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In order to recognize the local immune response of the definitive host to Calicophoron daubneyi natural infection, an immunohistochemical study was carried out in the reticulum and rumen in 49 naturally infected cattle. The role of cytokines (IL-4 and IL-10 interleukins and IFN-γ) in the activation of specific defence mechanisms was evaluated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays to study cytokine mRNA expression. In all infected animals, CD3+ T lymphocytes seemed to be the main element of the inflammatory infiltrate in the reticular and ruminal lamina propria at the point of the parasite adhesion. Intraepithelial globule leukocytes also showed immunolabelling for CD3. Most CD3+ cells also expressed CD4 (T cell helper) antigen although sporadic CD8+-cytotoxic lymphocytes were observed. Local expression of IFN-γ was observed in damaged papillae at the site of parasite attachment and in scattered cells in the lamina propria. B cells (CD79αcy+, CD45+ and IgG+) were found constantly in relation to lymphoid aggregates. MAC387 was expressed in squamous epithelium and in macrophages of the lamina propria of affected papillae. Macrophages in this location also stained positively for CD163 and CD68. Intraepithelial Langerhans cells and macrophages located in the lamina propria showed immunopositivity for MHCII in the affected areas. RT-qPCR analysis confirmed a statistical significant increase of IFN-γ, and IL-10 expression (p<0.01) in the rumen associated with the presence of flukes. These findings suggest a predominant Th1 polarized local immune response with the probable involvement of Th regulatory cells in cattle C. daubneyi natural infection., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Certain histochemical alterations in the different tunics of duodenum in kids were studied 20, 40, 60 and 80 days post-infection (DPI) with Paramphistomum cervi and the results compared with those of uninfected kids. There was a general reduction of polysaccharide complex substances and glycogen at 20 DPI. A marked decrease in polysaccharide complex substances and glycogen at 20 DPI. A marked decrease in polysaccharide complex substances and glycogen was especially discernible in the Brunner's gland and muscularis mucosa 20 DPI. Thereafter, these substances gradually increased and at 80 DPI this decrease was fully replenished. A slight reduction in mucin and protein content of the infected duodenal goblet cells was noticed at 20 DPI. It is suggested that juvenile P. cervi utilize host-tissue polysaccharide complex substances and glycogen for their growth and development during duodenal migration.