Differential cytokine gene expression profiles in the three pathological forms of sheep paratuberculosis.
BACKGROUND
Johne's disease is a chronic inflammatory disease of the gut caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP). Symptoms include wasting, diarrhoea, loss of condition and eventual death. Three forms of Johne's disease have been described in sheep - paucibacillary, multibacillary and asymptomatic. The paucibacillary form is characterized by an inflammatory, Th1-type immune response. The multibacillary form of the disease, which disseminates the infection, is characterized by macrophage infiltration mediated by a Th2-type immune response, and asymptomatic animals have no clinical symptoms or pathology but are infected with MAP. What determines these three forms of the disease is unknown. To further understand these differences, we used real-time RT-PCR to compare the expression of thirteen cytokine and cytokine-related genes in ileal tissue from sheep with the three forms of the disease.


RESULTS
Three pathological forms of sheep paratuberculosis were defined on the basis of histopathology, cytochemistry (Zeihl-Neelsen) and IS900 PCR. Paucibacillary lesions have largely T cell and eosinophil infiltration and are ZN negative; multibacillary lesions have macrophage infiltration and large numbers of acid-fast bacteria. The pauci- and multibacillary forms are linked to the differential expression of IFN gamma and IL-10 respectively. In addition the increased levels of the proinflammatory cytokines (IL-1 beta and TNFalpha), IL-8, IL-18 and TRAF-1 in both diseased forms is indicative of persistent inflammatory lesions. No changes were seen in IL-1 alpha in any sheep ileum tissues. Asymptomatic animals are IS900+ with normal histology but have significantly decreased levels of IL-18 and increased levels TNFalpha.


CONCLUSIONS
We have quantified the expression levels of thirteen cytokine and cytokine related genes in three forms of ovine paratuberculosis using real-time PCR analyses and confirm that sheep pauci- and multibacillary disease are linked to type 1 and type 2 T cell responses respectively. The expression patterns of other cytokines shows that both disease forms have an inflammatory aetiology but that the central role for IL-1 alpha in bovine paratuberculosis is not seen in the sheep infection. Asymptomatic animals are infected and show no pathology but can be distinguished, in terms of cytokine expression pattern, from uninfected controls.
Smeed
Jennifer A
JA
Centre for Infectious Diseases, Royal (Dick) School of Veterinary Studies, Summerhall, Edinburgh, EH9 1QH, UK. j.a.smeed@sms.ed.ac.uk
Watkins
Craig A
CA
Rhind
Susan M
SM
Hopkins
John
J
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D004251:DNA Transposable Elements / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D006651:Histocytochemistry / Q000662:veterinary; D007082:Ileum / Q000276:immunology / Q000382:microbiology; D007410:Intestinal Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D010283:Paratuberculosis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology / Q000382:microbiology; D018418:Th2 Cells / Q000276:immunology / Q000382:microbiology
D016207:Cytokines; D004251:DNA Transposable Elements; D012329:RNA, Bacterial
Vet Microbiol. 2000 Dec 20;77(3-4):465-73
11118731
Vet Microbiol. 2007 Jun 21;122(3-4):270-9
17317041
Vet Immunol Immunopathol. 2001 Sep 28;82(1-2):73-85
11557295
J Clin Microbiol. 2002 Jan;40(1):198-204
11773116
Infect Immun. 2002 Jul;70(7):3856-64
12065529
Genes Immun. 2002 Dec;3(8):441-53
12486602
Science. 2003 Sep 12;301(5639):1527-30
12970564
Infect Immun. 2003 Nov;71(11):6479-86
14573670
Infect Immun. 2004 Mar;72(3):1409-22
14977946
Annu Rev Immunol. 2004;22:599-623
15032590
Vet Immunol Immunopathol. 2004 May;99(1-2):39-46
15113652
Infect Immun. 2004 Jun;72(6):3089-96
15155609
Vet Pathol. 2004 Jul;41(4):378-87
15232138
Clin Exp Immunol. 1973 Aug;14(4):541-53
4583777
Annu Rev Immunol. 1989;7:145-73
2523712
Nucleic Acids Res. 1989 Nov 25;17(22):9063-73
2555783
Aust Vet J. 1990 Feb;67(2):47-50
2344336
Science. 1991 Oct 11;254(5029):277-9
1925582
Semin Dermatol. 1991 Sep;10(3):188-93
1931567
Am J Vet Res. 1992 Apr;53(4):477-80
1586015
Infect Immun. 1993 Aug;61(8):3482-9
8335379
J Invest Dermatol. 1994 Jun;102(6):828-32
8006444
Clin Microbiol Rev. 1994 Jul;7(3):328-45
7923053
Vet Immunol Immunopathol. 1996 Jan;49(4):331-45
8677635
Epidemiol Infect. 1996 Jun;116(3):373-9
8666083
J Comp Pathol. 1996 May;114(4):419-37
8814536
J Clin Invest. 1997 Jan 15;99(2):336-41
9006002
J Comp Pathol. 1997 Apr;116(3):217-61
9147244
Vet Immunol Immunopathol. 1998 May 29;63(3):265-87
9656460
Vet Immunol Immunopathol. 1998 Dec 11;66(3-4):343-58
9880110
J Allergy Clin Immunol. 1999 Jan;103(1 Pt 1):11-24
9893178
Can J Gastroenterol. 1998 Nov-Dec;12(8):559-68
9926266
Vet Immunol Immunopathol. 1999 May;68(2-4):139-48
10438314
Vet Immunol Immunopathol. 2005 Aug 15;107(1-2):153-61
15946745
J Comp Pathol. 2005 Aug-Oct;133(2-3):184-96
16045917
Vet Pathol. 2005 Sep;42(5):579-88
16145204
Cytokine Growth Factor Rev. 2006 Feb-Apr;17(1-2):97-106
16298544
Prev Vet Med. 2007 Jul 16;80(2-3):103-19
17350703
Annu Rev Immunol. 2001;19:93-129
11244032