Galectin-1 is associated with hematopoietic cell engraftment in murine MHC-mismatched allotransplantation.

Haploidentical hematopoietic cell transplantation (haplo-HCT) is associated with an increased risk of allograft rejection. Here, we employed a major histocompatibility complex (MHC)-mismatched allogeneic HCT (allo-HCT) murine model to better understand the role of Gal-1 in immune tolerance. Transplanted mice were classified into either rejected or engrafted based on donor chimerism levels. We noted significantly higher frequencies of CD4 ⁺ T cells, CD8 ⁺ T cells, natural killer cells, IFN-γ and TNF-α producing CD4 ⁺ T cells, and IFN-γ producing dendritic cells and macrophages in rejected mice. Conversely, we found significantly increased frequencies of regulatory T cells (Tregs), predominantly Helios ⁺ , IL-10-producing CD4 ⁺ T cells, type 1 regulatory (Tr1) cells, and the proportion of Tr1 ⁺ Gal-1 ⁺ cells in engrafted mice. Further, Gal-1 specific blockade in Tregs reduced suppression of effector T cells in engrafted mice. Lastly, effector T cells from engrafted mice were more prone to undergo apoptosis. Collectively, we have shown that Gal-1 may favor HSC engraftment in an MHC-mismatched murine model. Our results demonstrate that Gal-1-expressing Tregs, especially at earlier time points post-transplant, are associated with inducing immune tolerance and stable mixed chimerism after HCT.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2024 Shaikh, Gangaplara, Kone, Almengo, Kabore, Ali, Xu, Saxena, Lopez-Ocasio, McCoy and Fitzhugh.)