To study the anatomic parameters related to clival screw and establish reference data concerning the craniovertebral fixation technique.
Morphometric measurement of the clivus and the surrounding anatomic structures were obtained on 41 dry bone specimens. Then, 2-D CT reconstruction of the craniovertebral region of 30 patients (19 men and 11 women, ranging in age from 20–64 years with an average age of 38.8 years) were performed to measure the safety range for a 3.5-mm screw placement. Nine entry points were evaluated. Finally, one male fresh cadaver specimen (age 46 years) was dissected to observe the craniovertebral region.
The clivus faces the basilar artery, the V ~ XII cranial nerves, the pons, and ventral medulla oblongata at its intracranial surface. The longitudinal diameter of extracranial clivus was 25.87 ± 2.64 mm. The narrowest diameter of the clivus was 12.84 ± 1.08 mm, the distance between the left and right hypoglossal canal was 32.70 ± 2.09 mm at its widest part. The distance between the left and right structures, the maximum value was 49.31 ± 4.16 mm at carotid canal, the minimum value was 16.54 ± 2.04 mm at the occipital condyle. The measurement of clival screws placement simulation via 2-D CT reconstruction images shows the maximum upper insertion angle of three components the optimal entry points, the candidate points, the limit entry points was 130.19°, 125.23° and 85.72°, and the total mean screw length was 7.57, 10.13 and 15.6 mm at the vertical entry angle, respectively.
Clival screw placement is a viable option for craniovertebral fixation. There is a safe scope for the screw length and angle of the screw placement. And, these parameters obtained in the present study will be helpful for anyone contemplating the use of clival screw fixation.
Clivus; Craniovertebral fusion; Screw placement; Anatomical study
We have recently demonstrated that glucose-regulated protein 170 (Grp170), a stress-responsive molecular chaperone of the endoplasmic reticulum, can be exploited to stimulate anticancer immunity due to its superior antigen chaperoning and delivering capacity. The immune remodeling of the tumor microenvironment induced by a Grp170-based chaperone leads to immune responses that effectively control the progression of both primary neoplasms and their metastases. Our findings support the development of Grp170-based immunomodulating strategies to potentiate antitumor immune responses.
dendritic cells; glucose-regulated protein 170; immune modulator molecular chaperone; tumor microenvironment; vaccine
Extensive studies have established a role of scavenger receptor CD204 in pattern recognition and ligand uptake. Strikingly, we recently revealed a previously unrecognized feature of CD204 action in attenuating T-cell activation and antitumor immunity. Blocking its activity in dendritic cells represents a promising approach to the improvement of cancer immunotherapy.
innate immune receptor; dendritic cells; CD204; vaccine; T-cell response; tumor immunity
It is well established that certain stress proteins or molecular chaperones are highly efficient in cross-presenting tumor-derived antigens, resulting in a potent antitumor immune response. In this study we demonstrate that genetic modification of weakly immunogenic murine prostate tumor cells (TRAMP-C2) by stable transfection with a secretable form of endoplasmic reticulum resident chaperone grp170 significantly enhances its immunogenicity in vivo. Generation of systemic antitumor immunity is indicated by the growth suppression of distant parental tumors, which is associated with increased tumor infiltration, elevated effector functions of CD8+ T-cells. Immunization with inactivated grp170-secreting C2 cells augments a CD8+ T-cell dependent, tumor-protective effect. Furthermore, infection of C2 tumor cells with a nonreplicating adenoviral vectors encoding secretable grp170 promotes tumor immunogenicity more effectively than plasmid transduction, as shown by the increased production of pro-inflammatory cytokine TNF-α by dendritice cells and enhanced therapeutic efficacy in treating pre-established tumors. Given a repertoire of undefined antigens in prostate tumor, manipulation of cellular compartmentalization of immuno-stimulatory chaperone grp170 to elicit systemic tumor immunity may be used to improve treatment outcomes for prostate cancer when combined with other treatment modalities.
Prostate cancer; Stress protein; Chaperone; grp170; Immuogenicity
Structure-based modeling combined with rational drug design, and high throughput screening approaches offer significant potential for identifying and developing lead compounds with therapeutic potential. The present review focuses on these two approaches using explicit examples based on specific derivatives of Gossypol generated through rational design and applications of a cancer-specific-promoter derived from Progression Elevated Gene-3. The Gossypol derivative Sabutoclax (BI-97C1) displays potent anti-tumor activity against a diverse spectrum of human tumors. The model of the docked structure of Gossypol bound to Bcl-XL provided a virtual structure-activity-relationship where appropriate modifications were predicted on a rational basis. These structure-based studies led to the isolation of Sabutoclax, an optically pure isomer of Apogossypol displaying superior efficacy and reduced toxicity. These studies illustrate the power of combining structure-based modeling with rational design to predict appropriate derivatives of lead compounds to be empirically tested and evaluated for bioactivity. Another approach to cancer drug discovery utilizes a cancer-specific promoter as readouts of the transformed state. The promoter region of Progression Elevated Gene-3 is such a promoter with cancer-specific activity. The specificity of this promoter has been exploited as a means of constructing cancer terminator viruses that selectively kill cancer cells and as a systemic imaging modality that specifically visualizes in vivo cancer growth with no background from normal tissues. Screening of small molecule inhibitors that suppress the Progression Elevated Gene-3-promoter may provide relevant lead compounds for cancer therapy that can be combined with further structure-based approaches leading to the development of novel compounds for cancer therapy.
Progression Elevated Gene-3; Sabutoclax; Apogossypol; BI-97C1; Gossypol; AP-1; PEA3; ETV4; E1AF; c-fos; c-jun; Cancer Terminator Virus
The incidence of melanoma continues to rise and prognosis in patients with metastatic melanoma remains poor. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) serves as one of the primary immune checkpoints and downregulates T cell activation pathways. Enhancing T cell activation by antibody blockade of the CTLA-4 provides a novel approach to overcome tumor-induced immune tolerance. Recently, anti-CTLA-4 therapy demonstrated significant clinical benefit in patients with metastatic melanoma, which led to the approval of ipilimumab by the Food and Drug Administration in early 2011.
The fundamental concepts underlying CTLA-4 blockade-potentiated immune activation, the scientific rationale for and the preclinical evidence supporting CTLA-4-targeted cancer immunotherapy are presented. We also provide an update on clinical trials with anti-CTLA-4 inhibitors and discuss the associated autoimmune toxicity.
Given that overall survival is the only validated endpoint for the anti-CTLA-4 therapy, the clinical implications of the antigen or tumor-specific immunity in patients remain to be clarified. Additional research is necessary to elucidate the prognostic significance of immune-related side effects and significantly optimize the treatment regimens. An improved understanding of the mechanisms of action of CTLA-4 antibodies may also culminate in wide-ranging clinical applications of this novel therapy for other tumor types.
cytotoxic T-lymphocyte-associated antigen; CTL-A blockade; T cell activation; tumor immunity; overall survival
Recent observations suggest that immune-mediated tissue destruction is dependent upon coordinate activation of immune genes expressed by cells of the innate and adaptive immune systems.
Here, we performed a retrospective pilot study to investigate whether the coordinate expression of molecular signature mostly associated with NK cells could be used to segregate breast cancer patients into relapse and relapse-free outcomes.
By analyzing primary breast cancer specimens derived from patients who experienced either 58–116 months (~5-9 years) relapse-free survival or developed tumor relapse within 9–76 months (~1-6 years) we found that the expression of molecules involved in activating signaling of NK cells and in NK cells: target interaction is increased in patients with favorable prognosis.
The parameters identified in this study, together with the prognostic signature previously reported by our group, highlight the cooperation between the innate and adaptive immune components within the tumor microenvironment.
Breast cancer prognosis; Molecular markers; Innate immunity; NK cells; Tumour relapse; Tumour microenvironment
To compare the axis-line-distance technique (ALDT) and Cobb method for therapeutic evaluation of scoliosis.
Fifty-seven patients with scoliosis were treated in our hospital, 47 underwent conservative bracing therapy and 10 underwent surgery. Based on 171 full-spine X-ray images obtained from these 57 cases before treatment, during conservative treatment or surgery, and at final follow-up after removing the brace or after surgery, two radiologists independently measured and calculated the correction rate during treatment and at final follow-up and the rate of correction loss after treatment with the ALDT and Cobb methods. Paired t-test and correlation analysis were performed.
Based on the ALDT, the lateral deviations of the apical vertebrae before treatment, during treatment, and at final follow-up were 31 ± 14 mm, 16 ± 8 mm, and 20 ± 8 mm, respectively; the correction rates during treatment and at final follow-up were 48.7 ± 21.2% and 37.6 ± 14.2%, respectively, and the rate of correction loss after treatment was 11.3 ± 6.5%. The Cobb angles of scoliosis before treatment, during treatment, and at final follow-up were 34 ± 14°, 19 ± 7°, and 22 ± 6°, respectively; the correction rates during treatment and at final follow-up were 44.4 ± 17.3% and 33.9 ± 14.4%, respectively, and the rate of correction loss after treatment was 11.4 ± 4.3%. Calculation of the correction rate during treatment differed significantly between the two radiologists when using the Cobb method (P < 0.05); their calculations of the correction rate and rate of correction loss were not different (P > 0.05). The measurement data of the two radiologists using the Cobb method showed a weak to moderate correlation (r = 0.49, 0.57, and 0.51, respectively). When using the ALDT, there were no significant differences between the radiologists in their measurements of the correction rate during and after treatment (P > 0.05) or in the rate of correction loss. The measurement data of the two radiologists using the ALDT showed a good to excellent correlation (r = 0.92, 0.93, and 0.90, respectively).
The ALDT is better than the Cobb method for therapeutic evaluation of scoliosis during treatment and at follow-up visits.
Scoliosis; Radiography; Curative effect assessment; Measurement
Adenovirus (Ad)-based gene therapy represents a potentially viable strategy for treating colorectal cancer. The infectivity of serotype 5 adenovirus (Ad.5), routinely used as a transgene delivery vector, is dependent on Coxsackie-adenovirus receptors (CAR). CAR expression is downregulated in many cancers thus preventing optimum therapeutic efficiency of Ad.5-based therapies. To overcome the low CAR problem, a serotype chimerism approach was used to generate a recombinant Ad (Ad.5/3) that is capable of infecting cancer cells via Ad.3 receptors in a CAR-independent manner. We evaluated the improved transgene delivery and efficacy of Ad.5/3 recombinant virus expressing melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), an effective wide-spectrum cancer-selective therapeutic. In low CAR human colorectal cancer cells RKO, wild-type Ad.5 virus expressing mda-7/IL-24 (Ad.5-mda-7) failed to infect efficiently resulting in lack of expression of MDA-7/IL-24 or induction of apoptosis. However, a recombinant Ad.5/3 virus expressing mda-7/IL-24 (Ad.5/3-mda-7) efficiently infected RKO cells resulting in higher MDA-7/IL-24 expression and inhibition of cell growth both in vitro and in nude mice xenograft models. Addition of the novel Bcl-2 family pharmacological inhibitor Apogossypol derivative BI-97C1 (Sabutoclax) significantly augmented the efficacy of Ad.5/3-mda-7. A combination regimen of suboptimal doses of Ad.5/3-mda-7 and BI-97C1 profoundly enhanced cytotoxicity in RKO cells both in vitro and in vivo. Considering the fact that Ad.5-mda-7 has demonstrated significant objective responses in a Phase I clinical trial for advanced solid tumors, Ad.5/3-mda-7 alone or in combination with BI-97C1 would be predicted to exert significantly improved therapeutic efficacy in colorectal cancer patients.
Viral gene therapy; Mcl-1 inhibition; apoptosis induction; anti-tumor activity
Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), a unique member of the IL-10 gene family, displays a broad range of antitumor properties including cancer-specific induction of apoptosis, inhibition of tumor angiogenesis, and modulation of anti-tumor immune responses. Here we identify clusterin (CLU) as a MDA-7/IL-24 interacting protein in DU-145 cells and investigate the role of MDA-7/IL-24 in regulating CLU expression and mediating the antitumor properties of mda-7/IL-24 in prostate cancer. Ad.mda-7 decreased expression of soluble CLU (sCLU) and increased expression of nuclear CLU (nCLU). In the initial phase of Ad.mda-7 infection sCLU expression increased and CLU interacted with MDA-7/IL-24 producing a cytoprotective effect. Infection of stable clones of DU-145 prostate cancer cells expressing sCLU with Ad.mda-7 resulted in generation of nCLU that correlated with decreased cell viability and increased apoptosis. In the presence of mda-7/IL-24, sCLU-DU-145 cells displayed G2/M phase arrest followed by apoptosis. Similarly, Ad.mda-7 infection decreased cell migration by altering cytoskeleton in sCLU-DU-145 cells. Ad.mda-7-treated sCLU-DU-145 cells displayed a significant reduction in tumor growth in mouse xenograft models and reduced angiogenesis when compared to the vector control group. Tumor tissue lysates demonstrated enhanced nCLU generated from sCLU with increased apoptosis in the presence of MDA-7/IL-24. Our findings reveal novel aspects relative to the role of sCLU/nCLU in regulating the anticancer properties of MDA-7/IL-24 that may be exploited for developing enhanced therapies for prostate cancer.
MDA-7/IL-24; soluble clusterin; nuclear clusterin; G2/M arrest; apoptosis
Pattern recognition scavenger receptor SRA/CD204, primarily expressed on specialized antigen-presenting cells (APCs), including dendritic cells (DCs) and macrophages, has been implicated in multiple physiological and pathological processes, including atherosclerosis, Alzheimer's disease, endotoxic shock, host defense and cancer development. SRA/CD204 was also recently shown to function as an attenuator of vaccine response and antitumor immunity. Here we for the first time report that SRA/CD204 knockout (SRA−/−) mice developed a more robust CD4+ T cell response than wild-type mice after ovalbumin immunization. Splenic DCs from the immunized SRA−/− mice were much more efficient than those from WT mice in stimulating naïve OT-II cells, indicating that the suppressive activity of SRA/CD204 is mediated by DCs. Strikingly, antigen-exposed SRA−/− DCs with or without lipopolysaccharide treatment exhibited increased T cell-stimulating activity in vitro, which was independent of the classical endocytic property of the SRA/CD204. Additionally, absence of SRA/CD204 resulted in significantly elevated IL12p35 expression in DCs upon CD40 ligation plus IFN-γ stimulation. Molecular studies reveal that SRA/CD204 inhibited the activation of STAT1, MAPK p38 and NF-κB signaling activation in DCs treated with anti-CD40 antibodies and IFN-γ. Furthermore, splenocytes from the generated SRA−/− OT-II mice showed heightened proliferation upon stimulation with OVA protein or MHC II-restricted OVA323-339 peptide compared with cells from the SRA+/+ OT-II mice. These results not only establish a new role of SRA/CD204 in limiting the intrinsic immunogenicity of APCs and CD4+ T cell activation, but also provide additional insights into the molecular mechanisms involved in the immune suppression by this molecule.
dendritic cells; CD4 T cell; immunity; CD204
Although dendritic cell (DC) vaccines offer promise as cancer immunotherapy, further improvements are needed to amplify their clinical therapeutic efficacy. The pattern recognition scavenger receptor SRA/CD204 attenuates the ability of DCs to activate CD8+ T cell responses. Therefore, we examined the impact of SRA/CD204 on antitumor responses generated by DC vaccines and we also evaluated the feasibility of enhancing DC vaccine potency by SRA/CD204 blockade. DCs from SRA/CD204 deficient mice were more immunogenic in generating antitumor responses to B16 melanoma, compared to DCs from wild-type mice. Similarly, siRNA-mediated knockdown of SRA/CD204 by lentiviral vectors improved the ability of wild-type DCs to stimulate the expansion and activation of CD8+ T cells specific for idealized or established melanoma antigens in mice. Using SRA/CD204-silenced DCs to generate antigen-targeted vaccines, we documented a marked increase in the level of antitumor immunity achieved against established B16 tumors and metastases. This increase was associated with enhanced activation of antigen-specific CTLs, greater tumor infiltration by CD8+ T cells and NK cells, and increased intratumoral ratios of both CD4+ and CD8+ T effector cells to CD4+CD25+ T regulatory cells. Our studies establish that downregulating SRA/CD204 strongly enhances DC-mediated antitumor immunity. Additionally, they provide a rationale to enhance DC vaccine potency through SRA/CD204-targeting approaches that can improve clinical outcomes in cancer treatment.
dendritic cell vaccine; CD204; CTL; antitumor immunity
The advancement of cancer immunotherapy faces barriers which limit its efficacy. These include weak immunogenicity of the tumor, as well as immunosuppressive mechanisms which prevent effective antitumor immune responses. Recent studies suggest that aberrant expression of cancer testis antigens (CTAs) can generate robust antitumor immune responses, which implicates CTAs as potential targets for immunotherapy. However, the heterogeneity of tumor cells in the presence and quantity of CTA expression results in tumor escape from CTA-specific immune responses. Thus, the ability to modulate the tumor cell epigenome to homogenously induce expression of such antigens will likely render the tumor more immunogenic. Additionally, emerging studies suggest that suppression of antitumor immune responses may be overcome by reprogramming innate and adaptive immune cells. Therefore, this paper discusses recent studies which address barriers to successful cancer immunotherapy and proposes a strategy of modulation of tumor-immune cell crosstalk to improve responses in carcinoma patients.
We previously reported that scavenger receptor A (SRA/CD204), a binding structure on dendritic cells (DCs) for large stress/heat shock proteins (HSPs, e.g., hsp110 and grp170), attenuated an antitumor response elicited by large HSP-based vaccines. Here we show that SRA/CD204 interacts directly with exogenous hsp110 and lack of SRA/CD204 results in a reduction in the hsp110 binding and internalization by DCs. However, SRA−/− DCs pulsed with hsp110 or grp170-reconstituted gp100 chaperone complexes exhibit profoundly increased capability of stimulating melanoma antigen gp100-specific naïve T-cells compared to wild-type (WT) DCs. Similar results were obtained when SRA/CD204 was silenced in DCs using shRNAs-encoding lentiviruses. In addition, hsp110-stimulated SRA−/− DCs produced more inflammatory cytokines associated with increased NF-κB activation, implicating an immunosuppressive role of SRA/CD204. Immunization with the hsp110-gp100 vaccine resulted in a more robust gp100-specific CD8+ T cell response in SRA−/− mice than in WT mice. Lastly, SRA/CD204 absence markedly improved the therapeutic efficacy of the hsp110-gp100 vaccine in mice established with B16 melanoma, which was accompanied by enhanced activation and tumor infiltration of CD8+ T cells. Given the presence of multiple HSP-binding scavenger receptors on antigen-presenting cells, we propose that selective scavenger receptor interactions with HSPs may lead to highly distinct immunological consequences. Our findings provide new insights to the immune regulatory functions of SRA/CD204 and have important implications in the rational design of protein antigen-targeted recombinant chaperone vaccines for the treatment of cancer.
large heat shock protein; chaperone; grp170; hsp110; melanoma antigen; CD204; vaccination
Attempts to cure breast cancer by means of adoptive cellular therapy (ACT) have not been successful. This is primarily due to the presence of tumor-induced immune suppressive mechanisms as well as the failure of tumor-reactive T cells to provide long-term memory responses in vivo. In order to address these clinically important challenges we developed an ex vivo protocol for the expansion of tumor-reactive immune cells obtained from tumor-bearing animals prior to or after local radiation therapy. We used an antigen-free protocol which included bryostatin 1/ionomycin (B/I) and sequential common gamma-chain cytokines (IL-7/IL-15 + IL-2). The proposed protocol expanded tumor-reactive T cells as well as activated non-T cells, including NK T cells, NK cells and IFN-γ producing killer dendritic cells (IKDC). Anti-tumor efficacy of T cells depended on the presence of non-T cells. The effector non-T cells also rendered T cells resistant to myeloid-derived suppressor cells (MDSC). Radiation therapy altered phenotypic distribution and differentiation of T cells, as well as their ability to generate central memory T cells (TCM). ACT by means of the expanded cells protected animals from tumor challenge and generated long-term memory responses against the tumor, provided that leukocytes were derived from tumor-bearing animals prior to radiation therapy. The ex vivo protocol was also able to expand HER-2/neu-specific T cells derived from the PBMC of a single patient with breast carcinoma. These data suggest that the proposed ACT protocol should be studied further in breast cancer patients.
adoptive cellular therapy; breast cancer; common gamma chain cytokines; adiation therapy of cancer; myeloid-derived suppressor cells
Given the primary expression of scavenger receptor A (SRA) or CD204 on antigen presenting cells, we investigate the immune-regulatory activities of SRA/CD204 in the context of cross-presentation of cell-associated antigen and the immunogenicity of dying tumor cells. Immunization with dying prostate cancer cells results in profoundly increased control of subsequently inoculated tumors in SRA/CD204 knockout mice. Using OVA-expressing RM1 prostate tumor line (RM1-OVA), we show for the first time that SRA absence greatly enhances dendritic cells (DCs)-mediated cross-presentation of OVA antigen-derived from dying RM1 cells. While the phagocytic ability of DCs is not significantly impacted by the lack of SRA/CD204, DCs deficient in SRA/CD204 display increased expression of inflammatory cytokines and chemokines, as well as co-stimulatory molecules upon interaction with dying RM1 cells, implicating a suppressive regulation of the functional activation of DCs by SRA/CD204. Further, SRA/CD204 deficient DCs pulsed with dying RM1-OVA cells are more effective than wild-type counterparts in priming antigen-specific T-cell responses, resulting in improved control of RM1 tumor growth in both prophylactic and therapeutic settings. Our findings suggest that the increased immunogenicity of dying tumor cells in SRA/CD204 knockout mice is attributed to the altered functions of DCs in the absence of SRA/CD204, which underscores the important role of SRA/CD204 in host immune homeostasis. Selective downregulation or blockade of this immunoregulatory molecule may lead to enhanced potency of DC-based vaccines capable of breaking immune tolerance against cancer.
dendritic cells; antigen presentation; immune response; CD204; scavenger receptor
Large heat shock proteins (HSPs), including hsp110 and grp170, are unique immunochaperones capable of carrying and introducing antigens into professional antigen presenting cells (APCs) for efficient cross-presentation. Therefore, reconstituted chaperone complexes of large HSPs and protein antigen may be exploited for augmentation of an antigen-specific immune response. The methods for the preparation of the recombinant protein antigen chaperone complex and characterization of its T-cell priming capability in both in vitro and in vivo settings are described.
large heat shock protein; hsp110; grp170; chaperone vaccine; antigen presentation; T-cell priming
The cytokine melanoma differentiation associated gene 7 (mda-7) was identified by subtractive hybridization as a protein whose expression increased during the induction of terminal differentiation, and that was either not expressed or was present at low levels in tumor cells compared to non-transformed cells. Based on conserved structure, chromosomal location and cytokine-like properties, MDA-7, was classified as a member of the interleukin (IL)-10 gene family and designated as MDA-7/IL-24. Multiple studies have demonstrated that expression of MDA-7/IL-24 in a wide variety of tumor cell types, but not in corresponding equivalent non-transformed cells, causes their growth arrest and rapid cell death. In addition, MDA-7/IL-24 has been noted to radiosensitize tumor cells which in part is due to the generation of reactive oxygen species (ROS) and ceramide that cause endoplasmic reticulum stress and suppress protein translation. Phase I clinical trial data has shown that a recombinant adenovirus expressing MDA-7/IL-24 (Ad.mda-7 (INGN-241)) was safe and had measurable tumoricidal effects in over 40% of patients, strongly arguing that MDA-7/IL-24 could have significant therapeutic value. This review describes what is presently known about the impact of MDA-7/IL-24 on tumor cell biology and its potential therapeutic applications.
MDA-7; IL-24; Apoptosis; Autophagy; Ceramide; ROS; Ca2+; Clinical trial; Signal transduction; PERK; ER stress; MCL-1
To determine the location of left brachiocephalic vein (BCV) and tracheal bifurcation (TB) relative to the vertebral levels, and to ascertain the accessibility of three different corridors (C1: between the esophagus and trachea medially and the carotid sheath laterally, C2: between the right BCV and the brachiocephalic artery, and C3: between the ascending aorta and superior vena cava) for preoperative planning. From August 2008 to April 2009, normal chest CT scans of 150 subjects ranging in age from 18 to 78 years were selected. According to our definition, of the 150 studies, 132 T2 vertebral bodies (VBs) could be accessed through C1 (88.0%), 100 T3 VBs could be reached through C2 (66.7%), and 110 T4 VBs could be exposed through C3 (73.3%). The results suggest that the surgical accessibility of three different corridors is different and we conclude that T2, T3, and T4 are, respectively, readily accessible through C1, C2, and C3.
Surgical corridor; Cervicothoracic junction; CT scan; Anatomy
Multiple physiological and pathological conditions interfere with the function of Endoplasmic Reticulum (ER). However, much remains unknown regarding the impact of ER stress on inflammatory responses in dendritic cells (DCs) upon the recognition of pathogen molecules. We show that ER stress greatly potentiates the expression of inflammatory cytokines and IFN-β in murine DCs stimulated by polyIC, a synthetic mimic of virus dsRNA. Both toll-like receptor 3 and melanoma differentiation-associated gene-5 are involved in the enhanced IFN-β production, which is associated with increased activation of NF-κB and IRF3 signaling as well as the splicing of X-box binding protein-1 (XBP-1), an important regulator involved in ER stress response. Surprisingly, silencing of XBP-1 reduces polyIC-stimulated IFN-β expression in the presence or absence of ER stress, indicating that XBP-1 may be essential for polyIC signaling and ER stress-amplified IFN-β production. Overexpression of a spliced form of XBP-1(XBP-1s) synergistically augments polyIC-induced inflammatory response. For the first time we show that XBP-1s overexpression-enhanced IFN-β production in DCs markedly suppresses vesicular stomatitis virus infection, revealing a previously unrecognized role of XBP-1 in an antiviral response. Our findings suggest that evolutionarily conserved ER stress response and XBP-1 may function collaboratively with the innate immunity in maintaining cellular homeostasis.
endoplasmic reticulum; X-box binding protein-1; polyIC; dendritic cells; inflammatory response; VSV
Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) is a unique member of the IL-10 gene family that displays nearly ubiquitous cancer-specific toxicity, with no harmful effects toward normal cells or tissues. mda-7/IL-24 was cloned from human melanoma cells by differentiation induction subtraction hybridization (DISH) and promotes endoplasmic reticulum (ER) stress culminating in apoptosis or toxic autophagy in a broad-spectrum of human cancers, when assayed in cell culture, in vivo in human tumor xenograft mouse models and in a Phase I clinical trial in patients with advanced cancers. This therapeutically active cytokine also induces indirect anti-tumor activity through inhibition of angiogenesis, stimulation of an anti-tumor immune response, and sensitization of cancer cells to radiation-, chemotherapy- and antibody-induced killing.
mda-7/IL-24; apoptosis; autophagy; bystander antitumor activity; cancer terminator virus
In murine renal cell carcinoma and melanoma models, vaccination with crosslinked tumor antigen in the absence of other adjuvants inhibited the growth of RENCA and B16 tumors. Vaccination with crosslinked antigens (CA9 or gp100) enhanced the cellular immune response as measured by ELISPOT and cytotoxicity assays. Crosslinking antigens enhanced delivery of antigen to bone marrow derived dendritic cells, which were capable of internalizing and processing the antigens. Dendritic cells pulsed with crosslinked antigen were effective in stimulating antigen-specific CD8+ T lymphocyte proliferation and interferon-γ secretion. Crosslinking tumor antigens is a simple and effective strategy for enhancing tumor vaccines.
crosslinking; immunoadjuvant; tumor vaccine
Our previous studies have demonstrated that the natural chaperone complexes of full-length tumor protein antigens (e.g., gp100) and large stress proteins (e.g., hsp110 and grp170) with exceptional antigen holding capabilities augment potent tumor protective immunity. Here we assess the peptide-interacting property of these large chaperones and, for the first time, compare the immunogenicity of the recombinant chaperone vaccines targeting two forms of antigens (protein vs peptide). Both hsp110 and grp170 readily formed complexes with antigenic peptides under physiological conditions, and the peptide association could be further stimulated by heat shock. The large chaperones displayed similar, but distinct peptide-binding features compared to hsp70 and grp94/gp96. Immunization with hsp110- or grp170-tyrosinase-related protein 2 (TRP2175–192) peptide complexes effectively primed CD8+ T-cells reactive with TRP2-derived, MHC I-restricted epitope. However, the tumor protective effect elicited by the TRP2175–192 peptide vaccine was much weaker than that achieved by full-length TRP2 protein antigen chaperoned by grp170. Furthermore, immunization with combined chaperone vaccines directed against two melanoma protein antigens (i.e., gp100 and TRP2) significantly improved overall antitumor efficacy when compared to either of the single antigen vaccine. Lastly, treatment of tumor-bearing mice with these dual antigen-targeted chaperone complexes resulted in an immune activation involving epitope spreading, which was associated with a strong growth inhibition of the established tumors. Our results suggest that high molecular weight chaperones are superior to conventional chaperones as a vaccine platform to deliver large protein antigens, and provide a rationale for translating this recombinant chaperoning-based vaccine to future clinical investigation.
large stress protein; chaperone; grp170; hsp110; antigen; immuogenicity