Identification ofSchistosoma haematobium soluble egg antigens that elicit human granuloma formation in vitro

Abstract

Schistosoma haematobium soluble egg antigens (SH SEAs) induce intense granulomas in human hosts that often culminate in severe disease. In an attempt to identify the SH SEA fractions that are responsible for pathology, we combined T-cell Western blotting and an in vitro model of granuloma formation. Whole SH SEAs were dotted onto nitrocellulose pieces or were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrotransferred onto nitrocellulose paper. Horizontal strips bearing the separated antigens were solubilized in dimethylsulfoxide and precipitated in carbonate/bicarbonate buffer. Antigen-free and antigen-bearing particles were used to stimulate peripheral blood mononuclear cells (PBMCs) obtained from S. haematobium-infected patients and sex- and age-matched healthy controls to form granulomas in vitro. Whole SH SEA-bearing nitrocellulose particles elicited in vitro formation of granulomas by PBMCs from infected donors. The response was similar in sensitivity, specificity, and reproducibility to that evoked by SH SEA-bound polyacrylamide beads. The results obtained in samples form 30 patients and 10 controls tested with SH SEA-separated fractions revealed that SEA bands of 84,000, 63,000, 57,000, 55,000, 40,000, 30,000, and 28,000 Da elicited in vitro granuloma reactions by PBMCs of almost all infected patients. Conversely, separated soluble adult-worm antigens failed to stimulate PBMCs of infected patients to form granulomas. This study is the first to identify the SH SEA fractions that evoke in vitro granuloma formation and represents an initial step toward the development of an anti-urinary schistosomiasis pathology vaccine.

SDS-PAGE Protein Pattern and Antigenicity Cross Reaction of Human Schistosomes

“…Also these results somehow came in line with the results obtained by Hillyer and Pacheco (1986) who demonstrated six distinct bands with MW of 131, 76, 74, 55, 40 and 25 kDa on analyzing the protein components of S. haematobium adult worm antigen preparation. Concerning the bands obtained for S. haematobium SEA were came in line with Gaafar et al (1993) who revealed seven bands ranged from 84 to 28 kDa namely, 84, 63, 57, 55, 40, 30 and 28 kDa. While Mahfouz et al (2011) detected bands ranged from 106-18.5 kDa.…”

“…USA). Molecular mass of both the SDS-PAGE and western-blot was determined using GelProAnalyzer package (Media Cybernetica;1993). Both expirements were repeated three times.…”

A Novel Mouse Model of Schistosoma haematobium Egg-Induced Immunopathology

“…The unexcreted schistosome egg, in contrast, may persist for many years in host tissues and is a well-established, potent immunogen (e.g., soluble egg antigen or SEA [69]). Indeed, the systemic and granulomatous immune response to urogenital schistosomiasis is primarily driven by egg-associated antigens [70], [71]. Our model has methodologic similarities to synchronous granuloma formation induced by bolus injection of eggs into the mouse tail, cecal, or portal vein [64], [72], [73].…”

Cysteine Peptidases as Schistosomiasis Vaccines with Inbuilt Adjuvanticity

“…2-Cys peroxiredoxin [34] (H- 104 RKQEISKAYGVFDE EDGNA 122 -OH)-derived peptide, showing lowest homology to the murine counterpart, was synthesized as a tetra branched multiple antigen peptide (MAP) construct and purified at AnaSpec, Inc. (San Jose, California). Schistosoma mansoni soluble egg antigen (SEA) was prepared as described [35].…”