To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-alpha) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice.
Animals ; Brain/parasitology ; Cytokines/*metabolism ; Female ; Gene Expression Regulation ; Heart/parasitology ; Interleukins/*metabolism ; Intestines/parasitology ; Larva Migrans, Visceral/*immunology/parasitology ; Liver/parasitology ; Lung/parasitology/pathology ; Mice ; Mice, Inbred C57BL ; Muscles/parasitology ; Spleen/parasitology ; Th1 Cells/immunology ; Th17 Cells/immunology ; Th2 Cells/immunology ; Toxascaris/*immunology

Toxoplasma gondii can modulate host cell gene expression; however, determining gene expression levels in intermediate hosts after T. gondii infection is not known much. We selected 5 genes (ALDH1A2, BEX2, CCL3, EGR2 and PLAU) and compared the mRNA expression levels in the spleen, liver, lung and small intestine of genetically different mice infected with T. gondii. ALDH1A2 mRNA expressions of both mouse strains were markedly increased at day 1-4 postinfection (PI) and then decreased, and its expressions in the spleen and lung were significantly higher in C57BL/6 mice than those of BALB/c mice. BEX2 and CCR3 mRNA expressions of both mouse strains were significantly increased from day 7 PI and peaked at day 15-30 PI (P<0.05), especially high in the spleen liver or small intestine of C57BL/6 mice. EGR2 and PLAU mRNA expressions of both mouse strains were significantly increased after infection, especially high in the spleen and liver. However, their expression patterns were varied depending on the tissue and mouse strain. Taken together, T. gondii-susceptible C57BL/6 mice expressed higher levels of these 5 genes than did T. gondii-resistant BALB/c mice, particularly in the spleen and liver. And ALDH1A2 and PLAU expressions were increased acutely, whereas BEX2, CCL3 and EGR2 expressions were increased lately. Thus, these demonstrate that host genetic factors exert a strong impact on the expression of these 5 genes and their expression patterns were varied depending on the gene or tissue.
Aldehyde Dehydrogenase/*genetics/metabolism ; Animals ; Brain/metabolism/parasitology ; Chemokine CCL3/*genetics/metabolism ; Early Growth Response Protein 2/*genetics/metabolism ; Gene Expression Profiling ; Humans ; Lung/metabolism/parasitology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Inbred Strains ; Nerve Tissue Proteins/*genetics/metabolism ; Organ Specificity ; Spleen/metabolism/virology ; Toxoplasma/*physiology ; Toxoplasmosis/*genetics/metabolism/parasitology ; Urokinase-Type Plasminogen Activator/*genetics/metabolism