En viktig forskningsrapport från Kina

12 kinesiska forskare har studerat hur immunologi kan fås effektivare vid behandling av cancer.
Alltså att få kroppens eget immunförsvar att eliminera denna eländiga best.Immunterapi som behandlingsform skrevs det en hel del om för ca 1 år sen.De kinesiska forskarna levererar här med sin forskningsrapport viktig information till forskare/läkare inom just immunterapi.Man har konstaterat att kroppens produktion av hormonet melatonin har betydelse i att stärka immunförsvaret och därigenom bättre kunna bekämpa cancertumörer.

Artikeln är ännu ej godkänd,men anses förmodligen så viktig att den ändå offentliggörs men med markeringen att den är under granskning.

Från studien

Melatonin Maintains Macrophage M1 Phenotype to Reverse LPS-stimulated Tumor Immune Tolerance

Posted 29 Jun, 2020

Background: Lipopolysaccharide (LPS) is a potent trigger of macrophage-mediated inflammation and its repeated stimulation results in immune tolerance. This study is to explore the cellular mechanisms of LPS-mediated tumor immune tolerance and to investigate whether melatonin can reverse this tolerance.


Methods: The effect of melatonin and LPS on macrophages was assessed by cell proliferation, morphological changes, phagocytosis and autophagy in vitro. The tumor-preventing effect of melatonin and LPS were evaluated in the urethane-induced lung carcinoma model and in the H22 liver cancer allograft model. Immunofluorescence, immunohistochemistry and ELISA were used to examine protein expression. The related targets and pathways of melatonin were predicted by comprehensive bioinformatics, and the clinical association of bacterial infections and survival was evaluated in cancer patients by meta-analysis.

Results: In vitro，Raw264.7 macrophages were polarized toward the M1 phenotype by single LPS administration but toward the M2 phenotype by repeated LPS administration. Interestingly, combination treatment with repeated LPS and 10 µM melatonin prevented macrophage polarization toward the M2-like phenotype and exerted lasting antitumor efficacy. In the urethane-induced lung carcinoma model, repeated LPS administration stimulated macrophage polarization toward the M2 phenotype and promoted lung carcinogenesis, which was abrogated by macrophage depletion, while melatonin alone or in combination with repeated LPS challenge restored M1-like macrophages and prevented carcinogenesis. In the H22 liver cancer allograft model, melatonin maintained the macrophage phenotype and promoted the tumor-suppressing effect of repeated LPS challenge. Furthermore, we found that macrophages repeatedly stimulated with LPS had a high level of surface lipid rafts that mediated PI3K/AKT and JAK2/STAT3 signaling and prevented both LPS sensitivity and immune response by self-expression of PD-L1 and surface expression of PD-1 receptor on NK cells, whereas melatonin decreased surface lipid rafts and PI3K/AKT and JAK2/STAT3 signaling. Finally, we conducted a comprehensive bioinformatics analysis of melatonin-relevant targets and pathways involved in M2 macrophage polarization and evaluated the clinical associations of bacterial infections and survival in cancer patients.

Conclusions: This study suggests a function of melatonin in regulating macrophage polarization to maintain LPS-stimulated tumor immune surveillance.

Background

Cancer is one of the leading causes of human disease-related death, and much attention regarding cancer treatment has focused on targeting and killing the tumor itself, e.g. radiation, chemotherapy and targeted therapy. Recently, cancer immunotherapy has become one of the most promising therapeutic pillars in improving patient survival. Unlike other cancer treatments, cancer immunotherapy activates the host’s immune system or relieves “immune exhaustion” in the tumor environment to eliminate cancer cells. The 10-year datasets from first-line anti-CTLA4 therapy show an unprecedented long-term survival in 20% of terminal metastatic melanoma patients that had never been seen before with other approaches to cancer treatment, indicating an exciting success in cancer immunotherapy that can provide hope of becoming “super-survivors” to incurable cancer patients. Nevertheless, response rates with the most promising immunotherapy, such as PD-1 inhibitors, which represent immune-checkpoint-blockade(ICB)-mediated rejuvenation of exhausted T cells, only exhibit a modest 20% overall survival benefits in many solid tumors, whereas CAR-T cell therapy was reported to result in cerebral edema and cytokine release storms. In addition, a more recent clinical report showed that PD-1 inhibitors could speed up tumor growth and promote tumor hyperprogression in 9% of cancer patients, indicating a need to optimize cancer immunotherapeutic approaches. Current immunotherapies mainly activate tumor-infiltrating T lymphocytes and natural killer cells without regard to environmental changes that can cause various states of T cell dysfunction, such as anergy, tolerance, exhaustion, and senescence. In fact, antitumor T cell immunotherapies originally exhibited responses but subsequently became resistant during prolonged antigen exposure due to “immune exhaustion” induced by the immunosuppressive microenvironment that is shaped by tumor-associated inflammatory cells. Obviously, effective tumor immune rejection relies not only on antigen exposure-induced adaptive immune responses but also on the innate immune surveillance-regulated microenvironment.
Tumor-infiltrated macrophages (TIMs) are a major inflammatory cell infiltrating the tumor microenvironment and are responsible for the immunosuppressive microenvironment and tumor progression. Recent studies have shown that the inhibition of macrophage-mediated phagocytosis is an essential mechanism for tumor immune evasion. In the clinic, TIMs are positively associated with high tumor grade and poor prognosis in various cancers. In mouse cancer models, TIM depletion or reeducation can reverse their tumor-promoting functions. In addition, some recent reports have shown that innate macrophages also play important roles in the intratumor infiltration of CD8 cytotoxic T cells and the establishment of the long-lived memory lymphocytes. Therefore, targeting TIMs to reawaken innate immunity has emerged as a new cancer immunotherapy strategy. It is well known that activated macrophages are divided into antitumor M1 and protumor M2 phenotypes. LPS can polarize macrophage toward the M1 phenotype, but repeated stimulation results in immune tolerance. Melatonin is a neurohormone secreted by the pineal gland, This study explored the cellular mechanisms of LPS-mediated tumor immune tolerance and investigated whether melatonin can reverse this tolerance. Our results are the first to indicated a vital role of macrophage polarization in LPS tolerance and also suggests a new mechanism by which bacterial infections increase the risk of carcinogenesis.

Materials and Methods (urval)

Cell Culture and Assay
For proliferation analysis, LLC cells at 1 × 10⁵ cells/mL were seeded in a 96-well plate and treated with M1 or M2 cell-conditioned media for 48 h, M1-like or M2-like cells were also treated with LPS or melatonin alone or in combination for 7 d (changing the medium every 2 days), and living cells were examined by MTT reduction assay, according to our previous method. For the morphological assessment, the cells were analyzed by a Laser holographic cell imaging and analysis system (HoloMonitor M4, Phiab, Sweden).

Figure 1. There is a difference between M1-like and M2-like neutrophils. M1-like and M2-like macrophages were induced respectively by LPS and IL-10 from Raw264.7 macrophages. (A) and (B) Macrophages CD86 and CD163 expression was analysed by FITC-conjugated anti-mouse CD86 and CD163 staining (n=5, 40×). (C) Macrophages phagocytosis detected by neutral red (n=5, 40×). (D) and (E) Macrophages morphological changes analysed by laser holographic cell imaging and analysis system (n=5, 20×).(F) ROS detected by DCFH-DA (n=5). (G) Supernatant cytokine levels in cell culture (n=5). (H) Cell autophagy as indicated by LC3-B and P62 staining (n=5, 40×). The data present Mean ± SD, the experiments were repeated 3 times, and statistical significance was determined by a t-test. *P < 0.05, **P < 0.01 . Mel:Melatonin.

 
Min kommentar
De kinesiska forskarna har troligtvis levererat en av årets viktigaste studier kring immunterapi.
Att den kommer få genomslag och uppmärksammas världen över torde ingen behöva tvivla om.
Att dess resultat tillkommit med assistans av PHI`s excellenta HoloMonitor gör undertecknad extra glad å alla cancerdrabbades vägar (och stolt såklart).Som bloggen brukar uttrycka: Utrusta världens alla cancerforskare med varsin HoloMonitor så vi snabbare får stopp på denna best.

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