| |
Immune response of the mucosa in cattle with subclinical Johne´s disease
 |
Mycobacterium avium subsp. paratuberculosis is the causative agent of Johne`s disease, a chronic granulomatous enteritis of wild and domestic ruminants. During a long subclinical period, the organism persists in the intestine despite systemic cellular and humoral immune responses. What exactly happens in the mucosa over this period? It seems like a state of tolerance...
|
|
|
| |
To explore the mucosal immune response in Johne`s disease, we isolated mononuclear leukocytes from the ileum of cows naturally infected with M. avium subsp. paratuberculosis and from cows that were not infected.
We evaluated the immunophenotype of these cells and the proliferative responses after the addition of M. avium subsp. paratuberculosis sonicate or B-cell or T-cell mitogens.
Although the percentage of T cells was increased in infected cows, these cells consisted mostly of memory (CD2+CD62L–) and regulatory (CD4+CD25+) T cells.
Further evidence of immune hyporesponsiveness included a decrease in the percentage of T cells with an activated phenotype and a decrease in cells expressing major histocompatibility factor class II (MHC class II).
Unlike the spleen, ileal lymphocytes from infected cows failed to proliferate in response to M. avium subsp. paratuberculosis sonicate. Additionally, ileal lymphocytes from infected cows proliferated poorly in response to concanavalin A and pokeweed mitogen, suggesting generalized T cell and B cell hyporesponsiveness.
These results indicate that a state of tolerance may exist in the intestine of cows subclinically infected with M. avium subsp. paratuberculosis organisms in subclinically infected cows.
This effect may be induced, at least in part, by proliferation of regulatory T cells that nonspecifically suppress mucosal immune responsiveness.
Source: D. J. Weiss, O. A. Evanson and C. D. Souza (2006): Mucosal Immune Response in Cattle with Subclinical Johne`s Disease. In: Vet Pathol 43:127-135 (2006)
Tell a friend
|
Print version
|
Send this article
|
| |
Immune modulators and proliferation of peripheral blood mononuclear cells in cows peripartum Milk/plasma ratio and milk and plasma pharmacokinetics of amoxicillin in lactating cowsNeuromuscular block monitoring after cis-Âatracurium in the anaesthetized pigGrowth factor expression in cows with cystic ovarian diseaseProtecting protein to reduce methane production in ruminantsLifetime prognosis in cattle with necrotic laryngitisECG findings in neonatal calves with diarrhea and associated potassium balance disordersBacterial translocation in calves with atresia coliOptimising lameness detection in dairy cattle Role of melatonin and its receptors in animal reproductionPhysiological changes in inflammatory parameters in cows prae and post partumZinc Deficiency-Like Syndrome in Fleckvieh Calves
|
