Emerging viral infections in immunocompromised patients: A great challenge to better define the role of immune response.

The immune response to invading pathogens is characterized by the rapid establishment of a complex network of cellular interactions and soluble signals. The correct balancing of activating and regulating pathways and tissue-homing signals determines its effectiveness and persistence over time. Emerging viral pathogens have always represented a great challenge to the immune system and an often uncontrolled/imbalanced immune response has been described (e.g. cytokine storm, immune paralysis), contributing to the severity of the disease. Several immune biomarkers and cell subsets have been identified as major players in the cascade of events leading to severe diseases, highlighting the rationale for host-directed intervention strategy. There are millions of immunocompromised pediatric and adult patients worldwide (e.g. transplant recipients, hematologic patients, subjects with primary immune-deficiencies), experiencing an impaired immune reactivity, due to diseases and/or to the medical treatments. The reduced immune reactivity could have two paradoxical non-exclusive effects: a weak protective immunity on one hand, and a reduced contribution to immune-mediated pathogenetic processes on the other hand. In these sensitive contexts, the impact of emerging infections represents a still open issue to be explored with several challenges for immunologists, virologists, physicians and epidemiologists. In this review, we will address emerging infections in immunocompromised hosts, to summarize the available data concerning the immune response profile, its influence on the clinical presentation, the possible contribution of persistent viral shedding in generating new viral variants with improved immune escape features, and the key role of vaccination.

Aero-Medical Evacuation during SARS-CoV-2 Pandemic: Extraordinary Measure or Emerging Treatment Option?

Aero-medical evacuation has been considered as a feasible and safe treatment option during COVID pandemic, particularly when the needs of affected patients exceed what local clinics and hospitals are supposed to provide. In this article, we analyzed the clinical course of 17 patients medically evacuated to the "L. Spallanzani" Institute in Rome, Italy from foreign countries, mainly Africa and Eastern Europe, who had COVID-19 pneumonia with, or without, coinfections such as malaria, HIV, tuberculosis and microbiologically confirmed sepsis syndrome. The aero-medical evacuation of patients with infectious diseases has become one of the greatest medical achievements we have reached during this pandemic; in fact, only two patients with life threatening coinfections have died. Although logistically difficult and cost consuming, medical evacuation should be considered as a treatment option more than a single extraordinary measure, especially among complex cases that require specific technical and human resources.

Telemedicine During COVID-19 Pandemic: Lesson Learned from the Lazio Region Infectious Diseases and Emergency Department Network.

Telemedicine and teleconsultation can be powerful and useful tools for patients to hamper the physical barriers to access to health care services during COVID-19 pandemic. We describe the teleconsultation (TC) model in the Lazio Region. It uses a hub-and-spoke network system on geographic regional basis using a web based digital platform, termed ADVICE with the aim to connect regional Emergency Departments (EDs) and Infectious Diseases (ID) acute and critical care settings for patients with acute ID syndrome. Between January 2020 and June 2021, the ADVICE platform received 18.686 TCs: of them, 10838 requests (58%) were for ID TCs in 7996 patients, followed by 2555(13%) requests for trauma, 2286(12%) for acute complex syndrome and 1681 (8%) for Stroke TCs. Three quarter of ID TCs were requested for SARS-COV-2 infection, followed by sepsis management in 7% and tuberculosis in 6%. In 5416 TCs, 68%, diagnostic investigations and therapeutic prescriptions were recommended before admission, in 1941 TCs, 24%, the recommendation was patient admission and in 608 TCs, 7%, was to discharge patient at home. Telemedicine have ensured high-profile consultations for ID patients and during COVID-19 the use of this resource optimized clinical patient management.

Proteomic analysis identifies a signature of disease severity in the plasma of COVID-19 pneumonia patients associated to neutrophil, platelet and complement activation.

Most patients infected with SARS-CoV-2 display mild symptoms with good prognosis, while 20% of patients suffer from severe viral pneumonia and up to 5% may require intensive care unit (ICU) admission due to severe acute respiratory syndrome, which could be accompanied by multiorgan failure.Plasma proteomics provide valuable and unbiased information about disease progression and therapeutic candidates. Recent proteomic studies have identified molecular changes in plasma of COVID-19 patients that implied significant dysregulation of several aspects of the inflammatory response accompanied by a general metabolic suppression. However, which of these plasma alterations are associated with disease severity remains only partly characterized.A known limitation of proteomic studies of plasma samples is the large difference in the macromolecule abundance, with concentration spanning at least 10 orders of magnitude. To improve the coverage of plasma contents, we performed a deep proteomic analysis of plasma from 10 COVID-19 patients with severe/fatal pneumonia compared to 10 COVID-19 patients with pneumonia who did not require ICU admission (non-ICU). To this aim, plasma samples were first depleted of the most abundant proteins, trypsin digested and peptides subjected to a high pH reversed-phase peptide fractionation before LC-MS analysis.These results highlighted an increase of proteins involved in neutrophil and platelet activity and acute phase response, which is significantly higher in severe/fatal COVID-19 patients when compared to non-ICU ones. Importantly, these changes are associated with a selective induction of complement cascade factors in severe/fatal COVID-19 patients. Data are available via ProteomeXchange with identifier PXD036491. Among these alterations, we confirmed by ELISA that higher levels of the neutrophil granule proteins DEFA3 and LCN2 are present in COVID-19 patients requiring ICU admission when compared to non-ICU and healthy donors.Altogether, our study provided an in-depth view of plasma proteome changes that occur in COVID-19 patients in relation to disease severity, which can be helpful to identify therapeutic strategies to improve the disease outcome.

Long-term effect of SARS-CoV-2 infection on cardiovascular outcomes and all-cause mortality.

Since the very beginning of the coronavirus disease 2019 (COVID-19) pandemic in early 2020, it was evident that patients with cardiovascular disease (CVD) were at an increased risk of developing severe illness, and complications spanning cerebrovascular disorders, dysrhythmias, acute coronary syndrome, ischemic and non-ischemic heart disease, pericarditis, myocarditis, heart failure, thromboembolic disease, stroke, and death. Underlying these was excessive systemic inflammation and coagulopathy due to SARS-COV-2 infection, the effects of which also continued long-term as evidenced by post-COVID-19 cardiovascular complications. The acute and chronic cardiovascular effects of COVID-19 occurred even among those who were not hospitalized and had no previous CVD or those with mild symptoms. This comprehensive review summarizes the current understanding of molecular mechanisms triggered by the SARS-CoV-2 virus on various cells that express the angiotensin-converting enzyme 2, leading to endothelial dysfunction, inflammation, myocarditis, impaired coagulation, myocardial infarction, arrhythmia and a multisystem inflammatory syndrome in children or Kawasaki-like disease.

SARS-CoV-2 Infection of Airway Epithelium Triggers Pulmonary Endothelial Cell Activation and Senescence Associated with Type I IFN Production.

Airway epithelial cells represent the main target of SARS-CoV-2 replication but several pieces of evidence suggest that endothelial cells (ECs), lining pulmonary blood vessels, are key players in lung injury in COVID-19 patients. Although in vivo evidence of SARS-CoV-2 affecting the vascular endothelium exists, in vitro data are limited. In the present study, we set up an organotypic model to dissect the crosstalk between airway epithelium and pulmonary endothelial cells during SARS-CoV-2 infection. We showed that SARS-CoV-2 infected airway epithelium triggers the induction of endothelial adhesion molecules in ECs, suggesting a bystander effect of dangerous soluble signals from the infected epithelium. The endothelial activation was correlated with inflammatory cytokines (IL-1ß, IL-6, IL-8) and with the viral replication in the airway epithelium. Interestingly, SARS-CoV-2 infection determined a modulation of endothelial p21, which could be partially reversed by inhibiting IFN-ß production from ECs when co-cultured with HAE. Altogether, we demonstrated that SARS-CoV-2 infected epithelium triggers activation/senescence processes in ECs involving type I IFN-ß production, suggesting possible antiviral/damage mechanisms occurring in the endothelium.

Safety and immune response kinetics of GRAd-COV2 vaccine: phase 1 clinical trial results.

Despite the successful deployment of efficacious vaccines and therapeutics, the development of novel vaccines for SARS-CoV-2 remains a major goal to increase vaccine doses availability and accessibility for lower income setting. We report here on the kinetics of Spike-specific humoral and T-cell response in young and old volunteers over 6 months follow-up after a single intramuscular administration of GRAd-COV2, a gorilla adenoviral vector-based vaccine candidate currently in phase-2 of clinical development. At all three tested vaccine dosages, Spike binding and neutralizing antibodies were induced and substantially maintained up to 3 months, to then contract at 6 months. Potent T-cell responses were readily induced and sustained throughout the study period, with only minor decline. No major differences in immune response to GRAd-COV2 vaccination were observed in the two age cohorts. In light of its favorable safety and immunogenicity, GRAd-COV2 is a valuable candidate for further clinical development and potential addition to the COVID-19 vaccine toolbox to help fighting SARS-CoV-2 pandemic.

The immune response as a double-edged sword: The lesson learnt during the COVID-19 pandemic.

The COVID-19 pandemic has represented an unprecedented challenge for the humanity, and scientists around the world provided a huge effort to elucidate critical aspects in the fight against the pathogen, useful in designing public health strategies, vaccines and therapeutic approaches. One of the first pieces of evidence characterizing the SARS-CoV-2 infection has been its breadth of clinical presentation, ranging from asymptomatic to severe/deadly disease, and the indication of the key role played by the immune response in influencing disease severity. This review is aimed at summarizing what the SARS-CoV-2 infection taught us about the immune response, highlighting its features of a double-edged sword mediating both protective and pathogenic processes. We will discuss the protective role of soluble and cellular innate immunity and the detrimental power of a hyper-inflammation-shaped immune response, resulting in tissue injury and immunothrombotic events. We will review the importance of B- and T-cell immunity in reducing the clinical severity and their ability to cross-recognize viral variants.

Safety and serum distribution of anti-SARS-CoV-2 monoclonal antibody MAD0004J08 after intramuscular injection.

The emerging threat represented by SARS-CoV-2 variants, demands the development of therapies for better clinical management of COVID-19. MAD0004J08 is a potent Fc-engineered monoclonal antibody (mAb) able to neutralize in vitro all current SARS-CoV-2 variants of concern (VoCs) including the omicron variant even if with significantly reduced potency. Here we evaluated data obtained from the first 30 days of a phase 1 clinical study (EudraCT N.: 2020-005469-15 and ClinicalTrials.gov Identifier: NCT04932850). The primary endpoint evaluated the percentage of severe adverse events. Secondary endpoints evaluated pharmacokinetic and serum neutralization titers. A single dose administration of MAD0004J08 via intramuscular (i.m.) route is safe and well tolerated, resulting in rapid serum distribution and sera neutralizing titers higher than COVID-19 convalescent and vaccinated subjects. A single dose administration of MAD0004J08 is also sufficient to effectively neutralize major SARS-CoV-2 variants of concern (alpha, beta, gamma and delta). MAD0004J08 can be a major advancement in the prophylaxis and clinical management of COVID-19.

Persistent Spike-specific T cell immunity despite antibody reduction after 3 months from SARS-CoV-2 BNT162b2-mRNA vaccine.

Vaccine is the main public health measure to reduce SARS-CoV-2 transmission and hospitalization, and a massive scientific effort worldwide resulted in the rapid development of effective vaccines. This work aimed to define the dynamics and persistence of humoral and cell-mediated immune response in Health Care Workers who received a two-dose BNT162b2-mRNA vaccination. Serological response was evaluated by quantifying anti-RBD and neutralizing antibodies while cell-mediated response was performed by a whole blood test quantifying Th1 cytokines (IFN-γ, TNF-α, IL-2) produced in response to Spike peptides. BNT162b2-mRNA vaccine induced both humoral and cell-mediated immune response against Spike in all HCW early after the second dose. After 12 weeks from vaccination, the titer of anti-RBD antibodies as well as their neutralization function decreased while the Spike-specific T-cells persisted at the same level as soon after vaccine boost. Of note, a correlation between cellular and humoral response persevered, suggesting the persistence of a coordinated immune response. The long lasting cell-mediated immune response after 3 months from vaccination highlight its importance in the maintaining of specific immunity able to expand again to fight eventual new antigen encountering.

The interplay between SARS-CoV-2 infected airway epithelium and immune cells modulates regulatory/inflammatory signals.

To assess the cross-talk between immune cells and respiratory tract during SARS-CoV-2 infection, we analyzed the relationships between the inflammatory response induced by SARS-CoV-2 replication and immune cells phenotype in a reconstituted organotypic human airway epithelium (HAE). The results indicated that immune cells failed to inhibit SARS-CoV-2 replication in the HAE model. In contrast, immune cells strongly affected the inflammatory profile induced by SARS-CoV-2 infection, dampening the production of several immunoregulatory/inflammatory signals (e.g., IL-35, IL-27, and IL-34). Moreover, these mediators were found inversely correlated with innate immune cell frequency (NK and γδ T cells) and directly with CD8 T cells. The enriched signals associated with NK and CD8 T cells highlighted the modulation of pathways induced by SARS-CoV-2 infected HAE. These findings are useful to depict the cell-cell communication mechanisms necessary to develop novel therapeutic strategies aimed to promote an effective immune response.

Virological and Serological Characterisation of SARS-CoV-2 Infections Diagnosed After mRNA BNT162b2 Vaccination Between December 2020 and March 2021.

BACKGROUND: Vaccines for coronavirus disease 2019 (COVID-19) are proving to be very effective in preventing severe illness; however, although rare, post-vaccine infections have been reported. The present study focuses on virological and serological features of 94 infections that occurred in Lazio Region (Central Italy) between 27 December 2020, and 30 March 2021, after one or two doses of mRNA BNT162b2 vaccine. METHODS: We evaluated clinical features, virological (viral load; viral infectiousness; genomic characterisation), and serological (anti-nucleoprotein Ig; anti-Spike RBD IgG; neutralising antibodies, nAb) characteristics of 94 post-vaccine infections at the time of diagnosis. Nasopharyngeal swabs (NPSs) and serum samples were collected in the framework of the surveillance activities on SARS-CoV-2 variants established in Lazio Region (Central Italy) and analysed at the National Institute for Infectious Diseases "L. Spallanzani" in Rome. RESULTS: The majority (92.6%) of the post-vaccine infections showed pauci/asymptomatic or mild clinical course, with symptoms and hospitalisation rate significantly less frequent in patients infected after full vaccination course as compared to patients who received a single dose vaccine. Although differences were not statistically significant, viral loads and isolation rates were lower in NPSs from patients infected after receiving two vaccine doses as compared to patients with one dose. Most cases (84%) had nAb in serum at the time of infection diagnosis, which is a sub-group of vaccinees, were found similarly able to neutralise Alpha and Gamma variants. Asymptomatic individuals showed higher nAb titres as compared to symptomatic cases (median titre: 1:120 vs. 1:40, respectively). Finally, the proportion of post-vaccine infections attributed either to Alpha and Gamma variants was similar to the proportion observed in the contemporary unvaccinated population in the Lazio region, and mutational analysis did not reveal enrichment of a defined set of Spike protein substitutions depending on the vaccination status. CONCLUSION: Our study conducted using real-life data, emphasised the importance of monitoring vaccine breakthrough infections, through the characterisation of virological, immunological, and clinical features associated with these events, in order to tune prevention measures in the next phase of the COVID-19 pandemic.

Humoral- and T-Cell-Specific Immune Responses to SARS-CoV-2 mRNA Vaccination in Patients With MS Using Different Disease-Modifying Therapies.

BACKGROUND AND OBJECTIVES: To evaluate the immune-specific response after full severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination of patients with multiple sclerosis (MS) treated with different disease-modifying drugs by the detection of both serologic and T-cell responses. METHODS: Healthcare workers (HCWs) and patients with MS, having completed the 2-dose schedule of an mRNA-based vaccine against SARS-CoV-2 in the past 2-4 weeks, were enrolled from 2 parallel prospective studies conducted in Rome, Italy, at the National Institute for Infectious diseases Spallanzani-IRCSS and San Camillo Forlanini Hospital. Serologic response was evaluated by quantifying the region-binding domain (RBD) and neutralizing antibodies. Cell-mediated response was analyzed by a whole-blood test quantifying interferon (IFN)-γ response to spike peptides. Cells responding to spike stimulation were identified by fluorescence-activated cell sorting analysis. RESULTS: We prospectively enrolled 186 vaccinated individuals: 78 HCWs and 108 patients with MS. Twenty-eight patients with MS were treated with IFN-ß, 35 with fingolimod, 20 with cladribine, and 25 with ocrelizumab. A lower anti-RBD antibody response rate was found in patients treated with ocrelizumab (40%, p < 0.0001) and fingolimod (85.7%, p = 0.0023) compared to HCWs and patients treated with cladribine or IFN-ß. Anti-RBD antibody median titer was lower in patients treated with ocrelizumab (p < 0.0001), fingolimod (p < 0.0001), and cladribine (p = 0.010) compared to HCWs and IFN-ß-treated patients. Serum neutralizing activity was present in all the HCWs tested and in only a minority of the fingolimod-treated patients (16.6%). T-cell-specific response was detected in the majority of patients with MS (62%), albeit with significantly lower IFN-γ levels compared to HCWs. The lowest frequency of T-cell response was found in fingolimod-treated patients (14.3%). T-cell-specific response correlated with lymphocyte count and anti-RBD antibody titer (ρ = 0.554, p < 0.0001 and ρ = 0.255, p = 0.0078 respectively). IFN-γ T-cell response was mediated by both CD4+ and CD8+ T cells. DISCUSSION: mRNA vaccines induce both humoral and cell-mediated specific immune responses against spike peptides in all HCWs and in the majority of patients with MS. These results carry relevant implications for managing vaccinations, suggesting promoting vaccination in all treated patients with MS. CLASSIFICATION OF EVIDENCE: This study provides Class III data that SARS-CoV-2 mRNA vaccination induces both humoral and cell-mediated specific immune responses against viral spike proteins in a majority of patients with MS.

The interplay between SARS-CoV-2 infected airway epithelium and immune cells modulates the immunoregulatory/inflammatory signals

To assess the cross talk between immune cells and respiratory tract during SARS-CoV-2 infection, we analysed the relationships between the inflammatory response induced by SARS-CoV-2 replication and immune cells phenotype in a reconstituted organotypic human airway epithelium (HAE). The results indicated that immune cells failed to inhibit SARS-CoV-2 replication in HAE model. In contrast, immune cells strongly affected the inflammatory profile induced by SARS-CoV-2 infection, dampening the production of several immunoregulatory/inflammatory signals (e.g., IL-35, IL-27 and IL-34). Moreover, these mediators were found inversely correlated with innate immune cell frequency (NK and γδ T cells) and directly with CD8 T cells. The enriched signals associated with NK and CD8 T cells highlighted the modulation of pathways induced by SARS-CoV-2 infected HAE. These findings are useful to depict the cell-cell communication mechanisms necessary to develop novel therapeutic strategies aimed to promote an effective immune response. Graphical

Cysteamine with In Vitro Antiviral Activity and Immunomodulatory Effects Has the Potential to Be a Repurposing Drug Candidate for COVID-19 Therapy.

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.

Coinfection of tuberculosis and COVID-19 limits the ability to in vitro respond to SARS-CoV-2.

OBJECTIVES: The interaction of COVID-19 and tuberculosis (TB) are still poor characterized. Here we evaluated the immune response specific for Micobacterium tuberculosis (Mtb) and SARS-CoV-2 using a whole-blood-based assay-platform in COVID-19 patients either with TB or latent TB infection (LTBI). METHODS: We evaluated IFN-γ level in plasma from whole-blood stimulated with Mtb antigens in the Quantiferon-Plus format or with peptides derived from SARS-CoV-2 spike protein, Wuhan-Hu-1 isolate (CD4-S). RESULTS: We consecutively enrolled 63 COVID-19, 10 TB-COVID-19 and 11 LTBI-COVID-19 patients. IFN-γ response to Mtb-antigens was significantly associated to TB status and therefore it was higher in TB-COVID-19 and LTBI-COVID-19 patients compared to COVID-19 patients (p ≤ 0.0007). Positive responses against CD4-S were found in 35/63 COVID-19 patients, 7/11 LTBI-COVID-19 and only 2/10 TB-COVID-19 patients. Interestingly, the responders in the TB-COVID-19 group were less compared to COVID-19 and LTBI-COVID-19 groups (p = 0.037 and 0.044, respectively). Moreover, TB-COVID-19 patients showed the lowest quantitative IFN-γ response to CD4-S compared to COVID-19-patients (p = 0.0336) and LTBI-COVID-19 patients (p = 0.0178). CONCLUSIONS: Our data demonstrate that COVID-19 patients either TB or LTBI have a low ability to build an immune response to SARS-CoV-2 while retaining the ability to respond to Mtb-specific antigens.

Multi-omics approach to COVID-19: a domain-based literature review.

BACKGROUND: Omics data, driven by rapid advances in laboratory techniques, have been generated very quickly during the COVID-19 pandemic. Our aim is to use omics data to highlight the involvement of specific pathways, as well as that of cell types and organs, in the pathophysiology of COVID-19, and to highlight their links with clinical phenotypes of SARS-CoV-2 infection. METHODS: The analysis was based on the domain model, where for domain it is intended a conceptual repository, useful to summarize multiple biological pathways involved at different levels. The relevant domains considered in the analysis were: virus, pathways and phenotypes. An interdisciplinary expert working group was defined for each domain, to carry out an independent literature scoping review. RESULTS: The analysis revealed that dysregulated pathways of innate immune responses, (i.e., complement activation, inflammatory responses, neutrophil activation and degranulation, platelet degranulation) can affect COVID-19 progression and outcomes. These results are consistent with several clinical studies. CONCLUSIONS: Multi-omics approach may help to further investigate unknown aspects of the disease. However, the disease mechanisms are too complex to be explained by a single molecular signature and it is necessary to consider an integrated approach to identify hallmarks of severity.