Thymosin α 1 potentiates the release by CD8+cells of soluble factors able to inhibit HIV-1 and human T lymphotropic virus 1 infectionin vitro

Thymosin α1 modulated the immune landscape of COVID-19 patients revealed by single-cell RNA and TCR sequencing

BACKGROUND

The Coronavirus disease-19 (COVID-19) pandemic has posed a serious threat to global health. Thymosin α1 (Tα1) was considered to be applied in COVID-19 therapy. However, the data remains limited.

METHODS

Participants with or without Tα1 treatment were recruited. Single cell RNA-sequencing (scRNA-seq) and T cell receptor-sequencing (TCR-seq) of the peripheral blood mononuclear cell (PBMC) samples were done to analyze immune features. The differential expression analysis and functional enrichment analysis were performed to explore the mechanism of Tα1 therapy.

RESULTS

33 symptomatic SARS-CoV-2-infected individuals (COV) and 11 healthy controls (HC) were enrolled in this study. The proportion of CD3+ KLRD1+ NKT, TBX21+ CD8+ NKT was observed to increase in COVID-19 patients with Tα1 treatment (COVT) than those without Tα1 (COV) (p = 0.024; p = 0.010). These two clusters were also significantly higher in Health controls with Tα1 treatment (HCT) than those without Tα1 (HC) (p = 0.016; p = 0.031). Besides, a series of genes and pathways related to immune responses were significantly higher enriched in Tα1 groups TBX21+ CD8+ NKT, such as KLRB1, PRF1, natural killer cell-mediated cytotoxicity pathway, chemokine signaling pathway, JAK-STAT signaling pathway. The increased TRBV9-TRBJ1-1 pair existed in both HCs and COVID-19 patients after Tα1 treatment. 1389 common complementarity determining region 3 nucleotides (CDR 3 nt) were found in COV and HC, while 0 CDR 3 nt was common in COVT and HCT.

CONCLUSIONS

Tα1 increased CD3+ KLRD1+ NKT, TBX21+ CD8+ NKT cell proportion and stimulated the diversity of TCR clones in COVT and HCT. And Tα1 could regulate the expression of genes associated with NKT activation or cytotoxicity to promote NKT cells. These data support the use of Tα1 in COVID-19 patients.

Thymosin α1 interacts with Galectin-1 modulating the β-galactosides affinity and inducing alteration in the biological activity

The study of mechanism of action of Thymosin alpha 1 (Tα1) and the basis of the pleiotropic effect in health and disease, is one of the main focus of our ongoing research. Tα1 is a thymic peptide that demonstrates a peculiar ability to restore homeostasis in different physiological and pathological conditions (i.e., infections, cancer, immunodeficiency, vaccination, and aging) acting as multitasking protein depending on the host state of inflammation or immune dysfunction. However, few are the information about mechanisms of action mediated by specific Tα1-target protein interaction that could explain its pleiotropic effect. We investigated the interaction of Tα1 with Galectin-1 (Gal-1), a protein belonging to an oligosaccharide binding protein family involved in a variety of biological and pathological processes, including immunoregulation, infections, cancer progression and aggressiveness. Using molecular and cellular methodological approaches, we demonstrated the interaction between these two proteins. Tα1 specifically inhibited the hemagglutination activity of Gal-1, the Gal-1 dependent in vitro formation of endothelial cell tubular structures, and the migration of cancer cells in wound healing assay. Physico-chemical methods revealed the details of the molecular interaction of Tα1 with Gal-1. Hence, the study allowed the identification of the not known until now specific interaction between Tα1 and Gal-1, and unraveled a novel mechanism of action of Tα1 that could support understanding of its pleiotropic activity.

Thymosin Alpha 1 Restores the Immune Homeostasis in lymphocytes during Post-Acute Sequelae of SARS-CoV-2 infection

The complex alterations of the immune system and the immune-mediated multiorgan injury plays a key role in host response to SARS-CoV-2 infection and in the pathogenesis of COVID-19, being also associated with adverse outcomes. Thymosin alpha 1 (Tα1) is one of the molecules used in the treatment of COVID-19, as it is known to restore the homeostasis of the immune system during infections and cancer. The use of Tα1 in COVID-19 patients had been widely used in China and in COVID-19 patients, it has been shown to decrease hospitalization rate, especially in those with greater disease severity, and reduce mortality by restoring lymphocytopenia and more specifically, depleted T cells. Persistent dysregulation with depletion of naive B and T cell subpopulations and expansion of memory T cells suggest a chronic stimulation of the immune response in individuals with post-acute sequelae of SARS-CoV-2 infection (PASC). Our data obtained from an ex vivo study, showed that in PASC individuals with a chronically altered immune response, Tα1 improve the restoration of an appropriate response, most evident in those with more severe illness and who need respiratory support during acute phase, and in those with specific systemic and psychiatric symptoms of PASC, confirming Tα1 treatment being more effective in compromised patients. The results obtained, along with promising reports on recent trials on Tα1 administration in patients with COVID-19, offer new insights into intervention also for those patients with long-lasting inflammation with post-infectious symptoms, some of which have a delayed onset.

Combination of Gemcitabine and Thymosin alpha 1 exhibit a better anti-tumor effect on nasal natural killer/T-cell lymphoma

BACKGROUND

Nasal natural killer/T-cell lymphoma (NNKTL) is an aggressive and poor prognostic malignant tumor along with high-level infection of Epstein-Barr virus (EBV). Gemcitabine (Gem) and Thymosin alpha 1 (Tα1) exert an anti-tumor effect in various cancers. However, the effect of the combination of Gem and Tα1 in NNKTL remains unknown.

METHODS

SNK6 cells were treated with Gem, Tα1 and Gem plus Tα1 for 48 h. The expression levels of EBV and inflammatory factors were measured by qRT-PCR assay. The effect of Gem and Tα1 on cell viability, proliferation, apoptosis, autophagy was detected by CCK-8, colony formation, flow cytometry, autophagic flux measurement, respectively. Western blot was used to evaluate the expression of proteins related to epithelial-mesenchymal transition (EMT), apoptosis and autophagy. In vivo xenograft models were used to further verify the roles of Gem and Tα1. Tumors were removed for weight measurement, H&E and IHC staining.

RESULTS

We identified that the half maximal inhibitory concentration (IC50) of Gem and Tα1 was 116.5 μmol/ml and 1.334 μmol/ml. Alone or combined administration of Gem and Tα1 dramatically attenuated the EBV viral load and promoted inflammatory factors expression in SNK6 cells, among which the combination of Gem and Tα1 treatment showed the most significant effect. Besides, combination treatment with Gem and Tα1 markedly inhibited cell growth and EMT progress, and enhanced apoptosis and autophagy. Similarly, Gem combined with Tα1 suppressed tumor growth, promoted apoptosis and autophagy in vivo. Additionally, combination treatment with Gem and Tα1 inhibited PI3K/AKT/mTOR pathway.

CONCLUSION

In summary, combination administration of Gem and Tα1 suppressed the progression of NNKTL in vivo and in vitro. Our study provided an effective therapeutic strategy potentially for the clinical treatment of NNKTL.

The CD8+ T Cell Noncytotoxic Antiviral Responses

The CD8+ T cell noncytotoxic antiviral response (CNAR) was discovered during studies of asymptomatic HIV-infected subjects more than 30 years ago. In contrast to CD8+ T cell cytotoxic lymphocyte (CTL) activity, CNAR suppresses HIV replication without target cell killing. This activity has characteristics of innate immunity: it acts on all retroviruses and thus is neither epitope specific nor HLA restricted. The HIV-associated CNAR does not affect other virus families. It is mediated, at least in part, by a CD8+ T cell antiviral factor (CAF) that blocks HIV transcription. A variety of assays used to measure CNAR/CAF and the effects on other retrovirus infections are described. Notably, CD8+ T cell noncytotoxic antiviral responses have now been observed with other virus families but are mediated by different cytokines. Characterizing the protein structure of CAF has been challenging despite many biologic, immunologic, and molecular studies. It represents a low-abundance protein that may be identified by future next-generation sequencing approaches. Since CNAR/CAF is a natural noncytotoxic activity, it could provide promising strategies for HIV/AIDS therapy, cure, and prevention.

Plant microRNAs from Moringa oleifera Regulate Immune Response and HIV Infection

Traditional medicine is often chosen due to its affordability, its familiarity with patient’s cultural practices, and its wider access to the local community. Plants play an important role in providing indispensable nutrients, while specific small RNAs can regulate human gene expression in a cross-kingdom manner. The aim of the study was to evaluate the effects of plant-enriched purified extract microRNAs from Moringa oleifera seeds (MO) on the immune response and on HIV infection. Bioinformatic analysis shows that plant microRNAs (p-miRs) from MO belonging to 18 conserved families, including p-miR160h, p-miR166, p-miR482b, p-miR159c, p-miR395d, p-miR2118a, p-miR393a, p-miR167f-3p, and p-miR858b are predicted to target with high affinity BCL2, IL2RA, TNF, and VAV1, all these being involved in the cell cycle, apoptosis, immune response and also in the regulation of HIV pathogenesis. The effects of MO p-miRs transfected into HIV+ PBMCs were analyzed and revealed a decrease in viability associated with an increase of apoptosis; an increase of T helper cells expressing Fas and a decrease of intracellular Bcl2 protein expression. Meanwhile no effects were detected in PBMCs from healthy donors. In CD4⁺ T cells, transfection significantly reduced cell activation and modified the T cell differentiation, thereby decreasing both central and effector memory cells while increasing terminal effector memory cells. Interestingly, the p-miRs transfection induces a reduction of intracellular HIV p24 protein and a reduction of viral DNA integration. Finally, we evaluated the effect of synthetic (mimic) p-miR858b whose sequence is present in the MO p-miR pool and predicted to target VAV1, a protein involved in HIV-Nef binding. This protein plays a pivotal role in T cell antigen receptor (TCR) signaling, so triggering the activation of various pathways. The transfection of HIV+ PBMCs with the synthetic p-miR858b showed a reduced expression of VAV1 and HIV p24 proteins. Overall, our evidence defines putative mechanisms underlying a supplementary benefit of traditional medicine, alongside current antiretroviral therapy, in managing HIV infection in resource-limited settings where MO remains widely available.

The right immune-modulation at the right time: thymosin α1 for prevention of severe COVID-19 in cancer patients

We presented the rationale for the use of thymosin α1 as prophylaxis of severe COVID-19 in cancer patients undergoing active treatment, constituting the background for the PROTHYMOS study, a prospective, multicenter, open-label, Phase II randomized study, currently in its start-up phase (Eudract no. 2020-006020-13). We aim to offer new hope for this incurable disease, especially to frail patient population, such as patients with cancer. The hypothesis of an effective prophylactic approach to COVID-19 would have immediate clinical relevance, especially given the lack of curative approaches. Moreover, in the ‘COVID-19 vaccine race era’ both clinical and biological results coming from the PROTHYMOS trials could even support the rationale for future combinatorial approaches, trying to rise vaccine efficacy in frail individuals.

We present scientific evidence in favor of using a drug (thymosin-α1) that modulates the immune system functions to try and prevent severe COVID-19 in cancer patients who are currently receiving anticancer treatment. Thymosin-α1 is produced normally by the body in the thymus, which is present in children but not in adults. Given the better outcomes of SARS-CoV-2 infections in children, we thought that thymosin-α1 could help to protect adults from severe infections as well. In this review, we explain some scientific evidence and the background of our clinical trial, PROTHYMOS, which is investigating this preventive treatment. Our aim is to offer a new hope to these at-risk cancer patients, particularly for the elderly who are at most risk of developing severe COVID-19. Given the lack of approaches that can provide cures to COVID-19, any possibility to prevent severe infection should be explored.

Thymosin Alpha 1 Mitigates Cytokine Storm in Blood Cells From Coronavirus Disease 2019 Patients

Background

Coronavirus disease 2019 (COVID-19) is characterized by immune-mediated lung injury and complex alterations of the immune system, such as lymphopenia and cytokine storm, that have been associated with adverse outcomes underlining a fundamental role of host response in severe acute respiratory syndrome coronavirus 2 infection and the pathogenesis of the disease. Thymosin alpha 1 (Tα1) is one of the molecules used in the management of COVID-19, because it is known to restore the homeostasis of the immune system during infections and cancer.

Methods

In this study, we captured the interconnected biological processes regulated by Tα1 in CD8+ T cells under inflammatory conditions.

Results

Genes associated with cytokine signaling and production were upregulated in blood cells from patients with COVID-19, and the ex vivo treatment with Tα1-mitigated cytokine expression, and inhibited lymphocyte activation in a CD8+ T-cell subset specifically.

Conclusion

These data suggest the potential role of Tα1 in modulating the immune response homeostasis and the cytokine storm in vivo.

ThymicPeptides Reverse Immune Exhaustion in Patients with Reactivated Human Alphaherpesvirus1 Infections

Recurrent infection with human alphaherpesvirus 1 (HHV-1) may be associated with immune exhaustion that impairs virus elimination. Thymic peptides enhance immune function and thus could overcome immune exhaustion. In this study, we investigated whether reactivation of herpes infections was associated with immune exhaustion. Moreover, we examined the impact of treatment with thymostimulin on the expression of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) on T and B lymphocytes in patients suffering from recurrent HHV-1 reactivation. We also assessed the effector function of peripheral blood mononuclear cells (PBMCs) after stimulation with thymic peptides. We enrolled 50 women with reactivated HHV-1 infections and healthy volunteers. We measured the expression of various activation and exhaustion markers on the surface of PBMCs using flow cytometry. In ex vivo experiments, we measured the secretion of inflammatory cytokines by PBMCs cultured with thymostimulin. Compared with controls, patients with reactivated HHV-1 infections had increased percentages of CD3+ co-expressing CD25, an activation marker (p < 0.001). Moreover, these patients had increased percentages of CD4+ and CD8+ cells co-expressing the inhibitory markers PD-1 and PD-L1. In cultures of PBMCs from the patients, thymostimulin increased the secretion of interferon gamma (p < 0.001) and interleukin (IL)-2 (p = 0.023), but not IL-4 or IL-10.Two-month thymostimulin therapy resulted in no reactivation of HHV-1 infection during this period and the reduction of PD-1 and PD-L1 expression on the surface of T and B lymphocytes (p < 0.001). In conclusion, reactivation of herpes infection is associated with immune exhaustion, which could be reversed by treatment with thymic peptides.

Deciphering cellular biological processes to clinical application: a new perspective for Tα1 treatment targeting multiple diseases

BACKGROUND

Thymosin alpha 1 (Tα1) is a well-recognized immune response modulator in a wide range of disorders, particularly infections and cancer. The bioinformatic analysis of public databases allows drug repositioning, predicting a new potential area of clinical intervention. We aimed to decipher the cellular network induced by Tα1 treatment to confirm present use and identify new potential clinical applications.

RESEARCH DESIGN AND METHODS

We used the transcriptional profile of human peripheral blood mononuclear cells treated in vitro with Tα1 to perform the enrichment network analysis by the Metascape online tools and the disease enrichment analysis by the DAVID online tool.

RESULTS

Networked cellular responses reflected Tα1 regulated biological processes including immune and metabolic responses, response to compounds and oxidative stress, ion homeostasis, peroxisome biogenesis and drug metabolic process. Beyond cancer and infections, the analysis evidenced the association with disorders such as kidney chronic failure, diabetes, cardiovascular, chronic respiratory, neuropsychiatric, neurodegenerative and autoimmune diseases.

CONCLUSIONS

In addition to the known ability to promote immune response pathways, the network enrichment analysis demonstrated that Tα1 regulates cellular metabolic processes and oxidative stress response. Notable, the analysis highlighted the association with several diseases, suggesting new translational implication of Tα1 treatment in pathological conditions unexpected until now.

Thymosin alpha 1 and HIV-1: recent advances and future perspectives

In spite of the consistent benefits for HIV-1 infected patients undergoing antiretroviral therapy, a complete immune reconstitution is usually not achieved. Actually, antiretroviral therapy may be frequently accompanied by immunological unresponsiveness, persistent inflammatory conditions and inefficient cytotoxic T-cell response. Thymosin alpha 1 is a thymic peptide that demonstrates a peculiar ability to restore immune system homeostasis in different physiological and pathological conditions (i.e., infections, cancer, immunodeficiency, vaccination and aging) acting as multitasking protein depending on the host state of inflammation or immune dysfunction. This review reports the present knowledge on the in vitro and in vivo studies concerning the use of thymosin alpha 1 in HIV-1 infection. Recent findings and future perspectives of therapeutic intervention are discussed.

The EuroSciCon's 2015 Innate Immunity Summit

The EuroSciCon's 2015 Innate Immunity Summit, London, UK, 17–19 November 2015

A first line of defense against viral infection is prompted by the innate immune system. Viruses activate both extracellular and intracellular events that lead to a war between the virus and the host. In addition to vaccines which induce adaptive T- and B-cell response in readiness for infection, other therapies that potentiate the host immune response are in development, such as those that induce an increase in restriction factor activity or diminish inflammation through Toll-like receptors’ antagonists. Other modulators of immune response, such as thymosin α-1, contribute to the inhibition of HIV-1 and human T lymphotropic virus 1 infection. Understanding the mechanisms by which the innate immune response combats pathogen invasion will enable the generation of novel therapeutic strategies to cure viral infection.