Phase 1 Trial of Vaccination with Autologous Tumor Cells and Antisense Directed Against the Insulin Growth Factor Type 1 Receptor (IGF-1R AS ODN) in Patients with Recurrent Glioblastoma

Background: Extending a previous Phase I study, we report the results of a second Phase I autologous tumor cell vaccination trial for patients with recurrent glioblastomas (IND 14379-101, NCT01550523). Methods: Following surgery, subjects were treated by 24 hour implantation in the rectus sheath of ten biodiffusion chambers containing irradiated autologous tumor cells and IGF-1R AS ODN with the objective of stimulating tumor immunity. Patients were monitored for safety, clinical and radiographic as well as immune responses. Results: There were no Grade 3 toxicities related to protocol treatment and overall median survival from initial diagnosis was 91.4 weeks. Two protocol survival cohorts with median survivals of 48.2 and 10 weeks were identified and predicted by our pre-treatment assessments of immune function, corroborated by post-vaccination pro-inflammatory cytokine profiles. Longer survival subjects had imaging findings including transient elevations in cerebral blood volume (rCBV) and sustained elevations of apparent diffusion coefficient (ADC) interpreted as transient hyperemia and cell loss. Conclusions: The vaccine paradigm was well-tolerated with a favorable median survival. Our data support this as a novel treatment paradigm that promotes anti-tumor immunity

Intracellular Monitoring by Dendritic Cells - A New Way to Stay Informed - from a Simple Scavenger to an Active Gatherer

Dendritic cells (DCs) are required for the initiation of the adaptive immune response. Their ability to acquire antigens in the periphery is a critical step in this process. DCs express a wide variety of adhesion molecules and possess an extremely fluid plasma membrane that facilitates scavenging the extracellular environment and capturing material like exosomes, apoptotic bodies, and pathogens. Besides these standard routes, the acquisition of antigens by DCs can be further facilitated by tunneling nanotubes, trogocytosis, and gap junctions. However, in this article, we will argue that this is an incomplete picture, as certain observations in the literature cannot be explained if we assume DCs acquire antigens only through these means. Instead, it is more likely that DCs preferentially use adhesion molecules to form long-lasting cell-cell interactions to actively siphon material from cells they are in direct contact with. It is highly likely that DCs use this mechanism to continually capture membrane and cytosolic material directly from surrounding cells, which they scan to assess the health of the donor cell. Doing so would provide an array of advantages for the host immune system, as it would not be reliant on compromised cells to release antigens into the extracellular milieu. Therefore, we propose updating our view of DC antigen acquisition to include a process of active, contact-dependent capture of material directly from neighboring cell cytosol (cytocytosis), which we would term intracellular monitoring

Cerebrospinal Fluid Cytokine and Chemokine Patterns in Central Nervous System Infections, Hemorrhage and Neoplasms

Cytokines and chemokines are soluble proteins that act as regulators of cellular functions throughout the body. Cytokines and chemokines released in the setting of various CNS disorders appear in the CSF compartment where determination of their levels can provide insight into pathogenic processes such as neuroinflammation. We utilized the Millipore HCYTOMAG 60K assay/kit/system to perform multiplex profiling of 42 different cytokines/chemokines in the CSF of patients with a variety of distinct CNS disease processes, including infection, hemorrhage and neoplasia. CNS infections included viral (Chronic Parechovirus type 3 (HPeV3), Enterovirus (EV) 68, Adenovirus, JC virus, West Nile virus), bacterial (Mycobacterium tuberculosis, Borrelia burgdorferi, Propionibacterium acnes, Staphylococcus epidermidis, Streptococcus sp.), fungal (Cryptococcus neoformans) and single celled parasite (Toxoplasma gondii). CSF specimens negative for infectious organisms in noninflammatory conditions were selected as controls. Additional non-infectious samples tested were obtained from patients with subarachnoid hemorrhage (SAH) and following surgery for glioblastoma. The glioblastoma samples were noteworthy in having negligible elevations in the cytokines/chemokines tested. CSF from patients with SAH was elevated in only MCP-1/CCL2. Distinct patterns of cytokine/chemokine expression were detected for each infectious patient population. Picornavirus infections HPeV3 and EV68 were associated with increased levels of the monocyte chemoattractant protein MCP-1/CCL2 when compared to non-infectious, non-inflammatory samples. In contrast to chronic HPeV3 infection, EV68 encephalitis was associated with increased CSF levels of additional cytokines; CCLX1, IL-4 and IL-7. Adenovirus infection was associated with markedly higher levels of fractalkine in CSF when compared to any of the other non-inflammatory, infectious, hemorrhage or tumor cases. CSF from a Mycobacterium tuberculosis infection demonstrated increased levels of a greater variety of cytokines/chemokines than any of the other groups tested. Patterns of cytokine/chemokine expression in the CNS reveal characteristics of the host innate response that provide insight into the disease process and potential targets for therapeutic intervention

Continuous acquisition of MHC:peptide complexes by recipient cells contributes to the generation of anti-graft CD8+T cell immunity

Understanding the evolution of the direct and indirect pathways of allorecognition following tissue transplantation is essential in the design of tolerance-promoting protocols. On the basis that donor bone marrow-derived antigen presenting cells are eliminated within days of transplantation, it has been argued that the indirect response represents the major threat to long term transplant survival, and is consequently the key target for regulation. However, the detection of MHC transfer between cells, and particularly the capture of MHC:peptide complexes by dendritic cells, led us to propose a third, semi-direct, pathway of MHC allorecognition. Persistence of this pathway would lead to sustained activation of direct pathway T cells, arguably persisting for the life of the transplant. In this study, we focused on the contribution of acquired MHC class I, on recipient DCs, during the life span of a skin graft. We observed that MHC class I acquisition by recipient DCs occurs for at least one month following transplantation and may be the main source of alloantigen that drives CD8+ cytotoxic T cell responses. In addition, acquired MHC class I-peptide complexes stimulate T cell responses in vivo further emphasizing the need to regulate both pathways to induce indefinite survival of the graft

Prognostic Significance of Tumor-Associated Macrophage Content in Head and Neck Squamous Cell Carcinoma: A Meta-Analysis.

Background: Head and neck squamous cell carcinoma (HNSCC) exists within a microenvironment rich in immune cells. Macrophages are particularly abundant in and around tumor tissue, and have been implicated in the growth, malignancy, and persistence of HNSCC (1). However, current literature reports variable degrees of association between the density of tumor-associated macrophages (TAMs) and clinicopathologic markers of disease (2, 3). These inconsistent findings may be a result of differences in approach to TAM detection. Authors have measured total TAMs in tumor tissue, while others have stained tumor samples for individual subtypes of TAMs, which include pro-inflammatory (M1-like) and immunosuppressive (M2-like). Our aim is to more clearly define the prognostic significance of the phenotypes of tumor-associated macrophages in HNSCC. Methods: We conducted a meta-analysis of the existing publications investigating the relationship between TAMs (total and M2-like subtype) and T stage, nodal involvement, vascular invasion, lymphatic invasion, and tumor differentiation (Figure 1). A total of 12 studies were included. Forest plots and risk ratios were generated to report overall effect. Results: Higher density of both total and M2-like subtype of TAMs in the tumor microenvironment is associated with advanced T stage, increased rates of nodal positivity, presence of vascular invasion, and presence of lymphatic invasion (p \u3c 0.0001; Figures 2–9). There is no significant association between TAM density, either total or M2-like subtype, and tumor differentiation (Figures 10, 11). Conclusions: Increased density of TAMs, including those of the M2-like phenotype, correlate with poor clinicopathologic markers in HNSCC. Our findings warrant additional investigation into the subpopulations of TAMs, the mechanisms behind their recruitment and differentiation, and the associated influence of each phenotype on tumor growth and invasion. A greater understanding of TAM dynamics in HNSCC is critical for directing further research and employing TAM-targeted adjunct therapies

Human Parechovirus and Enterovirus Initiate Divergent Innate Immune Responses in the CNS: Pathogenic and Diagnostic Implications

The picornaviruses human parechovirus (HPeV) and enterovirus (EV) cause a wide range of diseases, including CNS infections, which can be severe and potentially fatal. EV causes most cases of pediatric meningoencephalitis worldwide, and HPeV type 3 (HPeV3) is the most common cause of viral meningitis in young infants. Each year in the United States, there are over 75,000 cases of aseptic meningitis. Despite reassuring short-term outcomes, negative neurodevelopmental sequalae are increasingly associated with HPeV and EV. The pathogenesis and severity of HPeV and EV infections are undoubtedly linked to the innate and adaptive immune responses elicited by these viruses. Until this work, the innate immune response mounted against HPeV was largely unknown. Pattern recognition receptors in the CNS, including a number of Toll-like receptors located in different cells and subcellular compartments, detect invading pathogens and cause the release of cytokines and chemokines almost immediately into the CSF compartment at measurable levels. Essentially, this allows for determination of an amplified, infectious agent-specific pattern. These virus specific patterns of innate immune activation may provide insight into the pathogenesis of the corresponding disease states. Also, since these infections have similar clinical presentations, the immune profiles may be useful for rapid pathogen diagnosis in the clinical setting

High Density of Tumor-Associated Macrophage Staining Correlates with Poor Clinicopathologic Markers in Head and Neck Squamous Cell Carcinoma: A Meta-Analysis

Background: Head and neck squamous cell carcinoma (HNSCC) develops within a complex cellular microenvironment that promotes tumor growth, but also represents many potential therapeutic targets. Macrophage presence within that environment has been implicated in the growth, aggression, and persistence of HNSCC. Current literature reports variable degrees of association between tumor-associated macrophage (TAMs) density and clinicopathologic markers of disease.Inconsistent findings may result from grouping of TAM subtypes, which include both M1 (pro-inflammatory) and M2 (immunosuppressive). Our aim is to define the prognostic significance of the phenotypes of tumor-associated macrophages in HNSCC. Methods: We conducted a meta-analysis of the existing publications investigating the relationship between TAMs (total and M2 subtype) and T stage, nodal involvement, vascular invasion, lymphatic invasion, and tumor differentiation. Forest plots and risk ratios were generated to report overall effect. Results: Higher density of both total and M2 subtype of TAMs in the tumor microenvironment is associated with advanced T stage, increased rates of nodal positivity, presence of vascular invasion, and presence of lymphatic invasion (p \u3c 0.0001). There is no significant association between either total or M2 TAM density and tumor differentiation. Conclusion: Increased density of TAMs, including those of the M2 phenotype, correlates with poor clinicopathologic markers in HNSCC, and therefore poor clinical prognosis. It is unknown whether this relationship is causative or correlative. Additional investigation into the mechanisms behind TAM recruitment and differentiation, and effect of TAM population manipulation on tumor behavior will help define the feasibility of TAM-targeted therapies

Cancer-Associated Fibroblast Density, Prognostic Characteristics, and Recurrence in Head and Neck Squamous Cell Carcinoma: A Meta-Analysis.

Introduction: The progression and clinical course of head and neck squamous cell carcinoma (HNSCC) relies on complex interactions between cancer and stromal cells in the tumor microenvironment (TME). Among the most abundant of these stromal cells are cancer-associated fibroblasts (CAFs). While their contribution to tumor progression is widely acknowledged, and various CAF-targeted treatments are under development, the relationship between CAF density and the clinicopathologic course of HNSCC has not been clearly defined. Here we examine the published evidence investigating the relationship of cancer-associated fibroblasts to local recurrence and indicators of prognostic significance in HNSCC. Methods: We conducted a meta-analysis of existing publications that compare the relationship between CAF density, local recurrence, and clinically significant pathologic criteria of disease development (T stage, nodal positivity, clinical stage, vascular invasion, perineural invasion, Ki67 expression, and differentiation). Thirteen studies met the selection criteria, providing a total study population of 926 patients. Forest plots and risk ratios were generated to illustrate overall relationships. Results: Higher CAF density within the tumor microenvironment is associated with advanced T stage, nodal infiltration, clinical stage, vascular invasion, perineural invasion, Ki67 expression, and differentiation (p Conclusions: Across multiple studies, increased CAF density is correlated with histopathological criteria of poor prognosis in HNSCC. These findings highlight that CAFs may play a pivotal role in HNSCC development and progression. Staining for CAFs may represent a valuable addition to current pathologic analysis and help to guide prognosis and treatment. Understanding the mechanisms by which CAFs reciprocally interact with cancer cells will be crucial for optimization of TME-focused treatment of HNSCC