Discovery of an immunosuppressive functional metabolite from the insect-derived endophytic Aspergillus taichungensis SMU01.

Three p-terphenyl metabolites (1-3), three indole-diterpenoids (4-6), an herbicide sesquiterpene (7), a flavonoid (8), and five other small molecules containing nitrogen (9-13) were isolated from the medicinal insect (Periplaneta americana)-derived endophytic Aspergillus taichungensis SMU01. Their chemical structures were elucidated on the basis of spectroscopic data and quantum chemical computational methods. Biological activity of these isolates in the differentiation of mouse CD4+ T cell subsets was evaluated. Importantly, metabolites 2 targeting JAK-STAT signaling pathway could hold potential benefits in maintaining peripheral immune homeostasis and alleviating the progression of autoimmune diseases.

Aspertaichunol A, an Immunomodulatory Polyketide with an Uncommon Scaffold from the Insect-Derived Endophytic Aspergillus taichungensis SMU01.

Aspertaichunol A (1), a polyketide with a novel scaffold, was isolated from the medicinal insect (Periplaneta americana)-derived endophytic Aspergillus taichungensis SMU01. Its structure was assigned on the basis of spectroscopic data and quantum chemical computational methods. Notably, 1 possesses an uncommon tricyclo[6.2.0.02,6]decane motif and an unusual bridgehead double bond (anti-Bredt system). A plausible biosynthetic pathway, involving a key intramolecular [2+2] cycloaddition and a reductive cyclization, is postulated. Finally, the immunomodulatory activity of 1 at 20 nM was evaluated by promoting Th9 cell differentiation from naive CD4+CD62L+ T cells.

Novel sinomenine derivative 1032 improves immune suppression in experimental autoimmune encephalomyelitis.

Sinomenine (SIN) is an alkaloid isolated from the Chinese medicinal plant Sinomenium acutum. It is widely used as an immunosuppressive drug for treating autoimmune diseases. Due to its poor efficiency, the large-dose treatment presents some side effects and limits its further applications. In this study, we used chemical modification to improve the therapeutic effect of SIN in vitro and in vivo. A new derivative of sinomenine, named 1032, demonstrates significantly improved immunosuppressive activity over that of its parent natural compound (SIN). In an experimental autoimmune encephalomyelitis (EAE) model, 1032 significantly reduced encephalitogenic T cell responses and induced amelioration of EAE, which outcome was related to its selective inhibitory effect on the production of IL-17. By contrast, SIN treatment only led to a moderate alleviation of EAE severity and the expression level of IL-17 was not significantly reduced. Furthermore, 1032 exhibited suppression of Th17, but not Treg, cell differentiation, a result probably related to its inhibitory effect on IkappaB-alpha degradation as well as on IL-6 and TNF-alpha secretion in BMDCs. We speculate that 1032 as a novel anti-inflammatory agent may target DC to block IL-6 production, which in turn would terminate Th17 cell development. Thus, SIN derivative 1032 presents considerable potential in new drug development for treating autoimmune and inflammatory disease.

IL-12p40 is not required for islet allograft rejection.

AIM: To investigate whether IL-12p40 plays a crucial role in regulating islet allograft rejection in a streptozotocin (STZ)-induced diabetes mouse model. METHODS: C57BL/6 and IL-12p40 gene knockout mice were selected as recipient mice, to which the diabetes was induced with a treatment of STZ (150-200 mg/kg) by a single ip injection. BALB/c mice were selected as donor mice and islet cells were isolated from the mice. The 500 islets were transplanted into recipient mice beneath the capsule of the left kidney. Following the islet transplantation the glucose from the mice sera was monitored and the rejection rate of islets was analyzed. RESULTS: STZ could induce diabetes in the recipient mice within 1 week. After transplantation of allograft islets, the increased glucose in wild-type (WT) mice returned to normal level and was maintained for 10 d. Unexpectedly, the rejection rate of islet allograft between IL-12p40-deficient mice and WT mice was similar. CONCLUSION: The results suggested that, although islet allograft rejection is believed to be Th1-cell predominant, the Th1 response inducer, IL-12 and IL-23 are not essential to induce islet allograft rejection.