Kinetics of mast cells, eosinophils and phospholipase B activity in the spontaneous-cure response of two strains of mice (rapid and slow responder) to the cestode Hymenolepis nana

Modulation of murine intestinal immunity by Moringa oleifera extract in experimental hymenolepiasis nana

The potential therapeutic value of Moringa oleifera extract (MOE), due to its anti-inflammatory and anti-oxidant effects, has been reported previously. In this study, Hymenolepis nana antigen (HNA) in combination with MOE was used in immunization against H. nana infection. Adult worm and egg counts were taken, while histological changes in the intestine were observed. Mucosal mast (MMCs) and goblet cells (GCs) were stained with specific stains, while serum and intestinal IgA were assayed using enzyme-linked immunosorbent assay (ELISA). Reduced glutathione (GSH) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS) were assayed. Real-time polymerase chain reaction (PCR) was used for detection of mRNA expression in ileum tissue. The results demonstrated an improvement in the architecture of intestinal villi, decreased inducible nitric oxide synthase (iNOs) and TBARS, and increased GSH in HNA, MOE and MOE + HNA groups. In the same groups, an increase in GCs, mucin 2 (MUC2), interleukins (IL)-4, -5 and -9, and stem cell factor (SCF) versus a decrease in both interferon-gamma (IFN-γ) and transforming growth factor (TGF-β) expression appeared. HNA and MOE + HNA increased serum and intestinal IgA, respectively. MOE decreased MMCs and achieved the highest reductions in both adult worms and eggs. In conclusion, MOE could achieve protection against H. nana infections through decreased TGF-β, IFN-γ and MMC counts versus increased GC counts, T-helper cell type 2 (Th2) cytokines and IgA level.

Granulocytes in helminth infection -- who is calling the shots?

Helminths are parasitic organisms that can be broadly described as “worms” due to their elongated body plan, but which otherwise differ in shape, development, migratory routes and the predilection site of the adults and larvae. They are divided into three major groups: trematodes (flukes), which are leaf-shaped, hermaphroditic (except for blood flukes) flatworms with oral and ventral suckers; cestodes (tapeworms), which are segmented, hermaphroditic flatworms that inhabit the intestinal lumen; and nematodes (roundworms), which are dioecious, cylindrical parasites that inhabit intestinal and peripheral tissue sites. Helminths exhibit a sublime co-evolution with the host´s immune system that has enabled them to successfully colonize almost all multicellular species present in every geographical environment, including over two billion humans. In the face of this challenge, the host immune system has evolved to strike a delicate balance between attempts to neutralize the infectious assault versus limitation of damage to host tissues. Among the most important cell types during helminthic invasion are granulocytes: eosinophils, neutrophils and basophils. Depending on the specific context, these leukocytes may have pivotal roles in host protection, immunopathology, or facilitation of helminth establishment. This review provides an overview of the function of granulocytes in helminthic infections.

Immune response to the cestode Hymenolepis nana: cytokine production during infection with eggs or cysts

Analysis of cytokine production (IFN-gamma, IL-2, IL-3, IL-4, IL-5) by in vitro Con A-stimulated mesenteric lymph node cells measured daily after egg or cyst infection of mice with Hymenolepis nana showed that cytokine production varies during parasite development and between different host strains (BALB/c and C3H/He mice). Egg infection stimulates a rapid increase in IFN-gamma, independent of mouse strain. In addition, in BALB/c mice a Th2-like response (IL-4, IL-5 secretion) was stimulated 4-5 days p.i., when the parasites are thought to begin their lumenal phase. After infection with cysts significant increases in IFN-gamma, IL-2, IL-4 and IL-5 were observed at the time when autoinfection with eggs is thought to occur. The level of IFN-gamma paralleled that seen after a primary egg infection. This suggests that there is a predominantly Th1-type response during the tissue phase of H. nana development and that, in BALB/c mice, a Th2 polarization occurs during the first few days of the lumenal phase. The cytokine patterns observed are discussed in relation to host responses during chronic helminth infection.

Expulsion of Hymenolepis nana from mice with congenital deficiencies of IgE production or of mast cell development

The roles of IgE and mast cells on expulsion of adult Hymenolepis nana from the intestine were examined in mice. IgE-dependency was determined by comparing congenitally IgE-deficient SJA/9 and IgE-producing SJL/J mice infected with 50 H. nana eggs. Anti-H. nana IgE antibody was detected at three weeks post infection (p.i.) in SJL but not in SJA mice. The number of adult worms in the intestines of SJA and of SJL mice were similar at two weeks, but significantly more were found in SJA mice at three weeks p.i. Treatment of mice with anti-epsilon antibody also resulted in an increased worm burden at three weeks, suggesting participation of IgE in expulsion of H. nana. Intestinal mastocytosis was induced by infection regardless of the IgE status of the mice. Mast cell-dependency was tested in mast cell-deficient W/Wv and in normal littermate +/+ mice infected with 100 H. nana eggs. Anti-H. nana antibody was detected in both groups of mice at three weeks p.i. Worm expulsion seemed to be mast cell dependent because expulsion was less complete in W/Wv mice at three weeks p.i. Peripheral blood eosinophilia was comparable at three weeks p.i. in both IgE and mast cell sufficient and deficient mice. These results suggest that IgE and mast cells participate in the expulsion of H. nana adults from intestine in mice.

Cellular and chemical mediators of type 1 hypersensitivity in calves infected with Ostertagia ostertagi: mast cells and eosinophils

Abomasal mucosal mast cell and eosinophil accumulation was morphometrically evaluated in 26 Holstein steers after natural or experimental infection with Ostertagia ostertagi. Results showed that following infection, accumulation of mast cells and eosinophils in abomasal tissue was dependent on infection pattern. Eosinophilia was greater in steers with type 1 ostertagiosis, while mastocytes was more pronounced in steers with type 2 ostertagiosis.

Failure to demonstrate suppressor T cell activity in the lamina propria of Hymenolepis diminuta-infected rats

The aim of this study was to examine whether there was an increase of suppressor T cells, relative to helper T cells, in the intestinal lamina propria of Hymenolepis diminuta-infected rats, a condition which might allow the parasite to survive for the life-span of the host. Lamina propria cells were isolated by enzymatic procedure. All lymphocytes were passed over nylon wool columns in order to remove B cells; then the T cells were purified by a panning technique using monoclonal anti-T cell antibodies. Changes in the mitogen-stimulated synthesis of IgM, IgG and IgA by normal peripheral blood indicator lymphocytes, as measured by sandwich ELISA, was used as an index of help and/or suppression. No significant suppressor T cell activity was observed in the cultures, either from control or infected intestine.

Hymenolepis diminuta: changes in the levels of certain intestinal regulatory peptides in infected C57 mice

The levels of 10 regulatory peptides in acid-alcohol extracts of three regions of the small intestine (0-20%, 30-60%, and 70-100%, with respect to distance from the pylorus) have been monitored radioimmunometrically in sham-infected male (6-8 week old) C57 mice and mice given a 5-cysticercoid infection of the rat tapeworm Hymenolepis diminuta and autopsied 10 days postprimary infection and 5 days postsecondary infection (administered 28 days postprimary infection). The regulatory peptides examined were gastrin, gastrin-releasing peptide (GRP), glucagon (= enteroglucagon), motilin, neurotensin (NT), pancreatic polypeptide (PP), peptide histidine isoleucine (PHI), somatostatin (SRIF), substance P (SP), and vasoactive intestinal peptide (VIP). Statistical analyses revealed significant deviations from control values of five of the peptides (enteroglucagon and SP, both elevated; NT, PHI and VIP, all lowered) in intestinal tissue from infected mice; measurement of the same peptides in colonic extracts revealed no significant differences between infected and sham-infected mice. Parallel changes in peptide levels between normal infected and immunosuppressed infected mice were not evident, although elevations in the tissue levels of enteroglucagon and SP were found in infected Wistar rats (normal host). Results are discussed with respect to a peptidergic involvement in the pathology and host immune response to an intestinal tapeworm.

Hymenolepis diminuta: intestinal goblet cell response to infection in male C57 mice

Intestinal goblet cell numbers in two regions of the small intestine (20-30% and 60-70% distance form the pylorus) of male, 6- to 8-week-old C57 mice have been monitored following a 5-cysticercoid infection of the rat tapeworm, Hymenolepis diminuta. Test and sham-infected control mice were autopsied 0, 4, 8, 10, 14, and 28 days postprimary infection (p-1 degree-i) and 2, 4, 5, 7, and 14 days postsecondary infection (p-2 degree-i), administered 28 days p-1 degree-i. Results show a statistically significant increase in the number of mucus-containing goblet cells in both regions of the intestine during primary and secondary infections. Peak goblet cell numbers occurred on Day 8 p-1 degree-i and Day 5 p-2 degree-i in the 20-30% region and on Day 10 p-1 degree-i and Day 5 p-2 degree-i in the 60-70% region. In both regions, cell numbers declined to control levels by Day 14 p-1 degree-i, but remained significantly above control values 14 days p-2 degree-i. The increase in cell numbers correlated with an increase in goblet cell theca size and observable amounts of luminal mucus. The same infection regime in mice treated with cortisone elicited no goblet cell response. Male Wistar rats given a 10-cysticercoid infection and autopsied on Day 0, Day 10, and 15 months p-i showed a statistically significant increase in mucus-containing goblet cells only in the 60-70% region of intestine 10 days p-i; however, the worm burden was not eliminated. The functional significance of these results is discussed in relation to host immunity and murine cestode rejection.