Disease relevance of Intestinal Volvulus

• The sequence of this 46-kD Ro/SS-A protein (calreticulin) has significant homology to lambda Ral-1, a recombinant cDNA clone corresponding to a major antigen of the nematode, Onchocerca volvulus, the infectious agent of onchocerciasis [1].
• C57BL/6 and B cell-deficient (microMT) mice were immunized s. c. and injected intrastromally with Ags from the parasitic helminth Onchocerca volvulus (which causes river blindness) [2].
• In addition, O. volvulus contains the rickettsial endosymbiont Wolbachia, which has molecules with lipopolysaccharide-like activities that also signal through TLR4 [3].
• PBMC populations from onchocerciasis patients were not expanded after restimulation with Onchocerca volvulus antigens in vitro, but both V delta 1 and V delta 2 T cells from normal donors were increased significantly in response to O. volvulus and Mycobacterium tuberculosis (P < .05), respectively [4].
• These findings indicate that on a BALB/c background, IL-4 has a critical role in regulating neutrophil recruitment to the cornea and development of O. volvulus keratitis [5].

High impact information on Intestinal Volvulus

• In O. volvulus adult worms the Ov-SPI proteins are localized to the sperm and to eggshells surrounding the developing embryos [6].
• The similar localization of the related Onchocerca volvulus cathepsin Z protein suggests that the function of CPZ-1 during molting might be conserved in other nematodes [7].
• Cloning and biochemical characterization of blisterase, a subtilisin-like convertase from the filarial parasite, Onchocerca volvulus [8].
• Both recombinant O. volvulus and C. elegans cyclophilins were found to possess an enzyme activity with similar substrate preference and insensitivity to cyclosporin A [9].
• We investigated the immunomodulatory potential of a secreted cysteine protease inhibitor (onchocystatin) of the human pathogenic filaria Onchocerca volvulus [10].

Chemical compound and disease context of Intestinal Volvulus

• Onchocerca volvulus. Monoclonal anti-idiotype antibody as antigen signal for the microfilaricidal cytotoxicity of diethylcarbamazine-treated platelets [11].
• We subsequently produced an anti-idiotype mAb to Ab1 (Ab2), and considered the possibility of replacing the O. volvulus glycoprotein recognized by IA2(23) mAb by Ab2 [11].
• Human anti-O. volvulus antibodies were found to bind to intact glutaraldehyde-fixed mf of D. immitis in immunoperoxidase assays [12].
• Substrate assays with fluorescent peptides show that O. volvulus blisterase requires a P4 arginine and a basic amino acid at P1 for cleavage [8].
• Twenty-eight patients who had skin snips positive for microfilariae (Mf) were studied 120 days after receiving amocarzine, when each was negative for Mf: 16 (57%) were positive for O. volvulus DNA in the PCR-based assay [13].

Biological context of Intestinal Volvulus

• Cloning of a cysteine protease required for the molting of Onchocerca volvulus third stage larvae [14].
• OV-1 was used to immunoscreen an O. volvulus adult worm cDNA library [15].
• Analysis of levels of stage-specific immunoglobulin G3 (IgG3) and IgE revealed a striking, age-dependent dissociation between antibody responses to larval antigens (L3 and a recombinant L3-specific protein, O. volvulus ALT-1) which were significantly increased or maintained with age and antibody responses to F-OvAg, which decreased [16].
• Ov20 is a structurally novel 20-kDa retinol binding protein secreted by Onchocerca volvulus [17].
• Effects of intermediary metabolites and electron transport inhibitors on action of chloroquine on Brugia pahangi and Onchocerca volvulus [18].

Anatomical context of Intestinal Volvulus

• Onchocerca volvulus provides ligands for the stimulation of human gamma/delta T lymphocytes expressing V delta 1 chains [4].
• Sigmoid volvulus presenting as chronic secretory diarrhea responsive to octreotide [19].
• As shown by transmission disequilibrium tests, variants of the IL-10 promoter at positions -1082(G/A), -819(C/T), and -592(C/A) in the haplotype of ATA were significantly associated with high peripheral blood cell (PBC) proliferative responses to O. volvulus antigen (OvAg) [20].
• Neutrophil granule proteins: evidence for the participation in the host reaction to skin microfilariae of Onchocerca volvulus after diethylcarbamazine administration [21].
• Lymphocyte blastogenic responses to O. volvulus antigen (Oncho Ag), SKSD, and the mitogen PHA were tested in three groups of persons: light to moderately infected persons (INF); previously exposed but uninfected persons (EXP) and normal controls (NC) [22].

Gene context of Intestinal Volvulus

• Onchocerca volvulus antigen (OvAg)-stimulated peripheral blood mononuclear cells (PBMC) from subjects with disease produced significantly more interleukin (IL)-10 (with disease = 447.34 vs. without disease = 292.22 pg/mL; P < .01) and IL-5 (with disease = 33.36 vs. without disease = 27.26 pg/mL; P = .02) [23].
• Therefore, the defect in the development of a protective immune response against O. volvulus in TLR4-mutant mice is not due to loss of Th2 immunity or the response to Wolbachia but is due to an unidentified TLR4-dependent larval killing mechanism [3].
• Onchocerca volvulus-exposed persons fail to produce interferon-gamma in response to O. volvulus antigen but mount proliferative responses with interleukin-5 and IL-13 production that decrease with increasing microfilarial density [24].
• Recently, significant sequence homologies were found with an antigen from Onchocerca volvulus, a fruit fly odorant-binding protein and the yeast protein TFS1 which is a dosage-dependent suppressor of CDC25 mutations [25].
• The protective immune response to third-stage larvae of O. volvulus in mice vaccinated with irradiated larvae has an absolute IL-4 requirement [26].

Analytical, diagnostic and therapeutic context of Intestinal Volvulus

• By using one mAb (IA2(23] directed against Onchocerca volvulus and recognizing circulating Ag (Ab1), we purified by affinity chromatography the target molecule of IA2(23) (an O. volvulus glycoprotein recognized by IA2(23) mAb) [11].
• Degenerate primers were designed based upon conserved regions of MnSOD sequences from other organisms, and were used in PCR on reverse-transcribed O. volvulus total RNA and genomic DNA to identify partial cDNA and genomic DNA fragments encoding the O. volvulus MnSOD (OvMnSOD) [27].
• METHODS: C57BL/6 mice received an intrastromal injection of recombinant IL-4 and IL-13 (rIL-4 and IL-13) or were immunized by subcutaneous injection prior to receiving an intrastromal injection of a soluble O. volvulus extract [28].
• Nodule examination, the Mazzotti test (a provocative challenge with diethylcarbamazine), and the enzyme-linked immunosorbent assay (ELISA) were compared for diagnostic efficacy in children who were born in an area endemic for onchocerciasis in Guatemala and were skin-biopsy negative for microfilaria of Onchocerca volvulus [29].
• Pooled sera of Mf- and Mf+ individuals reacted with similar O. volvulus antigens on Western blots [30].

References