Erythroid cells in immunoregulation: characterization of a novel suppressor factor

New Insight into an Old Concept: Role of Immature Erythroid Cells in Immune Pathogenesis of Neonatal Infection

“…For example, it was reported that erythroid precursors produce a species-non-specific type of soluble factor (1–10 kD) that suppresses both IgM and IgG secretion and proliferation of human B cells (21). In line with these observations, Seledtsova et al found that ESC not only exert suppression of LPS-driven B cell proliferation but also inhibit proliferative cytotoxic T cell responses (22). Although the underlying mechanism(s) of suppression was not clearly determined, their data indicated that a soluble heat stable molecule (80°C for 20 min) with low molecular weight was capable of effectively reducing the allogeneic-driven proliferation of peripheral blood mononuclear cells (PBMC) isolated from allergic patients (22).…”

“…In line with these observations, Seledtsova et al found that ESC not only exert suppression of LPS-driven B cell proliferation but also inhibit proliferative cytotoxic T cell responses (22). Although the underlying mechanism(s) of suppression was not clearly determined, their data indicated that a soluble heat stable molecule (80°C for 20 min) with low molecular weight was capable of effectively reducing the allogeneic-driven proliferation of peripheral blood mononuclear cells (PBMC) isolated from allergic patients (22). Subsequent studies by Seledtsova et al indicated that the immunosuppressive activity of ESC might be partially mediated through TGF-β (23) and direct cell–cell interactions (24).…”

“…In agreement, Mitasov et al reported that immature murine erythroid cells suppress both IgM and IgG secretion and the proliferation of B cells (21). In line with these observations, Seledtsova et al found that nucleated erythroid cells not only exert suppression of LPS-driven B cell proliferation but also proliferative cytotoxic T cell responses (22). More recent studies indicated that CD71 + erythroid cells hinder up-regulation of early activation markers (e.g., CD25 and CD69) among T cells following anti-CD3 antibody stimulation in vitro (11).…”

Effect of Regular Physical Training on Hemopoiesis in Experimental Animals

“…Immunosuppression can develop as a result of competitive relationships between cells of the erythroid and lymphoid lineages. In addition, activated erythroid cells can directly influence the immune re sponse: bearing in mind the suppressive effect of erythroblasts on the development of humoral immune response, stimulation of erythropoiesis in the spleen can inhibit proliferation and differentiation of antigenspecifi c B cells [13].…”

Erythropoietin exerts direct immunomodulatory effects on the cytokine production by activated human T-lymphocytes

“…It is important to emphasise that Epo-induced proliferating nucleated erythroid cells per se possess pronounced immunomodulatory activity. It has been shown previously that those cells could suppress both B cell-and T cell-mediated immune responses by producing transforming growth factor-β (TGF-β) and an ill-defined low molecular weight non-proteinaceous factor [22,23]. In conclusion, the immunomodulatory effect of Epo could be multifactorial, prolonged in time and devoid of serious side effects, which makes it a very promising immunomodulatory agent in treating various immune disorders in clinical settings.…”