Interleukin-10 Mediated Autoregulation of Murine B-1 B-Cells and Its Role in Borrelia hermsii Infection

B cells are typically characterized as positive regulators of the immune response, primarily by producing antibodies. However, recent studies indicate that various subsets of B cells can perform regulatory functions mainly through IL-10 secretion. Here we discovered that peritoneal B-1 (B-1P) cells produce high levels of IL-10 upon stimulation with several Toll-like receptor (TLR) ligands. High levels of IL-10 suppressed B-1P cell proliferation and differentiation response to all TLR ligands studied in an autocrine manner in vitro and in vivo. IL-10 that accumulated in cultures inhibited B-1P cells at second and subsequent cell divisions mainly at the G1/S interphase. IL-10 inhibits TLR induced B-1P cell activation by blocking the classical NF-κB pathway. Co-stimulation with CD40 or BAFF abrogated the IL-10 inhibitory effect on B-1P cells during TLR stimulation. Finally, B-1P cells adoptively transferred from the peritoneal cavity of IL-10−/− mice showed better clearance of Borrelia hermsii than wild-type B-1P cells. This study described a novel autoregulatory property of B-1P cells mediated by B-1P cell derived IL-10, which may affect the function of B-1P cells in infection and autoimmunity

Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes

Studies of marine mammal parasites in the Caribbean are scarce. An assessment for marine mammal endo- and ectoparasites from Puerto Rico and the Virgin Islands, but extending to other areas of the Caribbean, was conducted between 1989 and 1994. The present study complements the latter and enhances identification of anisakid nematodes using molecular markers. Parasites were collected from 59 carcasses of stranded cetaceans and manatees from 1994 to 2006, including Globicephala macrorhynchus, Kogia breviceps, Kogia sima, Lagenodelphis hosei, Mesoplodon densirostris, Peponocephala electra, Stenella longirostris, Steno bredanensis, Trichechus manatus. Tursiops truncatus, and Ziphius cavirostris. Sixteen species of endoparasitic helminthes were morphologically identified, including two species of acanthocephalans (Bolbosoma capitatum, Bolbosoma vasculosum), nine species of nematodes (Anisakis sp., Anisakis brevispiculata, Anisakis paggiae, Anisakis simplex, Anisakis typica, Anisakis ziphidarium, Crassicauda anthonyi, Heterocheilus tunicatus, Pseudoterranova ceticola), two species of cestodes (Monorygma grimaldi, Phyllobothrium delphini), and three species of trematodes (Chiorchis groschafti, Pulmonicola cochleotrema, Monoligerum blairi). The nematodes belonging to the genus Anisakis recovered in some stranded animals were genetically identified to species level based on their sequence analysis of mitochondrial DNA (629 bp of mtDNA cox 2). A total of five new host records and six new geographic records are presented.L'articolo è disponibile sul sito dell'editore http://www.springerlink.com

A distinct role for B1b lymphocytes in T cell-independent immunity

Pathogenesis of infectious disease is not only determined by the virulence of the microbe but also by the immune status of the host. Vaccination is the most effective means to control infectious diseases. A hallmark of the adaptive immune system is the generation of B cell memory, which provides a long-lasting protective antibody response that is central to the concept of vaccination. Recent studies revealed a distinct function for B1b lymphocytes, a minor subset of mature B cells that closely resembles that of memory B cells in a number of aspects. In contrast to the development of conventional B cell memory, which requires the formation of germinal centers and T cells, the development of B1b cell-mediated long-lasting antibody responses occurs independent of T cell help. T cell-independent (TI) antigens are important virulence factors expressed by a number of bacterial pathogens, including those associated with biological threats. TI antigens cannot be processed and presented to T cells and therefore are known to possess restricted T cell-dependent (TD) immunogenicity. Nevertheless, specific recognition of TI antigens by B1b cells and the highly protective antibody responses mounted by them clearly indicate a crucial role for this subset of B cells. Understanding the mechanisms of long-term immunity conferred by B1b cells may lead to improved vaccine efficacy for a variety of TI antigens

Laser saphenous ablations in more than 1,000 limbs with long-term duplex examination follow-up

Background: The goal of this study was to evaluate the duplex results of endovenous laser ablation in the treatment of incompetent great saphenous veins (GSV) and small saphenous veins (SSV) with at least 1-year follow-up. Methods: A retrospective registry was entered by 11 centers from Europe and America, organized by the International Endovenous Laser Working Group. Data concerning 1,020 limbs in patients with incompetence of the GSV and/or SSV, treated with the Endovenous Laser Ablation (EVLA) procedure, were collected. EVLA failures were defined on duplex imaging as reflux confined to the saphenofemoral or saphenopopliteal junction, reflux confined to the main saphenous trunk, or reflux of both junction and main trunk (totally patent saphenous vein) were analyzed at one or more years postoperatively. Results: The mean age of patients was 54 +/- 5 years (range: 18-91 years). The average body mass index was 25. There was a paucity of severe complications: One case of third-degree skin burn, six patients with postsurgical deep vein thrombosis (0.6%), and 27 cases of sensory nerve damage (2.7%). At 1-year, the rate of complete occlusion of the saphenous trunk was 93.1%. There were 79 cases of treatment failures as evidenced by duplex: 22 isolated junction failures (2.2%), 44 isolated trunk failures (4.4%), and 13 totally patent veins (1.3%). Two-year duplex results were reported for 329 limbs with the identification of 19 new cases of failure. No new cases of failure were reported at 3-year follow-up of 130 limbs. Cumulative failure rates estimated by Kaplane-Meier analysis were 7.7% at 1-year and 13.1% at 2- and 3-year follow-up. Conclusions: On the basis of a duplex scan performed at least 1-year post-treatment, this multicenter registry confirms the safety and efficacy of the EVLA procedure in the treatment of GSV and SSV reflux. Considering the continued failure rate documented in the present study, an annual follow-up by duplex is recommended to 2 years after EVLA