Potent induction of antibody-secreting B-cells by human dermal-derived CD14+ dendritic cells triggered by dual toll-like receptor ligation

Targeting CD14(+) dermal-derived dendritic cells (DDCs) is a rational approach for vaccination strategies aimed at improving humoral immune responses, because of their natural ability to stimulate naïve B-cells. Here, we show that CD14(+) DDCs express mRNA for TLRs 1–9, but respond differentially to single or paired TLR ligands. Compared to single ligands, some combinations were particularly effective at activating CD14(+) DDCs, as shown by enhanced expression of B-cell stimulatory cytokines (IL-6, IL-10 and TNF-α) and more pronounced phenotypic maturation. These combinations were Resiquimod (R-848) plus Polyinosinic:polycytidylic acid (Poly(I:C)); R-848 plus LPS; Pam3CSK4 plus Poly(I:C); LPS plus Poly(I:C). We also found that selected TLR ligand pairs (R-848 plus either LPS or Poly(I:C)) were superior to individual agents at boosting the inherent capacity of CD14(+) DDCs to induce naïve B-cells to proliferate and differentiate into CD27(+) CD38(+) B-cells that secrete high levels of IgG and IgA. When treated with the same TLR ligand combinations, CD14(+) DDCs also promoted the differentiation of Th1 (IFN-γ-secreting) CD4(+) T-cells, but not of Th2 or Th17 CD4(+) T-cells. These observations may help to identify adjuvant strategies aimed at inducing protective immune responses to various pathogens, including but not limited to HIV-1

Immunological survey of babesiosis ( Babesia peircei ) and toxoplasmosis in Jackass penguins in South Africa

Babesia peircei a été extrait d'érythrocytes nucléés provenant de Sphenicus demersus originaires d'Afrique du Sud infectés naturellement. Des fractions de Babesia peircei enrichies en glycoprotéines ont été obtenues par chromatographie sur colonne d'affinité concanavaline A-Sepharose et séparées par électrophorèse en gel de polyacrylamide-dodecylsulfate de sodium (SDS.PAGE). Quatorze bandes protéiques au minimum ont été observées (9, 11, 13, 20, 22, 23, 24, 43, 62, 90, 120, 204, et 205 kDa), la protéine majeure étant de 25 kDa. Des prélèvements sanguins provenant de 191 S. demersus adultes ont été testés par ELISA en utilisant les fractions de B. peircei enrichies en glycoprotéines pour détecter les IgG dirigées contre B. peircei. les prélèvements provenaient de trois groupes de manchots sauvages (n = 110), d'un groupe de manchots (n = 66) ayant été secourus après avoir été contaminés par une marée noire en mer et soignés à la Fondation Nationale Sud Africaine pour la Conservation des Oiseaux littoraux (SANCCOB), et d'un dernier groupe issu des manchots pensionnaires du SANCCOB (n = 15). La prévalence globale pour B. peircei était de 65 %, et la séropositivité moyenne s'échelonnait de 60 à 71 % parmi les cinq groupes de manchots. L'ELISA apparaissait spécifique pour les IgG dirigées contre B. peircei lorsque testée pour les IgG contre Haemoproteus columbae et les IgG contre le paludisme aviaire (Plasmodium relictum, et P. elongatum(, Les anticorps (Ac) dirigés contre Toxoplasma gondii ont été détectés par le test d'agglutination directe utilisant des tachyzoites de T. gondii tués. Tous les oiseaux étaient séronégatifs pour les Ac dirigés contre T. gondii. L'absence de manchots positifs pour T. gondii était due aux conditions sanitaires appropriées et aux méthodes de prévention contre T. gondii utilisées par le SANCCOB

Scale Dependence of Dark Energy Antigravity

We investigate the effects of negative pressure induced by dark energy (cosmological constant or quintessence) on the dynamics at various astrophysical scales. Negative pressure induces a repulsive term (antigravity) in Newton's law which dominates on large scales. Assuming a value of the cosmological constant consistent with the recent SnIa data we determine the critical scale $r_c$ beyond which antigravity dominates the dynamics ($r_c \sim 1Mpc$) and discuss some of the dynamical effects implied. We show that dynamically induced mass estimates on the scale of the Local Group and beyond are significantly modified due to negative pressure. We also briefly discuss possible dynamical tests (eg effects on local Hubble flow) that can be applied on relatively small scales (a few $Mpc$) to determine the density and equation of state of dark energy.Comment: Contributed talk at the 2nd Hellenic Cosmology Workshop at NOA (Athens) Jan. 2001.To appear in the proceedings. Based on work done in collaboration with M. Axenides and E. Florato

Restoration of diaphragmatic function after diaphragm reinnervation by inferior laryngeal nerve; experimental study in rabbits

OBJECTIVES: To assess the possibilities of reinnervation in a paralyzed hemidiaphragm via an anastomosis between phrenic nerve and inferior laryngeal nerve in rabbits. Reinnervation of a paralyzed diaphragm could be an alternative to treat patients with ventilatory insufficiency due to upper cervical spine injuries. MATERIAL AND METHOD: Rabbits were divided into five groups of seven rabbits each. Groups I and II were respectively the healthy and the denervated control groups. The 3 other groups were all reinnervated using three different surgical procedures. In groups III and IV, phrenic nerve was respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the trunk of the inferior laryngeal nerve. In group V, the fifth and fourth cervical roots were respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the nerve of the sternothyroid muscle (originating from the hypoglossal nerve). Animals were evaluated 4 months later using electromyography, transdiaphragmatic pressure measurements, sonomicrometry and histological examination. RESULTS: A poor inspiratory activity was found in quiet breathing in the reinnervated groups, with an increasing pattern of activity during effort. In the reinnervated groups, transdiaphragmatic pressure measurements and sonomicrometry were higher in group III with no significant differencewith groups IV and V. CONCLUSION: Inspiratory contractility of an hemidiaphragm could be restored with immediate anastomosis after phrenic nerve section between phrenic nerve and inferior laryngeal nerve

Super-resolving phase measurements with a multi-photon entangled state

Using a linear optical elements and post-selection, we construct an entangled polarization state of three photons in the same spatial mode. This state is analogous to a ``photon-number path entangled state'' and can be used for super-resolving interferometry. Measuring a birefringent phase shift, we demonstrate two- and three-fold improvements in phase resolution.Comment: 4 pages, 3 figure