Achim Schneeberger

Next-generation active immunization approach for synucleinopathies: implications for Parkinson's disease clinical trials.

Immunotherapeutic approaches are currently in the spotlight for their potential as disease-modifying treatments for neurodegenerative disorders. The discovery that α-synuclein (α-syn) can transmit from cell to cell in a prion-like fashion suggests that immunization might be a viable option for the treatment of synucleinopathies. This possibility has been bolstered by the development of next-generation active vaccination technology with short peptides-AFFITOPEs® (AFF)- that do not elicit an α-syn-specific T cell response. This approach allows for the production of long term, sustained, more specific, non-cross reacting antibodies suitable for the treatment of synucleinopathies, such as Parkinson’s disease (PD). In this context, we screened a large library of peptides that mimic the C-terminus region of α-syn and discovered a novel set of AFF that identified α-syn oligomers. Next, the peptide that elicited the most specific response against α-syn (AFF 1) was selected for immunizing two different transgenic (tg) mouse models of PD and Dementia with Lewy bodies, the PDGF- and the mThy1-α-syn tg mice. Vaccination with AFF 1 resulted in high antibody titers in CSF and plasma, which crossed into the CNS and recognized α-syn aggregates. Active vaccination with AFF 1 resulted in decreased accumulation of α-syn oligomers in axons and synapses, accompanied by reduced degeneration of TH fibers in the caudo-putamen nucleus and by improvements in motor and memory deficits in both in vivo models. Clearance of α-syn involved activation of microglia and increased anti-inflammatory cytokine expression, further supporting the efficacy of this novel active vaccination approach for synucleinopathies.

Active immunization against alpha-synuclein ameliorates the degenerative pathology and prevents demyelination in a model of multiple system atrophy

BackgroundMultiple system atrophy (MSA) is a neurodegenerative disease characterized by parkinsonism, ataxia and dysautonomia. Histopathologically, the hallmark of MSA is the abnormal accumulation of alpha-synuclein (α-syn) within oligodendroglial cells, leading to neuroinflammation, demyelination and neuronal death. Currently, there is no disease-modifying treatment for MSA. In this sense, we have previously shown that next-generation active vaccination technology with short peptides, AFFITOPEs®, was effective in two transgenic models of synucleinopathies at reducing behavioral deficits, α-syn accumulation and inflammation.ResultsIn this manuscript, we used the most effective AFFITOPE® (AFF 1) for immunizing MBP-α-syn transgenic mice, a model of MSA that expresses α-syn in oligodendrocytes. Vaccination with AFF 1 resulted in the production of specific anti-α-syn antibodies that crossed into the central nervous system and recognized α-syn aggregates within glial cells. Active vaccination with AFF 1 resulted in decreased accumulation of α-syn, reduced demyelination in neocortex, striatum and corpus callosum, and reduced neurodegeneration. Clearance of α-syn involved activation of microglia and reduced spreading of α-syn to astroglial cells.ConclusionsThis study further validates the efficacy of vaccination with AFFITOPEs® for ameliorating the neurodegenerative pathology in synucleinopathies.

Induction of Specific Immune Responses by Polycation-Based Vaccines

The s.c injection of tumor Ag-derived, MHC class I-binding peptides together with cationic poly-amino acids (e.g., poly-l-arginine; pR) has been shown to protect animals against a challenge with tumor cells expressing the respective peptide(s). Given our only restricted knowledge about immunogenic tumor-associated peptides, we sought to determine whether this pR-based vaccination protocol would also induce protective cancer immunity if large proteins were used instead of peptide epitopes. We found that the intracutaneous administration of the model Ag β-galactosidase (β-gal) together with pR (referred to as pR-based protein vaccine; pR-PV) was significantly more potent in protecting mice against the growth of β-gal-expressing RENCA cells than the protein alone. Coadministration of pR enhanced both the β-gal-induced specific humoral and CD8 response. The protective effect required CD8+, but neither CD4+ T lymphocytes nor β-gal-specific Abs. β-Gal priming of protective CD8+ T lymphocytes was found to be CD4+ T cell-independent, to take place within the draining lymph nodes, and to be accomplished by day 5 after vaccination. Ablation of the injection sites as early as 1.5 h after pR-PV administration still led to protection in a large proportion of the animals, indicating that certain protein Ags administered intradermally in the context of polycations are quickly transported to the draining nodes, where they induce molecular and cellular events resulting in the helper-independent priming and expansion of Tc1 cells. However, optimal protection required the prolonged presence of the injection site, suggesting that pR-PV injection facilitates the formation of a cutaneous depot of Ag-charged cells capable of migration and T cell activation.

Phase I study to the immunotherapy of metastatic malignant melanoma by a cancer vaccine consisting of autologous cancer cells transfected with the human IL-2 gene.

Vienna: 30 November 1994 Würzburg: 7 February 1995 Freiburg: 7 February 1995 Registration of protocol with state authority AMB: 7 November 1994 Bfarm: 30 October 1994 Registration of product with federal authority (Paul-Ehrlich-Institut) 30 December 1994 Therapeutic gene Human interleukin-2 Regulatory element(s) CMV promoter Vector constructed by Institute of Molecular Pathology, Vienna, Austria Vector produced by Bender & Co., Vienna, Austria Transfer method Receptor-mediated, adenovirus enhanced gene transfer (transferinfection) in vitro Packaging cells N/A Target cells Autologous human malignant melanoma cells Indication Metastatic malignant melanoma (stage IV) First patient enrolled 15 December 1994 (Vienna) Patient number 12 evaluable patients Expected accrual rate 3 patients per month

Management of malignant melanoma: new developments in immune and gene therapy

Thus far, the use of classical anti‐cancer treatment modalities had only rarely a beneficial impact on the prognosis of patients with metastatic melanoma. We as physicians have therefore the obligation as well as the chance to develop and test new therapeutic strategies. Our growing knowledge about the genetic basis of melanoma provides one platform to fulfil this task. Another one comes from our increasing understanding of the molecular and cellular mechanisms involved in the induction/modulation of immune responses, as well as the progress made in the field of identification of melanoma antigens, and allows for the development of a new generation of vaccines. The aim of this article is to discuss several of these new concepts towards the use of immune and gene therapy of melanoma.

Tailoring the antibody response to aggregated Aß using novel Alzheimer-vaccines.

Recent evidence suggests Alzheimer-Disease (AD) to be driven by aggregated Aß. Capitalizing on the mechanism of molecular mimicry and applying several selection layers, we screened peptide libraries for moieties inducing antibodies selectively reacting with Aß-aggregates. The technology identified a pool of peptide candidates; two, AFFITOPES AD01 and AD02, were assessed as vaccination antigens and compared to Aβ1-6, the targeted epitope. When conjugated to Keyhole Limpet Hemocyanin (KLH) and adjuvanted with aluminum, all three peptides induced Aß-targeting antibodies (Abs). In contrast to Aß1-6, AD01- or AD02-induced Abs were characterized by selectivity for aggregated forms of Aß and absence of reactivity with related molecules such as Amyloid Precursor Protein (APP)/ secreted APP-alpha (sAPPa). Administration of AFFITOPE-vaccines to APP-transgenic mice was found to reduce their cerebral amyloid burden, the associated neuropathological alterations and to improve their cognitive functions. Thus, the AFFITOME-technology delivers vaccines capable of inducing a distinct Ab response. Their features may be beneficial to AD-patients, a hypothesis currently tested within a phase-II-study.

Perforating folliculitis, angioedema, hand-foot syndrome--multiple cutaneous side effects in a patient treated with sorafenib.

A patient with clear cell renal cell carcinoma was treated with sorafenib, a multikinase inhibitor, which induced a variety of cutaneous side effects. In addition to xerosis, he developed angioedema (AE), hand‐foot syndrome (HFS) and perforating folliculitis (PF). The latter three occurred in a dose‐dependent manner. AE was observed at the recommended daily dose of 800 mg. Dose reduction to 400 mg prevented its recurrence. At this dose level, the patient exhibited HFS, which cleared upon further reduction of the dose. While receiving 200 mg, the patient developed PF. To the best of our knowledge, this is the first description of a case of PF during treatment with sorafenib.

Granulocyte-Macrophage Colony-Stimulating Factor-Based Melanoma Cell Vaccines Immunize Syngeneic and Allogeneic Recipients via Host Dendritic Cells

Subcutaneous injection of GM-CSF-expressing cancer cells into experimental animals results in protective cancer immunity. To delineate the mode of action of such vaccines, we used trinitrophenyl, the antigenic moiety of the contact allergen trinitrochlorobenzene, as surrogate Ag. Trinitrophenyl-derivatized bone marrow-derived dendritic cells were found to elicit a contact hypersensitivity response in syngeneic, but not in allogeneic recipients, compatible with their expected mode of direct Ag presentation. When expressing GM-CSF, haptenized M3 melanoma cells were also able to induce a contact hypersensitivity response but, in contrast to bone marrow-derived dendritic cells, not only in syngeneic but also in allogeneic recipients. This argues for a critical role of host APC. To identify their nature, we introduced the β-galactosidase (βgal) gene into M3-GM cells. Their administration activated βgal-specific, Ld-restricted CTL in syngeneic BALB/c mice. Evaluation of lymph nodes draining M3-GM-βgal injection sites revealed the presence of cells presenting the respective Ld-binding βgal peptide epitope. Based on their capacity to activate βgal-specific CTL, they were identified as being CD11c+ dendritic cells. These experiments provide a rational basis for the use of GM-CSF-based melanoma cell vaccines in an allogeneic setting.

IgA-Pemphigus – Vorkommen von Anti-Desmocollin-1-und Anti-Desmoglein-1-Antikörpern bei einem Patienten

Background: IgA pemphigus is a rare pustular autoimmune disease with exclusive IgA anti-keratinocyte cell surface antibody reactivity. Two subtypes have been discerned: in the subcorneal pustular dermatosis type, desmocollin 1 has been identified as a targeted autoantigen, while in few cases of the intraepidermal neutrophilic type, IgA anti-desmoglein 1 or IgA anti-desmoglein 3 reactivity has been demonstrated. Patients and Methods: A 48-year-old white male presented with generalized large confluent pustules. Skin pathology was assessed by histology and direct immunofluorescence analysis. IgG/lgA autoantibodies against desmoglein 1/3 and desmocollin 1 were measured by ELISA and indirect immunofluorescence using desmocollin 1 cDNA-transfected COS7 cells, respectively. Results: Histopathology revealed subcorneal pustules and direct immunofluorescence microscopy exclusively showed in vivo bound IgA with an intercellular pattern in the epidermis. Desmocollin 1 was identified as a target of IgA autoantibodies by indirect immunofluorescence microscopy utilizing desmocollin 1 cDNA-transfected COS7 cells. In addition, IgA anti-desmoglein 1 reactivity was demonstrated by ELISA. Neither IgA anti-desmoglein 3 nor IgG anti-desmoglein 1/3 autoantibodies were present. Conclusions: Both desmocollin 1 and desmoglein 1 were autoantigens in this patient with IgA pemphigus and a distinct clinical presentation. To our knowledge, this is the first IgA pemphigus case with dual autoantibody reactivity.