Containment measures have been applied in several countries in order to limit the diffusion of the SARS-CoV-2 epidemic. The scope of this study is to analyze the evolution of the first wave of the ...SARS-CoV-2 epidemic throughout Italy and factors associated to the different way it spread in the Italian Regions, starting from the day that the first indigenous cases were detected through day 81 (6 days after the end of the strict lockdown). Data were obtained from daily reports and are represented as number (and percentage) of cases/100,000 persons. A lockdown with movement restrictions, especially across Regions, was declared at day 20. At day 81, 219,070 cases (363/100,000 persons) were diagnosed. A regression analysis based on the Gompertz model predicts a total number 233,606 cases (386/100,000 persons) at the end of the epidemic. The 21 areas, divided into Italian Regions and autonomous Provinces, showed a wide range in the frequency of cases at day 81 (58-921, median 258/100,000 persons) and total predicted cases (58-946, median 267/100,000 persons). Similarly, the predicted time for the end of the wave of the epidemic (considering as surrogate marker the time at which 99% of the total cases are predicted to occur) was highly variable, ranging from 64 to 136 (median 99) days. We analyzed the impact of local and interventional variables on the epidemic curve in each Region. The number of cases correlated inversely with the distance from the area in which first cases were detected and directly also with the gross domestic product pro capite (as a marker of industrial activity) of the Region. Moreover, an earlier start of the lockdown (i.e. in the presence of a lower number of cases) and wider testing were associated with a lower final number of total cases. In conclusion, this analysis shows that population-wide testing and early lockdown enforcement appear effective in limiting the spreading of the SARS-CoV-2 epidemic.
The release of neutrophil extracellular traps (NETs), a process termed NETosis, avoids pathogen spread but may cause tissue injury. NETs have been found in severe COVID-19 patients, but their role in ...disease development is still unknown. The aim of this study is to assess the capacity of NETs to drive epithelial-mesenchymal transition (EMT) of lung epithelial cells and to analyze the involvement of NETs in COVID-19. Bronchoalveolar lavage fluid of severe COVID-19 patients showed high concentration of NETs that correlates with neutrophils count; moreover, the analysis of lung tissues of COVID-19 deceased patients showed a subset of alveolar reactive pneumocytes with a co-expression of epithelial marker and a mesenchymal marker, confirming the induction of EMT mechanism after severe SARS-CoV2 infection. By airway
in vitro
models, cultivating A549 or 16HBE at air-liquid interface, adding alveolar macrophages (AM), neutrophils and SARS-CoV2, we demonstrated that to trigger a complete EMT expression pattern are necessary the induction of NETosis by SARS-CoV2 and the secretion of AM factors (TGF-β, IL8 and IL1β). All our results highlight the possible mechanism that can induce lung fibrosis after SARS-CoV2 infection.
To assess the humoral and cell-mediated response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicited by the mRNA BNT162b2 vaccine in SARS-CoV-2-experienced and -naive subjects ...against a reference strain and SARS-CoV-2 variants.
The humoral response (including neutralizing antibodies) and T-cell-mediated response elicited by BNT162b2 vaccine in 145 healthcare workers (both naive and positive for previous SARS-CoV-2 infection) were evaluated. In a subset of subjects, the effect of SARS-CoV-2 variants on antibody level and cell-mediated response was also investigated.
Overall, 125/127 naive subjects (98.4%) developed both neutralizing antibodies and specific T cells after the second dose of vaccine. Moreover, the antibody and T-cell responses were effective against viral variants since SARS-CoV-2 NT Abs were still detectable in 55/68 (80.9%) and 25/29 (86.2%) naive subjects when sera were challenged against β and δ variants, respectively. T-cell response was less affected, with no significant difference in the frequency of responders (p 0.369). Of note, two doses of vaccine were able to elicit sustained neutralizing antibody activity against all the SARS-CoV-2 variants tested in SARS-CoV-2-experienced subjects.
BNT162b2 vaccine elicited a sustained humoral and cell-mediated response in immunocompetent subjects after two-dose administration of the vaccine, and the response seemed to be less affected by SARS-CoV-2 variants, the only exceptions being the β and δ variants. Increased immunogenicity, also against SARS-CoV-2 variant strains, was observed in SARS-CoV-2-experienced subjects. These results suggest that triple exposure to SARS-CoV-2 antigens might be proposed as valuable strategy for vaccination campaigns.
In solid-organ transplant recipients (SOTR) the protective role of human cytomegalovirus (HCMV)-specific CD4+, CD8+ and γδ T-cells vs. HCMV reactivation requires better definition. The aim of this ...study was to investigate the relevant role of HCMV-specific CD4+, CD8+ and γδ T-cells in different clinical presentations during the post-transplant period. Thirty-nine SOTR underwent virologic and immunologic follow-up for about 1 year after transplantation. Viral load was determined by real-time PCR, while immunologic monitoring was performed by measuring HCMV-specific CD4+ and CD8+ T cells (following stimulation with autologous HCMV-infected dendritic cells) and γδ T-cells by flow cytometry. Seven patients had no infection and 14 had a controlled infection, while both groups maintained CD4+ T-cell numbers above the established cut-off (0.4 cell/µL blood). Of the remaining patients, 9 controlled the infection temporarily in the presence of HCMV-specific CD8+ only, until CD4+ T-cell appearance; while 9 had to be treated preemptively due to a viral load greater than the established cut-off (3×10(5) DNA copies/mL blood) in the absence of specific CD4+ T-cells. Polyfunctional CD8+ T-cells as well as Vδ2- γδ T-cells were not associated with control of infection. In conclusion, in the absence of HCMV-specific CD4+ T-cells, no long-term protection is conferred to SOTR by either HCMV-specific CD8+ T-cells alone or Vδ2- γδ T-cell expansion.
In the setting of infectious diseases, antibodies show different functions beyond neutralizing activity. In this study, we investigated the activation of NK cells in vitro in the presence of human ...cytomegalovirus (HCMV)-specific antibodies and their potential role in the control of HCMV infection through antibody-dependent cell cytotoxicity (ADCC). Retinal pigmented epithelial cells (ARPE-19) infected with the HCMV strain VR1814 were co-cultured with cytokine-activated peripheral blood mononuclear cells (PBMCs) in the presence of sera collected from 23 HCMV-seropositive and 9 HCMV-seronegative donors. Moreover, 13 pregnant women sampled 3 and 6 months after HCMV primary infection and 13 pregnant women with pre-conception immunity were tested and compared. We determined the percentage of activated NK cells via the analysis of CD107a expression as a marker of degranulation. Significantly higher levels of NK-cell activation were observed using 1/100 and 1/10 dilutions of sera from HCMV-seropositive individuals, and when cells were infected for 96 and 120 h, suggesting that NK cells are activated by antibodies directed against late antigens. In the absence of serum NK cells, activation was negligible. In seropositive subjects, the median percentages of CD107a-positive NK cells in the presence of autologous serum and pooled HCMV-positive serum were similar (14.03% range 0.00–33.56 and 12.42% range 1.01–46.00, respectively), while NK-cell activation was negligible using an HCMV-negative serum pool. In HCMV-seronegative subjects, the median percentage of activated NK cells was 0.90% range 0.00–3.92 with autologous serum and 2.07% 0.00–5.76 in the presence of the HCMV-negative serum pool, while it was 8.97% 0.00–26.49 with the pool of HCMV-positive sera. NK-cell activation using hyperimmune globulin is comparable to what is obtained using autologous serum. Sera from subjects at 3 and 6 months post primary infection showed a lower capacity of NK-cell activation than sera from subjects with past infection (p < 0.001). NK activation against HCMV-infected epithelial cells is dependent on the presence of HCMV-specific antibodies. This serum activity increases with time after the onset of HCMV infection. The protective role of NK-cell activation by HCMV-specific serum antibodies should be verified in clinical settings.
The development and persistence of SARS-CoV-2-specific immune response in immunocompetent (IC) and immunocompromised patients is crucial for long-term protection. Immune response to SARS-CoV-2 ...infection was analysed in 57 IC and 15 solid organ transplanted (TX) patients. Antibody responses were determined by ELISA and neutralization assay. T-cell response was determined by stimulation with peptide pools of the Spike, Envelope, Membrane, and Nucleocapsid proteins with a 20-h Activation Induced Marker (AIM) and 7-day lymphoproliferative assays. Antibody response was detected at similar levels in IC and TX patients. Anti-Spike IgG, IgA and neutralizing antibodies persisted for at least one year, while anti-Nucleocapsid IgG declined earlier. Patients with pneumonia developed higher antibody levels than patients with mild symptoms. Similarly, both rapid and proliferative T-cell responses were detected within the first two months after infection at comparable levels in IC and TX patients, and were higher in patients with pneumonia. T-cell response persisted for at least one year in both IC and TX patients. Spike, Membrane, and Nucleocapsid proteins elicited the major CD4+ and CD8+ T-cell responses, whereas the T-cell response to Envelope protein was negligible. After SARS-CoV-2 infection, antibody and T-cell responses develop rapidly and persist over time in both immunocompetent and transplanted patients.
The efficacy of pre-emptive therapy in the prevention of cytomegalovirus (CMV) disease and the potential association of CMV infection with the occurrence of chronic lung allograft dysfunction (CLAD) ...was evaluated in 129 lung transplant recipients receiving pre-emptive therapy based on pp65-antigenemia or CMV-DNA in the blood and in the bronchoalveolar lavage. Seventy-one (55%) patients received pre-emptive ganciclovir/valganciclovir (GCV/VGCV) for CMV infection for a median of 28 (9-191) days. Possible CMV disease occurred in six (5%) patients and was healed after the GCV/VGCV therapy. The cumulative incidence of CLAD was 38% and 54% at 5 and 10 years. Acute rejection and CMV load in the blood (but not in the lung) were independent predictors of the occurrence of CLAD. Pre-emptive therapy is highly effective in preventing CMV disease in lung recipients and does not induce a superior incidence of CLAD compared to what reported for other cohorts of patients who received an extended antiviral prophylaxis.
MSC (mesenchymal stromal cells) can differentiate into renal adult cells, and have anti-inflammatory and immune-modulating activity. In the present study, we investigated whether MSC have ...protective/reparative effects in anti-Thy1 disease, an Ab (antibody)-induced mesangiolysis resulting in mesangioproliferative nephritis. We studied five groups of rats: (i) rats injected with anti-Thy1.1 Ab on day 0 (group A); (ii) rats injected with anti-Thy1.1 Ab on day 0+MSC on day 3 (group B); (iii) rats injected with anti-Thy1.1 Ab on day 0+mesangial cells on day 3 (group C); (iv) rats injected with saline on day 0+MSC on day 3 (group D); and (v) rats injected with saline on day 0 (group E). Rats were killed on days 1, 3, 7 and 14. MSC prevented the increase in serum creatinine, proteinuria, glomerular monocyte influx and glomerular histopathological injury. Furthermore, MSC suppressed the release of IL-6 (interleukin-6) and TGF-β (transforming growth factor-β), modulated glomerular PDGF-β (platelet-derived growth factor-β), and reset the scatter factors and their receptors, potentiating HGF (hepatocyte growth factor)/Met and inactivating MSP (macrophage-stimulating protein)/Ron (receptor origin nantaise). Few MSC were found in the kidney. These results indicate that MSC improve anti-Thy 1 disease not by replacing injured cells, but by preventing cytokine-driven inflammation and modulating PDGF-β and the scatter factors, i.e. systems that regulate movement and proliferation of monocytes and mesangial cells.
► Soluble form of CD40 (sCD40) is a natural antagonist of CD40/CD40L interaction. ► Patients with renal failure present elevated sCD40 serum levels. ► The loss of renal function is the main cause of ...sCD40 elevation in hemodialysis. ► The reduction of sCD40 could have important biological and clinical implications.
CD40 and its ligand (CD40L) regulate several cellular functions, including T and B-cell activation. The soluble form of CD40 (sCD40) antagonizes CD40/CD40L interaction. Patients undergoing hemodialysis (HD) present elevated sCD40 serum levels, which underlying molecular mechanisms are unknown.
We studied sCD40 serum and urinary levels, CD40 membrane and gene expression and membrane shedding in HD, uremic not-HD patients (UR) and healthy subjects (N).
We found that in HD sCD40 serum levels were higher than UR and N, being significantly elevated in anuric patients, and that sCD40 correlated to renal function in UR subjects, who presented also a reduced sCD40 urinary excretion rate. HD and UR presented reduced CD40 membrane and gene expression. The concentration of TNF-α converting enzyme (TACE), responsible for CD40 cleavage was not different between HD and N. Therefore the reduced renal clearance is the main cause of elevated sCD40 levels in HD. This finding could have relevant clinical implications.
Immune correlates of protection against human cytomegalovirus (HCMV) infection are still debated. This study aimed to investigate which arm of the immune response plays a major role in protection ...against HCMV infection in kidney transplant recipients (n = 40) and heart transplant recipients (n = 12). Overall, patients were divided into 2 groups: one including 37 patients with low viral load (LVL), and the other including 15 patients with high viral load (HVL). All LVL patients resolved the infection spontaneously, whereas HVL patients were all treated with one or more courses of antivirals. In HVL patients, viral DNAemia, which was more than 100 times higher than LVL, appeared and peaked at significantly earlier times, but disappeared much later than in LVL patients. During a 1‐year follow‐up, all LVL patients had levels of HCMV‐specific CD4+ (and CD8+) T cells significantly higher than HVL patients. On the contrary, titers of neutralizing antibodies and enzyme‐linked immunosorbent assay‐IgG antibodies to gB, gHgLgO, and pentamer gHgLpUL128L were overlapping in the 2 patient groups. In conclusion, while a valid HCMV‐specific T‐cell response was detected in more than 90% of LVL patients, >90% of HVL patients lacked an adequate T‐cell response. Antibody responses did not appear to be associated directly or indirectly with protection.
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