Impact of Immunosenescence on Viral Infections with an Emphasis on COVID-19

During aging, the immune system (IS) undergoes remarkable changes known as immunosenescence, a multifactorial and dynamic phenomenon that affects both natural and acquired immunity and plays an important role in most chronic diseases in older people. Among the determinants of immunosenescence, we find a low-grade sterile chronic inflammation, known as "inflamm-aging". This condition of chronic inflammation causes a progressive reduction in the ability to trigger antibody and cellular responses effective against infections and vaccinations. In this review, we wanted to explore the role of immunosenescence and inflamm-aging as determinants of the immunological aging process and predisposing viral infections phenomena, with a particular reference to cytomegalovirus (CMV), varicella zoster virus (VZV), influenza virus (IFV) diseases and SARS-CoV2. IS aging is also reflected in a reduction in the antibody response to vaccinations, hence there is a need to expand trials to elderly patients, in order to identify the most appropriate methods for developing effective and safe vaccination and preventive strategies.

Can bacterial lysates be useful in prevention of viral respiratory infections in childhood? The results of experimental OM-85 studies

Respiratory tract infections (RTI) are mainly viral in origin and among the leading cause of childhood morbidity globally. Associated wheezing illness and asthma are still a clear unmet medical need. Despite the continuous progress in understanding the processes involved in their pathogenesis, preventive measures and treatments failed to demonstrate any significant disease-modifying effect. However, in the last decades it was understood that early-life exposure to microbes, may reduce the risk of infectious and allergic disorders, increasing the immune response efficacy. These results suggested that treatment with bacterial lysates (BLs) acting on gut microbiota, could promote a heterologous immunomodulation useful in the prevention of recurrent RTIs and of wheezing inception and persistence. This hypothesis has been supported by clinical and experimental studies showing the reduction of RTI frequency and severity in childhood after oral BL prophylaxis and elucidating the involved mechanisms. OM-85 is the product whose anti-viral effects have been most extensively studied in vitro, animal, and human cell studies and in translational animal infection/disease models. The results of the latter studies, describing the potential immune training-based activities of such BL, leading to the protection against respiratory viruses, will be reported. In response to human rhinovirus, influenza virus, respiratory syncytial virus and severe acute respiratory coronavirus-2, OM-85 was effective in modulating the structure and the functions of a large numbers of airways epithelial and immune cells, when administered both orally and intranasally.

Perfusion kinetics in human brain tumor with DCE-MRI derived model and CFD analysis

Cancer is one of the leading causes of death all over the world. Among the strategies that are used for cancer treatment, the effectiveness of chemotherapy is often hindered by factors such as irregular and non-uniform uptake of drugs inside tumor. Thus, accurate prediction of drug transport and deposition inside tumor is crucial for increasing the effectiveness of chemotherapeutic treatment. In this study, a computational model of human brain tumor is developed that incorporates dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) data into a voxelized porous media model. The model takes into account realistic transport and perfusion kinetics parameters together with realistic heterogeneous tumor vasculature and accurate arterial input function (AIF), which makes it patient specific. The computational results for interstitial fluid pressure (IFP), interstitial fluid velocity (IFV) and tracer concentration show good agreement with the experimental results. The computational model can be extended further for predicting the deposition of chemotherapeutic drugs in tumor environment as well as selection of the best chemotherapeutic drug for a specific patient.

Jiawei-Yupingfeng-Tang, a Chinese herbal formula, inhibits respiratory viral infections in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Jiawei-Yupingfeng-Tang (JYT) is a Chinese herbal formula that is widely used to treat respiratory tract illness. However, the effect of JYT on respiratory viruses remains unknown. The influenza virus (IFV) and the human respiratory syncytial virus (HRSV) cause millions of cases of severe illness per year, and many of these illnesses develop into lethal pneumonia. The aim of this study is to evaluate whether JYT can be used to treat these infections.

MATERIALS AND METHODS

The effect of JYT against IFV and HRSV was tested using a plaque reduction assay in the lower respiratory tract cell line A549. The expression of ICAM-1 was determined by real-time RT-PCR and western blotting. A mouse model infected with lethal influenza developing into interstitial pneumonia was used to evaluate the effect of JYT in vivo.

RESULTS

JYT extract inhibited both IFV and HRSV in a dose-dependent manner when given before, during and after a viral infection. JYT was effective in blocking the entry of the virus. Furthermore, pre-treatment with JYT reduced the susceptibility of cells to the invasion of HRSV by inhibiting the expression of ICAM-1. Importantly, JYT extract increased the survival rate of lethal influenza-infected mice, prolonged the survival time and alleviated the virus-induced lung lesions, which is comparable with the effects of ribavirin treatment.

CONCLUSIONS

These data support JYT as an alternative modality to be used in the treatment of respiratory viral infection induced by HRSV and IFV.