T-helper-1 and T-helper-2 immune responses in mice infected with the intestinal fluke Neodiplostomum seoulense: their possible roles in worm expulsion and host fatality.
Neodiplostomum seoulense is highly pathogenic and lethal to experimental mice; most worms are expelled within 2 mo of acquisition. In this study, T-helper (Th) cell immune responses were studied in N. seoulense-infected BALB/c mice. Spleen and mesenteric lymph node (MLN) cells of infected mice proliferated in response to parasite antigens; CD4+ T cells proliferated more than CD8+ T cells. Antigen-induced interferon (IFN)-gamma (a Th1 cytokine) secretion began to increase at day 7 postinfection (PI) in spleen and MLN cells, and this was maintained at day 28 PI, whereas interleukin (IL)-4 (a Th2 cytokine) secretion was somewhat lower. Similar results were observed for mRNA signals of IFN-gamma and IL-4. Antigen-specific serum total immunoglobulin (Ig)G, IgG1, IgM, and IgA levels (Th2-induced) were elevated from days 7 to 14 to day 28 PI, and IgG2a (Th1-induced) was elevated at days 21 to 28 PI. Interestingly, the numbers of macrophages (Th1- or Th2-induced), which were found to kill N. seoulense worms in vitro, increased remarkably during days 14-28 PI in spleens and small intestines of infected mice. This study shows that mixed Th1 and Th2 responses occur during the course of N. seoulense infection in BALB/c mice. Heavy infiltrations of macrophages in the small intestine may participate in host damage and worm expulsion.
Shin
Eun-Hee
EH
Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, South Korea.
Lee
Sang-Hyup
SH
Kim
Jae-Lip
JL
Chai
Jong-Yil
JY
D000818:Animals; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D007411:Intestinal Diseases, Parasitic / Q000276:immunology / Q000401:mortality / Q000469:parasitology; D007413:Intestinal Mucosa / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology / Q000469:parasitology; D008213:Lymphocyte Activation; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000469:parasitology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D014200:Trematoda / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D014201:Trematode Infections / Q000276:immunology / Q000401:mortality / Q000469:parasitology
D015847:Interleukin-4; D007371:Interferon-gamma