Anti-CD3/anti-CD28 monoclonal antibody-coated suture enhances the immune response of patients with head and neck squamous cell carcinoma

Filaments with Affinity Binding and Wet Strength Can Be Achieved by Spinning Bifunctional Cellulose Nanofibrils

We demonstrate benzophenone (BP) conjugation via amine-reactive esters onto oxidized cellulosic fibers that were used as precursors, after microfluidization, of photoactive cellulose nanofibrils (CNF). From these fibrils, cellulose I filaments were synthesized by hydrogel spinning in an antisolvent followed by fast biradical UV cross-linking. As a result, the wet BP-CNF filaments retained extensively the original dry strength (a remarkable ∼80% retention). Thus, the principal limitation of these emerging materials was overcome (the wet tensile strength is typically <0.5% of the value measured in dry conditions). Subsequently, antihuman hemoglobin (anti-Hb) antibodies were conjugated onto residual surface carboxyl groups, making the filaments bifunctional for their active groups and properties (wet strength and bioactivity). Optical (surface plasmon resonance) and electroacoustic (quartz crystal microgravimetry) measurements conducted with the bifunctional CNF indicated effective anti-Hb conjugation (2.4 mg m^-2), endowing an excellent sensitivity toward Hb targets (1.7 ± 0.12 mg m^-2) and negligible nonspecific binding. Thus, the anti-Hb biointerface was deployed on filaments that captured Hb efficiently from aqueous matrices (confocal laser microscopy of FITC-labeled antibodies). Significantly, the anti-Hb biointerface was suitable for regeneration, while its sensitivity and selectivity in affinity binding can be tailored by application of blocking copolymers. The developed bifunctional filaments based on nanocellulose offer great promise in detection and affinity binding built upon 1D systems, which can be engineered into other structures for rational use of material and space.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

Covalent linking of proteins and cytokines to suture: Enhancing the immune response of head and neck cancer patients

BACKGROUND

The immune system of advanced stage head and neck cancer patients is frequently suppressed. Poor immune function has been correlated with poor clinical outcome. Immunotherapeutic strategies have been previously attempted in an effort to enhance immune function and improve survival. Previous studies have shown surgical suture can be transformed into an immune stimulant capable of activating the T lymphocytes of cancer patients. The development of a process for covalently linking proteins and cytokines to suture could have enormous potential for the in vivo manipulation of the immune system.

HYPOTHESIS

We hypothesize proteins and cytokines can be covalently linked to surgical suture while preserving their functional properties.

STUDY DESIGN

Prospective study testing normal donor and head and neck squamous cell carcinoma (HNSCC) patient lymphocytes.

METHOD

Polyester suture was acid hydrolyzed followed by reacting with 1-ethyl-3(-3-dimethylamino propyl carbodiimide) (EDAC) to create a suture-EDAC intermediate. Next, selected proteins (horseradish peroxidase [HRP] or bovine serum albumin [BSA]) or cytokines (interleukin [IL]-2 or interferon [IFN]-gamma) were reacted with the suture-EDAC intermediate to test the covalent linkage of the selected protein or cytokine to suture. Functional activity of the linked proteins was measured spectrophotometrically. The linking of cytokines to suture was tested by stimulating normal donor peripheral blood lymphocytes (PBL) or HNSCC patients' lymphocytes. The functional activity was confirmed by proliferation, enzyme linked immunoadsorbent assay (ELISA), and phenotype expression of T cells. RESULTS The conditions for optimally linking a protein to polyester suture were defined using HRP as a model protein. HRP retained its enzymatic activity. The optimal conditions for linking IL-2 or IFN-gamma were defined. The covalently linked cytokines retained their immune enhancing properties for stimulating PBL and lymph node lymphocytes (LNL) from HNSCC patients to proliferate, generate a TH1 immunologic profile of cytokines (IL-2, IL-12, IFN-gamma), and stimulate T lymphocytes.

CONCLUSION

This is the first report to demonstrate that cytokines can be covalently linked to surgical sutures and retain their immune-stimulating properties. Proteins linked to suture also retained their enzymatic activity. The clinical implications of functionally active cytokines or proteins linked to surgical suture may be very significant in the future for manipulating the immune system in vivo or enhancing wound healing.

Bioactive Sutures

With the first wave of bioactive sutures already in the marketplace, research is ongoing in the development of future products. Such sutures could potentially have not only antimicrobial activity but also anesthetic and antineoplastic functions. Some clinical trials have already been completed in Russia. This technology is likely to become commonplace. This article reviews the progress made to date in the development of this technology.

Linking of Bone Morphogenetic Protein-2 To Resorbable Fracture Plates for Enhancing Bone Healing

OBJECTIVE

To test whether bone morphogenetic protein (BMP)-2 may be covalently linked to resorbable fracture repair plates using an ester-hydrolysis reaction and determining whether the linked compound can facilitate bone growth.

STUDY DESIGN

Laboratory in vitro experiments.

METHOD

Resorbable fracture repair plates were partially hydrolyzed using varying concentrations of acid or base. This intermediate was then reacted with EDAC (1-ethyl-3[-3-dimethylamino propyl carbodiimide) to form an EDAC intermediate, which was then reacted with either horseradish peroxidase (HRP), interleukin (IL)-2, or BMP-2. Compound binding to the plate was confirmed by immunofluorescent staining. Confirmation of protein function was determined by the following assays: HRP's ability to cleave peroxide, IL-2's ability to stimulate lymphocytes, and BMP-2's ability to stimulate C3H10T1/2 cells to generate alkaline phosphatase.

RESULTS

Three compounds (HRP, IL-2, and BMP-2) were successfully linked to plates as confirmed by immunofluorescence staining or functional testing. Compounds demonstrated better covalent linking to plates under basic conditions. HRP, IL-2, and BMP-2 retained function after binding as measured by cleaved peroxide levels, lymphocytes proliferation, and alkaline phosphatase production.

CONCLUSIONS

Covalent linking of compounds such as HRP, IL-2, and BMP-2 to resorbable plates is possible and represents a novel protein delivery technique. BMP-2 covalently linked to resorbable plates may be used to facilitate bone healing. Covalent linking of compounds to plates represents a novel method for delivering concentrated levels of growth factors to a specific site and potentially extending their half-life. Further investigation into this application for bone healing may lead to quicker healing.

Plattenepithelkarzinome des Kopf-Hals-Bereichs

Biologic therapies able to induce or up-regulate anti-tumor immune responses could represent a complementary approach to improve the conventional treatment of squamous cell carcinomas of the head and neck (SCCHN). Patients with SCCHN are frequently immunocompromised due to the elimination and dysfunction of critical immune effector cells. Therefore, it might be necessary to restore these immune functions to allow for the generation of effective anti-tumor host responses. Simultaneously, to prevent tumor escape from immunological recognition and destruction, it might also be necessary to alter antigenic and immunogenic attributes of the malignant cells. The present overview summarizes general aspects, historical data, and recent advances in the field of immunotherapy of SCCHN, including non-specific immune stimulation, transfer of immunocompetent cells, gene therapy, use of monoclonal antibodies, and anti-cancer vaccines.

Targeting the immune system: novel therapeutic approaches in squamous cell carcinoma of the head and neck

Despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for patients with squamous cell carcinoma of the head and neck (SCCHN) have not changed over the last decades. Clearly, novel therapeutic strategies are needed for this cancer, which is highly immunosuppressive. Therefore, biologic therapies able to induce and/or up-regulate antitumor immune responses could represent a complementary approach to conventional treatments. Because patients with SCCHN are frequently immunocompromised due to the elimination or dysfunction of critical effector cells of the immune system, it might be necessary to restore these immune functions to allow for the generation of more effective antitumor host responses. Simultaneously, to prevent tumor escape, it might be necessary to alter attributes of the malignant cells. The present review summarizes recent advances in the field of immunotherapy of SCCHN, including techniques of nonspecific immune stimulation, the use of monoclonal antibodies, advances in adoptive immunotherapy and genetic engineering, as well as anticancer vaccines. These biologic therapies, alone or in combination with conventional treatment, are likely to develop into useful future treatment options for patients with SCCHN.

Bioactive Suture

PURPOSE

We have proposed to characterize the mechanism through which bioactive surgical sutures generate a T(H)1 immune response and to define the immune-stimulating half-life of the sutures.

EXPERIMENTAL DESIGN

Bioactive sutures of interferon gamma (IFNgamma), interleukin 2 (IL-2), anti-CD3/CD28, anti-CD3/CD28 + IL-2, or anti-CD3/CD28 + IFNgamma sutures were used to stimulate lymphocytes from normal donors and from head and neck cancer patients in vitro over a 24-day period. Cell supernatants were analyzed by ELISA, and T cells were phenotyped to characterize the immune response generated. Intracellular cytokine staining was performed to measure the expansion of flu-specific T cells. Electromobility shift assay and supershift assay were used to measure the intranuclear DNA binding activity of nuclear factor kappaB and its p65 subunit in T cells activated by sutures in the presence and absence of a proteasome inhibitor, MG-132.

RESULTS

Anti-CD3/CD28, anti-CD3/CD28 + IL-2, or anti-CD3/CD28 + IFNgamma generated a prolonged T(H)1 immune response for 18 days in vitro. Anti-CD3/CD28 expanded flu-specific T cells. Activated T cells demonstrated enhanced CD40 ligand (CD40L) expression within 72 hours of stimulation, which stimulated other cells to secrete IL-12. Stimulated T cells demonstrated increased intranuclear expression of nuclear factor-kappaB, which was blocked by MG-132, and also reduced CD40L and IL-12 expression.

CONCLUSIONS

This is the first report to demonstrate that bioactive surgical sutures can generate a prolonged T(H)1 immune response and expand flu-specific T cells. Bioactive sutures, which are primarily a T-cell stimulant, also stimulated other cells to secrete IL-12 and prolonged the immune response. Sutures may provide a novel in situ stimulating strategy for enhancing the immune system of cancer patients.

Absorbable microparticulate cation exchanger for immunotherapeutic delivery

An absorbable microparticulate cation exchanger was synthesized as a versatile carrier for biologically active proteins. In this work, acid-terminated polyglycolide (or polyglycolic acid) microparticulates (PG-MP) were surface modified for either sustained release of cytokines or as a platform for immunomodulation. The intended goal was to achieve in situ recruitment/maturation of dendritic cells and activation of T cells for tumor immunotherapy. PG-MP were prepared with a volume weighted mean diameter of 7.02 micro (range: 2.09-14.58 micro). Accessible carboxylic acid groups were determined to be 0.3 mmol/g with a corresponding zeta potential of -21.87 mV in phosphate-buffered saline. Under low magnification, scanning electron microscopy (SEM) revealed a highly textured surface due to processing from repetitive jet milling. However, a moderately porous architecture was noted at higher magnification. Electron spectroscopy for chemical analysis was used to characterize the PG-MP surface before and after adsorption of human granulocyte-macrophage colony stimulating factor (GM-CSF). Adsorption of GM-CSF on PG-MP (PG-GMCSF) resulted in a modest increase in the surface atomic concentration of nitrogen (0.97%). Pretreating the surface with poly-L-lysine (PG/Lys-GMCSF) prior to adding GM-CSF produced a nearly threefold increase in the surface nitrogen concentration (4.20% compared to 1.47%). This manipulation not only increased loading content, but also prolonged the release of GM-CSF released from 6 days to 26 days. ESCA on the post-release PG-MP samples (PG-GMCSF and PG/Lys-GMCSF) revealed a similar residual surface nitrogen concentration (2.26% vs. 2.35%). The observation was consistent with irreversibly adsorbed GM-CSF. It is postulated that irreversibly bound GM-CSF is released over time as a function of microparticulate degradation. Biological activity of released GM-CSF was confirmed by the proliferation of a GM-CSF-dependent cell line (TF-1) in the presence of microparticulates. PG-MP mediated activation of T cells was achieved through irreversible adsorption of either antimouse cd3 plus antimouse cd28 monoclonal antibodies (alpha-cd3/cd28-MP) or antihuman CD3 plus antihuman CD28 monoclonal antibodies (alpha-CD3/CD28-MP) on PG-MP. Irreversibly adsorbed antibodies were capable of activating both resting mouse and human T cells. Intracellular flow cytometry on mouse T cells revealed that nearly 50% of the activated cells produced interferon-gamma (IFN-gamma). This was consistent with a TH-1 or cell-mediated response. In vivo efficacy was evaluated in a mouse flank tumor model showing a significant antitumor effect both alone and in combination. Combination therapy was most effective at preventing tumor implantation (8/8 mice) and was able induce tumor regression (4/7 mice) and/or stable disease (3/7 mice) in a regression model. In these studies, immunohistochemistry was used to confirm local recruitment of dendritic cells. In conclusion, the PG-MP represents a novel absorbable cation exchanger that can be readily manipulated to deliver biologically active proteins for immunotherapy.

Locally advanced nasopharyngeal cancer

The Head and Neck Cancer Intergroup phase III clinical trial (Int 0099) for patients with locally advanced, squamous cell carcinomas (SCC) of the nasopharynx (or NPC) has been recently completed in the United States. The results of this study have defined the new standard of treatment for the group of patients studied. Patients with untreated, locally advanced stages III and IV NPC were randomized to a conventional course of radiation, or to radiation given concurrently with chemotherapy followed by three courses of combination chemotherapy. The 3-year progression-free survival (PFS) and overall survival (OS) were 24% versus 69% (P < 0.001) and 46% versus 76% (P < 0.001) for the control and experimental groups, respectively. Recent updates of these survival figures show that they have not changed appreciably. The considerable improvement in OS versus PFS for the patient group receiving radiation alone is accounted for primarily by re-treatment with concurrent radiation-chemotherapy, combination chemotherapy, and isolated salvage neck dissections. Highly significant differences in local control (41% vs 14%) and distant metastases (35% vs 13%) were demonstrated in favor of the chemoradiation treatment arm. The median age for these patients was 51 years, with a 2:1 male to female ratio. Although many patients had a significant history of tobacco exposure with or without alcohol use or abuse, only 24% had keratinizing or well-differentiated squamous (World Health Organization I) type tumors. Whether these results can be extrapolated to the more common Asian variety (WHO II and III) of advanced NPC must be addressed in future clinical trials.