Saeid Najafi Fard

Background: The identification of parasite- and stage-specific antigens is crucial for the development of new diagnostic tests for cystic echinococcosis (CE). We previously analysed the interleukin (IL)-4 response to T-specific peptides corresponding to the immunogenic regions of the five antigen B (AgB) subunits, demonstrating that AgB1 is the most immunogenic protein and that the response to all AgB peptides is associated with viable cysts. However, the response in patients with CE3a (WHO-IWGE) cystic stage was not evaluated and no other immunological factors besides IL-4 were included in the analysis. Methods: Four study groups were defined: “CE3a group” (transitional cysts), “CE3b group” (active cysts), “CE4/CE5 group” (inactive cysts), and “NO CE-group” encompassing patients with non-CE cysts (controls). Whole blood was stimulated in vitro with the five different T-specific peptide pools corresponding to the five AgB subunits and with a pool containing all five peptides’ pools (total pool). IL-4 and other immunological markers were evaluated by ELISA and a multiplex assay, respectively. Results: Twenty-four patients with CE (CE3a-group n = 3; CE3b-group n = 6; CE4/CE5-group n = 15) and 14 subjects with non-CE cysts were enrolled. IL-4 levels in response to AgB1 and AgB3 pools were significantly increased in CE compared to NO CE groups (p = 0.0201, p = 0.0041). Within the CE patients, the highest IL-4 median level was observed in response to the AgB total pool, the AgB3 and AgB4 pools, followed by the AgB1 pool. Moreover, the IL-4 levels in response to the AgB1 pool were found to be significantly higher in the CE3b group compared to the CE4/CE5 group (p = 0.0070), while no differences were found for the CE3a group. As for other cytokines, we found higher IL-7 levels in response to the AgB4 pool in the CE4/CE5 group compared to the CE3b group (p = 0.0012), higher IL-2 levels in response to the AgB1 pool and AgB total pool in CE3b patients compared to controls (p = 0.0016), and higher IL-13 levels in response to the AgB total pool in patients with CE3b and CE4/CE5 cysts compared to NO CE (p = 0.0016; p = 0.0009). Conclusions: These results contribute to a better knowledge of the immune interplay in the presence of CE and may be useful for further exploring the use of recombinant proteins/peptides in cytokine release assays for the diagnosis and follow-up of CE.

Background: Cystic echinococcosis (CE) cysts may persist for decades because of immune modulation mechanisms. Here, we characterize the cysts and the blood immune responses in patients with CE. Methods: We enrolled 61 patients with CE and 19 control subjects. We received tissue samples from seven patients with CE and a control subject requiring liver cystectomy. The immunohistochemistry evaluation of the immune cell subtypes and cytokines in the pericysts and surrounding liver and the antigen B (AgB)-specific response analysis of whole blood were performed. Results: In CE, the pericyst and the surrounding liver parenchyma showed aggregates of CD3⁺ T lymphocytes, mainly CD4⁺. B lymphocyte aggregates were present in the liver tissue. Monocytes/granulocytes were rarely observed. Th2 cytokine expression was scarce, whereas IFN-γ expression was present in the CE tissues. The control subject did not show an inflammatory infiltrate. The IL-4-specific response to AgB was increased in the patients with CE compared to the control, and this result was confirmed in a larger cohort (p = 0.003), whereas the IFN-γ-response was similar between the two groups (p = 0.5570). Conclusion: In patients with CE, CD4⁺ lymphocytes infiltrate the pericyst and the surrounding liver tissue with a low IL-4/IL-13 expression level and a moderate IFN-γ expression level; moreover, an IL-4 parasite-specific response is detected in the periphery. These results support adventitia involvement in CE immunopathogenesis.

The ongoing pandemic of coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), needs better treatment options both at antiviral and anti-inflammatory levels. It has been demonstrated that the aminothiol cysteamine, an already human applied drug, and its disulfide product of oxidation, cystamine, have anti-infective properties targeting viruses, bacteria, and parasites. To determine whether these compounds exert antiviral effects against SARS-CoV-2, we used different in vitro viral infected cell-based assays. Moreover, since cysteamine has also immune-modulatory activity, we investigated its ability to modulate SARS-CoV-2-specific immune response in vitro in blood samples from COVID-19 patients. We found that cysteamine and cystamine decreased SARS-CoV-2-induced cytopathic effects (CPE) in Vero E6 cells. Interestingly, the antiviral action was independent of the treatment time respect to SARS-CoV-2 infection. Moreover, cysteamine and cystamine significantly decreased viral production in Vero E6 and Calu-3 cells. Finally, cysteamine and cystamine have an anti-inflammatory effect, as they significantly decrease the SARS-CoV-2 specific IFN-γ production in vitro in blood samples from COVID-19 patients. Overall, our findings suggest that cysteamine and cystamine exert direct antiviral actions against SARS-CoV-2 and have in vitro immunomodulatory effects, thus providing a rational to test these compounds as a novel therapy for COVID-19.

Vaccination against SARS-CoV-2 is considered the most effective method of prevention to contain the pandemic. While highly effective SARS-CoV-2 vaccines are being applied on a large-scale, whether and to what extent the strength of the vaccine-induced immune response could be further potentiated is still an object of debate. Several reports studied the effect of different vaccines on the susceptibility and mortality of COVID-19, with conflicting results. We aimed to evaluate whether previous influenza and/or pneumococcal vaccination had an impact on the specific immune response to the SARS-CoV-2 BNT162b2 mRNA vaccine. The study population consists of 710 workers from our Institute who completed the BNT162b2 schedule and have been tested at least once after the second dose, from 27 December 2020 up to 15 April 2021. Of these, 152 (21.4%) had received an influenza and 215 (30.3%) a concomitant influenza and pneumococcal vaccination, a median of 102 days before the second dose of BNT162b2. Overall, 100% of workers were tested for anti-Spike receptor-binding domain (anti-S/RBD) antibodies, 224 workers for neutralization titer (Micro-neutralization assay, MNA), and 155 workers for a spike-specific T cell interferon-γ response (IFN-γ). The levels of anti-S/RBD, MNA and IFN-γ were evaluated and compared according to sex, age, involvement in direct care of COVID-19 patients, and previous influenza/pneumococcal vaccination. At the univariate analysis, no statistically significant association was observed with regard to a previous influenza and pneumococcal vaccination. A significant lower anti-S/RBD response was observed according to an older age and male sex, while MNA titers were significantly associated to sex but not to age. At the multivariable analysis, workers receiving a concomitant influenza and pneumococcal vaccination or only influenza showed a 58% (p 0.01) and 42% (p 0.07) increase in MNA titers, respectively, compared to those who did not receive an influenza/pneumococcal vaccination. Female workers showed an 81% MNA and a 44% anti-S/RBD increase compared to male workers (p < 0.001). Compared to workers aged 21 to 49 years, those aged 50 or older were associated with a reduction in the anti-S/RBD (16%; p 0.005), MNA (31%; p 0.019), and IFN.g (32%) immune response. Maintaining the influenza and pneumococcal immunization program for the coming season, in which COVID-19 could still be spreading, remains strongly recommended to protect those who are more vulnerable and to limit the potential burden of these infections on the healthcare system.

Coronaviruses (CoVs) are enveloped nonsegmented positive‐sense RNA viruses belonging to the family Coronaviridae that contain the largest genome among RNA viruses. Their genome encodes 4 major structural proteins, and among them, the Spike (S) protein plays a crucial role in determining the viral tropism. It mediates viral attachment to the host cell, fusion to the membranes, and cell entry using cellular proteases as activators. Several in vitro models have been developed to study the CoVs entry, pathogenesis, and possible therapeutic approaches. This article is aimed at summarizing the current knowledge about the use of relevant methodologies and cell lines permissive for CoV life cycle studies. The synthesis of this information can be useful for setting up specific experimental procedures. We also discuss different strategies for inhibiting the binding of the S protein to the cell receptors and the fusion process which may offer opportunities for therapeutic intervention.