Therapeutic potential of the immunomodulatory proteins Wuchereria bancrofti L2 and Brugia malayi abundant larval transcript 2 against streptozotocin-induced type 1 diabetes in mice.

Epidemiological and experimental evidence has supported the concept of using helminths as alternative bio-therapeutic agents in the treatment of type 1 diabetes (T1D). In the current study, two filarial proteins, recombinant Wuchereria bancrofti L2 (rWbL2) and Brugia malayi abundant larval transcript 2 (rBmALT-2) have been investigated, individually and in combination, for their therapeutic potential in streptozotocin (STZ)-induced T1D. The rWbL2 and rBmALT-2 proteins, when administered individually or in combination, have resulted in lowering of the blood glucose levels and reducing the incidence of T1D in mice. In addition, these proteins have led to reduced lymphocytic infiltration and decreased islet damage and inflammation. The curative effect was found to be associated with the suppression of release of tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and increased production of interleukin (IL)-4, IL-5 and IL-10 cytokines by the splenocytes of the diabetic mice. Insulin-specific IgG1 and antigen-specific IgE antibodies were found to be elevated in the sera of mice treated with rWbL2 and rBmALT-2 proteins. From the findings in this study, it can be envisaged that both of these filarial immunomodulatory proteins have the potential to ameliorate T1D by altering the regulatory immune responses.

Brugia malayi soluble and excretory-secretory proteins attenuate development of streptozotocin-induced type 1 diabetes in mice.

Understanding the modulation of the host-immune system by pathogens-like filarial parasites offers an alternate approach to prevent autoimmune diseases. In this study, we have shown that treatment with filarial proteins prior to or after the clinical onset of streptozotocin-induced type-1 diabetes (T1D) can ameliorate the severity of disease in BALB/c mice. Pre-treatment with Brugia malayi adult soluble (Bm A S) or microfilarial excretory-secretory (Bm mf ES) or microfilarial soluble (Bm mf S) antigens followed by induction of diabetes led to lowering of fasting blood glucose levels with as many as 57.5-62.5% of mice remaining nondiabetic. These proteins were more effective when they were used to treat the mice with established T1D as 62.5-71.5% of the mice turned to be nondiabetic. Histopathological examination of pancreas of treated mice showed minor inflammatory changes in pancreatic islet cell architecture. The therapeutic effect was found to be associated with the decreased production of cytokines TNF-α & IFN-γ and increased production of IL-10 in the culture supernatants of splenocytes of treated mice. A switch in the production of anti-insulin antibodies from IgG2a to IgG1 isotype was also seen. Together these results provide a proof towards utilizing the filarial derived proteins as novel anti-diabetic therapeutics.