Combination Therapy with Thymosin Alpha1 and Dexamethasone Helps Mice Survive Sepsis

Hypofractionated Radiation Therapy Combined With Weekly Chemotherapy in Patients With Unresectable or Recurrent Thymic Epithelial Tumor: A Prospective, Single-Arm Phase 2 Study (GASTO-1042)

PURPOSE

This prospective phase 2 study aimed to evaluate the efficacy and safety of hypofractionated radiation therapy (HRT) combined with concurrent weekly chemotherapy in patients with unresectable or recurrent thymic epithelial tumors (TETs).

METHODS AND MATERIALS

Patients with unresectable or recurrent intrathoracic TETs that could be encompassed within the radiation fields were enrolled. HRT using intensity modulated radiation therapy (IMRT) technique was administered with 3 different levels of radiation doses (51 Gy/17 fractions (fx), 48 Gy/12 fx, and 45 Gy/9 fx; biologically effective dose of 66.3-67.5Gy), combined with weekly docetaxel (25 mg/m²) and nedaplatin (25 mg/m²). Weekly thymosin α1 (1.6 mg) was administered from the start to 2 months after radiation therapy. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), health-related quality of life (QOL), and toxicity were recorded.

RESULTS

Fifty eligible patients enrolled from August 1, 2018, to July 1, 2020, were analyzed. Most patients (82.0%) had stage IVB tumors. Patients had IMRT-HRT (36-51 Gy in 9-17 fx, median biologically effective dose of 67.2 Gy) and concurrent weekly docetaxel/nedaplatin (2-4 cycles). During a median follow-up of 25.0 months (14.0-40.0), the ORR was 83.7%, the 2-year PFS was 59.1%, and the 2-year OS was 90.0%. There was 1 (2.0%) in-field recurrence while 19 (38.0%) patients developed out-of-field recurrence. Grade 3 pneumonitis was observed in 1 patient (2.0%). The ORR, 2-year PFS, 2-year OS, and toxicity were similar among 3 dose levels. Fourteen (28.0%) patients had 2 to 4 courses of radiation therapy because of recurrent diseases. Only 1 suffered from grade 1 pulmonary fibrosis during follow-up. Most patients (88%) maintained a stable QOL within 1 year after radiation therapy.

CONCLUSIONS

IMRT-HRT and concurrent weekly docetaxel/nedaplatin was effective and well tolerated in unresectable or recurrent TETs. Considering the common out-of-field recurrence, this combined regimen could be an option for repeated radiation therapy. Thymosin α1 might help lower the incidence of pneumonitis and maintain the QOL.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Combination therapy of Ulinastatin with Thrombomodulin alleviates endotoxin (LPS) - induced liver and kidney injury via inhibiting apoptosis, oxidative stress and HMGB1/TLR4/NF-κB pathway

Sepsis is a type of systemic inflammation response syndrome that leads to organ function disorders. Currently, there is no specific medicine for sepsis in clinical practice. Lipopolysaccharide (LPS) is an important endotoxin that causes sepsis. Here, we report an effective two-drug combination therapy to treat LPS-induced liver and kidney injury in endotoxic rats. Ulinastatin (UTI) and Thrombomodulin (TM) are biological macromolecules extracted from urine. In our study, combination therapy significantly improved LPS-induced liver and kidney pathological structure and functional injury, and significantly improved the survival rate of endotoxic rats. Results of TUNEL staining and Western blot showed that UTI combined with TM inhibited the excessive apoptosis of liver and kidney cells caused by LPS. The drug combination also promoted the proliferation of liver and kidney cells, reduced the levels of pro-inflammatory factors interleukin (IL)-6, IL-1β, tumor or necrosis factor (TNF)-α and nitric oxide, and down-regulated the expression of High Mobility Group Box 1 (HMGB1), Toll-like receptor (TLR) 4 and Nuclear Factor (NF)-κB phosphorylation to inhibit inflammation. In addition, the combination of UTI and TM also promoted the production of a variety of antioxidant enzymes in the tissues and inhibited the production of lipid peroxidation malondialdehyde (MDA) to enhance antioxidant defenses. Our experiments also proved that UTI combined with TM did not reduce the anticoagulant effect of TM. These results suggested that UTI combined with TM can improve endotoxin-induced liver and kidney damage and mortality by inhibiting liver and kidney cell apoptosis, promoting proliferation, and inhibiting inflammation and oxidative injury.

Thymosin Alpha1-Fc Modulates the Immune System and Down-regulates the Progression of Melanoma and Breast Cancer with a Prolonged Half-life

Thymosin alpha 1 (Tα1) is a biological response modifier that has been introduced into markets for treating several diseases. Given the short serum half-life of Tα1 and the rapid development of Fc fusion proteins, we used genetic engineering method to construct the recombinant plasmid to express Tα1-Fc (Fc domain of human IgG4) fusion protein. A single-factor experiment was performed with different inducers of varying concentrations for different times to get the optimal condition of induced expression. Pure proteins higher than 90.3% were obtained by using 5 mM lactose for 4 h with a final production about 160.4 mg/L. The in vivo serum half-life of Tα1-Fc is 25 h, almost 13 times longer than Tα1 in mice models. Also, the long-acting protein has a stronger activity in repairing immune injury through increasing number of lymphocytes. Tα1-Fc displayed a more effective antitumor activity in the 4T1 and B16F10 tumor xenograft models by upregulating CD86 expression, secreting IFN-γ and IL-2, and increasing the number of tumor-infiltrating CD4+ T and CD8+ T cells. Our study on the novel modified Tα1 with the Fc segment provides valuable information for the development of new immunotherapy in cancer.

Immunomodulatory and enhanced antitumor activity of a modified thymosin α1 in melanoma and lung cancer

Tumor-targeted therapy is an attractive strategy for cancer treatment. Peptide hormone thymosin α1 (Tα1) has been used against several diseases, including cancer, but its activity is pleiotropic. Herein, we designed a fusion protein Tα1-iRGD by introducing the tumor homing peptide iRGD to Tα1. Results show that Tα1-iRGD can promote T-cell activation and CD86 expression, thereby exerting better effect and stronger inhibitory against melanoma and lung cancer, respectively, than Tα1 in vivo. These effects are indicated by the reduced densities of tumor vessels and Tα1-iRGD accumulation in tumors. Moreover, compared with Tα1, Tα1-iRGD can attach more B16F10 and H460 cells and exhibits significantly better immunomodulatory activity in immunosuppression models induced by hydrocortisone. Circular dichroism spectroscopy and structural analysis results revealed that Tα1 and Tα1-iRGD both adopted a helical confirmation in the presence of trifluoroethanol, indicating the structural basis of their functions. These findings highlight the vital function of Tα1-iRGD in tumor-targeted therapy and suggest that Tα1-iRGD is a better antitumor drug than Tα1.

Immune Modulation with Thymosin Alpha 1 Treatment

Thymosin alpha 1 (Ta1) is a peptide originally isolated from thymic tissue as the compound responsible for restoring immune function to thymectomized mice. Ta1 has a pleiotropic mechanism of action, affecting multiple immune cell subsets that are involved in immune suppression. Ta1 acts through Toll-like receptors in both myeloid and plasmacytoid dendritic cells, leading to activation and stimulation of signaling pathways and initiation of production of immune-related cytokines. Due to the immune stimulating effects of Ta1, the compound would be expected to show utility for treatment of immune suppression, whether related to aging or to diseases such as infection or cancer. Extensive studies in both the preclinical and clinical setting will be summarized in the subsequent sections. These studies have demonstrated improvements in immune system cell subsets and the potential of Ta1 for the treatment of a range of diseases.

Tuftsin-derived T-peptide prevents cellular immunosuppression and improves survival rate in septic mice

The primary mechanisms of sepsis induced cellular immunesuppression involve immune dysfunction of T lymphocytes and negative immunoregulation of regulatory T cells (Tregs). It has been found that tuftsin is an immune modulating peptide derived from IgG in spleen. T-peptide is one of tuftsin analogs. Herein, we examined the effect of T-peptide on cell-mediated immunity in the presence of lipopolysaccharide (LPS) and the survival rate in septic mice. T-peptide regulated the proliferative ability of CD4⁺CD25⁻ T cells in dual responses. Meanwhile, 10 and 100 μg/ml T-peptides were able to enhance the apoptotic rate of CD4⁺CD25⁻ T cells compared with 1 μg/ml T-peptide, but markedly lowered interleukin (IL)-2 levels. When CD4⁺CD25⁺ Tregs were treated with T-peptide for 24 hours, and co-cultured with normal CD4⁺CD25⁻ T cells, the suppressive ability of CD4⁺CD25⁺ Tregs on CD4⁺CD25⁻ T cells was significantly lowered, along with decreased expression in forkhead/winged helix transcription factor p-3 (Foxp-3) as well as cytotoxic T lymphocyte-associated antigen (CTLA)-4, and secretion of transforming growth factor (TGF)-β. Moreover, T-peptide has the ability to improve outcome of septic mice in a dose- and time- dependent manner, and associated with improvement in the microenvironment of cellular immunosuppression in septic mice.

Evaluation of thymosin α 1 in nonclinical models of the immune-suppressing indications melanoma and sepsis

OBJECTIVES

Recent understanding of the complex pathophysiology of melanoma and severe sepsis suggests that immune-modulating compounds such as thymosin alpha 1 (INN: thymalfasin; abbreviated Ta1) could be useful in the treatment of these two unrelated immune-suppressing indications.

RESEARCH DESIGN AND METHODS

Three nonclinical murine models were utilized, including: i) a lung metastasis B16 model; ii) a B16-based tumor growth model; and iii) a cecal-ligation and puncture (CLP) sepsis model.

RESULTS

In the lung metastasis model, Ta1 treatment alone led to a 32% decrease in metastases (p < 0.05). Additionally, combinations of Ta1 and an anti-PD-1 antibody led to significantly fewer metastases than vehicle. In the tumor growth model, significant decreases in tumor growth were seen: 34% (p = 0.015) to 46% (p = 0.001) depending on the Ta1 dose. In the CLP sepsis model, Ta1 treatment showed a positive trend towards increased survival and decreased bacterial load. In this CLP model, Ta1 also appeared to have an effect on the levels of some biomarkers.

CONCLUSIONS

All three models demonstrated a benefit after treatment with Ta1, with no evidence of toxicity. These initial pilot studies support the hypothesis that immune-suppressive indications, including sepsis and melanoma, may be treated with Ta1 alone or by Ta1 in combination with other immunotherapies.