Please cite this article in press as: Simpson, H.V., et al., Histochemical study of the effects on abomasal mucins of Haemonchus contortus or Teladorsagia circumcincta infection in lambs. Vet. Parasitol. (2016), http://dx.doi.org/10.1016/j.vetpar.2016.06.026 ARTICLE IN PRESS G Model VETPAR-8059; No. of Pages 12 Veterinary Parasitology xxx (2016) xxx–xxx Contents lists available at ScienceDirect Veterinary Parasitology jou rn al h om epage: www.elsevier.com/locate/vetpar Research paper Histochemical study of the effects on abomasal mucins of Haemonchus contortus or Teladorsagia circumcincta infection in lambs H.V. Simpson a,∗ , S. Umair b , V.C. Hoang a , M.S. Savoian c a Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand b The Hopkirk Research Institute, AgResearch Ltd., Private Bag 11-008, Palmerston North, New Zealand c Institute of Fundamental Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand a r t i c l e i n f o Article history: Received 23 May 2016 Received in revised form 18 June 2016 Accepted 20 June 2016 Keywords: Haemonchus contortus Teladorsagia circumcincta Abomasal mucins Histochemistry Sulphation a b s t r a c t Previously, chemical analysis of gastric fundic mucin showed that infection of sheep with Haemonchus contortus or Teladorsagia circumcincta changed the proportions of monosaccharides and decreased terminal mucin fucosylation and sialylation. To identify the effects of these parasites on the two mucin- secreting cell lineages, fundic and antral tissues were collected for histochemistry from 69 lambs aged from 3–4 to 9–10 months-of-age which had received a single infection of either H. contortus or T. cir- cumcincta and euthanased at Day 21 or 28 post- infection respectively. All fundic tissues were stained separately with: (1) with Periodic Acid Schiff (PAS) for all mucins; (2) Alcian Blue (AB) pH 2.5 for acidic mucins (sialylated and sulphated); (3) AB pH 1 for sulphated mucins and (4) High Iron Diamine (HID) for sulphated mucins. Antral and fundic tissues from 24 lambs were also stained for acidic and neutral mucins or with specific lectins for -1-linked fucose and for -2,3- and -2,6-linked sialic acids. Only mucin sulphation appeared to differ visually in uninfected lambs over this age range: there was weak staining with HID in tissues from lambs 3–6 months-of-age, but was generally more intense in those over 7 months-of-age. Sulphomucins were not apparent in surface mucous cells (SMC) or generally in the upper pits. Sialylomucins were located predominantly in the pits and glands, with small amounts of sialylated mucins in SMC and on the luminal surface, mainly in younger animals up to 6 months-of-age and less in the older animals. Parasitism markedly reduced the predominantly neutral surface mucin5AC of the SMC and pit cells, despite pit elongation in both antrum and fundus, whereas the acidic Muc6 secreted by mucus neck cells (MNC) increased along with MNC hyperplasia. Sulphated mucins were present mainly from the mid-pits downward and heavy staining was more common in older animals. In these sheep, the markedly reduced neutral mucin in the SMC and pit cells in both antrum and fun- dus contrasts with reported hypersecretion of mucus in the intestine, which is believed to aid in parasite expulsion. It has been proposed that intestinal goblet cell hypersecretion occurs only in resistant animals, therefore reduced mucins in the abomasum may be indicative of susceptibility to abomasal parasites. © 2016 Elsevier B.V. All rights reserved. 1. Introduction Gastrointestinal and other epithelial surfaces are overlaid with a protective mucus gel containing mainly secreted high M.W. mucins, as well as ions, antibodies and other molecules which reduce phys- ical and chemical damage to the epithelium (Allen, 1981; Powell, 1981; Lichtenberger, 1995). Mucins consist of a polypeptide core to which are attached mainly O-linked oligosaccharides between GalNAc and hydroxyl groups of serine or threonine (Kobata, 1992), ∗ Corresponding author at: Institute of Veterinary, Animal and Biomedical Sci- ences, Massey University, Private Bag 11-222, Palmerston North 4442, New Zealand. E-mail address: H.V.Simpson@massey.ac.nz (H.V. Simpson). as well as by N-linkages, in which GlcNAc is linked to an amine group of asparagine (Kobata, 1992). Different epithelial tissues express genes for large secreted gel-forming mucins and smaller membrane-bound mucins. In the stomach, the secreted mucins are Muc5AC and Muc6 (Ho et al., 1995; Byrd et al., 1997), in con- trast to Muc2 in the intestine and also Muc6 in the duodenum (de Bolos et al., 2001). The lower M.W. membrane-bound mucins are mainly Muc1 in the stomach and Muc2 and 3 in the intestine (Andrianifahanana et al., 2006). The characteristics of mucins influence the susceptibility or resistance of a host to pathogens which attach to specific cell sur- face carbohydrate structures, often the oligosaccharides of mucins (Hakansson et al., 1996; Wadstrom et al., 1996; Freitas et al., 2002; Magalhâes et al., 2009). Altered mucin glycosylation can therefore http://dx.doi.org/10.1016/j.vetpar.2016.06.026 0304-4017/© 2016 Elsevier B.V. All rights reserved.