased in number as did antibody titres upon reappearance of HCMV-specific CD4+ T cells. © 2015 The Authors. Source


Fornara C.,Laboratori Sperimentali Of Ricerca | Furione M.,Struttura Semplice Virologia Molecolare | Lilleri D.,Laboratori Sperimentali Of Ricerca | Cane I.,Laboratori Sperimentali Of Ricerca | And 3 more authors.
Journal of Clinical Virology | Year: 2015

Background: Human cytomegalovirus infections are mostly asymptomatic in infants and young children, while they are often associated with overt clinical symptoms in adults. Objectives: To verify whether the antibody response to HCMV is more potent in symptomatic non-pregnant adults as compared to asymptomatic/paucisymptomatic pregnant women. Study design: Overall, 36 consecutive pregnant women with primary HCMV infection were compared with 10 consecutive symptomatic non-pregnant subjects with primary HCMV infection and overt clinical symptoms. Levels of IgG antibody responses to HCMV-infected cell lysate and the pentamer gH/gL/pUL128L, gH/gL and gB HCMV glycoprotein complexes as well as neutralizing antibodies preventing infection of epithelial cells (ARPE-19) and human embryonic lung fibroblast (HELF) cells were compared at intervals of 1-30, 31-60, 61-90, 91-180 and 181-360 days after onset of infection. In parallel, viral load was quantified by real-time PCR. Results: In symptomatic non-pregnant subjects, the IgG responses to HCMV lysate as well as to gH/gL and ARPE-19 neutralizing antibodies were significantly higher from 31 to 60 through 180 days after infection onset. In the same patients, the IgG antibody responses to the pentamer and HELF-neutralizing antibody were significantly higher starting 90 days post-infection. Conclusions: The presence of overt clinical symptoms is associated with a significantly higher antibody response (concomitantly with a higher viral load) in non-pregnant subjects with symptomatic primary HCMV infection as compared to pregnant women with paucisymptomatic/ asymptomatic primary infection (and lower viral load). © 2015 Elsevier B.V. Source


Piralla A.,Struttura Semplice Virologia Molecolare | Pariani E.,University of Milan | Rovida F.,Struttura Semplice Virologia Molecolare | Campanini G.,Struttura Semplice Virologia Molecolare | And 7 more authors.
PLoS ONE | Year: 2011

Background: Since its appearance in 2009, the pandemic influenza A(H1N1) virus circulated worldwide causing several severe infections. Methods: Respiratory samples from patients with 2009 influenza A(H1N1) and acute respiratory distress attending 24 intensive care units (ICUs) as well as from patients with lower respiratory tract infections not requiring ICU admission and community upper respiratory tract infections in the Lombardy region (10 million inhabitants) of Italy during the 2010-2011 winter-spring season, were analyzed. Results: In patients with severe ILI, the viral load was higher in bronchoalveolar lavage (BAL) with respect to nasal swab (NS), (p<0.001) suggesting a higher virus replication in the lower respiratory tract. Four distinct virus clusters (referred to as cluster A to D) circulated simultaneously. Most (72.7%, n = 48) of the 66 patients infected with viruses belonging to cluster A had a severe (n = 26) or moderate ILI (n = 22). Amino acid mutations (V26I, I116M, A186T, D187Y, D222G/N, M257I, S263F, I286L/M, and N473D) were observed only in patients with severe ILI. D222G/N variants were detected exclusively in BAL samples. Conclusions: Multiple virus clusters co-circulated during the 2010-2011 winter-spring season. Severe or moderate ILI were associated with specific 2009 influenza A(H1N1) variants, which replicated preferentially in the lower respiratory tract. © 2011 Piralla et al. Source


Lilleri D.,Laboratori Sperimentali Of Ricerca | Gerna G.,Laboratori Sperimentali Of Ricerca | Zelini P.,Struttura Semplice Virologia Molecolare | Chiesa A.,Struttura Semplice Virologia Molecolare | And 4 more authors.
PLoS ONE | Year: 2012

In allogeneic hematopoietic stem-cell transplantation (HSCT) recipients, outcome of human cytomegalovirus (HCMV) infection results from balance between viral load/replication and pathogen-specific T-cell response. Using a cut-off of 30,000 HCMV DNA copies/ml blood for pre-emptive therapy and cut-offs of 1 and 3 virus-specific CD4+ and CD8+ T cells/μl blood for T-cell protection, we conducted in 131 young patients a prospective 3-year study aimed at verifying whether achievement of such immunological cut-offs protects from HCMV disease. In the first three months after transplantation, 55/89 (62%) HCMV-seropositive patients had infection and 36/55 (65%) were treated pre-emptively, whereas only 7/42 (17%) HCMV-seronegative patients developed infection and 3/7 (43%) were treated. After 12 months, 76 HCMV-seropositive and 9 HCMV-seronegative patients (cumulative incidence: 90% and 21%, respectively) displayed protective HCMV-specific immunity. Eighty of these 85 (95%) patients showed spontaneous control of HCMV infection without additional treatment. Five patients after reaching protective T-cell levels needed pre-emptive therapy, because they developed graft-versus-host disease (GvHD). HSCT recipients reconstituting protective levels of HCMV-specific T-cells in the absence of GvHD are no longer at risk for HCMV disease, at least within 3 years after transplantation. The decision to treat HCMV infection in young HSCT recipients may be taken by combining virological and immunological findings. © 2012 Lilleri et al. Source


Zehender G.,University of Milan | Pariani E.,University of Milan | Piralla A.,Struttura Semplice Virologia Molecolare | Lai A.,University of Milan | And 10 more authors.
PLoS ONE | Year: 2012

The aim of this study was to reconstruct the evolutionary dynamics of the A(H1N1)pdm09 influenza virus in Italy during two epidemic seasons (2009/2010 and 2010/2011) in the light of the forces driving the evolution of the virus. Nearly six thousands respiratory specimens were collected from patients with influenza-like illness within the framework of the Italian Influenza Surveillance Network, and the A(H1N1)pdm09 hemagglutinin (HA) gene was amplified and directly sequenced from 227 of these. Phylodynamic and phylogeographical analyses were made using a Bayesian Markov Chain Monte Carlo method, and codon-specific positive selection acting on the HA coding sequence was evaluated. The global and local phylogenetic analyses showed that all of the Italian sequences sampled in the post-pandemic (2010/2011) season grouped into at least four highly significant Italian clades, whereas those of the pandemic season (2009/2010) were interspersed with isolates from other countries at the tree root. The time of the most recent common ancestor of the strains circulating in the pandemic season in Italy was estimated to be between the spring and summer of 2009, whereas the Italian clades of the post-pandemic season originated in the spring of 2010 and showed radiation in the summer/autumn of the same year; this was confirmed by a Bayesian skyline plot showing the biphasic growth of the effective number of infections. The local phylogeography analysis showed that the first season of infection originated in Northern Italian localities with high density populations, whereas the second involved less densely populated localities, in line with a gravity-like model of geographical dispersion. Two HA sites, codons 97 and 222, were under positive selection. In conclusion, the A(H1N1)pdm09 virus was introduced into Italy in the spring of 2009 by means of multiple importations. This was followed by repeated founder effects in the post-pandemic period that originated specific Italian clades. © 2012 Zehender et al. Source

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