In vivo administration of plasmid DNA encoding recombinant immunotoxin DT390-IP-10 attenuates experimental autoimmune encephalomyelitis

Therapeutic potential of a novel IP-10-(anti-HER2 scFv) fusion protein for the treatment of HER2-positive breast cancer

OBJECTIVES

Interferon-γ-inducible protein 10 (IP-10) is a potent antitumor agent and acts by its angiostatic and immunomodulatory properties. IP-10 can target to tumor site by linking with single chain variable fragment (scFv) that recognized specific tumor antigen. In this study, we evaluated biological activity of the fusion protein including IP-10 and anti-HER2 scFv (IP-10-(anti-HER2 scFv)).

RESULTS

The HER2- and cell-based ELISA as well as the flow cytometry analysis demonstrated that the fusion protein specifically binds to HER2 antigen. In addition, competitive ELISA demonstrated that the fusion protein recognized the same epitope of HER2 antigen as trastuzumab. The results of MTT assay demonstrated that the growth of HER2-enriched SK-BR3 cells was inhibited in the presence of the fusion protein. Moreover, the cytotoxic effect of the fusion protein was not significantly different from that of trastuzumab. However, no significant cytotoxic effect compared to trastuzumab and anti-HER2 scFv was observed in HER2-low-expressing MDA-MB-231 cells. The obtained findings demonstrated that IP-10-(anti-HER2 scFv) can selectively reduce the cell viability in HER2⁺ cells. Moreover, similar inhibitory effect on growth of both SK-BR-3 and MDA-MB-231 cell lines was observed in the presence of anti-HER2 scFv protein even at high concentration after 72 h. The chemotaxis properties of the fusion protein were also analyzed by a chemotaxis assay. It was demonstrated that the fusion protein induced migration of activated T cell similar to recombinant IP-10 protein.

CONCLUSIONS

Our findings suggested that IP-10-(anti-HER2 scFv) fusion protein can specifically direct IP-10 to the HER2-expressing tumor cells and may act as an adjuvant along with HER2-based vaccine to gather the elicited immune response at the site of HER2-overexpressimg tumors.

An insight into the role of liposomal therapeutics in the reversion of Multiple Sclerosis

INTRODUCTION

Multiple Sclerosis (MS), as an autoimmune disease, has complicated immunopathology, which makes its management relevant to various factors. Novel pharmaceutical vehicles, especially liposomes, can support efficacious handling of this disease both in early detection and prognosis and also in a therapeutic manner. The most well-known trigger of MS onset is the predominance of cellular to humoral immunity and enhancement of inflammatory cytokines level. The installation of liposomes as nanoparticles to control this disease holds great promise up to now.

AREAS COVERED

Various types of liposomes with different properties and purposes have been formulated and targeted immune cells with their surface manipulations. They may be encapsulated with anti-inflammatory, MS-related therapeutics, or immunodominant myelin-specific peptides for attaining a higher therapeutic efficacy of the drugs or tolerance induction. Cationic liposomes are also highly applicable for gene delivery of the anti-inflammatory cytokines or silencing the inflammatory cytokines. Liposomes have also been used as biotools for comprehending MS pathomechanisms or as diagnostic agents.

EXPERT OPINION

The efforts to manage MS through nanomedicine, especially liposomal therapeutics, pave a new avenue to a high-throughput medication of this autoimmune disease and their translation to the clinic in the future for overcoming the challenges that MS patients confront.

Chemokine-based immunotherapy: delivery systems and combination therapies

A major role of chemokines is to mediate leukocyte migration through interaction with G-protein-coupled receptors. Various delivery systems have been developed to utilize the chemokine properties for combating disease. Viral and mutant viral vectors expressing chemokines, genetically modified dendritic cells with chemokine or chemokine receptors, engineered chemokine-expressing tumor cells and pDNA encoding chemokines are among these methods. Another approach for inducing a targeted immune response is fusion of a targeting antibody or antibody fragment to a chemokine. In addition, chemokines induce more effective antitumor immunity when used as adjuvants. In this regard, chemokines are codelivered along with antigens or fused as a targeting unit with antigenic moieties. In this review, several chemokines with their role in inducing immune response against different diseases are discussed, with a major emphasis on cancer.

Therapeutic targets and recent advances in protein immunotoxins

Targeted therapy has replaced the conventional methods of disease management with the advances in recombinant technology and increased understanding of molecular mechanisms of diseases. The immunotoxin strategy for diseases like cancer and a variety of autoimmune disorders has been used successfully in the past since its discovery. Since bacterial, fungal and plant toxins have various limitations like toxicity and immunogenicity, studies on fully humanized immunotoxins have gained attraction recently, which reduced toxicity significantly. Improved methods of antibody engineering have led to the emergence of various new formats of immunotoxins. This review summarizes the target moieties used in immunotoxin constructs in different diseases and describes the recent advances in immunotoxin targeting.

Specific killing of CCR9 high-expressing acute T lymphocytic leukemia cells by CCL25 fused with PE38 toxin

We have previously demonstrated that CCR9 plays a pivotal role in drug resistance and invasion in human acute T-lymphocytic leukemia (T-ALL). In this study, we investigated whether the MOLT4 cells, which naturally express CCR9 at high levels, can be successfully killed by the specific ligand, CCL25 fused to Pseudomonas exotoxin 38 (PE38) toxin. Our results demonstrated that CCL25-PE38 was able to specifically kill MOLT4 cells via apoptosis induction, and suppress the growth of CCR9(+) tumors. This work shows that CCR9 high-expressing human T-ALL cells can be successfully killed by delivering PE38 toxin fused to the ligand CCL25.

A single intrathecal injection of DNA and an asymmetric cationic lipid as lipoplexes ameliorates experimental autoimmune encephalomyelitis

Intrathecal delivery of gene therapeutics is a route of administration that overcomes several of the limitations that plague current immunosuppressive treatments for autoimmune diseases of the central nervous system (CNS). Here we report intrathecal delivery of small amounts (3 μg) of plasmid DNA that codes for an immunomodulatory fusion protein, OX40-TRAIL, composed of OX40, a tumor necrosis factor receptor, and tumor necrosis factor related apoptosis inducing ligand (TRAIL). This DNA was delivered in a formulated nucleic acid-lipid complex (lipoplexes) with an asymmetric two-chain cationic lipid myristoyl (14:0) and lauroyl (12:1) rosenthal inhibitor-substituted compound (MLRI) formed from the tetraalkylammonium glycerol-based compound N-(1-(2,3-dioleoyloxy)-propyl-N-1-(2-hydroxy)ethyl)-N,N-dimethyl ammonium iodide. Delivery and expression in the CNS of OX40-TRAIL in the mouse prior to onset of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, decreased the severity of clinical disease. We believe this preclinical demonstration of rapid, widespread, and biologically therapeutic nonviral gene delivery to the CNS is important in further development of clinical lipid-based therapeutics for CNS disorders.

CXCL10/IP-10 in infectious diseases pathogenesis and potential therapeutic implications

C-X-C motif chemokine 10 (CXCL10) also known as interferon γ-induced protein 10 kDa (IP-10) or small-inducible cytokine B10 is a cytokine belonging to the CXC chemokine family. CXCL10 binds CXCR3 receptor to induce chemotaxis, apoptosis, cell growth and angiostasis. Alterations in CXCL10 expression levels have been associated with inflammatory diseases including infectious diseases, immune dysfunction and tumor development. CXCL10 is also recognized as a biomarker that predicts severity of various diseases. A review of the emerging role of CXCL10 in pathogenesis of infectious diseases revealed diverse roles of CXCL10 in disease initiation and progression. The potential utilization of CXCL10 as a therapeutic target for infectious diseases is discussed.

CCR6 as a possible therapeutic target in psoriasis

IMPORTANCE OF THE FIELD

Psoriasis is a common, chronic autoimmune disease of the skin. Despite a number of effective treatments, new therapies are needed with enhanced efficacy, safety and convenience. Chemokine receptors are GPCRs that control leukocyte trafficking, and like other GPCRs, are good potential drug targets. The chemokine receptor CCR6 is expressed on the T(H)17 subset of CD4(+) T cells, which produces IL-17A/F, IL-22, TNF-alpha and other cytokines, and which has been implicated in the pathogenesis of psoriasis. CCR6 and its ligand, CCL20/MIP-3alpha, are highly expressed in psoriatic skin and CCR6 is necessary for the pathology induced in a mouse model of psoriasis-like inflammation.

AREAS COVERED IN THIS REVIEW

This review summarizes the evidence for the importance of the IL-23/T(H)17 axis, and in particular CCR6 and CCL20 in psoriasis, dating from 2000 to the present, and discusses the possibility of inhibiting CCR6 as a treatment for the disease.

WHAT THE READER WILL GAIN

The review informs the reader of the current thinking on the mechanisms of inflammation in psoriasis and the possible roles for CCR6 (and CCL20) in disease pathogenesis.

TAKE HOME MESSAGE

We conclude that CCR6 should be investigated as a potential therapeutic target in psoriasis.

Gene therapy in autoimmune diseases: challenges and opportunities

Clinical treatment of autoimmune disorders presents a special challenge. For decades, most clinical regimens in autoimmunity has been largely symptomatic and non-disease specific. Although data from vigorous research has lead to accumulating knowledge on the pathogenic and immunological mechanisms of many autoimmune diseases, their direct clinical applications have been sparse. Advances in biotechnology have laid the groundwork for potent and specific molecular targeting therapies by gene therapy, and have just begun to be investigated in the treatment of autoimmune disorders. Such work has been largely based on the availability of well-established animal models of common autoimmune disorders, and the efficacy of strategic approaches initially investigated and validated in these models. Although these preclinical animal model studies have provided the proof-of-concept for multiple potential applications, human clinical trials on gene therapy in autoimmunity are still at its infancy. The recent success of Phase I/II clinical trials of gene therapy in rheumatoid arthritis and multiple sclerosis, development of cutting edge technology in target identification, as well as gene delivery systems have now set the stage for a more thorough and vigorous pace in the near future to advance this exciting field.

A novel recombinant immunotoxin with the smallest ribosome-inactivating protein Luffin P1: T-cell cytotoxicity and prolongation of allograft survival

In the creation of stable tolerance to MHC-incompatible allografts, reducing the large mass of donor-reactive cells via apoptosis is often required. Apoptosis induction by immunotoxins targeting surface molecules specifically presented on donor-reactive cytopathic T effector (T_eff) cells is a promising strategy. Traditionally, the toxin moieties are bacterial exotoxins or plant-derived ribosome-inactivating proteins (RIPs) with large molecular size and strong immunogenicity, hence causing the problems of tissue penetration, host immune reaction and quick clearance. We have identified a novel class of small molecule RIPs (<10 kD) from the seeds of the plant Luffa cylindrica. The smallest member of this family, Luffin P1, has a molecular weight of 5226.8 Da, yet possessing a highly potent inhibitory activity on cell-free protein synthesis with IC50 of 0.88 nM. We now report a recombinant hIL-2-Luffin P1 immunotoxin, which strongly inhibited T-cell proliferation in mixed lymphocyte reaction and ConA response with IC50 of 1.8–10 nM. In vivo, hIL-2-Luffin P1 significantly prolonged the survival of major MHC-mismatched skin and kidney allografts in animal models. Thus, we demonstrate for the first time the efficacy of the smallest immunotoxin that could be further combined with other pharmacological and immunological reagents for synergistic control of pathogenic lymphocytes in immune-mediated diseases.

The use of chemokine antagonists in EAE models

Multiple sclerosis is believed to be an autoimmune disease with an end-point of neuro-degeneration, but in which inflammation plays a predominant role. Therefore therapies which target inhibition of the excessive recruitment of leukocytes into the central nervous system (CNS) are actively sought after by medical research. Drug discovery relies heavily on animal models used for such research, called Experimental Autoimmune Encephalomyelitis (EAE). Several chemokines and their receptors have been shown to play a role in this recruitment into the CNS, and we have investigated several strategies which antagonize this system in EAE models. We will discuss these strategies and their successes and failures to prevent disease symptoms and the insights they have provided.