Model for Immune Responses to Mycobacterium avium Subspecies paratuberculosis in Cattle

Susceptibility to paratuberculosis infection in cattle is associated with single nucleotide polymorphisms in Toll-like receptor 2 which modulate immune responses against Mycobacterium avium subspecies paratuberculosis

“…After Map has crossed the intestinal barrier by M cell uptake, it is recognized by phagocytes, such as macrophages and dendritic cells (DC), as part of the innate immune response against pathogens (Coussens, 2004). Toll-like receptors (TLR) and cytosolic Nucleotide Oligomerization Domain (NOD)-like receptors are, among other pattern recognition receptors, involved in the recognition of mycobacteria, as well as in stimulating phagocytosis and the development of cell-mediated immunity (Quesniaux et al, 2004).…”

“…The loss of protective CMI leads to a widely disseminated infection and uncontrolled growth of mycobacteria in macrophages, causing the clinical manifestation of paratuberculosis (Koets et al, 2002). Hence, following a prolonged period of chronic diarrhoea, weight loss and decreased milk production, cows become emaciated and may die from this protein-loosing enteropathy (Coussens, 2004). Regulatory T cells may also play a role in suppression of Th1 activity, amongst others via the production of the immunosuppressive IL-10 (Weiss et al, 2005), and TLR2 may play a role in this process (Weiss and Souza, 2008).…”

Distribution of Mycobacterium avium subsp.paratuberculosis in tissues of naturally infected cattle as affected by age

“…In general, the majority of MAP positive samples in our study originated from the posterior jejunal lymph nodes (61.2%) and from the mucosa of the ileo-caecal junction (49.0%; Figure 2). Some papers considered the important role of ileal tissue (mostly lymph nodes than mucosa) as a reservoir of infection (Coussens, 2004;Wu et al, 2007). Therefore, these tissues are highly suitable for confirmation of infection (Amemori et al, 2004).…”

Modeling the Effect of Direct and Indirect Contamination of On-Farm Bulk Tank Milk with Mycobacterium avium subsp. paratuberculosis

“…MAP infection in cows follows different infection stages as described in detail elsewhere (Coussens et al, 2004). Briefly, in the early stage of infection, the host response is predominantly a cell-mediated immune response (CMI), where the infection remains latent but MAP proliferates in the jejunum and ileum and spreads to local lymph nodes.…”