Treg donation of sIL-6R to promote intestinal integrity and repair

IBD affects roughly 1.6 million US adults, with its prevalence increasing since the late 1990s. Characterized by unchecked intestinal inflammation, multiple proinflammatory cytokines including IL6 have been implicated as critical factors in this pathology. It has been established that EZH2 is a gene involved in the production of specific histone methyltransferase enzymes, as well as in the differentiation of Treg cells. The association between the Treg master transcription factor, Foxp3 and EZH2 results in the suppressive function of Tregs, with our previous work revealing impairment of this interaction under the influence of IL6 signaling in an inflamed intestinal setting. We investigated this further in a murine preventative T cell transfer model of colitis that involved injecting donor Treg cells that lacked IL6Ra, into immunocompromised mice. Histological scoring of the mice receiving the IL6Rko Tregs revealed a resolved inflammatory milieu and flow cytometric analysis of cells isolated from the spleens and MLNs showed increased Foxp3+ expression when compared to mice that received WT Tregs. Foxp3IL6Rako mice were subjected to a DSS model of colitis to further characterize the absence of the IL6R on Treg function in the intestinal milieu. Exacerbated signs of colitis were observed through histology and colon shortening of the conditional knockout mice when compared to their WT counterparts. We postulate that Tregs could be acting as a donor of sILR to promote intestinal integrity and healing. Further experiments will be conducted to define a role for the IL6R in the development of Foxp3+ cells, along with outlining the instrumental process of sIL6R donation in the intestinal milieu.

Supported by Mayo Clinic Graduate School for Biomedical Sciences

[Cardiac changes in children with AIDS]

PURPOSE

To describe the cardiac findings in children with AIDS, the follow-up with treatment and the correlation between clinical and pathological features.

METHODS

We studied prospectively 25 children with clinical-laboratorial diagnosis of AIDS, ages between 3 months and 11 years, even those without cardiac symptoms. We classified the signs of AIDS following that of CDC-Atlanta 1994. Eight children died and it was done necropsy in six with macro and microscopic examinations.

RESULTS

Fifteen cases had already complications of AIDS and were classified as C2 and C3, 5 as B2, 3 B1 and 2 as A1. Beside the symptoms related to the disease and infections we found signs of congestive heart failure III and IV (NYHA) in 5 children, pericardial effusion in 5, (one of them had cardiac tamponade). In the electrocardiogram (EKG), 8 children had repolarization abnormalities. In 1st echocardiogram (ECHO) we found some features of dilated myocardiopathy in 8 (6 were asymptomatic) 5 of those had pericardial effusion, one child had huge amount of pericardial liquid and also increased measures of intraventricular septum and posterior wall of left ventricle by ECHO and confirmed by necropsy examination. All cases of diagnosis of myocardiopathy received treatment with captopril and 4 also received furosemide and digoxina. Even under oral treatment three of them had deterioration of heart failure but after combined anti-retroviral drugs they showed better cardiac functions. From the six necropsied cases, two had increased heart weight without myocarditis, one had toxoplasma pancarditis and other one had fibrocalcic vasculopathy.

CONCLUSION

We found several assymptomatic cases already with decreased ventricular function. Some worsened of heart failure even under apropriate treatment and showed better cardiac index after combined anti-retroviral drugs.