Tumor necrosis factor-α pathway plays a critical role in regulating interferon-γ induced protein-10 production in initial allogeneic human monocyte-endothelial cell interactions

IP-10 Is a Sensitive Biomarker of Antigen Recognition in Whole-Blood Stimulation Assays Used for the Diagnosis of Mycobacterium bovis Infection in African Buffaloes (Syncerus caffer)

African buffaloes (Syncerus caffer) are maintenance hosts of Mycobacterium bovis, the causative agent of bovine tuberculosis. They act as reservoirs of this infection for a wide range of wildlife and domestic species, and the detection of infected animals is important to control the geographic spread and transmission of the disease. Interferon gamma (IFN-γ) release assays (IGRAs) utilizing pathogen-derived peptide antigens are highly specific tests of M. bovis infection; however, the diagnostic sensitivities of these assays are suboptimal. We evaluated the diagnostic utility of measuring antigen-dependent interferon gamma-induced protein 10 (IP-10) release as an alternative to measuring IFN-γ levels. M. bovis-exposed buffaloes were tested using the Bovigam PC-EC and Bovigam PC-HP assays and a modified QuantiFERON TB-Gold (mQFT) assay. IP-10 was measured in the harvested plasma and was produced in significantly greater abundance in response to M. bovis antigens in Bovigam-positive than in Bovigam-negative animals. For each assay, using the Bovigam results as a reference, receiver operating characteristic curve analysis was done to determine diagnostically relevant cutoff values for IP-10. Thereafter, mQFT test results derived from measurement of IP-10 and IFN-γ were compared and a larger number of Bovigam-positive animals were detected using IP-10 as a diagnostic marker. Moreover, using IP-10, agreement between the mQFT assay and the Bovigam assays was increased, while the excellent agreement between the Bovigam assays was retained. We conclude that IP-10 is a sensitive marker of antigen recognition and that measurement of this cytokine in antigen-stimulated whole blood might increase the sensitivity of conventional IGRAs in African buffaloes.

Claudin-1 regulates intestinal epithelial homeostasis through the modulation of Notch-signalling

OBJECTIVE

Claudin-1 expression is increased and dysregulated in colorectal cancer and causally associates with the dedifferentiation of colonic epithelial cells, cancer progression and metastasis. Here, we have sought to determine the role claudin-1 plays in the regulation of intestinal epithelial homeostasis.

DESIGN

We have used a novel villin-claudin-1 transgenic (Cl-1Tg) mouse as model (with intestinal claudin-1 overexpression). The effect of claudin-1 expression upon colonic epithelial differentiation, lineage commitment and Notch-signalling was determined using immunohistochemical, immunoblot and real-time PCR analysis. The frequently used mouse model of dextran sodium sulfate (DSS)-colitis was used to model inflammation, injury and repair.

RESULTS

In Cl-1Tg mice, normal colonocyte differentiation programme was disrupted and goblet cell number and mucin-2 (muc-2) expressions were significantly downregulated while Notch- and ERK1/2-signalling were upregulated, compared with the wild type-littermates. Cl-1Tg mice were also susceptible to colonic inflammation and demonstrated impaired recovery and hyperproliferation following the DSS-colitis. Our data further show that claudin-1 regulates Notch-signalling through the regulation of matrix metalloproteinase-9 (MMP-9) and p-ERK signalling to regulate proliferation and differentiation.

CONCLUSIONS

Claudin-1 helps regulate intestinal epithelial homeostasis through the regulation of Notch-signalling. An upregulated claudin-1 expression induces MMP-9 and p-ERK signalling to activate Notch-signalling, which in turn inhibits the goblet cell differentiation. Decreased goblet cell number decreases muc-2 expression and thus enhances susceptibility to mucosal inflammation. Claudin-1 expression also induces colonic epithelial proliferation in a Notch-dependent manner. Our findings may help understand the role of claudin-1 in the regulation of inflammatory bowel diseases and CRC.

Innate immune cells in transplantation

PURPOSE OF REVIEW

To examine the recent literature on the role of innate cells in immunity to transplanted tissue. It specifically addresses the impact of monocytes/macrophages, neutrophils, natural killer cells, and platelets.

RECENT FINDINGS

Current research indicates that innate immunity plays a dual role in response to transplanted tissue with the ability to either facilitate rejection or promote tolerance. Intriguingly, some of these cells are even capable of reacting to allogeneic cells, a feature usually only attributed to cells of the adaptive immune system.

SUMMARY

This review highlights the new therapeutic targets in the innate immune system that may be useful in the treatment of transplant recipients. It also emphasizes the need to use caution in exploring these new therapeutics.

Correlation between cytokine levels and changes in fatigue and quality of life in patients with acute myeloid leukemia

Cancer-related fatigue (CRF) is a major problem in patients with acute myeloid leukemia (AML) and may be mediated by circulating cytokines. We examined this relationship in 74 adult AML patients before and after the first cycle of induction chemotherapy. Plasma levels of 13 cytokines were measured via electrochemiluminescence. At baseline, potentially clinically important (r>0.30) correlations were seen between tumor necrosis factor (TNF)-α and fatigue (r=-0.336, p=0.017). Over time, correlations with fatigue were noted with TNF-α (r=-0.341, p=0.006) and interferon-inducible protein (IP)-10 (r=0.353, p=0.005). The link between IP-10 and fatigue is novel, implicating CXC chemokine pathways for CRF in hematologic malignancies.