Janus kinase 3-deficient T lymphocytes have an intrinsic defect in CCR7-mediated homing to peripheral lymphoid organs

Self-Cooperative Prodrug Nanovesicles Migrate Immune Evasion to Potentiate Chemoradiotherapy in Head and Neck Cancer

Chemoradiotherapy is the standard of care for the clinical treatment of locally advanced head and neck cancers. However, the combination of ion radiation with free chemotherapeutics yields unsatisfactory therapeutic output and severe side effects due to the nonspecific biodistribution of the anticancer drugs. Herein, a self-cooperative prodrug nanovesicle is reported for highly tumor-specific chemoradiotherapy. The nanovesicles integrating a prodrug of oxaliplatin (OXA) can passively accumulate at the tumor site and penetrate deep into the tumor mass via matrix metalloproteinase 2-mediated cleavage of the polyethylene glycol corona. The OXA prodrug can be restored inside the tumor cells with endogenous glutathione to trigger immunogenic cell death (ICD) of the tumor cells and sensitize the tumor to ion radiation. The nanovesicles can be further loaded with the JAK inhibitor ruxolitinib to abolish chemoradiotherapy-induced programmed death ligand 1 (PD-L1) upregulation on the surface of the tumor cells, thereby prompting chemoradiotherapy-induced immunotherapy by blocking the interferon gamma-Janus kinase-signal transducer and activator of transcription axis. The prodrug nanoplatform reported herein might present a novel strategy to cooperatively enhance chemoradiotherapy of head and cancer and overcome PD-L1-dependent immune evasion.

Nanoadjuvants Actively targeting lymph node conduits and blocking tumor invasion in lymphatic vessels

Great efforts have been made to manipulate nanoparticles (NPs) with a diameter of 10-100 nm to passively target lymph nodes (LNs) to magnitude anti-tumor activity of T cells. However, no attention has been paid to increasing the retention of NPs with active affinity in order to induce a prolonged release of antigens or molecular adjuvants in the LNs mattering the immune response. Here, we formulated two NPs encapsulated with imiquimod (IMQ), a TLR7/8 agonist, and paclitaxel (PTX) and further modified them with tannic acid (TA), respectively, to generate IMQ NP and PTX NP with a final diameter of approximately 40 nm. Attributing a strong affinity of TA molecules to the elastin of LN conduits, the TA modified IMQ NPs can bypass the gaps in the layer of lymphatic endothelial cells and enter the paracortex through the lymph node capsule-associated (LNC) conduits. Similarly, the TA modified PTX NPs increased delivery of PTX to the metastatic tumor site in LNs, where the tumor-associated antigens were released and presented by conduits-lining dendritic cells to activate T cells. Thus, the NPs with deposition to LN conduits showed excellent performance in preventing lymphovascular invasion of triple-negative breast cancer cells and lung metastasis thereafter. On the contrary, the NPs without TA flowed through the subcutaneous sinus existing LNs directly by efferent lymphatic vessels showing relatively poor therapeutic outcomes. This study reveals that TA may mediate the long retention of antigens and molecular adjuvants to be delivered to deep LNs for developing potent vaccination technology.

IL-23 signaling regulation of pro-inflammatory T-cell migration uncovered by phosphoproteomics

Interleukin 23 (IL-23) triggers pathogenic features in pro-inflammatory, IL-17-secreting T cells (Th17 and Tγδ17) that play a key role in the development of inflammatory diseases. However, the IL-23 signaling cascade remains largely undefined. Here, we used quantitative phosphoproteomics to characterize IL-23 signaling in primary murine Th17 cells. We quantified 6,888 phosphorylation sites in Th17 cells and found 168 phosphorylations regulated upon IL-23 stimulation. IL-23 increased the phosphorylation of the myosin regulatory light chain (RLC), an actomyosin contractibility marker, in Th17 and Tγδ17 cells. IL-23-induced RLC phosphorylation required Janus kinase 2 (JAK2) and Rho-associated protein kinase (ROCK) catalytic activity, and further study of the IL-23/ROCK connection revealed an unexpected role of IL-23 in the migration of Tγδ17 and Th17 cells through ROCK activation. In addition, pharmacological inhibition of ROCK reduced Tγδ17 recruitment to inflamed skin upon challenge with inflammatory agent Imiquimod. This work (i) provides new insights into phosphorylation networks that control Th17 cells, (ii) widely expands the current knowledge on IL-23 signaling, and (iii) contributes to the increasing list of immune cells subsets characterized by global phosphoproteomic approaches.

Phosphoproteomics of interleukin-17-secreting T cells (Th17 cells) identifies more than 100 phosphorylation events in response to interleukin-23 stimulation, revealing increased phosphorylation of myosin regulatory light chain (RLC) and a role for an IL-23/ROCK pathway in controlling migration of Th17 and Tγδ17 cells.

Bidirectional Regulation of Opioid and Chemokine Function

The opioid family of GPCRs consists of the classical opioid receptors, designated μ-, κ-, and δ-opioid receptors, and the orphanin-FQ receptor, and these proteins are expressed on both neuronal and hematopoietic cells. A number of laboratories have reported that an important degree of cross-talk can occur between the opioid receptors and the chemokine and chemokine receptor families. As a part of this, the opioid receptors are known to regulate the expression of certain chemokines and chemokine receptors, including those that possess strong pro-inflammatory activity. At the level of receptor function, it is clear that certain members of the chemokine family can mediate cross-desensitization of the opioid receptors. Conversely, the opioid receptors are all able to induce heterologous desensitization of some of the chemokine receptors. Consequently, activation of one or more of the opioid receptors can selectively cross-desensitize chemokine receptors and regulate chemokine function. These cross-talk processes have significant implications for the inflammatory response, since the regulation of both the recruitment of inflammatory cells, as well as the sensation of pain, can be controlled in this way.

Comprehensive characterization of differentially expressed genes in thyroid cancer

AIM

To explore the patterns of gene expression and functionally characterize the differentially expressed genes (DEGs) in thyroid cancer.

METHODS

DEGs were determined between 57 paired thyroid cancer and noncancerous tissues using DESeq2. Subsequently, the main functions of the DEGs were studied by a variety of analyses.

RESULTS

We identified a cohort of 752 upregulated and 309 downregulated DEGs in thyroid cancer. Several hub DEGs were found in the protein-protein interaction networks. We also revealed a set of DEGs that were dysmethylated, involved in copy number variations and associated with clinical features in thyroid cancer.

CONCLUSION

These results provide some novel findings on DEGs in thyroid cancer, which will be useful to guide further investigation and target therapy for this disease. [Formula: see text].

Jak3 is involved in CCR7-dependent migration and invasion in metastatic squamous cell carcinoma of the head and neck

Patients with cervical lymph node metastasis in squamous cell carcinoma of the head and neck (SCCHN) exhibit a poor prognosis and low 5-year survival rate. It has been proven that chemokine receptor 7 (CCR7) promotes cellular migration and invasion in metastatic SCCHN. In the present study, the metastatic SCCHN PCI-37B cell line was utilized to explore the role of Janus activated kinase-3 (Jak3) in the CCR7-mediated signaling pathway in metastatic SCCHN cells. It was observed that phospho-Jak3 was expressed in SCCHN tissues. In addition, when the PCI-37B cells were analyzed in response to chemokine ligand 19 (CCL19), the ligand of CCR7, at the indicated time points, the results of the present study demonstrated that CCR7 induced Jak3 activation, and inhibition of Jak3 activity using a specific inhibitor, ZM39923, significantly attenuated CCR7-induced Jak3 phosphorylation. Migration and invasion assays and immunofluorescence staining experiments demonstrated that CCL19 promoted cell migration, invasion and F-actin rearrangment in CCR7-expressing SCCHN cells partially due to the activation of the Jak3 signaling pathway. These results demonstrate that the Jak3 signaling pathway is important for the CCR7-induced malignant biological behavior of SCCHN cells.

A Key Role for Inhibins in Dendritic Cell Maturation and Function

Inhibins are members of the TGFβ superfamily, which regulate many cellular processes including differentiation, proliferation, survival and apoptosis. Although initially described as hormones regulating the hypothalamus-pituitary-gonadal axis, based on their ability to antagonize Activins, our group has recently reported that they play a role in thymocyte differentiation and survival, as well as in thymic stromal cell maturation and nTreg generation. Here, we used Inhibin knock out mice (Inhα-/-) to investigate the role of Inhibins in peripheral dendritic cell maturation and function. We first demonstrated that LPS treated Inhα+/+ bone marrow derived dendritic cells (BMDC) were capable to produce significant levels of Inhibin A. Interestingly, Inhα-/- BMDC showed reduced MHCII and CD86 upregulation and increased PD-L1 expression in response to LPS compared to Inhα+/+, which correlated with reduced ability to induce proliferation of allogeneic T cells. The "semi-mature" phenotype displayed by Inhα-/- mBMDC correlated with increased levels of IL-10 and slightly decreased IL-6 production after LPS stimulation. In addition, Inhα-/- mBMDC showed impaired migration towards CCL19 and CCL21, assessed by in vitro chemotaxis and in vivo competitive homing experiments, despite their normal CCR7 expression. Furthermore, in vivo LPS-induced DC maturation was also diminished in Inhα-/- mice, specially within the LC (CD207+ CD11b+ CD103-) subpopulation. Finally, analysis of delayed type hypersensitivity responses in Inhα-/- mice, showed reduced ear swelling as a result of reduced cellular infiltration in the skin, correlating with impaired homing of CD207+ DCs to the draining lymph nodes. In summary, our data demonstrate for the first time that Inhibins play a key role in peripheral DC maturation and function, regulating the balance between immunity and tolerance.

Common and biased signaling pathways of the chemokine receptor CCR7 elicited by its ligands CCL19 and CCL21 in leukocytes

Chemokines are pivotal regulators of cell migration during continuous immune surveillance, inflammation, homeostasis, and development. Chemokine binding to their 7-transmembrane domain, G-protein-coupled receptors causes conformational changes that elicit intracellular signaling pathways to acquire and maintain an asymmetric architectural organization and a polarized distribution of signaling molecules necessary for directional cell migration. Leukocytes rely on the interplay of chemokine-triggered migration modules to promote amoeboid-like locomotion. One of the most important chemokine receptors for adaptive immune cell migration is the CC-chemokine receptor CCR7. CCR7 and its ligands CCL19 and CCL21 control homing of T cells and dendritic cells to areas of the lymph nodes where T cell priming and the initiation of the adaptive immune response occur. Moreover, CCR7 signaling also contributes to T cell development in the thymus and to lymphorganogenesis. Although the CCR7-CCL19/CCL21 axis evolved to benefit the host, inappropriate regulation or use of these proteins can contribute or cause pathobiology of chronic inflammation, tumorigenesis, and metastasis, as well as autoimmune diseases. Therefore, it appears as the CCR7-CCL19/CCL21 axis is tightly regulated at numerous intersections. Here, we discuss the multiple regulatory mechanism of CCR7 signaling and its influence on CCR7 function. In particular, we focus on the functional diversity of the 2 CCR7 ligands, CCL19 and CCL21, as well as on their impact on biased signaling. The understanding of the molecular determinants of biased signaling and the multiple layers of CCR7 regulation holds the promise for potential future therapeutic intervention.

JAK tyrosine kinases promote hierarchical activation of Rho and Rap modules of integrin activation

Lymphocyte recruitment is regulated by signaling modules based on the activity of Rho and Rap small guanosine triphosphatases that control integrin activation by chemokines. We show that Janus kinase (JAK) protein tyrosine kinases control chemokine-induced LFA-1- and VLA-4-mediated adhesion as well as human T lymphocyte homing to secondary lymphoid organs. JAK2 and JAK3 isoforms, but not JAK1, mediate CXCL12-induced LFA-1 triggering to a high affinity state. Signal transduction analysis showed that chemokine-induced activation of the Rho module of LFA-1 affinity triggering is dependent on JAK activity, with VAV1 mediating Rho activation by JAKs in a Gαi-independent manner. Furthermore, activation of Rap1A by chemokines is also dependent on JAK2 and JAK3 activity. Importantly, activation of Rap1A by JAKs is mediated by RhoA and PLD1, thus establishing Rap1A as a downstream effector of the Rho module. Thus, JAK tyrosine kinases control integrin activation and dependent lymphocyte trafficking by bridging chemokine receptors to the concurrent and hierarchical activation of the Rho and Rap modules of integrin activation.

Jak3 enables chemokine-dependent actin cytoskeleton reorganization by regulating cofilin and Rac/Rhoa GTPases activation

We have previously shown that Jak3 is involved in the signaling pathways of CCR7, CCR9 and CXCR4 in murine T lymphocytes and that Jak3^−/− lymphocytes display an intrinsic defect in homing to peripheral lymph nodes. However, the molecular mechanism underlying the defective migration observed in Jak3^−/− lymphocytes remains elusive. Here, it is demonstrated for the first time, that Jak3 is required for the actin cytoskeleton reorganization in T lymphocytes responding to chemokines. It was found that Jak3 regulates actin polymerization by controlling cofilin inactivation in response to CCL21 and CXCL12. Interestingly, cofilin inactivation was not precluded in PTX- treated cells despite their impaired actin polymerization. Additionally, Jak3 was required for small GTPases Rac1 and RhoA activation, which are indispensable for acquisition of the migratory cell phenotype and the generation of a functional leading edge and uropod, respectively. This defect correlates with data obtained by time-lapse video-microscopy showing an incompetent uropod formation and impaired motility in Jak3-pharmacologically inhibited T lymphocytes. Our data support a new model in which Jak3 and heterotrimeric G proteins can use independent, but complementary, signaling pathways to regulate actin cytoskeleton dynamics during cell migration in response to chemokines.

Janus kinases 1 and 2 regulate chemokine-mediated integrin activation and naïve T-cell homing

Janus kinases (JAKs) are central signaling molecules in cytokine receptor cascades. Although they have also been implicated in chemokine receptor signaling, this function continues to be debated. To address this issue, we established a nucleofection model in primary, nonactivated mouse T lymphocytes to silence JAK expression and to evaluate the ability of these cells to home to lymph nodes. Reduced JAK1 and JAK2 expression impaired naïve T-cell migration in response to gradients of the chemokines CXCL12 and CCL21. In vivo homing of JAK1/JAK2-deficient cells to lymph nodes decreased, whereas intranodal localization and motility were unaffected. JAK1 and JAK2 defects altered CXCL12- and CCL21-triggered ezrin/radixin/moesin (ERM) dephosphorylation and F-actin polymerization, as well as activation of lymphocyte function-associated Ag-1 and very late Ag-4 integrins. As a result, the cells did not adhere firmly to integrin substrates in response to these chemokines. The results demonstrate that JAK1/JAK2 participate in chemokine-induced integrin activation and might be considered a target for modulation of immune cell extravasation and therefore, control of inflammatory reactions.

Jak3 is involved in dendritic cell maturation and CCR7-dependent migration

Background

CCR7-mediated signalling is important for dendritic cell maturation and homing to the lymph nodes. We have previously demonstrated that Jak3 participates in the signalling pathway of CCR7 in T lymphocytes.

Methodology and Principal Findings

Here, we used Jak3^−/− mice to analyze the role of Jak3 in CCR7-mediated dendritic cells migration and function. First, we found no differences in the generation of DCs from Jak3^−/− bone marrow progenitors, when compared to wild type cells. However, phenotypic analysis of the bone marrow derived DCs obtained from Jak3^−/− mice showed reduced expression of co-stimulatory molecules compared to wild type (Jak3^+/+). In addition, when we analyzed the migration of Jak3^−/− and Jak3^+/+ mature DCs in response to CCL19 and CCL21 chemokines, we found that the absence of Jak3 results in impaired chemotactic responses both in vitro and in vivo. Moreover, lymphocyte proliferation and contact hypersensitivity experiments showed that DC-mediated T lymphocyte activation is reduced in the absence of Jak3.

Conclusion/Significance

Altogether, our data provide strong evidence that Jak3 is important for DC maturation, migration and function, through a CCR7-mediated signalling pathway.