Trichinella spiralis: The influence of short chain fatty acids on the proliferation of lymphocytes, the goblet cell count and apoptosis in the mouse intestine J. Piekarska a,⇑ , D. Mis ´ta b , M. Houszka c , B. Króliczewska b , W. Zawadzki b , M. Gorczykowski a a Department of Internal and Parasitic Diseases, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 47, Poland b Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Norwida 31, Poland c Department of Pathology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Norwida 31, Poland article info Article history: Received 18 January 2011 Accepted 17 May 2011 Available online 24 May 2011 Keywords: Trichinella spiralis Short chain fatty acids (SCFA) Lymphocyte proliferation Goblet cells Apoptosis Mice abstract This study was carried out to determine the influence of short chain fatty acids (SCFA) on spleen and mes- enteric lymph node lymphocyte proliferation, goblet cells and apoptosis in the mouse small intestine dur- ing invasion by Trichinella spiralis. BALB/c mice were infected with 250 larvae of T. spiralis. An SCFA water solution containing acetic, propionic and butyric acids (30:15:20 mM) was administered orally starting 5 days before infection and ending 20 days post infection (dpi). Fragments of the jejunum were collected by dissection 7 and 10 dpi, and were examined for apoptotic cells in the lamina propria of the intestinal mucosa, and for goblet cells. The proliferation index of the cultured spleen and mesenteric lymph node lymphocytes with MTT test was also determined. The orally administered SCFA solution decreased the proliferation of mesenteric lymph node lymphocytes in the mice infected with T. spiralis at both exami- nation times, but did not influence the proliferative activity of the spleen cells. Seven dpi, both in the spleen and mesenteric lymph nodes, the highest proliferation index of concanavalin A (Con A)-stimulated lymphocytes was found in the group of uninfected animals receiving SCFA animals. This tendency could still be seen 10 dpi in the mesenteric lymph nodes but not in the spleen, where the proliferation index in this group had significantly decreased. In vitro studies revealed, that butyric and propionic acids added to the cell cultures suppressed the proliferation of Con A-stimulated mesenteric lymph nodes and spleen lymphocytes taken from uninfected and T. spiralis-infected mice. Acetic acid stimulated proliferation of splenocytes taken from uninfected mice but did not affect lymphocyte proliferation in mesenteric lymph nodes from uninfected or infected mice. Orally administered SCFA increased the number of goblet cells found in the epithelium of the jejunum 7 dpi, but this number had decreased 10 dpi. The number of apop- totic cells in the lamina propria of the intestinal mucosa of animals infected with the T. spiralis and receiv- ing SCFA was also lower, particularly 10 dpi. The above results show that SCFA can participate in the immune response during the course of trichinellosis in mice. Ó 2011 Elsevier Inc. All rights reserved. 1. Introduction Trichinellosis is parasitic zoonosis during which pathological processes occur in the intestines and muscles. The intestinal inva- sion is a very important stage of trichinellosis, because it deter- mines the development and subsequent course of the disease and its consequences. The presence in the intestine of mature forms of the parasite initiates a series of structural, cellular and physiological changes, resulting in acute inflammatory responses in the small intestine (Garside et al., 2000; Khan and Collins, 2004; Dehlawi et al., 2006). The elimination or destruction of mature forms of Trichinella spiralis in the intestine (self-cure phenomenon) may alter the local and general reaction of the host, reduce the invasion of larvae into the muscles and ultimately change the clinical out- come. Rapid expulsion of the parasites from the small intestine is associated with IgE-mediated protection against T. spiralis. The mucosal immune system of the gastrointestinal tract initially in- duces an acute phase of inflammatory cytokine release and then the cytokine-supported Th2 response (Grencis, 1997). The inflam- matory infiltration that develops in the intestine after infection with T. spiralis involves a subpopulation of T cells, and has the fea- tures of an allergic reaction (Garside et al., 2000). The predomi- nance of Th2 cell activation stimulates the synthesis of specific antibodies, including those of the IgE class. The local reaction is characterized by the accumulation of mast cells and eosinophils, respectively induced by IL-4 and IL-5. The secreted cytokines and growth factors stimulate the goblet cells of the intestinal epithe- lium to proliferate and secrete mucus. Specific IgE, mast cell and eosinophil products damage the parasites, which can then be 0014-4894/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.exppara.2011.05.019 ⇑ Corresponding author. E-mail address: piekarsk@wp.pl (J. Piekarska). Experimental Parasitology 128 (2011) 419–426 Contents lists available at ScienceDirect Experimental Parasitology journal homepage: www.elsevier.com/locate/yexpr