Recombinant Human Thymosin Beta-4 Protects against Mouse Coronavirus Infection

Development of two novel on-site detection visualization methods for murine hepatitis virus based on the multienzyme isothermal rapid amplification

Murine hepatitis virus (MHV) infection is one of the most prevalent types of mice infection in laboratory. MHV could cause death in mice and even interfere with the results in animal experiments. Herein, we developed two isothermal approaches based on the Multienzyme Isothermal Rapid Amplification (MIRA), for rapid detection of MHV in conserved M gene. We designed and screened several pairs of primers and probes and the isothermal fluorescence detector was applied for the exonuclease Ⅲ reverse transcription MIRA (exo-RT-MIRA) assay. To further simplify the workflow, the portable fluorescence visualization instrument, also as a palm-sized handheld system, was used for the naked-eye exo-RT-MIRA assay. The amplification temperature and time were optimized. The assay could be processed well at 42 °C 20 min for the exo-RT-MIRA and the naked-eye exo-RT-MIRA assay. The limit of detection (LoD) of the exo-RT-MIRA assay was 43.4 copies/μL. The LoD of the naked-eye exo-RT-MIRA assay was 68.2 copies/μL. No nonspecific amplifications were observed in the two assays. A total of 107 specimens were examined by qPCR and two assays developed. The experimental results statistical analysis demonstrated that the exo-RT-MIRA assay with the qPCR yielded sufficient agreement with a kappa value of 1.000 (p < 0.0001). The results also exhibited a good agreement (kappa value, 0.961) (p < 0.0001) between the naked-eye exo-RT-MIRA assay and the qPCR assay. In our study, the exo-RT-MIRA assay and the naked-eye exo-RT-MIRA assay presented the possibility of new methods in MHV point-of-testing diagnosis.

Th22 is the effector cell of thymosin β15-induced hair regeneration in mice

BACKGROUND

Thymosin beta family has a significant role in promoting hair regeneration, but which type of T cells play a key role in this process has not been deeply studied. This research aimed to find out the subtypes of T cell that play key role in hair regeneration mediated by thymosin beta 15 (Tβ15).

METHODS

Ready-to-use adenovirus expressing mouse Tmsb15b (thymosin beta 15 overexpression, Tβ15 OX) and lentivirus-Tβ15 short hairpin RNA (Tβ15 sh) were used to evaluate the role of Tβ15 in hair regeneration and development. The effect of Th22 cells on hair regeneration was further studied by optimized Th22-skewing condition medium and IL-22 binding protein (IL-22BP, an endogenous antagonist of IL-22, also known as IL-22RA2) in both ex vivo culture C57BL/6J mouse skin and BALB/c nude mice transplanted with thymus organoid model.

RESULTS

The results show that Tβ15, the homologous of Tβ4, can promote hair regeneration by increasing the proliferation activity of hair follicle cells. In addition, high-level expression of Tβ15 can not only increase the number of Th22 cells around hair follicles but also accelerate the transformation of hair follicles to maturity. Consistent with the expected results, when the IL-22BP inhibitor was used to interfere with Th22, the process of hair regeneration was blocked.

CONCLUSIONS

In conclusion, Th22 is the key effector cell of Tβ15 inducing hair regeneration. Both Tβ15 and Th22 may be the potential drug targets for hair regeneration.

Thymalfasin therapy accelerates COVID-19 pneumonia rehabilitation through anti-inflammatory mechanisms

INTRODUCTION

Thymosin drugs are commonly used for the treatment of viral infections due to their immunomodulatory effects. The comprehensive clinical efficacy of Thymalfasin therapy for COVID-19 associated pneumonia is not yet fully researched, another issue, whether the use of thymosin drugs can reduce the rate of COVID-19 progression to severe pneumonia has not been well documented. The aim of the present study was to multi-angle evaluate the clinical efficacy of Thymalfasin therapy for COVID-19 pneumonia by retrospective review of the clinical data of 338 inpatients with common COVID-19 infection who received treatment in our hospital.

METHODS

The primary index of observation was whether progression to severe pneumonia occurred within a week after admission, and the secondary indexes were the length of hospital stay, time of negative conversion of COVID-19 antigen, the number of peripheral lymphocytes and white blood cells (WBC), and C-reactive protein (CRP) and procalcitonin (PCT) levels,and the control of pneumonia related symptoms, for example, fever, listlessness, inflammatory exudate area shown on lung CT (%).

RESULTS

The length of hospital stay of patients in Thymalfasin group was significantly shorter than that of patients in the control group (p < 0.01). The proportion of relief of pneumonia related symptoms (fever, fatigue) in the Thymalfasin therapy group was significantly higher than that in the control group, and the inflammatory exudate area shown on CT was significantly lower than that in the control group (p < 0.05). Multivariate logistic regression analysis showed that the use of Thymalfasin was an independent protective factor affecting the progression to severe pneumonia. Multifactorial Cox model analysis indicated that negative conversion of COVID-19 antigen was significantly faster in patients using Thymalfasin and younger patients.

CONCLUSION

Thymalfasin therapy has shown excellent clinical efficacy in the treatment of COVID-19 pneumonia, it can reduce inflammatory reactions, promote the relief of COVID-19 pneumonia related symptoms such as fever and fatigue, facilitate effusion absorption, and accelerate COVID-19 pneumonia recovery. Thymalfasin can prevent progression of common COVID-19 infection to severe pneumonia via multiple immunity-enhancing and anti-inflammatory protective mechanisms.

Exogenous Thymosin Beta 4 Suppresses IPF-Lung Cancer in Mice: Possibly Associated with Its Inhibitory Effect on the JAK2/STAT3 Signaling Pathway

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung disease of unknown etiology. At present, the mortality rate of the deadly disease is still very high, while the existing treatments only delay the progression of the disease and improve the quality of life of patients. Lung cancer (LC) is the most fatal disease in the world. In recent years, IPF has been considered to be an independent risk factor for the development of LC. The incidence of lung cancer is increased in the patients with IPF and the mortality is also significantly increased in the patients inflicted with the two diseases. In this study, we evaluated an animal model of pulmonary fibrosis complicated with LC by implanting LC cells orthotopically into the lungs of mice several days after bleomycin induction of the pulmonary fibrosis in the same mice. In vivo studies with the model showed that exogenous recombinant human thymosin beta 4 (exo-rhTβ4) alleviated the impairment of lung function and severity of damage of the alveolar structure by the pulmonary fibrosis and inhibited the proliferation of LC tumor growth. In addition, in vitro studies showed that exo-rhTβ4 inhibited the proliferation and migration of A549 and Mlg cells. Furthermore, our results also showed that rhTβ4 could effectively inhibit the JAK2-STAT3 signaling pathway and this might exert an anti-IPF-LC effect. The establishment of the IPF-LC animal model will be helpful for the development of drugs for the treatment of IPF-LC. Exogenous rhTβ4 can be potentially used for the treatment of IPF and LC.

Human Wharton's Jelly Mesenchymal Stem Cells Secretome Inhibits Human SARS-CoV-2 and Avian Infectious Bronchitis Coronaviruses

Human SARS-CoV-2 and avian infectious bronchitis virus (IBV) are highly contagious and deadly coronaviruses, causing devastating respiratory diseases in humans and chickens. The lack of effective therapeutics exacerbates the impact of outbreaks associated with SARS-CoV-2 and IBV infections. Thus, novel drugs or therapeutic agents are highly in demand for controlling viral transmission and disease progression. Mesenchymal stem cells (MSC) secreted factors (secretome) are safe and efficient alternatives to stem cells in MSC-based therapies. This study aimed to investigate the antiviral potentials of human Wharton’s jelly MSC secretome (hWJ-MSC-S) against SARS-CoV-2 and IBV infections in vitro and in ovo. The half-maximal inhibitory concentrations (IC50), cytotoxic concentration (CC50), and selective index (SI) values of hWJ-MSC-S were determined using Vero-E6 cells. The virucidal, anti-adsorption, and anti-replication antiviral mechanisms of hWJ-MSC-S were evaluated. The hWJ-MSC-S significantly inhibited infection of SARS-CoV-2 and IBV, without affecting the viability of cells and embryos. Interestingly, hWJ-MSC-S reduced viral infection by >90%, in vitro. The IC50 and SI of hWJ-MSC secretome against SARS-CoV-2 were 166.6 and 235.29 µg/mL, respectively, while for IBV, IC50 and SI were 439.9 and 89.11 µg/mL, respectively. The virucidal and anti-replication antiviral effects of hWJ-MSC-S were very prominent compared to the anti-adsorption effect. In the in ovo model, hWJ-MSC-S reduced IBV titer by >99%. Liquid chromatography-tandem mass spectrometry (LC/MS-MS) analysis of hWJ-MSC-S revealed a significant enrichment of immunomodulatory and antiviral proteins. Collectively, our results not only uncovered the antiviral potency of hWJ-MSC-S against SARS-CoV-2 and IBV, but also described the mechanism by which hWJ-MSC-S inhibits viral infection. These findings indicate that hWJ-MSC-S could be utilized in future pre-clinical and clinical studies to develop effective therapeutic approaches against human COVID-19 and avian IB respiratory diseases.