A matter of timing: early, not chronic phase intestinal nematode infection restrains control of a concurrent enteric protozoan infection.
Infections with parasitic worms are often long lasting and associated with modulated immune responses. We analyzed the influence of the nematode Heligmosomoides polygyrus bakeri dwelling in the small intestine on concurrent protozoan infection with Eimeria falciformis residing in the cecum. To dissect the effects of a nematode infection in the early versus chronic phase, we infected animals with E. falciformis 6 or 28 days post H. p. bakeri infection. Only a concurrent early nematode infection led to an increased replication of the protozoan parasite, whereas a chronic worm infection had no influence on the control of E. falciformis. Increased protozoan replication correlated with the reduced production of IFN-γ, IL-12/23, CCL4, CXCL9 and CXCL10, reduced migration of T cells and increased expression of Foxp3 at the site of protozoan infection. This was accompanied by a stronger nematode-specific Th2 response in gut-draining LN. Protection of mice against challenge infections with the protozoan parasite was not altered. Hence, the detrimental effect of a nematode infection on the control of a concurrent protozoan infection is transient and occurs only in the narrow time window of the early phase of infection.
Rausch
Sebastian
S
Department of Molecular Parasitology, Humboldt-University of Berlin, Berlin, Germany. sebastian.rausch@hu-berlin.de
Held
Josephin
J
Stange
Joerg
J
Lendner
Matthias
M
Hepworth
Matthew R
MR
Klotz
Christian
C
Lucius
Richard
R
Pogonka
Thomas
T
Hartmann
Susanne
S
D000818:Animals; D002465:Cell Movement / Q000276:immunology; D054407:Chemokine CCL4 / Q000276:immunology; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9 / Q000276:immunology; D003048:Coccidiosis / Q000150:complications* / Q000276:immunology / Q000469:parasitology; D004539:Eimeria / Q000276:immunology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology; D056747:Immunomodulation / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007411:Intestinal Diseases, Parasitic / Q000150:complications* / Q000276:immunology / Q000469:parasitology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009351:Nematospiroides dubius / Q000276:immunology; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013047:Specific Pathogen-Free Organisms; D018709:Statistics, Nonparametric; D017206:Strongylida Infections / Q000150:complications* / Q000276:immunology / Q000469:parasitology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D054407:Chemokine CCL4; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; C485433:Cxcl10 protein, mouse; C485969:Cxcl9 protein, mouse; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D018664:Interleukin-12; D012313:RNA; D007371:Interferon-gamma