Prevalence of Mycobacterium avium subspecies paratuberculosis IS 900 DNA in biopsy tissues from patients with Crohn's disease: histopathological and molecular comparison with Johne's disease in Fars province of Iran

Accuracy of real-time PCR for the detection of paratuberculosis in actual samples: A systematic review and meta-analysis

Paratuberculosis, an infectious and chronic ailment that affects ruminants, causes significant annual economic losses to the livestock industry. Early diagnosis and prompt culling are the primary measures for controlling this disease, highlighting the need for accurate and rapid diagnostic methods. This systematic review and meta-analysis aimed to evaluate the efficacy of quantitative PCR (qPCR) in the diagnosis of paratuberculosis. We searched for and selected articles from databases including PubMed, Web of Science, Elsevier ScienceDirect, Wiley-Blackwell, Springerlink, AGRICOLA, and CAB Abstracts, with VETQUADAS (VQ) employed to assess the quality of the literature. Meta-analysis and heterogeneity investigation were conducted using the "Meta4diag" package in "R" software, Meta-Disc 2.0, and Meta-Disc, while the Deeks' test was utilized to detect publication bias. The studies included in the systematic review displayed a moderate level of heterogeneity (I² = 48.6 %) with no significant publication bias (p = 0.998). The pooled sensitivity was determined to be 0.92 [95 % confidence interval [CI], 0.85-0.96], and the specificity was 0.85 [95 % CI, 0.77-0.91], with a summary receiver operating characteristic area under the curve (SROCAUC) of 0.95 [95 % CI, 0.91-0.98]. These findings indicate that the qPCR method has high diagnostic value for identifying paratuberculosis in animals. Subgroup analysis revealed satisfactory stability in these studies; however, the current single-target qPCR detection strategy still has limitations, as it fails to simultaneously ensure both sensitivity and specificity. Future developments should focus on multi-target detection strategies to provide more reliable qPCR testing methods for controlling paratuberculosis.

Advancing therapeutic frontiers: a pipeline of novel drugs for luminal and perianal Crohn's disease management

Crohn's disease (CD) is a chronic, complex inflammatory disorder of the gastrointestinal tract that presents significant therapeutic challenges. Despite the availability of a wide range of treatments, many patients experience primary non-response, secondary loss of response, or adverse events, limiting the overall effectiveness of current therapies. Clinical trials often report response rates below 60%, partly due to stringent inclusion criteria. Emerging therapies that target novel pathways offer promise in overcoming these limitations. This review explores the latest investigational drugs in phases I, II, and III clinical trials for treating both luminal and perianal CD. We highlight promising therapies that target known mechanisms, including selective Janus kinase inhibitors, anti-adhesion molecules, tumor necrosis factor inhibitors, and IL-23 selective inhibitors. In addition, we delve into novel therapeutic strategies such as sphingosine-1-phosphate receptor modulators, miR-124 upregulators, anti-fractalkine (CX3CL1), anti-TL1A, peroxisome proliferator-activated receptor gamma agonists, TGFBRI/ALK5 inhibitors, anti-CCR9 agents, and other innovative small molecules, as well as combination therapies. These emerging approaches, by addressing new pathways and mechanisms of action, have the potential to surpass the limitations of existing treatments and significantly improve CD management. However, the path to developing new therapies for inflammatory bowel disease (IBD) is fraught with challenges, including complex trial designs, ethical concerns regarding placebo use, recruitment difficulties, and escalating costs. The landscape of IBD clinical trials is shifting toward greater inclusivity, improved patient diversity, and innovative trial designs, such as adaptive and Bayesian approaches, to address these challenges. By overcoming these obstacles, the drug development pipeline can advance more effective, accessible, and timely treatments for CD.

Early antibody responses to lipid antigens in red deer infected with Mycobacterium bovis

THE PROBLEM

Early and rapid diagnosis of bovine tuberculosis remains an issue of great interest.

AIM

The aim of this study was to evaluate the use of synthetic lipid antigens for diagnosis of tuberculosis in red deer (Cervus elaphus). The proposition: Synthetic mycolic acid derivatives, identical to components of mycobacterial cells, bind to antibodies to lipids produced in active human tuberculosis. Experimental infection studies in red deer (Cervus elaphus) allow the evaluation of such antigens for the serodiagnosis of bovine tuberculosis.

RESULTS

Antibody levels in plasma from deer experimentally infected with Mycobacterium bovis were evaluated in ELISA using synthetic antigens based on several classes of mycolic acid, using protein G as conjugate. All antigens gave significantly increased responses 60 days post-infection, when all animals had active disease. A significantly increased response was also observed with four antigens 15 days after infection.

CONCLUSION

ELISA using synthetic lipid antigens not only detects antibodies in the plasma of deer experimentally infected with M. bovis, but a strong response occurs early in the infection. With a full analysis of responses with naturally infected animals, this may offer a useful supplement to current diagnostic methods.

Mapping Crohn's Disease Pathogenesis with Mycobacterium paratuberculosis: A Hijacking by a Stealth Pathogen

Mycobacterium avium ssp. paratuberculosis (MAP) has been implicated in the development of Crohn's disease (CD) for over a century. Similarities have been noted between the (histo)pathological presentation of MAP in ruminants, termed Johne's disease (JD), and appearances in humans with CD. Analyses of disease presentation and pathology suggest a multi-step process occurs that consists of MAP infection, dysbiosis of the gut microbiome, and dietary influences. Each step has a role in the disease development and requires a better understanding to implementing combination therapies, such as antibiotics, vaccination, faecal microbiota transplants (FMT) and dietary plans. To optimise responses, each must be tailored directly to the activity of MAP, otherwise therapies are open to interpretation without microbiological evidence that the organism is present and has been influenced. Microscopy and histopathology enables studies of the mycobacterium in situ and how the associated disease processes manifest in the patient e.g., granulomas, fissuring, etc. The challenge for researchers has been to prove the relationship between MAP and CD with available laboratory tests and methodologies, such as polymerase chain reaction (PCR), MAP-associated DNA sequences and bacteriological culture investigations. These have, so far, been inconclusive in revealing the relationship of MAP in patients with CD. Improved and accurate methods of detection will add to evidence for an infectious aetiology of CD. Specifically, if the bacterial pathogen can be isolated, identified and cultivated, then causal relationships to disease can be confirmed, especially if it is present in human gut tissue. This review discusses how MAP may cause the inflammation seen in CD by relating its known pathogenesis in cattle, and from examples of other mycobacterial infections in humans, and how this would impact upon the difficulties with diagnostic tests for the organism.

Seroprevalence of Mycobacterium avium subsp. paratuberculosis in Swiss dairy herds and risk factors for a positive herd status and within-herd prevalence

Introduction

Bovine paratuberculosis (PTB) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis (MAP). Control of PTB is important given its negative economic consequences and the potential zoonotic role of MAP in Crohn's disease in humans.

Methods

To determine the seroprevalence of MAP in Swiss dairy herds and to identify risk factors associated with seropositive herd status and high within-herd seroprevalence, 10,063 serum samples collected from cattle over 12 months of age in 171 Swiss dairy farms were analyzed using a commercial ELISA test. Eight herds were excluded due to non-interpretable ELISA results. Risk factors associated with seropositive herd status and high within-herd seroprevalence were investigated with regression models using results from a questionnaire on management practices possibly associated with the introduction or spread of MAP in the remaining 163 herds. Univariable logistic regression was performed, carrying forward for multivariable regression analysis when p < 0.2.

Results

The calculated between-herd true seroprevalence was 3.6% (95% CI, 0.96-8.4%). Due to the low within-herd seroprevalence, it was not possible to calculate the true seroprevalence at animal level; the apparent within-herd seroprevalence ranged from 2.3 to 5.5% with a median of 3.6% in nine positive farms. Herd size (p = 0.037) and the common grazing of lactating cows with cows from other herds (p = 0.014) were associated with seropositive herd status, while heifers sharing alpine pasture with dairy cattle from other herds were associated with a decreased probability of the herd to test seropositive (p = 0.042). Reliable identification of significant risk factors associated with MAP spread and high seroprevalence of PTB within seropositive herds was not possible due to low observed seroprevalence within herds and low sensitivity of the ELISA test.

Discussion

These results highlight the limitation of serology for MAP diagnosis in small herds with low infection prevalence.

Long Non-Coding RNAs and Their "Discrete" Contribution to IBD and Johne's Disease-What Stands out in the Current Picture? A Comprehensive Review

Non-coding RNAs (ncRNA) have paved the way to new perspectives on the regulation of gene expression, not only in biology and medicine, but also in associated fields and technologies, ensuring advances in diagnostic means and therapeutic modalities. Critical in this multistep approach are the associations of long non-coding RNA (lncRNA) with diseases and their causal genes in their networks of interactions, gene enrichment and expression analysis, associated pathways, the monitoring of the involved genes and their functional roles during disease progression from one stage to another. Studies have shown that Johne's Disease (JD), caused by Mycobacterium avium subspecies partuberculosis (MAP), shares common lncRNAs, clinical findings, and other molecular entities with Crohn's Disease (CD). This has been a subject of vigorous investigation owing to the zoonotic nature of this condition, although results are still inconclusive. In this review, on one hand, the current knowledge of lncRNAs in cells is presented, focusing on the pathogenesis of gastrointestinal-related pathologies and MAP-related infections and, on the other hand, we attempt to dissect the associated genes and pathways involved. Furthermore, the recently characterized and novel lncRNAs share common pathologies with IBD and JD, including the expression, molecular networks, and dataset analysis results. These are also presented in an attempt to identify potential biomarkers pertinent to cattle and human disease phenotypes.

Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn's disease: the debate continues

Crohn's disease (CD) in humans and Johne's disease (JD) in ruminants share numerous clinical and pathologic similarities. As Mycobacteria avium subspecies paratuberculosis (MAP) is known to fulfill Koch's postulates as the cause of JD, there has been considerable debate over the past century about whether MAP also plays a role in CD. With recent advances in MAP identification techniques, we can now demonstrate a higher presence of MAP in CD patients compared to the general population. However, it remains unclear if MAP is playing a bystander role or is directly pathogenic in these patients. Studies have shown that there may be an immune response targeting MAP in these patients, which may underlie a pathologic role in CD. Clinical studies have yielded conflicting results as to whether anti-MAP therapy improves clinical outcomes in CD, leading to the lack of its inclusion within evidence-based clinical guidelines. Additionally, many of these studies have been small case series, with only a few randomized controlled trials published to date. In this article, we will discuss the historical context of MAP in CD, review clinical and laboratory data surrounding detection of MAP and possible pathogenesis in human disease, and suggest future directions which may finally provide some clarity to this debate.

Mycobacterium avium subsp. paratuberculosis and Hashimoto’s thyroiditis: Is MAP the trigger?

Hashimoto’s thyroiditis (HT) is an autoimmune disorder of the thyroid gland that can cause hypothyroidism. As HT is a multifactorial disorder, activation of immune responses in genetically predisposed individuals exposed to some environmental factors can contribute to it. Microorganisms, as environmental factors, including Mycobacterium avium ssp. paratuberculosis (MAP) by molecular mimicry, can be important in this autoimmune disorder. This study aimed to investigate the association between MAP and HT. This case–control study included 110 participants consisting of 60 HT patients and 50 healthy controls (HCs). Blood samples were collected. Nested PCR of the IS900 gene determined the presence of MAP DNA. The enzyme-linked immunosorbent assay (ELISA) was designed to identify antibodies (Abs) against the MAP3865c epitope, which has a homologous sequence with ZnT8 in the sera. The demographic information of all participants was recorded. Anti-TG, anti-TPO, TSH, anemia, and ruminant exposure were higer in HT patients than in the HCs (p < 0.05). MAP IS900 was detected significantly more in the patients (46.6% consisting of 30, 8.3, and 8.3% in clinical, subclinical, and unknown) than in the HCs (14%). The sera showed a remarkable frequency of reactivity against MAP3865c in the patients (38.3%) in comparison to the HCs (10%) (p = 0.0001). Furthermore, a significantly higher rate of livestock contact and traditional dairy consumption was found in individuals with MAP or anti-MAP3865c Abs positive result (p < 0.05). This study suggests a possible link between MAP and HT. These findings indicated that MAP frequency was not statistically different in the severity of HT and its shift into the clinical and subclinical forms; therefore, it could be assumed that MAPs are the initiators of the process. The results imply on a possible zoonosis transmission route of MAP from livestock products to humans. Further research is needed to confirm these results in larger groups of HT patients.

The Development and Validation of Anti-paratuberculosis-nocardia Polypeptide Antibody [Anti-pTNP] for the Diagnosis of Crohn's Disease

BACKGROUND AND AIMS

Non-invasive biomarkers in sera of patients with inflammatory bowel disease [IBD] are not currently available for rapidly and accurately diagnosing the disease. We aimed to investigate and validate the potential roles of anti-paratuberculosis-nocardia polypeptide antibodies [anti-pTNP] in the diagnosis of IBD.

METHODS

Serum samples were collected from 502 patients with diagnosed Crohn's disease [CD], 141 patients with ulcerative colitis [UC], and 109 healthy donors. The levels of anti-pTNPs and anti-Saccharomyces cerevisiae antibodies [ASCAs] were determined by enzyme-linked immunosorbent assay. The effects of each variable on the diagnosis were analysed by receiver operating characteristic [ROC] analysis. We also performed an estimate study by first developing a clinical prediction model, with external validation in CD patients from nine IBD medical centres in China.

RESULTS

The levels of anti-pTNPs in sera of CD patients were higher than those in UC patients and healthy donors. The positive rates of anti-pTNPs were significantly higher in ileal CD patients than in ileocolonic and colonic CD patients, and the levels of anti-pTNP IgG in perianal patients were significantly higher than those in non-perianal CD patients. Of note, anti-pTNPs and perianal diseases were important predictors for active stage of CD patients. Discriminative ability to predict active CD patients was 0.918 (95% confidence interval [CI]:0.886-0.949).

CONCLUSIONS

Anti-pTNP functions as a novel biological marker for diagnosing CD and can be used to assess disease severity, particularly in those with lesion locations in the terminal ileum and stricturing and perianal diseases. A validated prediction model reveals that anti-pTNPs are useful for estimating the likelihood of active CD.

Microbial pathogenesis in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal system. Previously, it is considered the disease of the western world but now the incidence and prevalence of IBD are increasing globally with urbanization and modernization. Additionally, the major problem is the highest incidence of IBD among children and adolescents. The precise etiology of IBD is unknown and there is no cure for IBD, which is also the reason for increasing the number of cases worldwide. The IBD is a complex interplay of environment, immune system, and microbiota in a genetically susceptible host. Among these factors, the alteration in intestinal microbiota has been detected in IBD patients. The bacterial species associated with IBD include Mycobacterium paratuberculosis, adherent-invasive E. coli (AIEC), Helicobacter pylori, and Campylobacter concisus. Moreover, the efficacy of antibiotics and probiotics further suggests the role of microbes in IBD. However, no study confirmed the bacterial species as a cause of IBD as per Koch's postulates. Thus, still controversies exist regarding the role of microbes in IBD. Therefore, this paper aims to review the current literature to evaluate the role of microbes in IBD that would be a useful inventory of researchers working in this area.

Application of Bayesian modeling for diagnostic assays of Mycobacterium avium subsp. paratuberculosis in sheep and goats flocks

Background

This study aimed to screen the sera of goats and sheep from flocks suspected of Mycobacterium avium subsp. paratuberculosis (MAP) infection by a newly standardized Mce-truncated ELISA (Mt-ELISA) kit for the detection of antibodies against MAP. Four diagnostic applied tests were evaluated including Indigenous plate-ELISA (IP-ELISA), Mt-ELISA, fecal Polymerase Chain Reaction (f-PCR) and fecal culture (FC).

Materials and methods

Assuming the absence of a gold standard, latent-class models in a Bayesian framework were used to estimate the diagnostic accuracy of the four tests for MAP.

Results

Mt-ELISA had higher Sensitivity (Se) in sheep (posterior median: 0.68 (95% Probability Interval (PI): 0.43–0.95), while IP-ELISA recorded the highest Se in goats as 0.83 (95% PI, 0.61–0.97). The f-PCR Se estimate slightly differed between species [sheep 0.36 (0.19–0.58), goats 0.19 (0.08–0.35)], while the Se of FC was similar between species [sheep 0.29 (0.15–0.51), goats 0.27 (0.13–0.45)]. The specificity estimates for all tests were high, close to unity, and similar between species.

Conclusion

Overall, the results showed that the Mt-ELISA method can be used for MAP detection in small ruminants’ flocks.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03141-7.

Metformin Affects Gut Microbiota Composition and Diversity Associated with Amelioration of Dextran Sulfate Sodium-Induced Colitis in Mice

Background: Inflammatory bowel disease (IBD) is an increasingly common and globally emergent immune-mediated disorder. The etiology of IBD is complex, involving multiple factors such as immune dysregulation, environmental factors, genetic mutations, and microbiota dysbiosis, exacerbated by a lack of effective clinical therapies. Recently, studies hypothesized that dysbiosis of intestinal flora might participate in the onset of IBD. Metformin is widely used to treat type 2 diabetes and has shown beneficial effects in mouse models of IBD, although its underlying mechanisms remain poorly understood. Accumulating studies found that metformin shows beneficial effects for diabetes by affecting microbiota composition. This study explores possible regulatory effects of metformin on intestinal microecology during treatment for IBD.

Methods: Inflammation was induced using 3% Dextran Sulfate Sodium (DSS) solution to generate mice models of IBD. Metformin treatments were assayed by measuring body weights and colon lengths of mice and H&E staining to observe histological effects on colon tissue structures. Changes in bacterial community composition and diversity-related to IBD and metformin treatment were assessed by high-throughput metagenomic sequencing analysis.

Results: Metformin administration significantly ameliorated body weight loss, inhibited colon shrinking, and contributed to preserving the integrity of colon histological structures. The gut microbiota profiles revealed that the biodiversity of intestinal flora lost during inflammation was restored under metformin treatment. Metformin administration was also associated with decreased pathogenic Escherichia shigella and increased abundance of Lactobacillus and Akkermansia.

Conclusion: Metformin appears to induce anti-inflammatory effects, thus ameliorating colitis symptoms, concurrent with enrichment for beneficial taxa and restored microbial diversity, suggesting a viable strategy against IBD.

Isotype-specific Antibody Responses to Mycobacterium avium paratuberculosis Antigens Are Associated With the Use of Biologic Therapy in Inflammatory Bowel Disease

BACKGROUND

The role of Mycobacterium avium paratuberculosis [MAP] in inflammatory bowel disease [IBD], especially Crohn's disease [CD] is controversial due conflicting results and lack of reproducibility and standardised tests. The current study focuses on the role of MAP in disease progression and genetic susceptibility, as MAP is likely one of many factors involved in the complex pathogenesis of IBD, potentially affecting a subgroup depending on genetic susceptibility.

METHODS

Serum from 812 patients was evaluated with seven immunoglobulin [Ig] isotype-specific serology tests assessing humoral response to three different MAP antigens. For each of these in total 21 tests, the intra-assay and inter-assay coefficients were used to evaluate test accuracy. Reliable assays were subsequently analysed in relation to disease characteristics and need for biologic therapy/surgery. Genome-wide genotyping was available for all participants. Genetic determinants of humoral response to MAP antigens were evaluated using genome-wide association analysis and polygenic risk scores [PRS].

RESULTS

High IgA or IgM response to MAP2609 was associated with increased use of biologic therapy in CD and ulcerative colitis [UC] [odds ratios 2.69; 95% confidence interval 1.44-5.01; and 2.60, 1.46-4.64, respectively]. No associations were seen for risk of surgery [p-values > 0.29]. We could not identify genetic determinants nor polygenic risk scores for MAP response with genome-wide significance.

CONCLUSIONS

Extensive assays for serological response to MAP were evaluated using stringent criteria for reliability. Increased IgA and IgM response to MAP antigens was seen in patients exposed to biologic therapy, but no genetic determinants underlying this humoral response were found.

Anti-Mycobacterium paratuberculosis (MAP) therapy for Crohn's disease: an overview and update

The role of Mycobacterium avium subspecies paratuberculosis (MAP) in the pathogenesis of Crohn's disease (CD) has been strongly debated for many years. MAP is the known aetiological agent of Johne's disease, a chronic enteritis affecting livestock. At present, due to the paucity of high-quality data, anti-MAP therapy (AMT) is not featured in international guidelines as a treatment for CD. Although the much-quoted randomised trial of AMT did not show sustained benefits over placebo, questions have been raised regarding trial design, antibiotic dosing and the formulation used. There are several lines of evidence supporting the CD and MAP association with uncontrolled and controlled trials demonstrating effectiveness, including a retrospective review of cases treated at our own institution. Here, we provide an overview of the evidence supporting and refuting AMT in CD before focussing on updates of the current research in the field, including the ongoing trials with the novel RHB-104 formulation and the MAP vaccine trial. While controversial, gastroenterologists are often asked about long-term combination antibiotic therapy for CD. There has been broadcast and social media coverage surrounding this, particularly with regard to current trials. Although patients should not be deterred from treatments of proven effectiveness, this review aims to help with commonly asked questions and highlights our own approach for the use of anti-MAP in specific circumstances.

"They've got to be testing and doing something about it": Farmer and veterinarian views on drivers for Johne's disease control in dairy herds in England

There needs to be an understanding of the reasons why key stakeholders engage in disease control efforts if disease is to be successfully and sustainably controlled. It is increasingly recognised within veterinary epidemiology and policy making in animal health that these 'people factors' are important influences on the success or otherwise of animal disease control programmes. Research methodologies adopted from the social sciences offer ways to understand this important dimension through investigating the attitudes and opinions of the key actors involved. The study reported in this paper, based on qualitative interview research, investigates the views of dairy farmers and cattle veterinarians on the drivers and incentives for controlling Johne's disease in English dairy herds. Twenty semi-structured interviews involving 17 dairy farmers and seven veterinarians were conducted in two dairy-intensive regions of England. The findings demonstrate the varied influences of veterinary advice and encouragement; appreciation of the economic cost of the disease at herd level; a voluntary national control plan; and fear of a future consumer food scare as the main reasons to engage in Johne's disease control on dairy farms. The study demonstrates how a combination of a voluntary industry-led control scheme, compulsory participation through retailer and processor contractual requirements, and threats of reputational harm and market loss have strongly influenced farmer and veterinary behaviour in relation to Johne's control without statutory involvement. The findings illustrate the importance of considering the political economy and societal impact of animal disease.

Paratuberculosis: A Potential Zoonosis and a Neglected Disease in Africa

The Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of paratuberculosis, which is an economically important disease of ruminants. The zoonotic role of MAP in Crohn’s disease and, to a lesser extent, in ulcerative colitis, the two major forms of idiopathic inflammatory bowel disease (IIBD), has been debated for decades and evidence continues to mount in support of that hypothesis. The aim of this paper is to present a review of the current information on paratuberculosis in animals and the two major forms of IIBD in Africa. The occurrence, epidemiology, economic significance and “control of MAP and its involvement IIBD in Africa” are discussed. Although the occurrence of MAP is worldwide and has been documented in several African countries, the epidemiology and socioeconomic impacts remain undetermined and limited research information is available from the continent. At present, there are still significant knowledge gaps in all these areas as far as Africa is concerned. Due to the limited research on paratuberculosis in Africa, in spite of growing global concerns, it may rightfully be considered a neglected tropical disease with a potentially zoonotic role.

Mycobacterium avium Subspecies paratuberculosis Infects and Replicates within Human Monocyte-Derived Dendritic Cells

BACKGROUND

Mycobacterium avium subspecies paratuberculosis (MAP), a member of the mycobacteriaceae family, causes Johne's disease in ruminants, which resembles Crohn's disease (CD) in humans. MAP was proposed to be one of the causes of human CD, but the evidence remains elusive. Macrophages were reported to be the only cell where MAP proliferates in ruminants and humans and is likely the major producer of TNFα-associated inflammation. However, whether human dendritic cells (DCs), another major antigen-presenting cell (APC), have the ability to harbor MAP and disseminate infection, remains unknown.

METHODS

Human monocyte-derived dendritic cells (moDCs) were infected with MAP and phagocytosis and intracellular survival were quantified by immunofluorescence (IF) and colony counts, respectively. MoDC cytokine expression was measured via ELISA and their activation state was measured via flow cytometry.

RESULTS

We showed that MAP can infect and replicate in human moDCs as means to evade the immune system for successful infection, through inhibition of the phago-lysosome fusion via the secretion of protein tyrosine phosphatase PtpA. This mechanism initially led to a state of tolerance in moDCs and then subsequently caused a pro-inflammatory response as infection persisted, characterized by the upregulation of IL-6 and TNFα, and downregulation of IL-10. Moreover, we showed that moDCs have the ability to phagocytose up to 18% of MAP, when exposed at a multiplicity of infection of 1:1.

CONCLUSION

Infection and subsequent proliferation of MAP within moDCs could provide a unique means for the dissemination of MAP to lymphoid tissue, while altering immune responses to facilitate the persistence of infection of host tissues in CD.