Potent immunomodulatory and antitumor effect of anti-CD20-IL2no-alpha tri-functional immunocytokine for cancer therapy.

Introduction: The anti-CD20 antibody rituximab (RTX) has substantially improved outcomes of patients with B-cell lymphomas, although more efficient therapies are needed for refractory or relapsing lymphomas. An approach to increase the clinical effectiveness of anti-tumor therapy is the use of antibody-cytokine fusion proteins (immunocytokines (ICKs)) to deliver at the tumor site the antibody effector functions and cytokines that trigger anti-tumor activities. In particular, IL-2-based ICKs have shown significant results in preclinical studies but not in clinical trials due to the toxicity profile associated to high doses IL-2 and the undesired expansion of Tregs. Methods: To improve the efficacy of RTX therapy, we fused a murine (mIgG2a) or a human (hIgG1) version of RTX to a mutated IL-2 (no-alpha mutein), which has a disrupted affinity for the high affinity IL-2 receptor (IL-2R) to prevent the stimulation of Tregs and reduce the binding to endothelial cells expressing CD25, the α chain of high affinity IL-2R. Characterization of anti-CD20-IL2no-alpha ICKs was performed by SDS-PAGE, Western-blotting and SEC-HPLC and also by several functional in vitro techniques like T-cell proliferation assays, apoptosis, CDC and ADCC assays. The in vivo activity was assessed by using murine tumor cells expressing huCD20 in C57/Bl6 mice. Results: Both ICKs exhibited similar in vitro specific activity of their IL2no-alpha mutein moieties and kept CD20-binding capacity. Anti-CD20-IL2no-alpha (hIgG1) retained antibody effector functions as complement-dependent cytotoxicity and enhanced direct apoptosis, NK cell activation and antibody-dependent cellular cytotoxicity relative to RTX. In addition, both ICKs demonstrated a higher antitumor efficacy than parental molecules or their combination in an EL4-huCD20 tumor model in immunocompetent mice. Anti-CD20-IL2no-alpha (hIgG1) strongly expanded NK and CD8+ T cells but not Tregs in tumor-bearing mice. Discussion: These findings suggest that anti-CD20-IL2no-alpha could represent an alternative treatment for B cell lymphoma patients, mainly those refractory to RTX therapy.

A cytotoxic humanized anti-ganglioside antibody produced in a murine cell line defective of N-glycolylated-glycoconjugates.

Gangliosides containing the N-glycolyl (NGc) form of sialic acid are tumor-associated antigens and promising candidates for cancer therapy. We previously generated the murine 14F7 monoclonal antibody (mAb), specific for the N-glycolyl-GM3 ganglioside (NGcGM3), which induced an oncosis-like type of cell death on malignant cell lines expressing this antigen and recognized breast carcinoma by immunoscintigraphy in cancer patients. As humanization is expected to enhance its use for human cancer therapy, herein we describe the design and generation of two humanized versions of the 14F7 mAb by disrupting potential human T cell epitopes on its variable region. No differences in antigen reactivity or cytotoxic properties were detected among the variants tested and with respect to the chimeric counterpart. Humanized 14F7 genes were transfected into the NGcGM3-expressing NS0 cell line. Therefore, in the industrial scaling-up of the transfectoma in serum-free medium, cell viability was lost due to the cytotoxic effect of the secreted antibody. This shortcoming was solved by knocking down the CMP-N-acetylneuraminic acid hydroxylase enzyme, thus impairing the synthesis of NGc-glycoconjugates. Humanized 14F7 mAb is of potential value for the therapy of NGcGM3-expressing tumors.

Phase I single-dose study of intracavitary-administered Nimotuzumab labeled with 188 Re in adult recurrent high-grade glioma.

Radioimmunotherapy (RIT) may improve the management of malignant gliomas. A Phase I clinical trial was performed to evaluate, for the first time, the toxicity and clinical effect of an intracavitary administration of a single dose of Nimotuzumab (h-R3) labeled wit (188)Re. Nimotuzumab is a humanized monoclonal antibody directed against epidermal growth factor receptors. Three patients with anaplastic astrocytoma (AA) and 8 with glioblastoma multiforme (GBM) were intended to be treated with 3 mg of mAb labelled with 10 or 15 mCi of (188)Re. In patients treated with 10 mCi (n=6) transitory worsening of pre-existing neurological symptoms were observed. Two patients treated with 15 mCi (n=4) developed early severe neurological symptoms and one also developed late severe toxicity (radionecrosis). In the group treated with 10 mCi, 1 GBM patient died in progression 6 months after the treatment, 2 patients (1 GBM and 1 AA) developed stable disease during 3 months. One GBM patient had partial response for more than 1 year and 2 patients (1 GBM and 1 AA) were asymptomatic and in complete response after 3 years of treatment. Maximal tolerated dose of the radioimmunoconjugate (188)Re-Nimotuzumab was 3 mg of the h-R3 labelled with 10 mCi of (188)Re. The radioimmunoconjugate showed a high retention in the surgical created resection cavity and the brain adjacent tissues with a mean value of 85.5 % of the injected dose one hour post-administration. This radioimmunoconjugate may be relatively safe and a promising therapeutic approach for treating high grade gliomas.

Efectos antipsoriásico, antiinflamatorio y analgésico del propoleo rojo colectado en Cuba

Se evaluaron los efectos antipsoriásico, antiinflamatorio y analgésico de un extracto de propóleo rojo. Este extracto induce la formación de la capa granular en la prueba de la cola de ratón usada como modelo de psoriasis. El propóleo a la dosis de 50 mg/kg (vía oral) mostró actividad antiinflamatoria en el modelo de granuloma por algodón en ratas, así como en la prueba de permeabilidad capilar en el peritoneo de ratas en la dosis de 10 mg/kg. El extracto de propóleo (25 mg/kg, vía oral) presentó propiedades analgésicas en el modelo de estiramiento por ácido acético, mientras que la dosis de 40 mg/kg fue efectiva en la prueba del plato caliente en ratones. Estos resultados demuestran evidencias acerca de la utilidad potencial del propóleo rojo en trastornos inflamatorios y particularmente en el tratamiento de la psoriasis.

The antipsoriatic, antiinflammatory, and analgesic effects of a red propolis extract, were assessed. This extract induces the formation of a granular layer in the mouse tail test, used as a model for psoriasis. Propolis at a 50 mg/kg dose (oral) showed antiinflammatory activity in the cotton granuloma model in rats, as well as in the capillary permeability test in rats peritoneum at a 10 mg/kg dose. Propolis extract (25 mg/kg, oral) presented analgesic properties in the acetic acid stretching model, while the 40 mg/kg dose was effective in the hot plate test in mice. These results demonstrate evidence about the potential usefulness of red propolis in inflammatory disorders, and particularly, in the management of psoriasis.

Efecto hepatoprotector del propoleo rojo cubano en la toxicidad inducida por paracetamol en ratones / Hepatoprotective effect of the Cuban red propolis on the toxicity induced in mice by the administration of acetaminophen

Se estudia el efecto del propóleo rojo cubano en la hepatotoxicidad aguda inducida en ratones por una dosis oral elevada de 600 mg/kg de paracetamol. El propóleo a las dosis de 25,50 y 100 mg/kg por vía intraperitoneal disminuyó significativamente la actividad de la enzima alanino amino transferasa en suero, la cual había sido incrementada por elparacetamol solo, e incrementó la concentración de glutatión reducido en hígado de ratones, la cual es disminuida por el paracetamol. El propóleo también redujo el daño de hígado inducido por paracetamol en ratones, lo cual fue observado por microscopia óptica y microscopia electrónica. El efecto hepatoprotector fue independiente de la dosis y éste fue producido cuando el propóleo se administró 30 min antes que el paracetamol y 2 horas después que éste. Nuestros resultados evidencian que el propóleo rojo posee propiedades hepatoprotectoras en el modelo experimental utilizado