Anti-tumor mechanism of Z-100, an immunomodulatory Arabinomannan extracted from Mycobacterium tuberculosis strain Aoyama B, on pulmonary metastases of B16F10 melanoma: restoration of helper T cell responses via suppression of glucocorticoid-genesis

Immune-inflammatory modulation by natural products derived from edible and medicinal herbs used in Chinese classical prescriptions

BACKGROUND

Edible and medicinal herbs1 (EMHs) refer to a class of substances with dual attribution of food and medicine. These substances are traditionally used as food and also listed in many international pharmacopoeias, including the European Pharmacopoeia, the United States Pharmacopoeia, and the Chinese Pharmacopoeia. Some classical formulas that are widely used in traditional Chinese medicine include a series of EMHs, which have been shown to be effective with obvious characteristics and advantages. Notably, these EMHs and Chinese classical prescriptions2 (CCPs) have also attracted attention in international herbal medicine research because of their low toxicity and high efficiency as well as the rich body of experience for their long-term clinical use.

PURPOSE

Our purpose is to explore the potential therapeutic effect of EMHs with immune-inflammatory modulation for the study of modern cancer drugs.

STUDY DESIGN

In the present study, we present a detailed account of some EMHs used in CCPs that have shown considerable research potential in studies exploring modern drugs with immune-inflammatory modulation.

METHODS

Approximately 500 publications in the past 30 years were collected from PubMed, Web of Science and ScienceDirect using the keywords, such as natural products, edible and medicinal herbs, Chinese medicine, classical prescription, immune-inflammatory, tumor microenvironment and some related synonyms. The active ingredients instead of herbal extracts or botanical mixtures were focused on and the research conducted over the past decade were discussed emphatically and analyzed comprehensively.

RESULTS

More than ten natural products derived from EMHs used in CCPs are discussed and their immune-inflammatory modulation activities, including enhancing antitumor immunity, regulating inflammatory signaling pathways, lowering the proportion of immunosuppressive cells, inhibiting the secretion of proinflammatory cytokines, immunosuppressive factors, and inflammatory mediators, are summarized.

CONCLUSION

Our findings demonstrate the immune-inflammatory modulating role of those EMHs used in CCPs and provide new ideas for cancer treatment in clinical settings.

Potential of Z-100, extracted from Mycobacterium tuberculosis strain Aoyama B, as a hot tumor inducer

The tumor microenvironment is one of the most important factors determining the efficacy of cancer immunotherapy. In particular, variability in efficacy has been linked to whether tumors are hot or cold, with hot tumors exhibiting greater T cell infiltration and responding better to immunotherapy. Z-100 extracted from Mycobacterium tuberculosis Aoyama B strain has been reported to increase cytokine production from immune cells. In this study, we examined its effect on the tumor microenvironment and its potential as a hot tumor inducer. The antitumor effect of Z-100 was confirmed in a mouse oral squamous cell carcinoma (Sq-1979) tumor model by starting administration before tumor injection. Treated tumors were collected to identify infiltrating CD8⁺ T cells. The antitumor effects of Z-100 were additionally examined in mice treated with anti-CD8 antibody and in IL-12p40 knockout (KO) mice. We found that Z-100 had strong antitumor effects and increased the proportion of CD8⁺ T cells in tumors. Moreover, the CD8⁺ T cells infiltrating tumors were identified as effector memory CD8⁺ T cells. Furthermore, the antitumor effects of Z-100 were abolished in mice treated with an anti-CD8 antibody and in IL-12p40 KO mice. Thus, Z-100 induces its antitumor effects by increasing tumor-infiltrating CD8⁺ T cells, suggesting that Z-100 may be a useful cancer therapy by acting as a hot tumor inducer.

Integration of immunotherapy into treatment of cervical cancer: Recent data and ongoing trials

Cervical cancer constitutes a significant health burden for women globally. While most patients with early-stage disease can be cured with radical surgery or chemoradiotherapy, patients with high-risk locally advanced disease or with recurrent/metastatic disease have a poor prognosis with standard treatments. Immunotherapies are a rational treatment for this HPV-driven cancer that commonly expresses programmed cell death ligand-1. Before 2021, pembrolizumab was the only United States Food and Drug Administration-approved immunotherapy in cervical cancer, specifically for the second-line recurrent or metastatic (r/m) setting. In late 2021, the antibody-drug conjugate tisotumab vedotin was approved for second-line r/m cervical cancer and pembrolizumab combined with chemotherapy ± bevacizumab was approved for first-line r/m disease based on results from KEYNOTE-826. Moreover, with at least 2 dozen additional immunotherapy clinical trials in the second-line and first-line r/m setting, as well as in locally advanced disease, the treatment landscape for cervical cancer may eventually encounter a potential paradigm shift. Pivotal trials of immunotherapies for cervical cancer that were recently approved or with the potential for regulatory consideration through 2024 are reviewed. As immunotherapy has the opportunity to establish new standards of care in the treatment of cervical cancers, new biomarkers to identify the ideal patient populations for these therapies may also become important. However, issues with access, affordability, and compliance in low- and middle-income countries are anticipated.

Combination of immune check inhibitor and immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis: A case report

The present study selected two patients with lung cancer and epidermal growth factor receptor (EGFR) mutations who were treated with a programmed cell death protein 1 (PD-1) antibody and an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis. In the first case, a 67-year-old female was diagnosed with lung adenocarcinoma with an EGFR mutation (exon 19 deletion) and Stage IVB disease. Initial treatment with an EGFR mutation-targeted tyrosine kinase inhibitor (TKI), erlotinib, demonstrated a partial response. After disease progression this was followed by carboplatin and pemetrexed with bevacizumab, and re-challenged by erlotinib plus bevacizumab; however, the tumor eventually progressed. Subsequently, the patient was treated with immunomodulatory arabinomannan for 3 months. Immediately after, she was treated with nivolumab and showed a partial response. In the second case, a 57-year-old male with a history of smoking was diagnosed with stage IVB pulmonary adenocarcinoma with an EGFR mutation (exon 19 deletion). He was treated with afatinib, followed by osimertinib when a T790M mutation was identified later. After disease progressed with TKIs, cisplatin plus pemetrexed and re-challenge with erlotinib plus bevacizumab were administered subsequently. Nivolumab was administered for recurrent disease. Although he experienced tumor remission, regrowth of the tumors was observed. Under continuing nivolumab, he was treated by palliative irradiation treatments to the right pelvic bone metastasis and left adrenal metastasis with immunomodulatory arabinomannan. A chest computed tomography scan showed a reduction in the sizes of the primary site and pulmonary metastases, with a decreasing trend of carcinoma embryonic antigen. Overall, these cases may indicate that the immune adjuvant actions of immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis improves the effect of PD-1 antibody treatments.

Mycobacteria-Based Vaccines as Immunotherapy for Non-urological Cancers

The arsenal against different types of cancers has increased impressively in the last decade. The detailed knowledge of the tumor microenvironment enables it to be manipulated in order to help the immune system fight against tumor cells by using specific checkpoint inhibitors, cell-based treatments, targeted antibodies, and immune stimulants. In fact, it is widely known that the first immunotherapeutic tools as immune stimulants for cancer treatment were bacteria and still are; specifically, the use of Mycobacterium bovis bacillus Calmette-Guérin (BCG) continues to be the treatment of choice for preventing cancer recurrence and progression in non-invasive bladder cancer. BCG and also other mycobacteria or their components are currently under study for the immunotherapeutic treatment of different malignancies. This review focuses on the preclinical and clinical assays using mycobacteria to treat non-urological cancers, providing a wide knowledge of the beneficial applications of these microorganisms to manipulate the tumor microenvironment aiming at tumor clearance.

Anti-metastatic study of liposome-encapsulated all trans retinoic acid (ATRA) in B16F10 melanoma cells-implanted C57BL/6 mice

B16F10 cells-induced C57BL/6 mice were divided into several groups and the free all trans retinoic acid (ATRA) and liposome-encapsulated ATRA were given for 21 days. The encapsulated ATRA treatment lowered the oxidative stress and lipid profile near to the normal level in the drug-treated mice. Encapsulated ATRA treatment showed substantial decrease in serum cytokines and increase in lifespan when compared with free ATRA treatment. These results imply that the liposome-encapsulated ATRA may help to achieve a higher level of ATRA in comparison with free ATRA treatment and helps to enhance anticancer drug delivery in liposome-encapsulated ATRA treatment.

Phase III placebo-controlled double-blind randomized trial of radiotherapy for stage IIB-IVA cervical cancer with or without immunomodulator Z-100: a JGOG study

BACKGROUND

Based on the result of our previous study showing better overall survival (OS) at the lower dose (0.2 µg) of immunomodulator Z-100 than higher dose (40 µg) in patients with locally advanced cervical cancer who received radiotherapy, we conducted a placebo-controlled double-blind randomized trial.

PATIENTS AND METHODS

Patients of stages IIB-IVA squamous cell carcinoma of the uterine cervix were randomly assigned to receive Z-100 at 0.2 µg (Z) or placebo (P). The study agent was given subcutaneously twice a week during the radiotherapy, followed by maintenance therapy by administering once every 2 weeks until disease progression. Primary end point was OS, and secondary end points were recurrence-free survival, and toxicity.

RESULTS

A total of 249 patients were randomized. Death events occurred extremely slower than expected, and Independent Data Monitoring Committee recommended to analyze the survival result prematurely. The 5-year OS rate was 75.7% [95% confidence interval (CI) 66.4% to 82.8%] for Arm Z and 65.8% (95% CI 56.2% to 73.8%) for Arm P (P = 0.07); hazard ratio was 0.65 (95% CI 0.40-1.04). Survival benefit in Arm Z was observed regardless of chemoradiation or radiation alone. There was no trend in recurrence-free survival between the two arms. Side-effects were not different between two arms.

CONCLUSION

Z-100 showed a trend of improvement on OS in locally advanced cervical cancer, although the statistical power was less than anticipated because survival rates were unexpectedly higher than expected for both arms. Validation of potential survival benefit of immune modulation should be made.

TRIAL REGISTRATION

umin.ac.jp/ctr Identifier: C000000221.

Capsular Arabinomannans from Mycobacterium avium with Morphotype-specific Structural Differences but Identical Biological Activity

The capsules of two colony morphotypes of Mycobacterium avium strain 2151 were investigated, i.e. the virulent smooth-transparent (SmT1) and the nonvirulent smooth-opaque (SmO) types. From both morphotypes we separated a nonacylated arabinomannan (AM) from an acylated polysaccharide fraction by affinity chromatography, of which the AMs were structurally characterized. The AMs from the virulent morphotype, in contrast to that from the nonvirulent form, possessed a larger mannan chain and a shorter arabinan chain. Incubation of murine bone marrow-derived macrophages and human dendritic cells showed that the acylated polysaccharide fractions were potent inducers of tumor necrosis factor-alpha, interleukin-12, and interleukin-10 compared with nonacylated AMs, which led to only a marginal cytokine release. Further in vitro experiments showed that both the acylated polysaccharide fractions and the nonacylated AMs were able to induce in vitro anti-tumor cytotoxicity of human peripheral blood mononuclear cells. Thus, morphotype-specific structural differences in the capsular AMs of M. avium do not correlate with biological activity; however, their acylation is a prerequisite for effective stimulation of murine macrophages and human dendritic cells.

Polysaccharide biological response modifiers

Biological response modifiers (BRMs) are substances which augment immune response. BRMs can be cytokines which are produced endogenously in our body by immune cells or derivatives of bacteria, fungi, brown algae, Aloe vera and photosynthetic plants. Such exogeneous derivatives (exogeneous BRMs) can be nucleic acid (CpG), lipid (lipotechoic acid), protein or polysaccharide in nature. The receptors for these exogeneous BRMs are pattern recognition receptors. The binding of exogeneous BRMs to pattern recognition receptors triggers immune response. Exogenous BRMs have been reported to have anti-viral, anti-bacterial, anti-fungal, anti-parasitic, and anti-tumor activities. Among different exogeneous BRMs, polysaccharide BRMs have the widest occurrence in nature. Some polysaccharide BRMs have been tested for their therapeutic properties in human clinical trials. An overview of current understandings of polysaccharide BRMs is summarized in this review.

The Safety and Tolerability of Z-100 in Patients Infected with HIV-1

Z-100 is an extract of the Mycobacterium tuberculosis strain Aoyama B, which contains various polysaccharides. Aoyama B has previously been shown to induce a T helper 1-type cytokine response in various murine oncological models and has also demonstrated inhibitory activity against HIV-1 in vitro. This multicentre study primarily determined the safety of Z-100 in early HIV-1-infected patients who were treatment naive; were treatment experienced, but had elected to discontinue highly active antiretroviral therapy (HAART) 8 weeks or longer before the study; or were stable on their first or second HAART regimen for at least 12 weeks before the study. Thirty-two individuals participated in this study and self-injected either placebo, 20 μg or 40 μg Z-100 twice a week for 8 weeks. Z-100 was well tolerated and the safety profiles of the Z-100 treatment groups were not meaningfully different compared with the placebo group. Plasma levels of HIV-1 RNA were not statistically significantly different in any treatment group at the end of the treatment period. There were no statistically significant differences among the treatment groups in the change from baseline to week 8 for any of the biological endpoints including plasma levels of HIV-1 RNA; CD4+ and CD8+ T-cell counts; levels of macrophage inflammatory protein 1; soluble tumour necrosis factor receptor 1; C-reactive protein; interleukin-6; and granulocyte colony stimulating factor. Consequently, this trial demonstrates the safety of Z-100 in HIV-1 infected patients without evidence of any activity at the doses administered.

The antituberculosis, antitumor, multibranched dodecafuranoarabinan of Mycobacterium species has been assembled from a single n-pentenylfuranoside source

An n-pentenyl furanosyl-1,2-orthoester can function as a donor or be rearranged leading to an n-pentenyl furanoside acceptor which is glycosylated by its progenitor, regioselectively or doubly, thereby enabling rapid fabrication of a multibranched dodecasaccharide, known to possess a wide variety of biological interactions.

Highly Ordered Supra-Molecular Organization of the Mycobacterial Lipoarabinomannans in Solution. Evidence of a Relationship Between Supra-Molecular Organization and Biological Activity

The complex mycobacterial mannosylated lipoarabinomannans (ManLAMs) are currently considered to be the major virulence factors of the pathogenic Mycobacterium tuberculosis. The recognition and the interaction of ManLAMs with immune system receptors have been shown to promote M.tuberculosis phagocytosis but also to down-regulate the bactericidal immune response of the host in favor of the survival of the pathogenic bacilli. To date these original biological activities were mainly associated to the presence of mannose residues capping the non-reducing ends of the ramified polysaccharide moiety of these complex lipoglycans. However, we demonstrated recently that the molecular recognition of ManLAM terminal mannose units by human pulmonary surfactant protein A (hSP-A) carbohydrate recognition domains depends on the presence of the lipid moiety of the ManLAMs as proposed by Sidobre et al. in 2002. Thus, we investigated the putative role of the ManLAM aglycon moiety. The data presented here, indicate that the hydrophobic aglycon part of ManLAM is associated to a characteristic concentration-dependent supra-molecular organization of these complex molecules. Furthermore, we observed that the deacylated ManLAMs or the lipid-free mannosylated arabinomannans, which do not exhibit characteristic ManLAM activities, do not display this supra-molecular organization. These observations strongly suggest that the ManLAMs immunomodulatory activities might be associated to their particular organization. Finally, the determination of the critical micellar concentration of ManLAMs obviously supports the notion that this supra-molecular organization may be responsible for the specific biological activities of these complex molecules.

Z-100, an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis strain Aoyama B, augments anti-tumor activities of X-ray irradiation against B16 melanoma in association with the improvement of type 1T cell responses

In this study, the effects of combination therapy consisting of X-ray irradiation and Z-100 on the survival time of C57BL/6 mice inoculated with B16F10 melanoma were investigated. Survival time was significantly prolonged in B16F10 melanoma-bearing mice treated with the X-ray irradiation (5 Gy) and Z-100 (10 mg/kg s.c.) combination therapy compared with mice irradiated with X-rays alone. The weight of primary tumors and number of metastatic colonies were also significantly suppressed by the combination therapy compared with that in the X-ray irradiation group. These results indicated that Z-100 could enhance the anti-tumor effects of radiotherapy against B16F10 melanoma. On the other hand, the survival time of CD4 knockout mice bearing the same tumors was not prolonged by the combination therapy compared with mice irradiated with X-rays alone, suggesting that CD4+ cells are partly involved in augmentation of the anti-tumor effect of radiotherapy by Z-100. In addition, type 1 cytokine (IL-2, IFN-gamma) production was significantly increased and type 2 cytokine (IL-4, IL-10) production was significantly suppressed in the tumor-bearing mice treated with the combination therapy compared with the X-ray irradiation group. Moreover, interleukin-12 production by CD11c+ cells was also significantly increased in mice treated with the combination therapy compared with the X-ray irradiation group. These results indicate that Z-100 augmented the anti-tumor effects of X-ray irradiation. Moreover, we demonstrated that the effects of Z-100 were expressed at least in part, by the improvement of the T cell responses from type 2-dominant to type 1-dominant via up-regulation of IL-12 production.

Antimetastatic effect of an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis strain Aoyama B, Z-100, through the production of interleukin-12

In this study, the role of interleukin (IL)-12 on the antimetastatic effect of Z-100 was investigated using wild-type C57BL/6 mice or IL-12p40 knockout (IL-12p40 KO) mice inoculated with highly metastatic B16F10 melanoma. When C57BL/6 mice were inoculated with B16F10 melanoma (2x10(5) cells/mouse i.v.), Z-100 (10 mg/kg i.p.) significantly suppressed the pulmonary metastasis of B16F10 melanoma 14 d after tumor inoculation. On the other hand, the antimetastatic effect of Z-100 was not observed in IL-12p40 KO mice inoculated with B16F10 melanoma. These results indicate that IL-12 is essentially required for the appearance of the antimetastatic effect of Z-100. Since helper T (Th) 2 cell responses have been reported to have a role in tumor metastasis, the regulatory effect of Z-100 on the immune balance of Th1/Th2 cell responses was investigated. In both C57BL/6 mice and IL-12p40 KO mice bearing B16F10 melanoma, Th1 cytokine production (IL-2, interferon-gamma) was significantly suppressed as compared with those in normal mice. On the other hand, Th2 cytokine production (IL-4, IL-10) in these mice was increased. The administration of Z-100 (10 mg/kg i.p.) in C57BL/6 mice bearing B16F10 melanoma improved the balance of Th1/Th2 cell responses from the Th2-dominant state to the normal state. However, the improvement of Th1/Th2 cell responses by Z-100 was not observed in IL-12p40 KO mice bearing the same tumors. In addition, Z-100 significantly increased IL-12 production by macrophages in a concentration-dependent manner, while Z-100 significantly decreased IL-10 production by these cells in vitro. These results suggested that up-regulation of IL-12 production and down-regulation of IL-10 production by Z-100 are related to the improvement of Th1/Th2 cell responses from the Th2-dominant state to the normal state, which resulted in suppression of tumor metastasis.