Abstract
Background The use of immunodeficient mice transplanted with human hematopoietic stem cells is an accepted approach to study human-specific infectious diseases, like HIV-1, and to investigate multiple aspects of human immune system development. However, mouse and human are different in sialylation patterns of proteins due to evolutionary mutations of the CMP-N-acetylneuraminic acid hydroxylase (CMAH) gene that prevent formation of N-glycolylneuraminic acid from N-acetylneuraminic acid. How changes of mouse glycoproteins chemistry will affect phenotype and function of transplanted human hematopoietic stem cells and mature human immune cells in the course of HIV-1 infection is not known.
Results We mutated mouse CMAH on the most widely human cells transplantation strain NOD/scid-IL2Rγ c-/- (NSG) mouse background using the CRISPR/Cas9 system. The new strain provides a better environment for human immune cells. Transplantation of human hematopoietic stem cells leads to broad B cells repertoire, higher sensitivity to HIV-1 infection, and enhanced proliferation of transplanted peripheral blood lymphocytes. The mice showed low effects on the clearance of human immunoglobulins and enhanced transduction efficiency of recombinant adeno-associated viral vector rAAV2/DJ8.
Conclusion NSG-cmah-/- mice expand the mouse models suitable for human cells transplantation and this new model has advantages in generating a human B cell repertoire. This strain is suitable to study different aspects of the human immune system development, might provide advantages in patient-derived tissue and cell transplantation, and could allow studies of viral vectors and infectious agents that are sensitive to human-like sialylation of mouse glycoproteins.
List of abbreviations
- CMAH
- CMP-N-acetylneuraminic acid hydroxylase
- HRP
- Horseradish peroxidase
- HSPC
- Hematopoietic stem/progenitor cells
- HIV-1
- Human immunodeficiency virus type 1
- IHC
- Immunohistochemistry
- Neu5Ac
- N-acetylneuraminic acid
- Neu5Gc
- N-glycolylneuraminic acid
- NSG
- NOD/scid-IL2Rγc−/− mice
- PBMC
- Peripheral blood immune cells
- rAAV
- Recombinant adeno-associated viral vector
- Siglecs
- Sialic acid–binding Ig-like lectins
- WB
- Western blot
- WT mice
- Wild-Type mice