An effector-reduced anti-β-amyloid (Aβ) antibody with unique aβ binding properties promotes neuroprotection and glial engulfment of Aβ.

Passive immunization against β-amyloid (Aβ) has become an increasingly desirable strategy as a therapeutic treatment for Alzheimer's disease (AD). However, traditional passive immunization approaches carry the risk of Fcγ receptor-mediated overactivation of microglial cells, which may contribute to an inappropriate proinflammatory response leading to vasogenic edema and cerebral microhemorrhage. Here, we describe the generation of a humanized anti-Aβ monoclonal antibody of an IgG4 isotype, known as MABT5102A (MABT). An IgG4 subclass was selected to reduce the risk of Fcγ receptor-mediated overactivation of microglia. MABT bound with high affinity to multiple forms of Aβ, protected against Aβ1-42 oligomer-induced cytotoxicity, and increased uptake of neurotoxic Aβ oligomers by microglia. Furthermore, MABT-mediated amyloid plaque removal was demonstrated using in vivo live imaging in hAPP((V717I))/PS1 transgenic mice. When compared with a human IgG1 wild-type subclass, containing the same antigen-binding variable domains and with equal binding to Aβ, MABT showed reduced activation of stress-activated p38MAPK (p38 mitogen-activated protein kinase) in microglia and induced less release of the proinflammatory cytokine TNFα. We propose that a humanized IgG4 anti-Aβ antibody that takes advantage of a unique Aβ binding profile, while also possessing reduced effector function, may provide a safer therapeutic alternative for passive immunotherapy for AD. Data from a phase I clinical trial testing MABT is consistent with this hypothesis, showing no signs of vasogenic edema, even in ApoE4 carriers.

Unusual association of diseases/symptoms: Encephalitis with herpes simplex-2 in the cerebrospinal fluid and anti-RI (ANNA-2) antibodies: an infectious or a paraneoplastic syndrome?

We report on a 70-year-old woman with partial complex status epilepticus who was initially diagnosed with herpes simplex-2 (HSV-2) encephalitis, based on brain magnetic resonance imaging (MRI) findings, cerebrospinal fluid (CSF) lymphocytic pleocytosis and HSV-2 DNA detection by polymerase chain reaction (PCR) in the CSF, but without improvement on intravenous acyclovir. Anti-Ri antibodies were positive and computed tomography (CT) investigations revealed a small cell carcinoma at biopsy suggesting paraneoplastic encephalitis. The outcome was unfavourable and the autopsy showed typical features of paraneoplastic encephalitis but no evidence of viral inclusions. This case report is interesting because: (1) it is the first report of an autopsy proven paraneoplastic widespread encephalitis with anti-Ri antibodies; (2) despite a positive HSV-2 PCR in the CSF, there was no sign of herpetic infections of the nervous system; and (3) it illustrates the fact that if paraneoplastic antibodies are usually good markers of the underlying tumour, they are not always predictive of neurological deficits.

The efficacy and safety of a third anti-TNF monoclonal antibody in Crohn's disease after failure of two other anti-TNF antibodies.

BACKGROUND: Adalimumab (ADA) and certolizumab pegol (CZP) have demonstrated efficacy in Crohn's disease (CD) patients previously treated with infliximab (IFX). AIM: To assess the efficacy and tolerability of a third anti-TNF in CD after failure of and/or intolerance to two different anti-TNF antibodies. METHODS: Crohn's disease patients who received ADA or CZP after loss of response and/or intolerance to two anti-TNF agent were included in this retrospective study. Data were collected using a standardized questionnaire. Clinical response, duration, safety and reasons for discontinuation were assessed. RESULTS: Sixty-seven patients treated with CZP (n = 40) or ADA (n = 27) were included. A clinical response was observed in 41 (61%) at week 6 and 34 patients (51%) at week 20. The probability of remaining under treatment at 3 months, 6 months and 9 months was 68%, 60% and 45%, respectively. At the end of follow-up, the third anti-TNF had been stopped in 36 patients for intolerance (n = 13), or failure (n = 23). Two deaths were observed. CONCLUSIONS: The treatment with a third anti-TNF (CZP or ADA) agent of CD patients, who have experienced loss of response and/or intolerance to two anti-TNF antibodies, has favourable short-term and long-term efficacy. It is an option to be considered in patients with no other therapeutic options.

Analytical progresses of the International Olympic Committee and World Anti-Doping Agency Olympic laboratories.

The Summer Olympic Games constitute the biggest concentration of human sports and activities in a particular place and time since 776 BCE, when the written history of the Olympic Games in Olympia began. Summer and Winter Olympic anti-doping laboratories, accredited by the International Olympic Committee in the past and the World Anti-Doping Agency in the present times, acquire worldwide interest to apply all new analytical advancements in the fight against doping in sports, hoping that this major human event will not become dirty by association with this negative phenomenon. This article summarizes the new analytical progresses, technologies and knowledge used by the Olympic laboratories, which for the vast majority of them are, eventually, incorporated into routine anti-doping analysis.

Biodistribution of anti-CEA F(ab')2 fragments after intra-arterial and intravenous injection in patients with liver metastases due to colorectal carcinoma.

The biodistribution of simultaneous intra-arterial and intravenous injections of a radiolabelled anti-CEA MAb F(ab')2 fragment was studied in three patients with liver metastases from colorectal cancer. Identical MAb fragments, labelled with either 125I or 131I, were injected over a period of 30 min into the hepatic artery and into a peripheral vein. After 1 or 2 days, biodistribution was measured in the surgically removed metastases, normal tissue samples and blood. By tissue radioactivity counting, tumour uptake in the range 6.3-9.1% of injected dose per gram was found. Superimposable metastasis-to-blood and metastasis-to-normal liver ratios were obtained for both iodine isotopes in all three patients. The results indicate that the intra-arterial injection of MAb F(ab')2 fragments gives no measurable advantage over more convenient injections into a peripheral vein.

Benefit of anti-HER2-coated paclitaxel-loaded immuno-nanoparticles in the treatment of disseminated ovarian cancer: Therapeutic efficacy and biodistribution in mice.

The benefit of polymeric immuno-nanoparticles (NPs-Tx-HER), consisting of paclitaxel (Tx)-loaded nanoparticles coated with anti-HER2 monoclonal antibodies (Herceptin, trastuzumab), in cancer treatment was assessed in a disseminated xenograft ovarian cancer model induced by intraperitoneal inoculation of SKOV-3 cells overexpressing HER2 antigens. The study was focused on the evaluation of therapeutic efficacy and biodistribution of NPs-Tx-HER compared to other Tx formulations. The therapeutic efficacy was determined by two methods: bioluminescence imaging and survival rate. The treatment regimen consisted in an initial dose of 20mg/kg Tx administered as 10mg/kg intravenously (IV) and 10mg/kg intraperitonealy (IP), followed by five alternative IP and IV injections of 10mg/kg Tx every 3 days. The bioluminescence study has clearly shown the superior anti-tumor activity of NPs-Tx-HER compared to free Tx. As a confirmation of these results, a significantly longer survival of mice was observed for NPs-Tx-HER treatment compared to free Tx, Tx-loaded nanoparticles coated with an irrelevant mAb (Mabthera, rituximab) or Herceptin alone, indicating the potential of immuno-nanoparticles in cancer treatment. The biodistribution pattern of Tx was assessed on healthy and tumor bearing mice after IV or IP administration. An equivalent biodistribution profile was observed in healthy mice for Tx encapsulated either in uncoated nanoparticles (NPs-Tx) or in NPs-Tx-HER. No significant difference in Tx biodistribution was observed after IV or IP injection, except for a lower accumulation in the lungs when NPs were administered by IP. Encapsulated Tx accumulated in the organs of the reticulo-endothelial system (RES) such as the liver and spleen, whereas free Tx had a non-specific distribution in all tested organs. Compared to free Tx, the single dose injection (IV or IP) of encapsulated Tx in mice bearing tumors induced a higher tumor accumulation. However, no difference in overall tumor accumulation between NPs-Tx-HER and NPs-Tx was observed. In conclusion, the encapsulation of Tx into NPs-Tx-HER immuno-nanoparticles resulted in an improved efficacy of drug in the treatment of disseminated ovarian cancer overexpressing HER2 receptors.

Combination of lentivector immunization and low-dose chemotherapy or PD-1/PD-L1 blocking primes self-reactive T cells and induces anti-tumor immunity.

In the last two decades, anti-cancer vaccines have yielded disappointing clinical results despite the fact that high numbers of self/tumor-specific T cells can be elicited in immunized patients. Understanding the reasons behind this lack of efficacy is critical in order to design better treatment regimes. Recombinant lentivectors (rLVs) have been successfully used to induce antigen-specific T cells to foreign or mutated tumor antigens. Here, we show that rLV expressing a murine nonmutated self/tumor antigen efficiently primes large numbers of self/tumor-specific CD8(+) T cells. In spite of the large number of tumor-specific T cells, however, no anti-tumor activity could be measured in a therapeutic setting, in mice vaccinated with rLV. Accumulating evidence shows that, in the presence of malignancies, inhibition of T-cell activity may predominate overstimulation. Analysis of tumor-infiltrating lymphocytes revealed that specific anti-tumor CD8(+) T cells fail to produce cytokines and express high levels of inhibitory receptors such as programmed death (PD)-1. Association of active immunization with chemotherapy or antibodies that block inhibitory pathways often leads to better anti-tumor effects. We show here that combining rLV vaccination with either cyclophosphamide or PD-1 and PD-L1 blocking antibodies enhances rLV vaccination efficacy and improves anti-tumor immunity.

Nanomedicines for active targeting: physico-chemical characterization of paclitaxel-loaded anti-HER2 immunonanoparticles and in vitro functional studies on target cells.

Paclitaxel (Tx)-loaded anti-HER2 immunonanoparticles (NPs-Tx-HER) were prepared by the covalent coupling of humanized monoclonal anti-HER2 antibodies (trastuzumab, Herceptin) to Tx-loaded poly (dl-lactic acid) nanoparticles (NPs-Tx) for the active targeting of tumor cells that overexpress HER2 receptors. The physico-chemical properties of NPs-Tx-HER were compared to unloaded immunonanoparticles (NPs-HER) to assess the influence of the drug on anti-HER2 coupling to the NP surface. The immunoreactivity of sulfo-MBS activated anti-HER2 mAbs and the in vitro efficacy of NPs-Tx-HER were tested on SKOV-3 ovarian cancer cells that overexpress HER2 antigens. Tx-loaded nanoparticles (NPs-Tx) obtained by a salting-out method had a size of 171+/-22 nm (P.I.=0.1) and an encapsulation efficiency of about of 78+/-10%, which corresponded to a drug loading of 7.8+/-0.8% (w/w). NPs-Tx were then thiolated and conjugated to activated anti-HER2 mAbs to obtain immunonanoparticles of 237+/-43 nm (P.I.=0.2). The influence of the activation step on the immunoreactivity of the mAbs was tested on SKOV-3 cells using 125I-radiolabeled mAbs, and the activity of the anti-HER2 mAbs was minimally affected after sulfo-MBS functionalization. Approximately 270 molecules of anti-HER2 mAbs were bound per nanoparticle. NPs-Tx-HER exhibited a zeta potential of 0.2+/-0.1 mV. The physico-chemical properties of the Tx-loaded immunonanoparticles were very similar to unloaded immunonanoparticles, suggesting that the encapsulation of the drug did not influence the coupling of the mAbs to the NPs. No drug loss was observed during the preparation process. DSC analysis showed that encapsulated Tx is in an amorphous or disordered-crystalline phase. These results suggest that Tx is entrapped in the polymeric matrix and not adsorbed to the surface of the NPs. In vitro studies on SKOV-3 ovarian cancer cells demonstrated the greater cytotoxic effect of NPs-Tx-HER compared to other Tx formulations. The results showed that at 1 ng Tx/ml, the viability of cells incubated with drug encapsulated in NP-Tx-HER was lower (77.32+/-5.48%) than the viability of cells incubated in NPs-Tx (97.4+/-12%), immunonanoparticles coated with Mabthera, as irrelevant mAb (NPs-Tx-RIT) (93.8+/-12%) or free drug (92.3+/-9.3%).

Report of the ECCO workshop on anti-TNF therapy failures in inflammatory bowel diseases: biological roles and effects of TNF and TNF antagonists.

This second section of the first ECCO pathogenesis workshop on anti-TNF therapy failures in inflammatory bowel diseases addresses the biological roles of TNFα and the effects and mechanisms of action of TNFα antagonists. Mechanisms underlying their failure, including induction of TNF-independent inflammatory pathways and phenomena of paradoxical inflammation are discussed.

Prevalence and significance of anti-HILA antibodies after liver transplantation : P236

Background: The pathogenic role of anti-HLA antibodies (AHA) after kidney transplantation is well established. However, its significance after liver transplantation remains unclear. The aim of our study was to determine the prevalence and significance of AHA after liver transplantation. Methods: Between January 2007 and November 2007, all liver transplant recipients who were greater than 6 months posttransplantation and followed regularly at our transplant outpatient clinic (n = 95) were screened for AHA. All clinical and electronic records were reviewed. Serum samples were tested using multiplex technology (Luminex). A liver biopsy had been performed in 55 out of the 95 patients based on clinical grounds but no routine protocol biopsies were performed. Immunosuppression was calcineurin inhibitor-based in 90 patients, sirolimus-based in 4 patients and one patient had no anti-rejection therapy (operationally tolerant recipient). Results: The mean time from transplantation to study was 85 months (range 6-248 months). Overall, AHA were found in 23/95 (24.2%) of patients (5 had anti-class I alone, 13 anti-class II alone, and 4 had both anti-class I and II). However, only 4/95 patients (4.2%) had donor-specific antibodies (DSA) (one anti-class I and 3 anti-class II). Twenty-one out of 95 patients (22.1%) had a history of past or current biopsy-proven or radiological biliary complications (chronic rejection, ischemic cholangitis, ischemic type biliary lesions or biliary anastomosis stricture). Among patients with AHA, 4/23 (17,4%) had biliary complications, while it was 17/72 (23.6%) in patients without AHA (NS). Among patients with DSA, 3/4 (75%) had biliary complications (two with biopsy-proven chronic rejection in association with biliary strictures and one with ischemic cholangitis following hepatic artery thrombosis), versus 1/19 (5.3%) patients with AHA but no DSA (p = 0.009), versus 16/72 (22.2%) patients without AHA (p = 0.046). In patients with DSA, immunosuppression was not different than in patients without DSA. Conclusions: We found a 24% AHA prevalence. The presence of DSA, but not of AHA, was significantly associated with an increased incidence of biliary complications including chronic liver allograft rejection. The exact mechanisms and possible causal relationship linking DSA to biliary complications remain to be studied. Larger prospective trials are thus needed to further define the role of AHA and in particular of DSA after liver transplantation.

Pattern dystrophy with high intrafamilial variability associated with Y141C mutation in the peripherin/RDS gene and successful treatment of subfoveal CNV related to multifocal pattern type with anti-VEGF (ranibizumab) intravitreal injections.

OBJECTIVE: To identify disease causing mutation in three generations of a Swiss family with pattern dystrophy and high intrafamilial variability of phenotype. To assess the effect of intravitreal ranibizumab injections in the treatment of subfoveal choroidal neovascularization associated with pattern dystrophy in one patient. METHODS: Affected family members were ascertained for phenotypic and genotypic characterization. Ophthalmic evaluations included fundus photography, autofluorescence imaging, optical coherence tomography, and International Society for Clinical Electrophysiology of Vision standard full-field electroretinography. When possible family members had genetic testing. The proband presented with choroidal neovascularization and had intravitreal injections as needed according to visual acuity and optical coherence tomography. RESULTS: Proband had a multifocal type pattern dystrophy, and his choroidal neovascularization regressed after four intravitreal injections. The vision improved from 0.8 to 1.0, and optical coherence tomography showed complete anatomical restoration. A butterfly-shaped pattern was observed in her cousin, whereas a fundus pulverulentus pattern was seen in a second cousin. Aunt had a multifocal atrophic appearance, simulating geographic atrophy in age-related macular degeneration. The Y141C mutation was identified in the peripherin/RDS gene and segregated with disease in the family. CONCLUSION: This is the first report of marked intrafamilial variation of pattern dystrophy because of peripherin/RDS Y141C mutation. Intravitreal ranibizumab injections might be a valuable treatment for associated subfoveal choroidal neovascularization.

IL-7/anti-IL-7 mAb complexes restore T cell development and induce homeostatic T Cell expansion without lymphopenia.

IL-7, a member of the common gamma-chain family of cytokines, is essential for B and T lymphocyte development and homeostasis of mature T cell subsets. Thus, naive and memory T cells are both dependent on IL-7 for survival and homeostatic proliferation under lymphopenic conditions. In line with prior findings with IL-2, we show in this study that the biological activity of IL-7 in vivo is greatly increased by association with anti-IL-7 mAb. Under in vivo conditions, IL-7/mAb complexes displayed 50- to 100-fold higher activity than free IL-7 and induced massive expansion of pre-B cells. IL-7/mAb complexes also increased thymopoiesis in normal mice and restored thymopoeisis in IL-7-deficient mice. For mature T cells, IL-7/mAb complexes induced marked homeostatic proliferation of both naive and memory CD4(+) and CD8(+) cell subsets even under normal T cell-replete conditions. Finally, IL-7/mAb complexes were able to enhance the magnitude of the primary response of Ag-specific naive CD8(+) cells. The strong stimulatory activity of IL-7/mAb complexes could be useful for treatment of immunodeficiency and cancer.

Differential effects of pro- and anti-inflammatory cytokines alone or in combinations on the metabolic profile of astrocytes.

We have previously reported that the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β) induce profound modifications of the metabolic profile of astrocytes. The present study was undertaken to further characterize the effects of cytokines in astrocytes and to determine whether similar effects could also be observed in neurons. To do so, selected pro-inflammatory (IL-6 and interferon-γ, in addition to the above-mentioned TNFα and IL-1β) and anti-inflammatory cytokines (IL-4, IL-10, transforming growth factor-β1 and interferon-β) were applied to primary neuronal and astrocytic cultures, and key metabolic parameters were assessed. As a general pattern, we observed that pro-inflammatory cytokines increased glucose utilization in astrocytes while the anti-inflammatory cytokines IL-4 and IL-10 decreased astrocytic glucose utilization. In contrast, no significant change could be observed in neurons. When pairs of pro-inflammatory cytokines were co-applied in astrocytes, several additive or synergistic modifications could be observed. In contrast, IL-10 partially attenuated the effects of pro-inflammatory cytokines. Finally, the modifications of the astrocytic metabolism induced by TNFα + IL-1β and interferon-γ modulated neuronal susceptibility to an excitotoxic insult in neuron-astrocyte co-cultures. Together, these results suggest that pro- and anti-inflammatory cytokines differentially affect the metabolic profile of astrocytes, and that these changes have functional consequences for surrounding neurons.