Divya Chaudhary, Tapas Kumar Goswami, Ashok Kumar Munjal, M Yaqoob Wanid
Indian Veterinary Research Institute, Izzatnagar, Bareilly, India.

ABSTRACT

Mesenchymal stem cell (MSC) research has become increasingly important because of multipotent nature of MSCs. As MSCs are now a days used clinically in patients, it becomes important to evaluate how they affect immune response either in transplantation antigen or to microbial antigens as they have been found to have immunomodulatory effects both in vitro and in vivo. To compare the effect of proliferating and non-proliferating allogenic bone marrow derived MSCs on antibody production in blood by Enzyme Linked Immuno Sorbent Assay (ELISA) using bacterial flagellin as antigen (Ag). Six groups of mice (6 animals each) received mitomycin C treated (non-proliferating) or untreated allogenic MSCs with or without Ag, while PBS and Ag received group acted as control. Immunization was done on 0, 7, 14, 21 days by intraperitonial route and serum was collected after collecting blood from inner canthus of eye weekly on 0, 7, 14, 21, 28, 35 days and stored at -20°C until used. ELISA was carried out using goat-antimouse IgG, HRPO conjugated (Promega, USA) and colored product intensity was measured at 492 nm. In the present study the significantly highest antibody response was recorded in the group which received antigen along with non proliferating MSC (1.704±0.070) followed by group which received antigen along with proliferating MSC (1.606±0.089) (p<0.05). In contrast to the other groups, antigen alone group could not exhibited higher antibody response (1.289±0.029) rather the values were sufficiently low. In our finding MSCs were found to stimulate B cells by antibody secretion, rather than suppressive effect as usually reported by several authors previously. Divided opinion have suggested that the up regulated or down regulated activity of B cell resulting in final outcome exhibited by secreted IgG and their isotypes may be result of the heterogenous MSC populations having diverse MHC molecules expressed on those cells produced by different culture regimens used in different studies, intrinsic diversities among species or the different stimulation cocktail used. Read more…