Mimori T et al. (1987) Exp Parasitol "Strongyloides ratti: formation of protection in rats by excretory/secretory products of adult worms."

Tanaka M, Tada I, Mimori T

[Exp Parasitol, 1987]

Formation of a marked protective immunity against the challenge infection was found in the rats immunized with excretory/secretory (ES) products of Strongyloides ratti adult worms. Immunization by intraduodenal injection of ES products reduced both the fecal egg counts and the adult worm burden by subcutaneous inoculation of infective larvae and by an intraduodenal implantation. The duration of parasitism in the immunized rats, however, was not shortened compared with that of control rats. The normal migration of subcutaneously challenged larvae was not affected by ES product immunization. Intestinal mastocytosis occurred according to the appearance of adult worms in the small intestine of the immunized rats earlier than it did in controls. This result suggests that mastocytosis is involved in the induction of protection by ES products of S. ratti adult worms.

Nawa Y et al. (1982) J Parasitol "Stage-specific cross-resistance between Nippostrongylus brasiliensis and Strongyloides ratti (Nematoda) in rats."

Tada I, Mimori T, Nawa Y, Korenaga M

[J Parasitol, 1982]

Stage-specificity of cross-resistance between Nippostrongylus brasiliensis and Strongyloides ratti was investigated. Results showed that immunization with tissue-migrating larvae was sufficient to generate cross-resistance and that host defense mechanisms operating in the cross-resistance were directed against tissue-migrating larvae but not against intestinal adult worms. In addition, no significant potentiation of the cross-resistance was observed after multiple immunization. These observations suggest that host defense mechanisms against heterologous challenge infection were qualitatively and/or quantitatively different from those against homologous challenge infection.

Samuel ADT et al. (2003) J Neurosci "Synaptic activity of the AFD neuron in Caenorhabditis elegans correlates with thermotactic memory."

Murthy VN, Samuel ADT, Silva RA

[J Neurosci, 2003]

Thermotactic behavior in Caenorhabditis elegans is sensitive to both a worm's ambient temperature (T-amb) and its memory of the temperature of its cultivation (T-cult). The AFD neuron is part of a neural circuit that underlies thermotactic behavior. By monitoring the fluorescence of pH-sensitive green fluorescent protein localized to synaptic vesicles, we measured the rate of the synaptic release of AFD in worms cultivated at temperatures between 15 and 25degreesC, and subjected to fixed, ambient temperatures in the same range. We found that the rate of AFD synaptic release is high if either T-amb > T-cult or T-amb > T-cult, but AFD synaptic release is low if T-amb congruent to T-cult. This suggests that AFD encodes a direct comparison between T-amb and T-cult.

Korenaga M et al. (1983) J Parasitol "Effects of preintestinal larval antigenic stimuli on the generation of intestinal immunity in Strongyloides ratti infection in rats."

Tada I, Korenaga M, Mimori T, Nawa Y

[J Parasitol, 1983]

Generation of intestinal immunity by antigenic stimulation with preintestinal, tissue-migrating larvae was investigated in the Strongyloides ratti-rat model. The results of daily fecal egg counts showed that the intestinal immunity against adult worms could be partially generated by priming with preintestinal migrating larvae. A further study demonstrated that this partial reduction of daily fecal egg count was mainly the result of inhibitory effects on the fecundity of the parasitic females, although the expulsion of the parasite from the gut could be advanced by several days. After tertiary immunization with preintestinal larvae, no significant potentiation in the protection was observed when compared with the rats treated by primary immunization alone.

Bommireddy R et al. (2007) Trends Mol Med "TGFbeta1 and Treg cells: alliance for tolerance."

Bommireddy R, Doetschman T

[Trends Mol Med, 2007]

Transforming growth factor beta1 (TGFbeta1), an important pleiotropic, immunoregulatory cytokine, uses distinct signaling mechanisms in lymphocytes to affect T-cell homeostasis, regulatory T (T(reg))-cell and effector-cell function and tumorigenesis. Defects in TGFbeta1 expression or its signaling in T cells correlate with the onset of several autoimmune diseases. TGFbeta1 prevents abnormal T-cell activation through the modulation of Ca(2+)-calcineurin signaling in a Caenorhabditis elegans Sma and Drosophila Mad proteins (SMAD)3 and SMAD4-independent manner; however, in T(reg) cells, its effects are mediated, at least in part, through SMAD signaling. TGFbeta1 also acts as a pro-inflammatory cytokine and induces interleukin (IL)-17-producing pathogenic T-helper cells (T(h) IL-17 cells) synergistically during an inflammatory response in which IL-6 is produced. Here, we will review TGFbeta1 and its signaling in T cells with an emphasis on the regulatory arm of immune tolerance.

Korenaga M et al. (1983) Exp Parasitol "Strongyloides ratti: the role of enteral antigenic stimuli by adult worms in the generation of protective immunity in rats."

Mimori T, Nawa Y, Korenaga M, Tada I

[Exp Parasitol, 1983]

Immunogenicity of adult Strongyloides ratti was studied in rats. Immunization of rats by intraduodenal implantation of adult worms could completely inhibit the egg production and hasten the expulsion of challenged worms which were developed from subcutaneously inoculated L3 or were implanted intraduodenally as adults. Enteral immunization by intraduodenal implantation of adult worms was, however, not able to affect the esophageal larval output of the challenge infection with L3. In contrast to enteral immunization with adult worms, immunization by full sequence of a primary infection or by a combination of drug-abbreviated infection and adult worm implantation could suppress the esophageal larval output of the challenge infection. The relationship between the host defense mechanism and the life cycle of S. ratti is discussed.

Tanaka M et al. (1989) Int J Parasitol "The acquirement of growth ability for third-stage larvae of Strongyloides ratti during the head-passage in the rat."

Tada I, Minematsu T, Mimori T, Tanaka M

[Int J Parasitol, 1989]

The role of larval passage through the head in the course of the migration of Strongyloides ratti in rats was investigated. Third-stage larvae (L3) recovered from various portions of donor rats were re-injected into the skin, cranial cavity and small intestine of recipient rats to check their ability for further growth. Cultured L3 (L3c) and the L3 recovered from the skin of donor rats (L3s) did not survive in the small intestine after intestinal inoculation. However, intestinal inoculation of L3 recovered from the head of donor rats (L3h) revealed growth to the adult stage. Cultured L3 injected into the cranial cavity of rats also became adult worms in the small intestine. L3 incubated in the cranial cavity for more than 24 h could grow in the small intestine of the recipient rats. These experiments suggest that S. ratti L3 acquire their ability to mature in the small intestine during their migration through the head of rats.

Agulnik SI et al. (1995) Genomics "Conservation of the T-box gene family from Mus musculus to Caenorhabditis elegans."

Bollag RJ, Silver LM, Agulnik SI

[Genomics, 1995]

Recently, a novel family of genes with a region of homology to the mouse T locus, which is known to play a crucial, and conserved, role in vertebrate development, has been discovered. The region of homology has been named the T-box. The T-box domain of the prototypical T locus product is associated with sequence-specific DNA binding activity. In this report, we have characterized four members of the T-box gene family from the nematode Caenorhabditis elegans. All lie in close proximity to each other in the middle of chromosome III. Homology analysis among all completely sequenced T-box products indicates a larger size for the conserved T-box domain (166 to 203 residues) than previously reported. Phylogenetic analysis suggests that one C. elegans T-box gene may be a direct ortholog of the mouse Tbx2 and Drosophila omb genes. The accumulated data demonstrate the ancient nature of the T-box gene family and suggest the existence of at least three separate T-box-containing genes in a common early metazoan ancestor to nematodes and vertebrates.

Ju T et al. (2006) Glycobiology "Identification of core 1 O-glycan T-synthase from Caenorhabditis elegans."

Ju T, Zheng Q, Cummings RD

[Glycobiology, 2006]

The common O-glycan core structure in animal glycoproteins is the core 1 disaccharide Galbeta1-3GalNAcalpha1-Ser/Thr, which is generated by addition of Gal to GalNAcalpha1-Ser/Thr by core 1 UDP-Gal:GalNAcalpha1-Ser/Thr beta1,3-galactosyltransferase (core 1 beta3-Gal-T or T-synthase, EC2.4.1.122)(2). Although O-glycans play important roles in vertebrates, much remains to be learned from model organisms such as the free-living nematode Caenorhabditis elegans, which offer many advantages in exploring O-glycan structure/function. Here we report the cloning and enzymatic characterization of T-synthase from C. elegans (Ce-T-synthase). A putative C. elegans gene for T-synthase, C38H2.2, was identified in GenBank by a BlastP search using the human T-synthase protein sequence. The full-length cDNA for Ce-T-synthase, which was generated by PCR using a C. elegans cDNA library as the template, contains 1,170 bp including the stop TAA. The cDNA encodes a protein of 389 amino acids with typical type-II membrane topology and a remarkable 42.7% identity to the human T-synthase. Ce-T-synthase has 7 Cys residues in the lumenal domain including 6 conserved Cys residues in all of the orthologs. The Ce-T-synthase has 4 potential N-glycosylation sequons, whereas the mammalian orthologs lack N-glycosylation sequons. Only one gene for Ce-T-synthase was identified in the genome-wide search and it contains 8 exons. Promoter analysis of the Ce-T-synthase using green fluorescent protein constructs show that the gene is expressed at all developmental stages and appears to be in all cells. Unexpectedly, only minimal activity was recovered in the recombinant, soluble Ce-T-synthase secreted from a wide variety of mammalian cell lines, whereas robust enzyme activity was recovered in the soluble Ce-T-synthase expressed in Hi-5 insect cells. Vertebrate T-synthase requires the molecular chaperone Cosmc, but our results show that Ce-T-synthase does not require Cosmc, and might require invertebrate-specific factors for formation of the optimally active enzyme. These results show that the Ce-T-synthase is a functional ortholog to the human T-synthase in generating core 1 O-glycans and opens new avenues to explore O-glycan function in this model organism.

Muir RE et al. (2007) Int J Syst Evol Microbiol "Leucobacter chromiireducens subsp. solipictus subsp. nov., a pigmented bacterium isolated from the nematode Caenorhabditis elegans, and emended description of L. chromiireducens."

Muir RE, Tan MW

[Int J Syst Evol Microbiol, 2007]

A yellow-pigmented, Gram-positive, aerobic, non-motile, non-spore-forming, irregular rod-shaped bacterium (strain TAN 31504(T)) was isolated from the bacteriophagous nematode Caenorhabditis elegans. Based on 16S rRNA gene sequence similarity, DNA G+C content of 69.5 mol%, 2,4-diaminobutyric acid in the cell-wall peptidoglycan, major menaquinone MK-11, abundance of anteiso- and iso-fatty acids, polar lipids diphosphatidylglycerol and phosphatidylglycerol and a number of shared biochemical characteristics, strain TAN 31504(T) was placed in the genus Leucobacter. DNA-DNA hybridization comparisons demonstrated a 91 % DNA-DNA relatedness between strain TAN 31504(T) and Leucobacter chromiireducens LMG 22506(T) indicating that these two strains belong to the same species, when the recommended threshold value of 70 % DNA-DNA relatedness for the definition of a bacterial species by the ad hoc committee on reconciliation of approaches to bacterial systematics is considered. Based on distinct differences in morphology, physiology, chemotaxonomic markers and various biochemical characteristics, it is proposed to split the species L. chromiireducens into two novel subspecies, Leucobacter chromiireducens subsp. chromiireducens subsp. nov. (type strain L-1(T)=CIP 108389(T)=LMG 22506(T)) and Leucobacter chromiireducens subsp. solipictus subsp. nov. (type strain TAN 31504(T)=DSM 18340(T)=ATCC BAA-1336(T)).