Influence of vitamin A on the immune response of Schistosoma mansoni-infected rats.

Nutritional (vitamin A levels, weights), parasitological (adult worm burden, count of eggs in liver, stool examination) and immunological (IgE serum levels, anti-Schistosoma mansoni antibodies, lymphocyte stimulation by concanavalin A and S. mansoni antigenic extract) parameters were studied in three groups of rats, a non-infected and normally fed control group, a S. mansoni-infected but normally fed group, and a S. mansoni-infected group with experimentally induced vitamin A deficiency. The number of worms was found significantly higher in the third (53 +/- 19) than in the second group (2 +/- 2) (p less than 0.001). There were many eggs in the liver surrounded by granulomatous reactions in the third group (399 +/- 73 epg liver). All stool examinations were negative. IgE levels and anti-S. mansoni antibody titres were significantly lower (p less than 0.001) in the third than in the second group. The concanavalin A lymphocyte stimulation indexes did not differ significantly between groups 2 and 3; the S. mansoni lymphocyte stimulation index was only significantly positive in group 3 (p less than 0.001). These results indicate a decrease in the humoral immune response without alteration of cellular immune response in vitamin A-deficient rats infected with S. mansoni.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Involvement of a gelsolin-related protein in spermatogenesis of the earthworm Lumbricus terrestris

Krueger E, Hinssen H, D'Haese J. Involvement of a gelsolin-related protein in spermatogenesis of the earthworm Lumbricus terrestris. CELL AND TISSUE RESEARCH. 2008;332(1):141-150.A gelsolin-related protein was isolated from seminal vesicles of the annelid Lumbricus terrestris. Compared with the isoforms of the gelsolin-related protein previously found in the muscle of the annelid body wall, the isolated protein was assigned to the first isoform (EWAM-P1) because of its electrophoretic mobility, chromatographic elution behaviour, immunological cross-reactivity and identical nucleotide sequence of segments obtained by reverse transcription/polymerase chain reaction. Immunofluorescence studies with smear preparations of developing male germ cells revealed characteristic changes of the local distribution of actin and EWAM-P1 during spermatogenesis. These changes were correlated with the developmental transport processes and structural alterations. F-actin, as revealed by rhodamine-phalloidin staining, formed a toroid-shaped structure in cytoplasmic bridges connecting the germ cells to a central cytophore during the developmental stages. An actin antibody reacting with both G- and F-actin demonstrated that actin was concentrated at the proximal and distal parts of the spermatocytes. EWAM-P1 was also localized in these regions, with intense staining in the distal part of spermatocytes and young spermatids in which the Golgi complex and proacrosome resided. The anti-actin antibody further stained the periphery of the nucleus. This staining gradually reduced during sperm maturation and covered about half of the length of the nucleus in elongated spermatids. Co-localization of EWAM with actin implied a functional significance of this gelsolin-related protein for the rearrangement of the actin cytoskeleton during earthworm spermiogenesis