An activation to memory differentiation trajectory of tumor-infiltrating lymphocytes informs metastatic melanoma outcomes

There is a need for better classification and understanding of tumor-infiltrating lymphocytes (TILs). Here, we applied advanced functional genomics to interrogate 9,000 human tumors and multiple single-cell sequencing sets using benchmarked T cell states, comprehensive T cell differentiation trajectories, human and mouse vaccine responses, and other human TILs. Compared with other T cell states, enrichment of T memory/resident memory programs was observed across solid tumors. Trajectory analysis of single-cell melanoma CD8+ TILs also identified a high fraction of memory/resident memory-scoring TILs in anti-PD-1 responders, which expanded post therapy. In contrast, TILs scoring highly for early T cell activation, but not exhaustion, associated with non-response. Late/persistent, but not early activation signatures, prognosticate melanoma survival, and co-express with dendritic cell and IFN-γ response programs. These data identify an activation-like state associated to poor response and suggest successful memory conversion, above resuscitation of exhaustion, is an under-appreciated aspect of successful anti-tumoral immunity.

IFNγ-Dependent Tissue-Immune Homeostasis Is Co-opted in the Tumor Microenvironment

Homeostatic programs balance immune protection and self-tolerance. Such mechanisms likely impact autoimmunity and tumor formation, respectively. How homeostasis is maintained and impacts tumor surveillance is unknown. Here, we find that different immune mononuclear phagocytes share a conserved steady-state program during differentiation and entry into healthy tissue. IFNγ is necessary and sufficient to induce this program, revealing a key instructive role. Remarkably, homeostatic and IFNγ-dependent programs enrich across primary human tumors, including melanoma, and stratify survival. Single-cell RNA sequencing (RNA-seq) reveals enrichment of homeostatic modules in monocytes and DCs from human metastatic melanoma. Suppressor-of-cytokine-2 (SOCS2) protein, a conserved program transcript, is expressed by mononuclear phagocytes infiltrating primary melanoma and is induced by IFNγ. SOCS2 limits adaptive anti-tumoral immunity and DC-based priming of T cells in vivo, indicating a critical regulatory role. These findings link immune homeostasis to key determinants of anti-tumoral immunity and escape, revealing co-opting of tissue-specific immune development in the tumor microenvironment.

The origin of DCs and capacity for immunologic tolerance in central and peripheral tissues

Dendritic cells (DCs) are specialized immune sentinels that play key role in maintaining immune homeostasis by efficiently regulating the delicate balance between protective immunity and tolerance to self. Although DCs respond to maturation signals present in the surrounding milieu, multiple layers of suppression also co-exist that reduce the infringement of tolerance against self-antigens. These tolerance inducing properties of DCs are governed by their origin and a range of other factors including distribution, cytokines, growth factors, and transcriptional programing, that collectively impart suppressive functions to these cells. DCs directing tolerance secrete anti-inflammatory cytokines and induce naïve T cells or B cells to differentiate into regulatory T cells (Tregs) or B cells. In this review, we provide a detailed outlook on the molecular mechanisms that induce functional specialization to govern central or peripheral tolerance. The tolerance-inducing nature of DCs can be exploited to overcome autoimmunity and rejection in graft transplantation.

Nano-Bio Engineered Carbon Dot-Peptide Functionalized Water Dispersible Hyperbranched Polyurethane for Bone Tissue Regeneration

The present study delves into a combined bio-nano-macromolecular approach for bone tissue engineering. This approach relies on the properties of an ideal scaffold material imbued with all the chemical premises required for fostering cellular growth and differentiation. A tannic acid based water dispersible hyperbranched polyurethane is fabricated with bio-nanohybrids of carbon dot and four different peptides (viz. SVVYGLR, PRGDSGYRGDS, IPP, and CGGKVGKACCVPTKLSPISVLYK) to impart target specific in vivo bone healing ability. This polymeric bio-nanocomposite is blended with 10 wt% of gelatin and examined as a non-invasive delivery vehicle. In vitro assessment of the developed polymeric system reveals good osteoblast adhesion, proliferation, and differentiation. Aided by this panel of peptides, the polymeric bio-nanocomposite exhibits in vivo ectopic bone formation ability. The study on in vivo mineralization and vascularization reveals the occurrence of calcification and blood vessel formation. Thus, the study demonstrates carbon dot/peptide functionalized hyperbranched polyurethane gel for bone tissue engineering application.

Molecular Mechanisms Associated With Particulate and Soluble Heteroglycan Mediated Immune Response

Immune responses are outcomes of complex molecular machinery which occur inside the cells. Unravelling the cellular mechanisms induced by immune stimulating molecules such as glycans and determining their structure-function relationship are therefore important factors to be assessed. With this viewpoint, the present study identifies the functional receptor binding unit of a well characterized heteroglycan and also delineates the cellular and molecular processes that are induced upon heteroglycan binding to specific cell surface receptors in immune cells. The heteroglycan was acid hydrolysed and it was revealed that 10-30 kDa fractions served as the functional receptor binding unit of the molecule. Increasing the size of 10-30 kDa heteroglycan showed prominent immune activity. The whole soluble heteroglycan was also conjugated with hyperbranched dendrimers so as to generate a particulate form of the molecule. Dectin-1 and TLR2 were identified as the major receptors in macrophages that bind to particulate as well as soluble form of the heteroglycan and subsequently caused downstream signaling molecules such as NF-κβ and MAPK to get activated. High levels of 1L-1β and IL-10 mRNA were observed in particulate heteroglycan treated macrophages, signifying that increasing the size and availability of the heteroglycan to its specific receptors is pertinent to its biological functioning. Upregulated expression of PKC and iNOS were also noted in particulate heteroglycan treated RAW 264.7 cells than the soluble forms. Taken together, our results indicate that biological functions of immunomodulatory heteroglycan are dependent on their size and molecular weight. J. Cell. Biochem. 117: 1580-1593, 2016. © 2015 Wiley Periodicals, Inc.

Immune augmentation and Dalton's Lymphoma tumor inhibition by glucans/glycans isolated from the mycelia and fruit body of Pleurotus ostreatus

With the increase in cancer progression, alternatives in the medicinal field with minimal side effects need to be ascertained. In this context, for the first time novel glucans/glycans isolated from the mycelia and fruit body of Pleurotus ostreatus have been compared for their exquisite property as immunoceuticals. Glucans from both the sources displayed immunological functions which include lymphocyte proliferation, macrophage activation (nitric oxide production, ROS generation, phagocytosis, TNF-α production) as well as macrophage and NK cell mediated cytotoxicity. In vivo studies with Dalton's Lymphoma mice tumor model further enumerated the immune enhancing and tumor regression potential of the two glucan molecules. Highest tumor inhibition of about 75% and 71.4% were observed at 20mg/kg of mycelia and fruit body glucan/glycan treatments. A concomitant increase in the survival period of glucan treated tumor bearing mice was found to be primarily associated with immune boosting and apoptosis of cancerous cells. Both the glucan molecules exhibited similar degree of immune response at the systemic level with only subtle amount of differences in two dimensional in vitro cultures. Efficacy of glucans/glycans as immunomodulators may thereby provide decisive leads in strengthening the immune system along with other therapies.

AMPK-mediated crosstalk of heteroglycan-induced reactive species and autophagic cascade in RAW 264.7 cells

AMPK mediates the crosstalk among heteroglycan-induced autophagy and reactive species in RAW 264.7 cells.

Biochemical analysis and antitumour effect of Abrus precatorius agglutinin derived peptides in Ehrlich's ascites and B16 melanoma mice tumour model

Anticancer and immunostimulatory properties of tryptic digest peptides of Abrus precatorius agglutinin protein (10kDAGP) have already been reported. Here attempt has been made to further validate anticancer properties of 10kDAGP peptides in Ehrlich's ascites carcinoma (EAC) and B16 melanoma (B16M) bearing mice models and to analyze 10kDAGP by anion exchange chromatography and RP-HPLC for obtaining the bioactive fraction from the total peptide pool. 10kDAGP treatment decreased the tumour pack volume by ∼82% for EAC and 58.8% for B16M. It also showed increase in ex vivo proliferation of splenocyte and thymocyte isolated from tumour bearing mice and increase in TNF-α and Interferon-γ in splenocyte culture supernatant. From chromatographic analysis it was found that anionic peptide fraction may be responsible for anti-proliferative activities of 10kDAGP. As most anticancer peptides are cationic in nature, further studies regarding bioactivity of anionic peptide fraction may lead to novel anticancer peptides and pathways of action.

Heteroglucan-dendrimer glycoconjugate: a modulated construct with augmented immune responses and signaling phenomena

BACKGROUND

Newer strategies for augmenting immune responses of pharmacologically active glucans may serve to improve the medicinal potential of these biomolecules. With this aim, the present work was focused on generating targeted high molecular size glucan particles with magnified immune response activity.

METHODS

Heteroglucans were conjugated with PAMAM dendrimers using a Schiff base reductive amination reaction to generate a polytethered molecule with multiple glucan motifs. The modulated construct was characterized by FTIR, TEM, (1)H NMR and dynamic light scattering (DLS) methods. Effects of conjugated glucans were examined in RAW 264.7 macrophage cells as well as in S-180 murine tumor models.

RESULTS

Dendrimer-conjugated glucans were found to exhibit a two-fold increase in immune stimulation in comparison to unconjugated glucans. This may be corroborated by the predominant enhancement in immunological functions such as nitric oxide production, ROS generation and immune directed tumor inhibition in murine models. Immune cell surface markers (CD4, CD8, CD19, MHC-II) and cytokine levels were also found to be highly up-regulated in the splenocytes of mice subjected to particulate glucan administration. Our study also demonstrated that conjugated glucan treatment to RAW 264.7 cells strongly enhanced the phosphorylation of two downstream signalling molecules of the mitogen activated protein kinase (MAPKs) family: p38 and MEK1/2 relative to single glucans thereby relating molecular mechanisms with enhanced immune stimulation.

CONCLUSIONS AND GENERAL SIGNIFICANCE

The results obtained thus support that particulate format of soluble heteroglucan will thereby improve its functionality and identify leads in therapeutic competence.

Thermal and pH responsive polymer-tethered multifunctional magnetic nanoparticles for targeted delivery of anticancer drug

Targeted and efficient delivery of therapeutics to tumor cells is one of the key issues in cancer therapy. In the present work, we report a temperature and pH dual responsive core-shell nanoparticles comprising smart polymer shell coated on magnetic nanoparticles as an anticancer drug carrier and cancer cell-specific targeting agent. Magnetite nanoparticles (MNPs), prepared by a simple coprecipitation method, was surface modified by introducing amine groups using 3-aminopropyltriethoxysilane. Dual-responsive poly(N-isopropylacrylamide)-block-poly(acrylic acid) copolymer, synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, was then attached to the amine-functionalized MNPs via EDC/NHS method. Further, to accomplish cancer-specific targeting properties, folic acid was tethered to the surface of the nanoparticles. Thereafter, rhodamine B isothiocyanate was conjugated to endow fluorescent property to the MNPs required for cellular imaging applications. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), zeta potential, vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS) measurements, and FTIR, UV-vis spectral analysis. Doxorubicin (DOX), an anticancer drug used for the present study, was loaded into the nanoparticles and its release behavior was subsequently studied. Result showed a sustained release of DOX preferentially at the desired lysosomal pH and temperature condition. The biological activity of the DOX-loaded MNPs was studied by MTT assay, fluorescence microscopy, and apoptosis. Intracellular-uptake studies revealed preferential uptake of these nanoparticles into cancer cells (HeLa cells) compared to normal fibroblast cells (L929 cells). The in vitro apoptosis study revealed that the DOX-loaded nanoparticles caused significant death to the HeLa cells. These nanoparticles were capable of target specific release of the loaded drug in response to pH and temperature and hence may serve as a potential drug carrier for in vivo applications.

Characterization and lectin microarray of an immunomodulatory heteroglucan from Pleurotus ostreatus mycelia

Glucans isolated from various mushroom and mycelia sources are interestingly being studied nowadays as a potent therapeutic agent. The present work was focused on the isolation, characterization and immunomodulatory study of a novel water soluble glucan from the pure mycelia of Pleurotus ostreatus. The extracted glucan was found to have a high molecular weight of ∼2.7 × 10(6)Da and mainly comprised of glucose, mannose and fucose in a ratio of 3:2:1 with both β and α linkages. Presence of terminal or interior glucose, mannose and fucose residues was also revealed using a high throughput miniaturized platform of lectin microarray. The heteroglucan folded into a triple helical conformation and exhibited enhanced immune cell activation and anti-tumor potential in tumor bearing mice model. Thus, potential biological functions incorporated in these glucan molecules acts in accord with its structural property and exploration of such structure-function relationship will unveil its diverse mechanism of action.

Structural elucidation of a biologically active heteroglycan isolated from a hybrid mushroom of Pleurotus florida and Lentinula edodes

A water soluble heteroglycan isolated from hot aqueous extract of fruit bodies of an edible hybrid mushroom Pfle1r of Pleurotus florida and Lentinula edodes consists of d-glucose, d-mannose, and d-galactose residues in a molar ratio of nearly 1:1:1. This polysaccharide showed macrophage, splenocyte, and thymocyte activation. On the basis of sugar hydrolysis, methylation, periodate oxidation study, and NMR studies (1H, 13C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as: -->6)-α-D-Galp-(1-->6)-α-D-Glcp-(1-->2<--1β-D-Manp.