Gorantla, S. | Search bioRxiv

bioRxiv2018

Human-like NSG mouse glycoproteins sialylation pattern changes the phenotype of human lymphocytes and sensitivity to HIV-1 infection

BackgroundThe 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.\n\nResultsWe mutated mouse CMAH on the most widely human cells transplantation strain NOD/scid-IL2R{gamma} 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.\n\nConclusionNSG-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.

immunology↗

bioRxiv2017

Systemic HIV-1 Infection Produces a Unique Glial Footprint in Humanized Mouse Brains

Studies of innate glial cell responses for progressive human immunodeficiency virus type one (HIV-1) infection are hindered by the availability of relevant small-animal models. To overcome this hindrance, a mouse model reconstituted with humanized brain and immune systems was created. Newborn NOD/SCID/IL2R{gamma}c-/- mice of both sexes were transplanted with human neuroglial progenitors (NPC) and hematopoietic stem cells. Intraventricular injection of NPC yielded an anatomical symmetrical glia (human astrocyte and oligodendrocyte) repopulation of the mouse brain. The human glia were observed in periventricular areas, white matter tracts, the olfactory bulb and brain stem. HIV-1 infection of these dual humanized mice led to meningeal and perivascular human leukocyte infiltration into brain. The species-specific viral-neuroimmune interactions in the infected animals were identified by deep RNA sequencing. In the corpus callosum and hippocampus overlapping human-specific transcriptional alterations were seen for interferon type 1 and 2 signaling pathways (STAT1, 2, IRF9, ISG15, IFI6) and a range of host antiviral responses (MX1, OAS1, RSAD2, BST2, SAMHD1) in infected animals. Glial cytoskeleton reorganization, oligodendrocyte differentiation and myelin ensheathment (MBP, MOBP, PLP1, MAG and ZNF488) were downregulated. The data sets were confirmed by real-time PCR. The viral defense signaling patterns observed in these mice parallels the neuroimmune communication networks present in the HIV-1 infected human brain. In this manner, the new mouse model can facilitate discovery of therapeutics, viral eradication targets for virus induced nervous system diseases, and simplify HIVCure research approaches.\n\nSummary StatementWe created mice with both a humanized brain and an immune system. The animals were used to investigate glial responses to HIV-1 infection. At a transcriptional level we defined the interactions between human glia and immune cells in the presence of the systemic HIV-1 infection. Noticeably, altered transcriptional changes were human specific. At five weeks after viral infection humanized mouse brain displayed potent interferon-mediated antiviral innate immune responses and alteration of neuronal progenitors differentiation and myelination. This model can be used to tests both diagnostic and therapeutic interventions for cure HIV-associated brain impairment.

neuroscience↗