Myeloid cells comprise a major component of the tumor microenvironment (TME) that promotes tumor growth and immune evasion. By employing a small-molecule inhibitor of glutamine metabolism, not only were we able to inhibit tumor growth, but we markedly inhibited the generation and recruitment of myeloid-derived suppressor cells (MDSCs). Targeting tumor glutamine metabolism led to a decrease in CSF3 and hence recruitment of MDSCs as well as immunogenic cell death, leading to an increase in inflammatory tumor-associated macrophages (TAMs). Alternatively, inhibiting glutamine metabolism of the MDSCs themselves led to activation-induced cell death and conversion of MDSCs to inflammatory macrophages. Surprisingly, blocking glutamine metabolism also inhibited IDO expression of both the tumor and myeloid-derived cells, leading to a marked decrease in kynurenine levels. This in turn inhibited the development of metastasis and further enhanced antitumor immunity. Indeed, targeting glutamine metabolism rendered checkpoint blockade-resistant tumors susceptible to immunotherapy. Overall, our studies define an intimate interplay between the unique metabolism of tumors and the metabolism of suppressive immune cells.

• MeSH
• buněčná imunita * MeSH
• experimentální nádory imunologie   patologie   terapie   MeSH
• glutamin imunologie   MeSH
• imunoterapie MeSH
• makrofágy imunologie   patologie   MeSH
• myeloidní supresorové buňky imunologie   patologie   MeSH
• myši inbrední BALB C MeSH
• myši knockoutované MeSH
• myši MeSH
• nádorové mikroprostředí imunologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Programmed cell death protein 1 (PD-1)/PD-1 ligand 1 (PD-L1) blockade is a promising therapy for various cancer types, but most patients are still resistant. Therefore, a larger number of predictive biomarkers is necessary. In this study, we assessed whether a loss-of-function mutation of the interferon (IFN)-γ receptor 1 (IFNGR1) in tumor cells can interfere with anti-PD-L1 therapy. For this purpose, we used the mouse oncogenic TC-1 cell line expressing PD-L1 and major histocompatibility complex class I (MHC-I) molecules and its TC-1/A9 clone with reversibly downregulated PD-L1 and MHC-I expression. Using the CRISPR/Cas9 system, we generated cells with deactivated IFNGR1 (TC-1/dIfngr1 and TC-1/A9/dIfngr1). In tumors, IFNGR1 deactivation did not lead to PD-L1 or MHC-I reduction on tumor cells. From potential inducers, mainly IFN-α and IFN-β enhanced PD-L1 and MHC-I expression on TC-1/dIfngr1 and TC-1/A9/dIfngr1 cells in vitro. Neutralization of the IFN-α/IFN-β receptor confirmed the effect of these cytokines in vivo. Combined immunotherapy with PD-L1 blockade and DNA vaccination showed that IFNGR1 deactivation did not reduce tumor sensitivity to anti-PD-L1. Thus, the impairment of IFN-γ signaling may not be sufficient for PD-L1 and MHC-I reduction on tumor cells and resistance to PD-L1 blockade, and thus should not be used as a single predictive marker for anti-PD-1/PD-L1 cancer therapy.

• MeSH
• antigeny CD274 antagonisté a inhibitory   MeSH
• antigeny CD279 antagonisté a inhibitory   MeSH
• experimentální nádory farmakoterapie   imunologie   metabolismus   patologie   MeSH
• imunoterapie MeSH
• interferon gama antagonisté a inhibitory   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buňky kultivované MeSH
• protinádorové látky imunologicky aktivní farmakologie   MeSH
• transformované buněčné linie účinky léků   imunologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Using a porcine model, we describe Melanoma-Associated CD4+CD8hi T-lymphocytes (MATL) in peripheral blood that increase during melanoma regression. These MATL possess the CD4+CD8hi phenotype and they have their direct counterparts in Tumor Infiltrating Lymphocytes (TIL) isolated from melanoma loci. Both MATL and CD4+CD8hi TIL have a similar expression of selected markers indicating that they represent effector/memory αβ T-cell subset. Moreover, although TIL also contain CD4-CD8+ T-cells, only CD4+CD8hi TIL expand during melanoma regression. Importantly, TIL isolated from different pigs and different melanoma loci among the same pig have similar composition of CD4/CD8 subsets, indicating that the composition of the MATL and TIL compartment is identical. Analysis of sorted cells from regressing pigs revealed a unique MATL subpopulation with mono-specific T-cell receptor that was further analyzed by sequencing. These results indicate that pigs regressing melanomas possess a characteristic population of recirculating T-cells playing a role in tumor control and regression.

• MeSH
• antigeny CD4 metabolismus   MeSH
• antigeny CD8 metabolismus   MeSH
• cytotoxicita imunologická MeSH
• experimentální nádory imunologie   MeSH
• imunofenotypizace MeSH
• kultivované buňky MeSH
• lidé MeSH
• melanom imunologie   MeSH
• modely nemocí na zvířatech MeSH
• prasata imunologie   MeSH
• receptory antigenů T-buněk alfa-beta metabolismus   MeSH
• spontánní regrese nádoru MeSH
• T-lymfocyty imunologie   MeSH
• tumor infiltrující lymfocyty imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

To elucidate the immunological mechanisms critical for tumor progression, we bred novel mouse strains, different in the NKC and H-2D domains. We used inbreeding to generate hybrids of Balb/c and C57BL/6 of stable H-2Db+d-NK1.1neg and H-2Db-d+NK1.1high phenotypes. We analyzed the growth of three established MHC class I-deficient tumor cell lines: TC-1/A9 tumor (HPV-associated) and B16F10 melanoma, both syngeneic to C57BL/6, and the MCB8 (3-methycholanthrene-induced tumor) syngeneic to Balb/c. Furthermore, we induced colorectal carcinoma by azoxymethane-DSS treatment to test the susceptibility to chemically-induced primary cancer. We found that the novel strains spontaneously regressed the tumor transplants syngeneic to both Balb/c (MCB8) and C57BL/6 (B16F10 and TC-1/A9) mice. The H2-Db+d-NK1.1neg, but not the H2-Db-d+NK1.1high strain was also highly resistant to chemically-induced colorectal cancer in comparison to the parental mice. The immune changes during TC-1/A9 cancer development involved an increase of the NK cell distribution in the peripheral blood and spleen along with higher expression of NKG2D activation antigen; this was in correlation with the time-dependent rise of cytotoxic activity in comparison to C57BL/6 mice. The TC-1/A9 cancer regression was accompanied by higher proportion of B cells in the spleen and B220+/CD86+ activated antigen-presenting B cells distributed in the lymphoid organs, as well as in the periphery. The changes in the T-cell population were represented mainly by the prevalence of T helper cells reflected by grown CD4/CD8 ratio, most prominent in the b+d-NK1.1neg strain. The results of the present study imply usefulness of the two novel mouse strains as an experimental model for further studies of tumor resistance mechanisms.

• MeSH
• buňky NK imunologie   patologie   MeSH
• experimentální nádory genetika   imunologie   patologie   MeSH
• histokompatibilita - antigeny třídy I genetika   imunologie   MeSH
• lektinové receptory NK-buněk - podrodina K biosyntéza   imunologie   MeSH
• lidé MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• regulace genové exprese u nádorů genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Caloric restriction mimetics (CRMs) mimic the biochemical effects of nutrient deprivation by reducing lysine acetylation of cellular proteins, thus triggering autophagy. Treatment with the CRM hydroxycitrate, an inhibitor of ATP citrate lyase, induced the depletion of regulatory T cells (which dampen anticancer immunity) from autophagy-competent, but not autophagy-deficient, mutant KRAS-induced lung cancers in mice, thereby improving anticancer immunosurveillance and reducing tumor mass. Short-term fasting or treatment with several chemically unrelated autophagy-inducing CRMs, including hydroxycitrate and spermidine, improved the inhibition of tumor growth by chemotherapy in vivo. This effect was only observed for autophagy-competent tumors, depended on the presence of T lymphocytes, and was accompanied by the depletion of regulatory T cells from the tumor bed.

• MeSH
• Atg5 genetika   MeSH
• autofagie MeSH
• citráty aplikace a dávkování   farmakologie   MeSH
• experimentální nádory dietoterapie   farmakoterapie   imunologie   MeSH
• kalorická restrikce metody   MeSH
• lidé MeSH
• methotrexát aplikace a dávkování   farmakologie   MeSH
• monitorování imunologické MeSH
• mutace MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protoonkogenní proteiny p21(ras) genetika   MeSH
• regulační T-lymfocyty účinky léků   MeSH
• spermidin aplikace a dávkování   farmakologie   MeSH
• transplantace nádorů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Development of DNA vaccines against transcription factors SOX2 and NANOG that are necessary for self-renewal of cancer stem cells in various human tumors. Enhancement of immunogenicity of these vaccines by the addition of cell localization signals and sequences from the tetanus toxin that encode strong helper epitopes activating Th cells. Analysis of the effect of xenogeneic genes on vaccine efficacy. Reduction of potential oncogenicity of SOX2 and NANOG by the mutagenesis of nuclear localization signals and by the removal of their initiation codons in fusion genes. Detection of immune responses induced with the constructed DNA vaccines by in vitro tests and by observation of an anti-tumor effect of the vaccines in mouse tumor models using embryonal carcinoma cell lines.

Vývoj DNA vakcín proti transkripčním faktorům SOX2 a NANOG, které jsou nezbytné pro sebeobnovu nádorových kmenových buněk u různých typů lidských nádorů. Zvýšení imunogennosti těchto vakcín přidáním buněčných lokalizačních signálů a sekvencí z genu tetanového toxinu kódujících silné pomocné epitopy aktivující buňky Th. Analýza vlivu xenogenních genů na imunogennost vakcín. Snížení potenciální onkogennosti SOX2 a NANOG mutagenezí jaderných lokalizačních signálů a odstraněním jejich iniciačních kodonů u fúzních genů. Stanovení imunitních reakcí vyvolaných připravenými DNA vakcínami testy in vitro a sledováním protinádorového účinku na myších nádorových modelech s použitím buněčných linií získaných z embryonálních karcinomů.

• MeSH
• antigeny heterofilní MeSH
• DNA vakcíny MeSH
• embryonální karcinom MeSH
• epitopy T-lymfocytární MeSH
• experimentální nádory imunologie   MeSH
• imunogenetika MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• oktamerní transkripční faktory MeSH
• proteiny - lokalizační signály MeSH
• terapeutická ekvivalence MeSH
• transkripční faktory SOXB2 MeSH
• Check Tag
• myši MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• hematologie a transfuzní lékařství
• onkologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR

The asparaginyl endopeptidase legumain that is overexpressed in M2-polarized tumor-associated macrophages has been identified as a suitable target for elimination of these cells supporting tumor progression. To enhance the efficacy of DNA immunization against legumain, we performed several modifications in this protein that could improve induction of immune responses. First, we mutated the RGD motif into GGD or RGG sequences. This alteration resulted in diminished maturation of legumain and impaired cellular localization. Then, as tolerance to self-antigens can be broken by the activation of CD4 T-cell help, we tried to enhance the immunogenicity of legumain by the insertion of a foreign helper epitope, namely the p30 epitope from the tetanus toxin. Finally, the 2 modifications were combined. After gene gun DNA immunization of C57BL/6 mice with these constructs, we identified the Lgmn111-119 CD8 T-cell epitope that binds to H-2D molecules. Furthermore, we showed that mutagenesis in the RGD motif significantly enhanced the immune response against legumain. The addition of the p30 helper epitope induced the specific production of IFN-γ by T cells, but did not significantly increase legumain-specific immunity activated after mutagenesis in the RGD motif which might be caused by simultaneous activation of a Th2 response demonstrated by the production of IL-4. However, the beneficial effect of the helper epitope on legumain-specific response was proved after the depletion of regulatory T cells by antibody against CD25 that preferentially stimulated Th1 immunity. The antitumor effect of the modified legumain gene was shown in the immunization against tumors induced by MK16 cells.

• MeSH
• aminokyselinové motivy genetika   MeSH
• biolistika MeSH
• buňky NIH 3T3 MeSH
• CD8-pozitivní T-lymfocyty imunologie   MeSH
• cysteinové endopeptidasy genetika   metabolismus   MeSH
• DNA vakcíny * MeSH
• epitopy T-lymfocytární genetika   metabolismus   MeSH
• experimentální nádory imunologie   terapie   MeSH
• HEK293 buňky MeSH
• imunoterapie metody   MeSH
• interferon gama metabolismus   MeSH
• lidé MeSH
• makrofágy imunologie   MeSH
• mutace genetika   MeSH
• mutageneze cílená MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové biomarkery genetika   metabolismus   MeSH
• peptidové fragmenty genetika   metabolismus   MeSH
• protinádorové vakcíny * MeSH
• T-lymfocyty pomocné-indukující imunologie   MeSH
• tetanový toxin genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Recognition of glycosylation patterns is one of the basic features of innate immunity. Ability of C-type lectin-like receptors such as NKR-P1 to bind saccharide moieties has become recently a controversial issue. In the present study, binding assay with soluble fluorescently labeled recombinant rat NKR-P1A and mouse NKR-P1C proteins revealed apparently no affinity to the various neoglycoproteins. Lack of functional linkage between NKR-P1 and previously described saccharide binder was supported by the fact, that synthetic N-acetyl-D-glucosamine octabranched dendrimer on polyamidoamine scaffold (GN8P) did not change gene expression of NKR-P1 isoforms in C57BL/6 and BALB/c mice divergent in the NK gene complex (both in vitro and in vivo). Surprisingly, N-acetyl-D-glucosamine-coated tetrabranched polyamido-amine dendrimer specifically binds to NKT cells and macrophages but not to NK cells (consistently with changes in cytokine patterns). Despite the fact that GN8P has been tested as an immunomodulator in anti-cancer treatment animal models for many years, surprisingly no changes in cytokine profiles in serum relevant to anti-cancer responses using B16F10 and CT26 harboring mouse strains C57BL/6 and BALB/c are observed. Our results indicate possible indirect involvement of NK cells in GN8P mediated immune responses.

• MeSH
• acetylglukosamin imunologie   metabolismus   MeSH
• buňky NK imunologie   metabolismus   MeSH
• dendrimery metabolismus   MeSH
• experimentální nádory farmakoterapie   genetika   imunologie   MeSH
• exprese genu účinky léků   imunologie   MeSH
• glykokonjugáty imunologie   metabolismus   farmakologie   MeSH
• interferon gama krev   genetika   imunologie   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• lektinové receptory NK-buněk - podrodina B genetika   imunologie   metabolismus   MeSH
• lektiny typu C genetika   imunologie   metabolismus   MeSH
• makrofágy imunologie   metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• NKT buňky imunologie   metabolismus   MeSH
• oligosacharidy imunologie   metabolismus   MeSH
• polyaminy imunologie   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protein - isoformy genetika   imunologie   metabolismus   MeSH
• průtoková cytometrie MeSH
• slezina cytologie   imunologie   metabolismus   MeSH
• TNF-alfa krev   genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs) and CD1d-restricted invariant natural killer T (iNKT) cells are two cell types that are known to regulate immune reactions. Depletion or inactivation of Tregs using specific anti-CD25 antibodies in combination with immunostimulation is an attractive modality especially in anti-tumour immunotherapy. However, CD25 is not expressed exclusively on Tregs but also on subpopulations of activated lymphocytes. Therefore, the modulatory effects of the specific anti-CD25 antibodies can also be partially attributed to their interactions with the effector cells. Here, the effector functions of iNKT cells were analysed in combination with anti-CD25 mAb PC61. Upon PC61 administration, α-galactosylceramide (α-GalCer)-mediated activation of iNKT cells resulted in decreased IFN-γ but not IL-4 production. In order to determine whether mutual interactions between Tregs and iNKT cells take place, we compared IFNγ production after α-GalCer administration in anti-CD25-treated and "depletion of regulatory T cell" (DEREG) mice. Since no profound effects on IFNγ induction were observed in DEREG mice, deficient in FoxP3(+) Tregs, our results indicate that the anti-CD25 antibody acts directly on CD25(+) effector cells. In vivo experiments demonstrated that although both α-GalCer and PC61 administration inhibited TC-1 tumour growth in mice, no additive/synergic effects were observed when these substances were used in combination therapy.

• MeSH
• antigeny CD1d imunologie   metabolismus   MeSH
• ELISA MeSH
• experimentální nádory farmakoterapie   imunologie   patologie   MeSH
• exprese genu účinky léků   imunologie   MeSH
• forkhead transkripční faktory imunologie   metabolismus   MeSH
• galaktosylceramidy aplikace a dávkování   imunologie   farmakologie   MeSH
• interferon gama genetika   imunologie   metabolismus   MeSH
• interleukin-4 genetika   imunologie   metabolismus   MeSH
• Kaplanův-Meierův odhad MeSH
• mezibuněčné signální peptidy a proteiny genetika   imunologie   metabolismus   MeSH
• monoklonální protilátky aplikace a dávkování   imunologie   farmakologie   MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• NKT buňky účinky léků   imunologie   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protokoly antitumorózní kombinované chemoterapie terapeutické užití   MeSH
• průtoková cytometrie MeSH
• receptor interleukinu-2 - alfa-podjednotka imunologie   metabolismus   MeSH
• regulační T-lymfocyty účinky léků   imunologie   metabolismus   MeSH
• tumor burden účinky léků   imunologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Myeloid-derived suppressor cells (MDSC) play an important role in tumor escape from antitumor immunity. MDSC accumulate in the lymphoid organs and blood during tumor growth and their mobilization was also reported after cyclophosphamide (CY) administration. In this communication, spleen MDSC accumulating after CY therapy (CY-MDSC) were compared with those expanded in mice bearing human papilloma viruses 16-associated TC-1 carcinoma (TU-MDSC). Although both CY-MDSC and TU-MDSC accelerated growth of TC-1 tumors in vivo, their phenotype and immunosuppressive function differed. CY-MDSC consisted of higher percentage of monocyte-like subpopulation and this was accompanied by lower relative expression of immunosuppressive genes and lower suppression of T-cell proliferation. After interferon-γ stimulation, the expression of immunosuppressive genes increased, but the suppressive ability of CY-MDSC did not reach that of TU-MDSC. The phenotype and function of MDSC obtained from mice bearing TC-1 tumors treated with CY was, in general, found to lie between CY-MDSC and TU-MDSC. After in vitro cultivation of MDSC in the presence of interleukin 12 (IL-12), the percentage of CD11b+/Gr-1+ cells decreased and was accompanied by an increase in the percentage of CD86+/MHCII+ cells. The strongest modulatory effect was noticed in the group of CY-MDSC. The susceptibility of CY-MDSC to all-trans-retinoic acid (ATRA) was also evaluated. In vitro cultivation with ATRA resulted in MDSC differentiation, and ATRA inhibited MDSC accumulation induced by CY administration. Our findings identified differences between CY-MDSC and TU-MDSC and supported the rationale for utilization of ATRA or IL-12 to alter MDSC accumulation after CY chemotherapy with the aim to improve its antitumor effect.

• MeSH
• aktivace lymfocytů MeSH
• antigeny CD11b biosyntéza   imunologie   MeSH
• antigeny CD86 biosyntéza   imunologie   MeSH
• antitumorózní látky farmakologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• cyklofosfamid farmakologie   MeSH
• experimentální nádory imunologie   patologie   virologie   MeSH
• interferon gama farmakologie   MeSH
• interleukin-12 farmakologie   MeSH
• lidé MeSH
• lidský papilomavirus 16 imunologie   MeSH
• myeloidní buňky účinky léků   imunologie   patologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• regulace genové exprese u nádorů MeSH
• slezina účinky léků   imunologie   patologie   MeSH
• T-lymfocyty účinky léků   imunologie   patologie   MeSH
• transplantace nádorů MeSH
• tretinoin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH