Gut bacterial diversity and physiological traits of Anastrepha fraterculus Brazilian-1 morphotype males are affected by antibiotic treatment.

Background: The interaction between gut bacterial symbionts and Tephritidae became the focus of several studies that showed that bacteria contributed to the nutritional status and the reproductive potential of its fruit fly hosts. Anastrepha fraterculus is an economically important fruit pest in South America. This pest is currently controlled by insecticides, which prompt the development of environmentally friendly methods such as the sterile insect technique (SIT). For SIT to be effective, a deep understanding of the biology and sexual behavior of the target species is needed. Although many studies have contributed in this direction, little is known about the composition and role of A. fraterculus symbiotic bacteria. In this study we tested the hypothesis that gut bacteria contribute to nutritional status and reproductive success of A. fraterculus males.Methods: Wild and laboratory-reared males were treated with antibiotics (AB) and provided sugar (S) or sugar plus protein (S+P) as food sources. The effect of AB on the gut bacteria diversity was assessed through DGGE and sequencing of the V6-V9 variable region of the bacterial 16S rRNA gene.Results: AB affected the bacterial community of the digestive tract of A. fraterculus, in particular59 bacteria belonging to the Enterobacteriaceae family, which was the dominant bacterial group in the control flies (i.e., non-treated with AB). AB negatively affected parameters directly related to the mating success of laboratory males and their nutritional status. AB also affected males?survival under starvation conditions. The effect of AB on the behaviour and nutritional status of the males depended on two additional factors: the origin of the males and the presence of a proteinaceous source in the diet.Conclusions: our results suggest that A. fraterculus 65 males gut contain symbiotic organisms that are able to exert a positive contribution on A. fraterculus males? fitness, although the physiological mechanisms still need further studies.Fil: Juárez, María Laura. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra Terapéutica Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Pimper, Lida Elena. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Genética de la Estructura Poblacional; ArgentinaFil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Conte, Claudia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Ruiz, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Goane, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Medina Pereyra, Pilar. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Castro, Felipe. Fundación Miguel Lillo; ArgentinaFil: Salgueiro, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Caldera, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Fernández, Patricia Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Bourtzis, Kostas. Insect Pest Control Laboratory; AustriaFil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Vera, María Teresa. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

CD6 modulates thymocyte selection and peripheral T cell homeostasis

The CD6 glycoprotein is a lymphocyte surface receptor putatively involved in T cell development and activation. CD6 facilitates adhesion between T cells and antigen-presenting cells through its interaction with CD166/ALCAM (activated leukocyte cell adhesion molecule), and physically associates with the T cell receptor (TCR) at the center of the immunological synapse. However, its precise role during thymocyte development and peripheral T cell immune responses remains to be defined. Here, we analyze the in vivo consequences of CD6 deficiency. CD6(-/-) thymi showed a reduction in both CD4(+) and CD8(+) single-positive subsets, and double-positive thymocytes exhibited increased Ca(2+) mobilization to TCR cross-linking in vitro. Bone marrow chimera experiments revealed a T cell-autonomous selective disadvantage of CD6(-/-) T cells during development. The analysis of TCR-transgenic mice (OT-I and Marilyn) confirmed that abnormal T cell selection events occur in the absence of CD6. CD6(-/-) mice displayed increased frequencies of antigen-experienced peripheral T cells generated under certain levels of TCR signal strength or co-stimulation, such as effector/memory (CD4(+)TEM and CD8(+)TCM) and regulatory (T reg) T cells. The suppressive activity of CD6(-/-) T reg cells was diminished, and CD6(-/-) mice presented an exacerbated autoimmune response to collagen. Collectively, these data indicate that CD6 modulates the threshold for thymocyte selection and the generation and/or function of several peripheral T cell subpopulations, including T reg cells

Rediscovering the Wetlands of Berisso: an extension course within the framework of Environmental Education

Nuestro proyecto de extensión está destinado a niños de edad escolar, ya que son sujetos proactivos en la transmisión de la educación ambiental hacia el núcleo familiar y el contexto social. La ciudad de Berisso (Buenos Aires, Argentina) no sólo comprende paisajes urbanísticos y portuarios, si no también ambientes costeros y humedales, siendo estos últimos vulnerables a la actividad humana que contribuye a su progresivo deterioro. La metodología planteada es la interacción directa e intercambio de ideas con los actores sociales, abordando la problemática a partir de distintas actividades en los ámbitos donde visitamos (colegios, fiestas populares, jornadas). Los objetivos de los talleres son: fomentar actitud crítica, participativa y responsable frente a la problemática ambiental regional; concientizar sobre la necesidad de conservar la biodiversidad; fortalecer el vínculo entre universidad y sociedad. En cuanto al resultado general resaltamos la aceptación y concientización de la responsabilidad de la colectividad en su rol como copartícipes del ecosistema.Our extension project is intended for children of school age, because they are proactive subjects in the knowledge transfer of environmental education to their family and their social context. The city of Berisso, (Buenos Aires, Argentina) includes not only urbanistic and port areas, but also coastal and wetlands which are vulnerable to human activity that contributes to their progressive deterioration. The methodology proposed is the direct interaction and exchange of ideas with social actors, addressing the problem from different activities in the areas where we visit (schools, popular festivals, conferences). The objectives of the workshop are to encourage participative and responsible attitude towards the local environmental problems; to raise awareness about the need for preserving biodiversity; to strengthen the relationship between university and society. Regarding the general result, we highlight the acceptance and awareness of the responsibility of the community and its role as co-participants of the ecosystem.Facultad de Ciencias Naturales y Muse

TLR4 and TRIF-dependent stimulation of B lymphocytes by peptide liposomes enables T-cell independent isotype switch in mice

Immunoglobulin class switching from IgM to IgG in response to peptides is generally T cell–dependent and vaccination in T cell–deficient individuals is inefficient. We show that a vaccine consisting of a dense array of peptides on liposomes induced peptide-specific IgG responses totally independent of T-cell help. Independency was confirmed in mice lacking T cells and in mice deficient for MHC class II, CD40L, and CD28. The IgG titers were high, long-lived, and comparable with titers obtained in wild-type animals, and the antibody response was associated with germinal center formation, expression of activation-induced cytidine deaminase, and affinity maturation. The T cell–independent (TI) IgG response was strictly dependent on ligation of TLR4 receptors on B cells, and concomitant TLR4 and cognate B-cell receptor stimulation was required on a single-cell level. Surprisingly, the IgG class switch was mediated by TIR-domain-containing adapter inducing interferon-β (TRIF), but not by MyD88. This study demonstrates that peptides can induce TI isotype switching when antigen and TLR ligand are assembled and appropriately presented directly to B lymphocytes. A TI vaccine could enable efficient prophylactic and therapeutic vaccination of patients with T-cell deficiencies and find application in diseases where induction of T-cell responses contraindicates vaccination, for example, in Alzheimer disease