Recombinant AAV-mediated in vivo long-term expression and antitumour activity of an anti-ganglioside GM3(Neu5Gc) antibody.

The ganglioside GM3(Neu5Gc) has gained increasing attention as therapeutic target because of its selective expression in various human tumours, such as melanoma, breast and lung cancer. 14F7 is a mouse IgG1 with specific reactivity to GM3(Neu5Gc)-positive tumours. The therapeutic activity of 14F7 has also been demonstrated in vivo, through its repetitive passive administration in tumour-bearing animals. In this work we used an alternative strategy to deliver recombinant 14F7 in vivo and analysed the therapeutic efficacy of this approach. We engineered a recombinant adeno-associated vector to direct the expression of secretable recombinant 14F7 in BALB/c animals. A single administration of the rAAV induced efficient production and secretion of the antibody in the bloodstream, with an expression level reaching plateau at ∼3 weeks after injection and persisting for almost a year. Strikingly, upon challenge with GM3(Neu5Gc)-positive X63-AG8.653 myeloma cells, tumour development was significantly delayed in animals treated with rAAV-14F7 with respect to animals treated with a control rAAV codifying for an irrelevant antibody. Finally, no significant differences in survival proportion were detected in animals injected with rAAV-14F7 or treated by standard administration of repetitive doses of purified monoclonal antibody 14F7.

Sticholysin II shows similar immunostimulatory properties to LLO stimulating dendritic cells and MHC-I restricted T cell responses of heterologous antigen.

Induction of CD8+ T cell responses against tumor cells and intracellular pathogens is an important goal of modern vaccinology. One approach of translational interest is the use of liposomes encapsulating pore-forming proteins (PFPs), such as Listeriolysin O (LLO), which has shown efficacy at priming strong and sustained CD8+ T cell responses. Recently, we have demonstrated that Sticholysin II (StII), a PFP from the sea anemone Stichodactyla helianthus, co-encapsulated into liposomes with ovalbumin (OVA) was able to stimulate, antigen presenting cells, antigen-specific CD8+ T cells and anti-tumor activity in mice. In the present study, we aimed to compare StII and LLO in terms of their abilities to stimulate dendritic cells and to induce major histocompatibility complex (MHC) class I restricted T cell responses against OVA. Interestingly, StII exhibited similar abilities to LLO in vitro of inducing dendritic cells maturation, as measured by increased expression of CD40, CD80, CD86 and MHC-class II molecules, and of stimulating OVA cross-presentation to a CD8+ T cell line. Remarkably, using an ex vivo Enzyme-Linked ImmunoSpot Assay (ELISPOT) to monitor gamma interferon (INF-γ) producing effector memory CD8+ T cells, liposomal formulations containing either StII or LLO induced comparable frequencies of OVA-specific INF-γ producing CD8+ T cells in mice that were sustained in time. However, StII-containing liposomes stimulated antigen-specific memory CD8+ T cells with a higher potential to secrete IFN-γ than liposomes encapsulating LLO. This StII immunostimulatory property further supports its use for the rational design of T cell vaccines against cancers and intracellular pathogens. In summary, this study indicates that StII has immunostimulatory properties similar to LLO, despite being evolutionarily distant PFPs.

Leishmania (Viannia) panamensis-specific IgE and IgA antibodies in relation to expression of human tegumentary leishmaniasis.

Leishmania (Viannia) panamensis-specific IgE and IgA antibodies were quantified in patients with parasitologically confirmed American tegumentary leishmaniasis using a radioallergosorbent test (RAST) and an enzyme-linked immunosorbent assay (ELISA), respectively. The RAST values, presented as the mean +/- SEM percentage of total isotope added, were significantly elevated in patients having disease evolution greater than 12 months (3.14 +/- 0.91), as compared with those with an evolution time of 12 or fewer months (1.66 +/- 0.15) (P = 0.017). A separate group of patients, those with eosinophils in the biopsy specimen of their lesion, also had elevated mean RAST values (2.55 +/- 0.58) when compared with patients who did not demonstrate these cells in their biopsy specimens (1.32 +/- 0.24) (P = 0.038). Leishmania-specific IgA levels, presented as the mean +/- SEM optical density, were significantly higher for patients with mucocutaneous disease (0.40 +/- 0.03) than for patients with cutaneous disease (0.28 +/- 0.023) (P = 0.0063). Inhibition testing with homologous and heterologous antigens confirmed the specificity of these assays, and were used to assess cross-reactivity among L. (Viannia) subspecies and other kineto-plastic hemoparasites. Results demonstrate that patients with more severe forms of American tegumentary leishmaniasis, defined either as increased duration of disease or invasion of the mucosa, have elevated levels of Leishmania-specific IgE and IgA antibodies, respectively.

[Evaluation of immunoglobin isotype specific to Leishmania in tegumentary American leishmaniasis]. / Evaluación de la respuesta de isotipos de inmunoglobulina específica a Leishmania en leishmaniasis tegumentaria Americana.

Leishmania-specific immunoglobulin subclass response was evaluated in 133 patients infected with Leishmania braziliensis. The indirect immunofluorescent antibody test (IFAT) was employed with amastigotes of L. mexicana amazonensis as antigen. Among the 133 sera obtained at consultation for diagnosis of active lesions, IgM was detected in 54 following absorption with Staphylococcus aureus Cowan strain I, and in 5 sera prior to absorption. IgM reactive with Leishmania antigen was only found in sera from patients whose lesions had evolved over the past two months or less. Leishmania-specific IgG was detected in all sera prior to absorption. Sera obtained at the time of recurrence or after complete healing of lesions presented only specific IgG. The combined use of the Montenegro skin test and specific IgM increased the sensitivity of immunodiagnostic methods in patients with lesions of less than 2 months duration. Normal control volunteers were negative for specific IgM and unreactive to Montenegro skin testing. Among 16 patients with non-leishmanial lesions, 3 with sporotrichosis showed IgG reactive with Leishmania; none, including 4 with lesions of less than two months duration, showed specific IgM. We conclude that in patients infected with L. braziliensis the presence of specific IgG and IgM is associated with the time of lesion evolution and the primary or recurrent nature of the lesions. In addition, the combined use of IgM titer and Montenegro reactivity is of potential utility in the diagnosis of early lesions.

Monoclonal antibodies against Der s 1, a major allergen of Dermatophagoides siboney.

Six stable clones secreting murine monoclonal antibodies (Mabs) against Der s 1 were obtained. The binding of Mabs showed cross-reactivity with Dermatophagoides farinae, as determined by enzyme-linked immunosorbent assay (ELISA). In a Western blot assay, antibodies reacted with a 24-kD protein considered to represent the major allergen Der s 1. The repertoire of antigenic sites on Der s 1 was studied using a panel of Mabs. Epitope specificity of the Mabs was determined by both competitive inhibition and sandwich ELISA assays. The results defined six different, non-overlapping and non-repeated antigenic sites on the allergen molecule. Der s 1 allergen from Dermatophagoides siboney extracts was purified by Mab affinity chromatography, this procedure gave 43% recovery of >90% pure allergen. The purified allergen had capacity to bind specific human IgE and demonstrated an allergenic activity of up to 77% of total D. siboney extract. An Mab-ELISA was developed using Mabs directed against different epitopes on Der s 1. This assay could detect up to 1 ng/ml of Der s 1 and Der f 1 in allergen preparations.

The relationship of Leishmania braziliensis subspecies and immune response to disease expression in New World leishmaniasis.

Multivariate analyses of clinical presentation, subspecies identity of the causal organism, and the Leishmania-specific immune response parameters (indirect fluorescent antibody test [IFAT], cutaneous delayed type hypersensitivity [DTH], and in vitro lymphocyte transformation [LT]) of 441 patients with tegumentary leishmaniasis were used to examine the human host-parasite interaction in L. braziliensis infection. Mucocutaneous disease (P less than .002) and L. braziliensis braziliensis infection (P less than .001) were independently associated with significantly higher IFAT titers and cutaneous DTH than were cutaneous disease or L. braziliensis panamensis infection. Lesion size was also correlated with IFAT titer (P. less than .001). Although time of lesion evolution was highly correlated with all parameters, differences associated with subspecies and disease form were independent of lesion duration (three-way analysis of variance). In contrast with the cutaneous DTH response, the in vitro lymphocyte proliferative response to Leishmania antigen did not correlate with disease form and only weakly with infecting subspecies when time of evolution and subspecies were controlled. The association of mucosal disease presentation with a particular subspecies and the independent correlation of both variables with heightened IFAT titers and cutaneous DTH to Leishmania antigen supports the possibility of immune mechanisms of pathogenesis in human tegumentary leishmaniasis.

Condiloma acuminado: eficacia terapéutica comparativa entre el 5-fluorouracilo tópico y la criocirugía / No disponible

ANTECEDENTES. En el condiloma acuminado se han estado utilizando numerosas modalidades terapéuticas; sin embargo, existen pocos estudios que comparen la efectividad entre estas. PACIENTES Y MÉTODO. Se realizó un estudio prospectivo, abierto, para comparar la eficacia terapéutica entre el 5-fluorouracilo en crema al 5% y la criocirugía en el tratamiento tópico del condiloma acuminado. Se incluyeron al azar 40pacientes adultos con este diagnóstico: los primeros 20 pacientes que acudieron a la consulta del consultorio médico de familia 9 del policlínico Managua y los primeros 20 pacientes que acudieron al policlínico docente Joaquín Albarrán, en el período comprendido entre febrero y abril de2006. Se formaron por tanto dos grupos de 20 pacientes cada uno, aplicándose un esquema terapéutico diferente en cada caso, recibiendo los pacientes del policlínico Managua (grupo I) dos aplicaciones semanales de 5-fluorouracilo en crema al 5% y los pacientes del policlínico Joaquín Albarrán (grupo II) una aplicación quincenal de criocirugía. La duración de ambos tratamientos fue la misma (6 semanas en cada grupo).La eficacia terapéutica fue evaluada dos semanas después de culminar el tratamiento, comparando el estado inicial y final de las lesiones. A los pacientes con respuesta total al medicamento se les realizó un seguimiento trimestral durante un año para detectar posibles recidivas. RESULTADO. El análisis pareado inicio-final demostró una respuesta significativa al tratamiento en ambos grupos. Hubo diferencias estadísticamente significativas entre los grupos estudiados. Las tasas de recidivas fueron elevadas en ambos grupos. Los principales eventos adversos observados en ambos grupos fueron: ardor, dolor e inflamación; de intensidad leve y de desaparición espontánea. COMENTARIO. Se demostró que la criocirugía es más eficaz que el 5-fluorouracilo en crema al 5% en el tratamiento tópico del condiloma acuminado (AU)

BACKGROUND. Many different therapies have been used for condyloma acuminata, however, few studies comparing their effectivity have been made. PATIENTS AND METHODS. A prospective, open-label study was conducted to compare therapeutical efficacy between topical 5-fluorouracil (5% cream) and cryosurgery in the topical treatment of condyloma acuminata. Forty adult patients with this diagnosis were randomly chosen, these being the first 20 patients who came to the family doctor’s office 9 in the Managua polyclinic and the first 20 patients who came to the Joaquín Albarrán teaching polyclinic in the period from February to April 2006. Two groups of 20 patients each were formed, applying a different therapeutical scheme in each case. Thus, the patients from the Managua polyclinic (group I) received a twice a week application of topical 5-fluorouracil and those from the Joaquín Albarrán polyclinic (group II) received a fortnightly application of cryosurgery. Both treatments had the same duration (6 weeks in each group). Therapeutical efficacy was assessed two weeks after completing the treatment, comparing the initial and final state of lesions. The patients who responded totally to the medicine were followed-up quarterly for one year in order to detect possible relapses. RESULTS. The start-end comparative analysis showed an outstanding response to the treatment in both groups. There were statistically significant differences between the groups studied. Relapse rates were high in both groups. The majored verse events observed in both group were burning sensation, pain and swelling having mild intensity and spontaneous disappearance. COMMENT. It has been demonstrated that cryosurgery is more effective than topical 5-fluorouracil in the topical treatment of the condyloma acuminate (AU)

Presentacion poco usual de arthritis tuberculosa. Reporte de un caso. / Unusual clinical presentation of a patient with tuberculous arthritis

Una caracteristica de la artritis tuberculosa es su tendencia a la cronicidad si no se hace el diagnostico oportuno, lleva a la destruccion articular progresiva con la consiguiente perdida de la funcion. Reportamos un caso de artritis tuberculosa de 10 anos de evolucion, en la interfalangica de pulgar izquierdo, en una mujer de 70 anos de edad