ASCIA‐P53: THE IMMUNOMODULATORY ROLE OF HELMINTH PROTEIN Bm TGH‐2 IN ATOPIC DISEASE – AN IN VITRO PILOT STUDY

Abstract

Helminth proteins evade the host's immune system by mimicking downregulatory proteins in the T regulatory pathway. We hypothesize that they are potential therapeutic agents as immunotherapy for atopic disease. The helminth protein Brugia malayi TGF-β homologue protein 2 (Bm-TGH-2) has been studied via genome sequencing and found to mimic human TGF-β closely. However there are no studies on its downstream immunomodulatory effects. This pilot study aims to look at the in-vitro effects of Bm-TGH-2 on naïve T-regulatory cells through determination of Foxp3 expression. Recombinant full length Bm-TGH-2 was expressed in an Escherichia Coli system. CD4 + CD25 − naïve mouse T cells were stimulated using anti-CD3/CD28+ IL-2 ± recombinant Bm-TGH-2 or TGF-β. in the presence of antigen presenting cells. Subsequent Foxp3 expression was studied via flow cytometry. The results of our in-vitro mouse study were negative with no significant increase in the Foxp3 expression in CD4 + naïve mouse T cells stimulated by recombinant Bm-TGH-2 compared to our control. (Positive control 87.4%, Negative control 1.24%, 100 ng/ml recombinant Bm-TGH-2 1.41%, 1000 ng/ml recombinant Bm-TGH-2 1.11% Foxp3 expression in CD4+ T cells). We were unable to demonstrate in-vitro Foxp3 enhancement of recombinant Bm-TGH-2. This is postulated to be due differences in functional expression despite close structural similarities to human TGF-β. We will be further confirming this by measuring downstream cytokine profiles (IL-2, IL-10 and IFN-γ)