Abdellatif Bouazzaoui
Umm Al-Qura University, Saudi Arabia
University of Regensburg Medical Center, Germany
Posters & Accepted Abstracts: J Microb Biochem Technol
Graft versus host disease remains the major cause of morbidity and mortality after allogeneic stem cell transplantation despite the use of modern immunosuppressive drugs. For this reason, new methods for prophylaxis and treatment of GVHD are urgently needed. One approach is the blocking of bacterial endotoxins or reduction of pathogenic bacteria. Using a haploidentical murine model, B6D2F1 mice conditioned with total body irradiation (TBI) received bone marrow cells (BM) and splenocytes (SC) from either syngeneic (Syn=B6D2F1) or allogeneic (Allo=C57BL/6) donors. After that, animals received from day -2 until day +28 chow contained hen antibodies (IgY=Immunoglobulin Yolk). In alternative protocol the animals received chow from day -2 until day 15. Thereafter severity of a GVHD, microbial constitution, cytokines, chemokines and pathogen-associated molecular pattern products (PAMP) were analyzed and compared to control animals (received chow without IgY). We found that animals receiving chow with IgY antibody showed reduced GVHD severity and improved survival compared to control animals. On day 28 after alloBMT, the organ damages of IgY treated animals were reduced and associated with significantly diminished expression of inflammatory cytokines in the serum. Interestingly, the GVHD improvement in the animals treated with IgY chow correlated with a significant decrease in E. coli and Bacteroidetes bacteria 15 days after transplantation whereas the L. reuteri and Firmicutes bacteria were significantly increased. In conclusion, feed pellets containing IgY antibodies improved GVHD and reduced the cytokine and pathogen receptor (NOD2, TLR2 and 4) expression which may involve decrease of E. coli and increase of Lactobcillus load.