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Mast cells and intestinal nematodiasis

Specific enzyme-linked immunosorbent assays (ELISA) for rat mast cell proteinase I and II (RMCP I and II), intestinal mast cell proteinase (IMCP) and sheep mast cell proteinase (SMCP) were developed. Sheep serum or lymph contained potent inhibitory factors which interfered with the ELISA for SMCP, whereas little or no effect was demonstrated in the rodent ELISA by homologous serum. Secretion of SMCP into gastric lymph was noted in immune sheep following oral challenge with <i>Ostertagia circumcincta</i>. Development of immunity to <i>Haemonchus contortus</i> in sheep, expressed as the ability to exclude larvae from the mucosal surface, was characterised by an increase in mucosal mast cells (MMC) and increased abomasal tissue concentrations of SMCP. Increased concentrations of SMCP were demonstrated in serum and mucus in immune, but not in naive, sheep following direct abomasal challenge with 1 x 10<SUP>6</SUP> L<SUB>3</SUB> <i>Haemonchus</i> larvae. The abrogation of immune exclusion by treatment with corticosteroids was associated with a significant reduction in the number of MMC and concentrations of SMCP in abomasal tissue. Immune exclusion persisted for 6 weeks but had declined by 12 weeks following the cessation of larval challenge. This decline was associated with a significant reduction in the number of MMC and concentrations of SMCP in abomasal tissue. Ovine mast cells derived from <i>in vitro</i> culture of bone marrow cells (BMMC) were compared with MMC. BMMC contained similar constituents to MMC including SMCP, histamine, dopamine and arylsulphatase. BMMC contained an additional <SUP>3</SUP>[H]-DFP reactive protein not demonstrated in MMC. In the mouse, the major source of IMCP was the gastrointestinal tract. During infection with <i>Trichinella spiralis</i>, secretion of IMCP was demonstrated. Murine mast cells of the gastrointestinal tract exhibited heterogeneity in their proteinase phenotype, with many cells apparently containing a mixture of proteinases. Heterogeneity in the proteinase expression of mast cells in the rat was also demonstrated, with mast cells containing either RMCP I, RMCP II or RMCP I and II. Cells expressing dual proteinase phenotype were observed in some non-mucosal locations. During a primary infection of <i>Nippostrongylus brasiliensis</i>, changes in the RMCP I and II concentrations occurred in almost all tissues of the rat. These included significant increases in RMCP II concentrations in mesenteric lymph node, lung and intestinal tract 12 days after infection. Other changes, including those of RMCP I concentrations in bone marrow, are described.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:652749
Date January 1991
CreatorsHuntley, John Frederick
PublisherUniversity of Edinburgh
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/1842/15070

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