Monoclonal Antibody chP3R99 Reduces Subendothelial Retention of Atherogenic Lipoproteins in Insulin-Resistant Rats: Acute Treatment Versus Long-Term Protection as an Idiotypic Vaccine for Atherosclerosis.

BACKGROUND: Atherosclerosis is triggered by the retention of apolipoprotein B-containing lipoproteins by proteoglycans. In addition to low-density lipoprotein, remnant lipoproteins have emerged as pivotal contributors to this pathology, particularly in the context of insulin resistance and diabetes. We have previously reported antiatherogenic properties of a monoclonal antibody (chP3R99) that recognizes sulfated glycosaminoglycans on arterial proteoglycans. METHODS AND RESULTS: Solid-phase assays demonstrated that chP3R99 effectively blocked >50% lipoprotein binding to chondroitin sulfate and vascular extracellular matrix in vitro. The preperfusion of chP3R99 (competitive effect) resulted in specific antibody-arterial accumulation and reduced fluorescent lipoprotein retention by ~60% in insulin resistant JCR:LA-cp rats. This competitive reduction was dose dependent (25-250 µg/mL), effectively decreasing deposition of cholesterol associated with lipoproteins. In a 5-week vaccination study in insulin resistant rats with (200 µg subcutaneously, once a week), chP3R99 reduced arterial lipoprotein retention, and was associated with the production of antichondroitin sulfate antibodies (Ab3) able to accumulate in the arteries (dot-blot). Neither the intravenous inoculation of chP3R99 (4.5 mg/kg), nor the immunization with this antibody displayed adverse effects on lipid or glucose metabolism, insulin resistance, liver function, blood cell indices, or inflammation pathways in JCR:LA-cp rats. CONCLUSIONS: Both acute (passive) and long-term administration (idiotypic cascade) of chP3R99 antibody reduced low-density lipoprotein and remnant lipoprotein interaction with proteoglycans in an insulin-resistant setting. These findings support the innovative approach of targeting proatherogenic lipoprotein retention by chP3R99 as a passive therapy or as an idiotypic vaccine for atherosclerosis.

Recurrent reactive infectious mucocutaneous eruption (RIME) secondary to Chlamydophila pneumoniae infection in an adult.

The terminology surrounding the clinical syndrome characterized by acute mucositis with minimal skin involvement has been a subject of debate over time. In recent years, terms such as mycoplasma-induced rash and mucositis and reactive infectious mucocutaneous eruption (RIME) have been introduced to encompass milder mucocutaneous diseases associated with respiratory infections, with implications for management and prognosis. We report the first case of recurrent RIME associated with Chlamydophila pneumoniae infection in an adult patient. RIME is likely underreported due to misclassification and a lack of testing for potential pathogens. Early recognition of recurrent RIME is of particular interest from the patient's perspective to reduce the frequency and duration of hospital admissions.

Patient Outcomes After Early Versus Late Tracheostomy in the Puerto Rico Trauma Hospital.

OBJECTIVE: This study aimed to evaluate the impact of early tracheostomy (ET, ≤7 days) versus that of late tracheostomy (LT, >7 days) on outcomes such as hospital length of stay (LOS), intensive care unit (ICU) days, mechanical ventilation (MV) days, and mortality ratio. METHODS: A historical cohort study was undertaken using charts of patients admitted to the Puerto Rico Trauma Hospital who required MV and underwent tracheostomies, from 2000 to 2013. A logistic regression was performed to evaluate the association between timing of tracheostomy and complications and mortality. To estimate the relationship between ET and outcomes related to hospital stay, a binomial-negative regression was performed. A P < 0.05 was considered statistically significant. RESULTS: A total of 1134 patients were evaluated, 313 of whom underwent ET and 821 underwent LT. Early tracheostomy patients had a lower Injury Severity Score compared with their counterparts (P = 0.004) and showed lower complications (respiratory failure: odds ratio [OR], 0.61; 95% confidence interval [CI], 0.45-0.84; acute respiratory distress syndrome: OR, 0.44; 95% CI, 0.30-0.64; pneumonia: OR, 0.53; 95% CI, 0.40-0.71; septicemia: OR, 0.48; 95% CI, 0.33-0.70; bacteremia: OR, 0.59; 95% CI, 0.40-0.86) than LT patients. Those with ET had lower MV days (RRadj, 0.74; 95% CI, 0.68-0.82), ICU days (RRadj, 0.66; 95% CI, 0.59-0.73), and LOS (RRadj, 0.74; 95% CI, 0.69-0.80) compared with those with LT, after adjusting for age, Injury Severity Score, and complications. However, there were no differences in mortality ratio (ORadj, 0.66; 95% CI, 0.44-1.01) among ET and LT patients, after adjusting for confounders. CONCLUSIONS: Our results suggested that ET reduced complications, MV days, ICU days, and LOS, having an indirect effect on mortality ratio. Standardized protocols for ET are recommended to enhance health outcomes in trauma patients.

Mutación de novo en heterocigosis en el gen MBD5 asociada a heterotopía en banda bilateral y polimicrogiria / De novo heterozygous mutation in the MBD5 gene associated with bilateral band heterotopia and polymicrogyria

Introducción: La etiología del retraso mental autosómico dominante 1, también conocido como pseudo-Angelman, trastorno del neurodesarrollo asociado a MBD5 o haploinsuficiencia MBD5, radica en una microdeleción del cromosoma 2q23.1 o en una alteración específica del gen MBD5, que constituye la mínima región afectada en la citada microdeleción. Objetivo: Comunicar el caso de una niña con una mutación heterocigota y de novo en el gen MBD5 asociada a heterotopía en banda bilateral y polimicrogiria. Caso clínico: Niña de 8 años, seguida evolutivamente desde los 18 meses por presentar la asociación de discapacidad intelectual y retraso motor graves, ausencia de desarrollo del lenguaje, hipotonía segmentaria, frente ancha y cifoescoliosis. En la resonancia magnética cerebral se observó la presencia de una heterotopía en banda bilateral y polimicrogiria parietooccipital de predominio izquierdo. En el exoma se detectó la variante de novo c.397+1G > C en heterocigosis en el gen MBD5. Conclusión: Constituye la primera observación con una mutación heterocigota en el gen MBD5 asociada a un trastorno en la migración neuronal

Introduction: The aetiology of autosomal dominant mental retardation type 1, also known as pseudo-Angelman, MBD5-associated neurodevelopmental disorder or MBD5 haploinsufficiency, lies in a microdeletion of chromosome 2q23.1 or in a specific alteration of the MBD5 gene, which constitutes the minimum region affected in the aforementioned microdeletion. Aim: To report the case of a girl with a heterozygous de novo mutation in the MBD5 gene associated with bilateral band heterotopia and polymicrogyria. Case Report: We report the case of an 8-year-old girl who was submitted to a developmental follow-up from the age of 18 months after presenting the association of severe intellectual disability and motor delay, lack of language development, segmental hypotonia, a wide forehead and kyphoscoliosis. Magnetic resonance imaging of the brain revealed the presence of a bilateral band heterotopia and parietooccipital polymicrogiria predominant on the left side. In the exome the de novo heterozygous variant c.397+1G > C was detected in the MBD5 gene. Conclusion: This is the first observation of a heterozygous mutation in the MBD5 gene associated with a neuronal migration disorder

Multivariate optimization of a HS-SPME/GC-MS technique for the characterization of volatile compounds present in Hedeoma multiflorum Benth / Optimización Multivariada de una técnica HS-SPME/GC para la caracterización de los compuestos volátiles presentes en Hedeoma multiflorum Benth

The aim of the present work was to optimize the main experimental variables of a procedure using HS-SPME/GC-MS as the analytical methodology to establish the profile of the volatile compounds present in aerial parts of Hedeoma multiflorum Benth. The influence of the type of fiber, equilibrium time, extraction time and extraction temperature on the composition of the volatile compounds was determined using response surface methodology (RSM), and the parameters of the models were corroborated by multiple linear regressions. The results showed that the regression models generated adequately explained the data variation and represented the relationships between the parameters and their responses. The optimal analysis conditions from the contour plots were established (DVB/CAR/PDMS fiber, with a 10 min equilibrium time, 10 min extraction time, and 40°C). Under these conditions, 41 volatile components in the whole plant were determined, which represents more than those reported using hydrodistillation.

El objetivo del presente trabajo fue optimizar las principales variables experimentales de un procedimiento HS-SPME/GC para establecer el perfil de compuestos volátiles presentes en la parte aérea de Hedeoma multiflorum Benth. Se determinó la influencia de las variables tipo de fibra, tiempo de equilibrio, tiempo de extracción y temperatura de extracción sobre la composición de los volátiles, utilizando una met odología de superficie de respuesta (RSM) y los parámetros del modelo se corroboraron por regresión lineal múltiple. Los resultados demostraron que los modelos de regresión generados explican adecuadamente la variación de los datos y representaron significativamente las relaciones reales entre los parámetros y sus respuestas. Las condiciones óptimas de análisis fueron establecidas (DVB/CAR/PDMS, con un tiempo de equilibrio de 10 minutos, un tiempo de extracción de 10 minutos y trabajando a 40°C). Utilizando esta metodología, se determinaron 41 componentes volátiles en planta entera, más que los reportados mediante hidrodestilación.

Vivencias y sentimientos de las personas cuidadoras principales de familiares con enfermedad de Alzheimer / Experiences and feelings of the primary caregivers for relatives with Alzheimer's disease

Objetivo: el objetivo de este trabajo fue conocer las vivencias y sentimientos de las personas cuidadoras principales de familiares con enfermedad de Alzheimer. Método: se realizó un estudio cualitativo con enfoque fenomenológico. Las personas participantes fueron captadas a través de la Asociación de Familiares de Enfermos de Alzheimer de Ourense. Los datos se obtuvieron a través de entrevistas semiestructuradas efectuadas por dos entrevistadoras, enfermeras, hasta que se llegó a la saturación del discurso. Resultados: se identificaron 10 categorías: diagnóstico y cambio de identidad; cuidados; organización del núcleo familiar; impacto psicológico en las personas cuidadoras; autocuidado del cuidador; recursos; miedo al futuro; experiencias positivas; relación con el profesional de Enfermería; institucionalización. Conclusiones: las personas cuidadoras refirieron la importancia de su autocuidado, intentando encontrar tiempo para ellas mismas y poder desconectar. Su mayor inquietud es la evolución de la enfermedad y el "irse apagando" del familiar, lo que ocasiona sentimientos de tristeza e impotencia. A raíz de esta experiencia de cuidar, descubrieron aptitudes y sentimientos que eran desconocidos, desarrollando su capacidad para hacer frente a las adversidades y aprender de ellas

Objective: the objective of this study was to understand the experiences and feelings of the primary caregiver persons for relatives with Alzheimer's disease. Method: a qualitative study was conducted, with phenomenological approach. Participants were recruited through the Association of Relatives of Alzheimer's Patients from Orense. Data were collected through semistructured interviews conducted by two nurse interviewers, until reaching speech saturation. Results: ten (10) categories were identified: diagnosis and change of identity; care; organization of the family unit; psychological impact on caregivers; self-care of the caregiver; resources; fear of the future; positive experiences; relationship with the Nursing professional; institutionalization. Conclusions: caregivers reported the importance of self-care, trying to find time for themselves and being able to disengage. Their higher concern was disease evolution, and the "fading out" of their relative, which causes feelings of sadness and impotence. Through this caregiving experience, they discovered attitudes and feelings that were unknown to them, thus developing their ability to face adversities and learn from them

GM3(Neu5Gc) ganglioside: an evolution fixed neoantigen for cancer immunotherapy.

Numerous molecules have been considered as targets for cancer immunotherapy because of their levels of expression on tumor cells, their putative importance for tumor biology, and relative immunogenicity. In this review we focus on the ganglioside GM3(Neu5Gc), a glycosphingolipid present on the outer side of the plasma membrane of vertebrate cells. The reasons for selecting GM3(Neu5Gc) as a tumor-specific antigen and its use as a target for cancer immunotherapy are discussed, together with the development of antitumor therapies focused on this target by the Center of Molecular Immunology (CIM, Cuba).

Atheroregressive Potential of the Treatment with a Chimeric Monoclonal Antibody against Sulfated Glycosaminoglycans on Pre-existing Lesions in Apolipoprotein E-Deficient Mice.

The retention of lipoprotein particles in the intima, in particular to glycosaminoglycan side chains of proteoglycans, is a critical step in atherosclerosis initiation. Administration of chP3R99, a chimeric mouse/human monoclonal antibody inducing an anti-idiotypic network response against glycosaminoglycans was previously shown to prevent atherosclerotic lesion progression, yet its effect in the late-stage progression of lesions remains unknown. This study investigated the effect of chP3R99 at a late stage of disease development in apolipoprotein E-deficient mice and the vascular mechanisms involved. Male apolipoprotein E-deficient mice were fed a high-fat high-cholesterol diet from 4 to 19 weeks old, at which time mice were fed normal chow and 5 doses of chP3R99 (50 µg) or isotype-matched IgG (hR3) were administered subcutaneously weekly for the first 3 administrations, then at weeks 24 and 26 before sacrifice (week 28). Lesions progression was reduced by 88% in treated mice with no change in total plasma cholesterol levels, yet with increased sera reactivity to chP3R99 idiotype and heparin, suggesting the induction of an anti-idiotype antibody cascade against glycosaminoglycans, which was likely related with the atheroprotective effect. chP3R99 treatment initiated regression in a significant number of mice. Circulating levels of interleukin-6 were reduced along with a striking diminution of inflammatory cell accumulation in the vessel wall, and of VCAM-1 labeling in vivo. The ratio of IL-10/iNOS gene expression in aortas increased in chP3R99-treated mice. In conclusion, our results show that treatment with chP3R99 reduces vascular inflammatory burden and halts lesion progression with potential for regression in the late phase of the disease in atherosclerotic mice, and support the therapeutic intervention against glycosaminoglycans as a novel strategy to reverse atherosclerosis.

Arresting progressive atherosclerosis by immunization with an anti-glycosaminoglycan monoclonal antibody in apolipoprotein E-deficient mice.

Atherogenesis is associated with the early retention of low-density lipoproteins (LDL) in the arterial intima by interaction with glycosaminoglycan (GAG)-side chains of proteoglycans. Retained LDL undergo reactive oxygen species-mediated oxidation. Oxidized LDL trigger oxidative stress (OS) and inflammation, contributing to atherosclerosis development. Recently, we reported the preventive anti-atherogenic properties of the chimeric mouse/human monoclonal antibody (mAb) chP3R99-LALA, which were related to the induction of anti-chondroitin sulfate antibody response able to inhibit chondroitin sulfate dependent LDL-enhanced oxidation. In the present work, we aimed at further investigating the impact of chP3R99-LALA mAb vaccination on progressive atherosclerosis in apolipoprotein E-deficient mice (apoE(-/-)) fed with a high-fat high-cholesterol diet receiving 5 doses (50 µg) of the antibody subcutaneously, when ~5% of the aortic area was covered by lesions. Therapeutic immunization with chP3R99-LALA mAb halted atherosclerotic lesions progression. In addition, aortic OS was modulated, as shown by a significant (p<0.05) reduction of lipid and protein oxidation, preservation of antioxidant enzymes activity and reduced glutathione, together with a decrease of nitric oxide levels. chP3R99-LALA mAb immunization also regulated aortic NF-κB activation, diminishing the proinflammatory IL1-ß and TNF-α gene expression as well as the infiltration of macrophages into the arterial wall. The therapeutic immunization of apoE(-/-) with progressive atheromas and persistent hypercholesterolemia using chP3R99-LALA mAb arrested further development of lesions, accompanied by a decrease of aortic OS and NF-κB-regulated pro-inflammatory cytokine gene expression. These results contribute to broaden the potential use of this anti-GAG antibody-based immunotherapy as a novel approach to target atherosclerosis at different phases of progression.

Targeting arterial wall sulfated glycosaminoglycans in rabbit atherosclerosis with a mouse/human chimeric antibody.

The progression of atherosclerosis is favored by increasing amounts of chondroitin sulfate proteoglycans in the artery wall. We previously reported the reactivity of chP3R99 monoclonal antibody (mAb) with sulfated glycosaminoglycans and its association with the anti-atherogenic properties displayed. Now, we evaluated the accumulation of this mAb in atherosclerotic lesions and its potential use as a probe for specific in vivo detection of the disease. Atherosclerosis was induced in NZW rabbits (n = 14) by the administration of Lipofundin 20% using PBS-receiving animals as control (n = 8). Accumulation of chP3R99 mAb in atherosclerotic lesions was assessed either by immunofluorescence detection of human IgG in fresh-frozen sections of aorta, or by immunoscintigraphy followed by biodistribution of the radiotracer upon administration of (99m)Tc-chP3R99 mAb. Immunofluorescence studies revealed the presence of chP3R99 mAb in atherosclerotic lesions 24 h after intravenous administration, whereas planar images showed an evident accumulation of (99m)Tc-chP3R99 mAb in atherosclerotic rabbit carotids. Accordingly, (99m)Tc-chP3R99 mAb uptake by lesioned aortic arch and thoracic segment was increased 5.6-fold over controls and it was 3.9-folds higher in carotids, in agreement with immunoscintigrams. Moreover, the deposition of (99m)Tc-chP3R99 mAb in the artery wall was associated both with the presence and size of the lesions in the different portions of evaluated arteries and was greater than in non-targeted organs. In conclusion, chP3R99 mAb preferentially accumulates in arterial atherosclerotic lesions supporting the potential use of this anti-glycosaminoglycans antibody for diagnosis and treatment of atherosclerosis.

Large volume injection in gas chromatography using the through oven transfer adsorption desorption interface operating under vacuum.

The present work describes a modification of the Through Oven Transfer Adsorption Desorption (TOTAD) interface, consisting of coupling a vacuum system to reduce the consumption of the helium needed to totally remove the eluent for large volume injection (LVI) in gas chromatography (GC). Two different retention materials in the liner of the TOTAD interface were evaluated: Tenax TA, which was seen to be unsuitable for working under vacuum conditions, and polydimethylsiloxane (PDMS), which provided satisfactory repeatability as well as a good sensitivity. No variability was observed in the retention times in either case. Solutions containing organophosphorous pesticides in two different solvents, a polar (methanol/water) and a non-polar (hexane) solvent, were used to evaluate the modification. The vacuum system coupled to the TOTAD interface allowed up to 90% helium to be saved without affecting the performance.

Use of nitrogen to remove solvent from through oven transfer adsorption desorption interface during analysis of polycyclic aromatic hydrocarbons by large volume injection in gas chromatography.

The through oven transfer adsorption desorption (TOTAD) interface allows large volume injection (LVI) in gas chromatography and the on-line coupling of liquid chromatography and gas chromatography (LC-GC), enabling the LC step to be carried out in normal as well as in reversed phase. However, large amounts of helium, which is both expensive and scarce, are necessary for solvent elimination. We describe how slight modification of the interface and the operating mode allows nitrogen to be used during the solvent elimination steps. In order to evaluate the performance of the new system, volumes ranging from 20 to 100µL of methanolic solutions of four polycyclic aromatic hydrocarbons (PAHs) were sampled. No significant differences were found in the repeatability and sensitivity of the analyses of standard PAH solutions when using nitrogen or helium. The performance using the proposed modification was similar and equally satisfactory when using nitrogen or helium for solvent elimination in the TOTAD interface. In conclusion, the use of nitrogen will make analyses less expensive.

Anti-ganglioside anti-idiotypic vaccination: more than molecular mimicry.

Surgery, chemotherapy, and radiation therapy are standard modalities for cancer treatment, but the effectiveness of these treatments has reached a plateau. Thus, other strategies are being explored to combine with the current treatment paradigms in order to reach better clinical results. One of these approaches is the active immunotherapy based on the induction of anti-tumor responses by anti-idiotypic vaccination. This approach arose from Jerne's idiotypic network theory, which postulates that B lymphocytes forms a functional network, with a role in the establishment of the immune repertoires, in the regulation of natural antibody production and even in the establishment of natural tolerance. Due to the large potential diversity of the immunoglobulin variable regions, the idiotypes repertoire can mimic the universe of self and foreign epitopes, even those of non-protein nature, like gangliosides. Gangliosides are sialic acid-containing glycolipids that have been considered attractive targets for cancer immunotherapy, based on the qualitative and quantitative changes they suffer during malignant transformation and due to their importance for tumor biology. Although any idiotype could be able to mimic any antigen, only those related to antigens involved in functions relevant for organism homeostasis, and that in consequence has been fixed by evolution, would be able not only to mimic, but also to activate the idiotypic cascades related with the nominal antigen. The present review updates the results, failures and hopes, obtained with ganglioside mimicking anti-idiotypic antibodies and presents evidences of the existence of a natural response against gangliosides, suggesting that these glycolipids could be idiotypically relevant antigens.

Preclinical evaluation of racotumomab, an anti-idiotype monoclonal antibody to N-glycolyl-containing gangliosides, with or without chemotherapy in a mouse model of non-small cell lung cancer.

N-glycolylneuraminic acid (NeuGc) is a sialic acid molecule usually found in mammalian cells as terminal constituents of different membrane glycoconjugates such as gangliosides. The NeuGcGM3 ganglioside has been described as a tumor antigen for non-small cell lung cancer (NSCLC) in humans. Racotumomab is an anti-NeuGc-containing gangliosides anti-idiotype monoclonal antibody (mAb) (formerly known as 1E10) that has received attention as a potential active immunotherapy for advanced lung cancer in clinical trials. In this work, we have examined the antitumor activity of racotumomab in combination or not with chemotherapy, using the 3LL Lewis lung carcinoma as a preclinical model of NSCLC in C57BL/6 mice. Vaccination with biweekly doses of racotumomab at 50-200 µg/dose formulated in aluminum hydroxide (racotumomab-alum vaccine) demonstrated a significant antitumor effect against the progression of lung tumor nodules. Racotumomab-alum vaccination exerted a comparable effect on lung disease to that of pemetrexed-based chemotherapy (100 mg/kg weekly). Interestingly, chemo-immunotherapy was highly effective against lung nodules and well-tolerated, although no significant synergistic effect was observed as compared to each treatment alone in the present model. We also obtained evidence on the role of the exogenous incorporation of NeuGc in the metastatic potential of 3LL cells. Our preclinical data provide support for the combination of chemotherapy with the anti-idiotype mAb racotumomab, and also reinforce the biological significance of NeuGc in lung cancer.

Racotumomab: an anti-idiotype vaccine related to N-glycolyl-containing gangliosides - preclinical and clinical data.

Neu-glycolyl (NeuGc)-containing gangliosides are attractive targets for immunotherapy with anti-idiotype mAbs, because these glycolipids are not normal components of the cytoplasmic membrane in humans, but their expression has been demonstrated in several human malignant tumors. Racotumomab is an anti-idiotype mAb specific to P3 mAb, an antibody which reacts to NeuGc-containing gangliosides, sulfatides, and other antigens expressed in tumors. Preparations containing racotumomab were able to induce a strong anti-metastatic effect in tumor-bearing mice. Different Phase I clinical trials have been conducted in patients with advanced melanoma, breast cancer, and lung cancer. The results of these clinical trials demonstrated the low toxicity and the high immunogenicity of this vaccine. The induced antibodies recognized and directly killed tumor cells expressing NeuGcGM3. A Phase II/III multicenter, controlled, randomized, double blind clinical trial was conducted to evaluate the effect of aluminum hydroxide-precipitated racotumomab vaccine in overall survival in patients with advanced non-small cell lung cancer. The clinical results of this study showed a significant clinical benefit in the patients who were treated with the anti-idiotype vaccine.

Alternativas inmunoterapéuticas para el tratamiento de la aterosclerosis / Immunotherapeotical alternatives for the atherosclerosis treatment

La aterosclerosis representa la primera causa de muerte en el mundo occidental. Aunque existen varias hipótesis que explican su patogénesis, una de las de mayor reconocimiento es la hipótesis autoinmune. La activación del sistema inmunológico frente a diferentes estímulos aterogénicos provoca en el organismo una reacción que puede dañar el endotelio vascular y con ello inducir el desarrollo de una lesión aterogénica. El diseño de nuevas estrategias terapéuticas, entre ellas las vacunas, representan una herramienta con resultados promisorios en el tratamiento de la aterosclerosis. Teniendo en cuenta estos antecedentes, en el presente trabajo se examinó el estado del arte en el campo de la inmunomodulación de esta enfermedad crónica(AU)

Atherosclerosis represents the first cause of death in the western world. Although there are several hypothesis which explain its pathogenesis, one of the most recognized is the autoimmune hypothesis. The activation of the immunological system against different atherogenic stimulus induces a reaction which may affect the vascular endothelium with the consequent atherogenic lesion development. The design of new therapeutic strategies, among them vaccines, represents a tool with promissory result in atherosclerosis treatment. Taking into account these antecedents, in the present work it was examined the state of the art on the immunomodulation of this chronic disease(AU)

Anti-ganglioside antibodies induced in chickens by an alum-adsorbed anti-idiotype antibody targeting NeuGcGM3.

Racotumomab is a murine anti-idiotype cancer vaccine targeting NeuGcGM3 on melanoma, breast, and lung cancer. In order to characterize the immunogenicity of alum-adsorbed racotumomab in a non-clinical setting, Leghorn chickens were immunized in dose levels ranging from 25 µg to 1600 µg. Racotumomab was administered subcutaneously in the birds' neck with three identical boosters and serum samples were collected before, during and after the immunization schedule. A strong antibody response was obtained across the evaluated dose range, confirming the immunogenicity of racotumomab even at dose levels as low as 25 µg. As previously observed when using Freund's adjuvant, alum-adsorbed racotumomab induced an idiotype-specific response in all the immunized birds and ganglioside-specific antibodies in 60-100% of the animals. In contrast to the rapid induction anti-idiotype response, detection of ganglioside-specific antibodies in responsive animals may require repeated boosting. Kinetics of anti-NeuGcGM3 antibody titers showed a slight decline 2 weeks after each booster, arguing in favor of repeated immunizations in order to maintain antibody titer. Interestingly, the intensity of the anti-NeuGcGM3 response paralleled that of anti-mucin antibodies and anti-tumor antibodies, suggesting that the in vitro detection of anti-ganglioside antibodies might be a surrogate for an in vivo activity of racotumomab. Taken together, these results suggest that Leghorn chicken immunization might become the means to test the biological activity of racotumomab intended for clinical use.