The immune correlate of host resistance induced by reinfection of Trichinella spiralis remains unclear. In this study, we investigated immune correlates between the resistance and serum IgG antibody level, CD23⁺ IgM⁺ B cells, and eosinophil responses induced by T. spiralis reinfection. Mice were primarily infected with 10 or 100 T. spiralis larvae (10 TS, 100 TS), respectively, and after 4 weeks, they were challenge infected with 100 T. spiralis larvae (10–100 TS, 100-100 TS). Upon challenge infections, 10–100 TS mice induced significantly higher levels of T. spiralis-specific total IgG antibody responses in sera and antibody secreting cell responses in spleens compared to 100-100 TS mice, resulting in significantly reduced worm burdens in 10–100 TS mice (60% and 70% reductions for adult and larvae, respectively). Higher levels of eosinophils were found in mice primarily infected with 10 TS compared to those of 100 TS at week 8 upon challenge. CD23+ IgM+ B cells were found to be increased significantly in mice primarily infected with 10 TS. These results indicate that primary infection of 10 larvae of T. spiralis, rather than 100 larvae, induces significant resistance against reinfection which closely correlated with T. spiralis-specific IgG, eosinophil, and CD23+ IgM+ B cell responses.
Adult ; Animals ; Antibody Formation ; B-Lymphocytes ; Eosinophils ; Humans ; Immunoglobulin G ; Larva ; Mice* ; Spleen ; Trichinella spiralis* ; Trichinella*

Trichinosis is a worldwide parasitic infection caused by ingesting an uncooked raw meat containing viable larvae of nematode Trichinella. Although most cases have been reported in Western countries, the incidence has decreased due to strict control of meat handlings and improved hygiene in these countries. In Korea, the first case of Trichinella spiralis was reported in a patient who ingested an uncooked badger. We have also experienced four cases of Trichinella spiralis infestation among family members who showed typical clinical manifestations and laboratory findings after ingesting raw wild swine meat, and herein report the finding.
Animals ; Eating* ; Humans ; Hygiene ; Incidence ; Korea ; Larva ; Meat* ; Mustelidae ; Swine* ; Trichinella ; Trichinella spiralis ; Trichinellosis*

Trichinosis is a worldwide parasitic infection caused by ingesting an uncooked raw meat containing viable larvae of nematode Trichinella. Although most cases have been reported in Western countries, the incidence has decreased due to strict control of meat handlings and improved hygiene in these countries. In Korea, the first case of Trichinella spiralis was reported in a patient who ingested an uncooked badger. We have also experienced four cases of Trichinella spiralis infestation among family members who showed typical clinical manifestations and laboratory findings after ingesting raw wild swine meat, and herein report the finding.
Animals ; Eating* ; Humans ; Hygiene ; Incidence ; Korea ; Larva ; Meat* ; Mustelidae ; Swine* ; Trichinella ; Trichinella spiralis ; Trichinellosis*

As most infections by the helminth parasite elicit the recruitment of CD4+CD25+Foxp3+ T (T(reg)) cells, many scientists have suggested that these cells could be used for the treatment of immune-mediated inflammation and associated diseases. In order to investigate the distribution and alteration of activated T(reg) cells, we compared the expression levels of T(reg) cell activation markers in the ileum and gastrocnemius tissues 1, 2, and 4 weeks after infection. The number of T(reg) cells was monitored using GFP-coded Foxp3 transgenic mice. In mice at 1 week after Trichinella spiralis infection, the number of activated T(reg) cells was higher than in the control group. In mice at 2 weeks after infection, there was a significant increase in the number of cells expressing Foxp3 and CTLA-4 when compared to the control group and mice at 1 week after infection. At 4 weeks after infection, T. spiralis was easily identifiable in nurse cells in mouse muscles. In the intestine, the expression of Gzmb and Klrg1 decreased over time and that of Capg remained unchanged for the first and second week, then decreased in the 4th week. However, in the muscles, the expression of most chemokine genes was increased due to T. spiralis infection, in particular the expression levels of Gzmb, OX40, and CTLA-4 increased until week 4. In addition, increased gene expression of all chemokine receptors in muscle, CXCR3, CCR4, CCR5, CCR9, and CCR10, was observed up until the 4th week. In conclusion, various chemokine receptors showed increased expressions combined with recruitment of T(reg) cells in the muscle tissue.
Animals ; Gene Expression ; Helminths ; Ileum ; Inflammation ; Intestines ; Mice* ; Mice, Transgenic ; Muscles ; Parasites ; Receptors, Chemokine ; T-Lymphocytes, Regulatory* ; Trichinella spiralis ; Trichinella*

Eosinophils are multifunctional leukocytes implicated in protection against helminth infections. Although eosinophils comprise between 1~5% of peripheral blood leukocytes, they primarily reside in the gastrointestinal tract under homeostatic conditions, and rapidly proliferate upon parasitic infection. Intestinal infection with Trichinella spiralis (T. spiralis) induces eosinophilia when the parasite enters the larval stages and larvae finally migrate to the skeletal muscle. Eosinophils are known to mediate parasite death through antibody-dependent cellular cytotoxicity. In this study, we aimed to address the functional significance of eosinophils in the intestinal phase of T. spiralis infection by analysis of immune responses in the Peyer's patch (PP) of infected BALB/c and eosinophil-ablated ΔdblGATA mice. Trafficking of eosinophils to the PP was significantly increased, with upregulation of interleukin-5 at 14 days post infection. Eosinophil deficiency led to a significant augmentation of serum immunoglobulin (Ig) M and IgG1 antibody levels. In accordance with this, IgG1+ B cells in the PP were substantially increased in ΔdblGATA mice compared to that in BALB/c mice. Transforming growth factor-β expression in the PP of infected ΔdblGATA mice was significantly decreased compared to that in BALB/c mice, whereas the number of T. spiralis larvae in the diaphragm was increased. Taken together, these findings indicate that eosinophils contribute to the regulation of Th2 immune responses, and protect the host from T. spiralis attempting to establish larvae in the skeletal muscle.
Animals ; B-Lymphocytes ; Diaphragm ; Eosinophilia ; Eosinophils* ; Gastrointestinal Tract ; Helminths ; Immunoglobulin G ; Immunoglobulins ; Interleukin-5 ; Larva ; Leukocytes ; Mice ; Muscle, Skeletal ; Parasites ; Trichinella spiralis* ; Trichinella* ; Up-Regulation

The immune response against Trichinella spiralis at the intestinal level depends on the CD4⁺ T cells, which can both suppress or promote the inflammatory response through the synthesis of diverse cytokines. During the intestinal phase, the immune response is mixed (Th1/Th2) with the initial predominance of the Th1 response and the subsequent domination of Th2 response, which favor the development of intestinal pathology. In this context, the glucocorticoids (GC) are the pharmacotherapy for the intestinal inflammatory response in trichinellosis. However, its therapeutic use is limited, since studies have shown that treatment with GC suppresses the host immune system, favoring T. spiralis infection. In the search for novel pharmacological strategies that inhibit the Th1 immune response (proinflammatory) and assist the host against T. spiralis infection, recent studies showed that resiniferatoxin (RTX) had anti-inflammatory activity, which decreased the serum levels of IL-12, INF-γ, IL-1β, TNF-α, NO, and PGE₂, as well the number of eosinophils in the blood, associated with decreased intestinal pathology and muscle parasite burden. These researches demonstrate that RTX is capable to inhibit the production of Th1 cytokines, contributing to the defense against T. spiralis infection, which places it as a new potential drug modulator of the immune response.
Cytokines ; Drug Therapy ; Eosinophils ; Glucocorticoids ; Immune System ; Inflammation* ; Interleukin-12 ; Parasites ; Pathology ; T-Lymphocytes ; Therapeutic Uses* ; Trichinella spiralis ; Trichinellosis*

BACKGROUND/AIMS: Currently, there exists no biomarker for visceral hypersensitivity in irritable bowel syndrome (IBS). Piezo proteins have been proven to play an important role in the mechanical stimulation to induce visceral pain in other tissues and may also be a biomarker candidate. The aim of this study was to test the expressions of Piezo1 and Piezo2 proteins in the intestinal epithelial cells from different intestinal segments and to explore the correlation between Piezo proteins expression and visceral pain threshold. METHODS: Post-infectious IBS was induced in mice via a Trichinella spiralis infection. Visceral sensitivity was measured with abdominal withdrawal reflex to colorectal distention. Inflammation in the small intestine and colon was scored with H&E staining. Expression location of Piezo proteins was confirmed by immunohistochemistry. Abundance of Piezo proteins were measured with real-time reverse transcriptase polymerase chain reaction. RESULTS: Piezo1 and Piezo2 proteins were expressed in the intestinal epithelial cells. The expression levels of Piezo1 and Piezo2 were abundant in the colon than the small intestine (P < 0.001 for Piezo1, P = 0.003 for Piezo2). Expression of Piezo2 in the colon significantly correlated to the visceral sensitivity (r = −0.718, P = 0.001) rather than the mucosal inflammation. CONCLUSION: Piezo2 is a candidate biomarker for visceral hypersensitivity in IBS.
Animals ; Colon ; Epithelial Cells ; Humans ; Hyperalgesia ; Hypersensitivity* ; Immunohistochemistry ; Inflammation ; Intestine, Small ; Ion Channels ; Irritable Bowel Syndrome* ; Mice ; Reflex ; Reverse Transcriptase Polymerase Chain Reaction ; Trichinella spiralis ; Visceral Pain

The application of Giemsa technique to stain compressed diaphragm samples obtained from rodents experimentally infected with Trichinella spiralis is described. Diaphragm samples from rats heavily infected with 20 muscle larvae per gram of body weight (20 ML/gbw) were cut into several pieces and stained with Giemsa; on the other hand, whole diaphragms from slightly infected mice (1 ML/gbw) were also stained with Giemsa. Besides, muscle samples were also stained with Giemsa. Observation at 10 x magnification revealed that both ML and nurse cells (NC) look as bluish structures clearly contrasting with the pinkish color of the non-infected muscle fibers. NC in the diaphragms of mice could be easily observed at naked eye as blue points contrasting with the pink surrounding areas formed by the non-infected muscle fibers. Among NC observed in the diaphragms of rats infected with 20 ML/gbw, 4.4% was multiple infection. These findings were confirmed in sectioned and hematoxylin-eosin stained specimens. This data could be usefulness for a rapid diagnosis of trichinellosis in post-mortem mammals without magnification procedures.
Animals ; Azure Stains/*chemistry ; Diaphragm/*parasitology ; Larva/ultrastructure ; Male ; Mice ; Rats ; Rats, Wistar ; Trichinella spiralis/*isolation & purification/ultrastructure ; Trichinosis/diagnosis/*parasitology

The application of Giemsa technique to stain compressed diaphragm samples obtained from rodents experimentally infected with Trichinella spiralis is described. Diaphragm samples from rats heavily infected with 20 muscle larvae per gram of body weight (20 ML/gbw) were cut into several pieces and stained with Giemsa; on the other hand, whole diaphragms from slightly infected mice (1 ML/gbw) were also stained with Giemsa. Besides, muscle samples were also stained with Giemsa. Observation at 10 x magnification revealed that both ML and nurse cells (NC) look as bluish structures clearly contrasting with the pinkish color of the non-infected muscle fibers. NC in the diaphragms of mice could be easily observed at naked eye as blue points contrasting with the pink surrounding areas formed by the non-infected muscle fibers. Among NC observed in the diaphragms of rats infected with 20 ML/gbw, 4.4% was multiple infection. These findings were confirmed in sectioned and hematoxylin-eosin stained specimens. This data could be usefulness for a rapid diagnosis of trichinellosis in post-mortem mammals without magnification procedures.
Animals ; Azure Stains/*chemistry ; Diaphragm/*parasitology ; Larva/ultrastructure ; Male ; Mice ; Rats ; Rats, Wistar ; Trichinella spiralis/*isolation & purification/ultrastructure ; Trichinosis/diagnosis/*parasitology

In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T (T(reg)) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and T(reg) cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/TIRAP-/- MEF cells, and quite substantially decreased in TRIF-/- MEF cells. In contrast, IL-10 and TGF-beta expression levels were not elevated in MyD88/TIRAP-/- MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and T(reg) cell mediated immune responses, although additional data are needed to convincingly prove this observation.
Animals ; Gene Expression ; Humans ; Interleukin-10/genetics ; Mice ; Mice, Knockout ; Th2 Cells/metabolism ; Toll-Like Receptors/*genetics/metabolism ; Trichinella spiralis/genetics/*physiology ; Trichinellosis/genetics/metabolism/*parasitology