Immunodeficient mice are better for modeling the transfusion of human blood components than wild-type mice

Abstract

Animal models are vital to the study of transfusion and development of new blood products. Post-transfusion recovery of human blood components can be studied in mice, however, there is a need to identify strains that can best tolerate xenogeneic transfusions, as well as to optimize such protocols. Specifically, the importance of using immunodeficient mice, such as NOD.Cg- Prkdc scid Il2rg tm1Wjl /SzJ (NSG) mice, to study human transfusion has been questioned. In this study, strains of wild-type and NSG mice were compared as hosts for human transfusions with outcomes quantified by flow cytometric analyses of CD235a + erythrocytes, CD45 + leukocytes, and CD41 + CD42b + platelets. Complete blood counts were evaluated as well as serum cytokines by multiplexing methods. Circulating human blood cells were maintained better in NSG than in wild-type mice. Lethargy and hemoglobinuria were observed in the first hours in wild-type mice along with increased pro-inflammatory cytokines/chemokines such as monocyte chemoattractant protein-1, tumor necrosis factor α, keratinocyte-derived chemokine (KC or CXCL1), and interleukin-6, whereas NSG mice were less severely affected. Whole blood transfusion resulted in rapid sequestration and then release of human cells back into the circulation within several hours. This rebound effect diminished when only erythrocytes were transfused. Nonetheless, human erythrocytes were found in excess of mouse erythrocytes in the liver and lungs and had a shorter half-life in circulation. Variables affecting the outcomes of transfused erythrocytes were cell dose and mouse weight; recipient sex did not affect outcomes. The sensitivity and utility of this xenogeneic model were shown by measuring the effects of erythrocyte damage due to exposure to the oxidizer diamide on post-transfusion recovery. Overall, immunodeficient mice are superior models for xenotransfusion as they maintain improved post-transfusion recovery with negligible immune-associated side effects.

Reduced dimethyl sulfoxide concentrations successfully cryopreserve human hematopoietic stem cells with multi-lineage long-term engraftment ability in mice

“…The authors have previously observed that some engrafted mice may harbor only a single lineage of lymphocytes or monocytic cells; thus, longevity of these cells makes their detection alone insufficient evidence for HSC engraftment [34]. Although erythrocytes have a long life span, their survival in the circulation of NSG mice is short [33,39]. Thus, the authors' observation of fewer of these cells in the spleen than the bone marrow was not surprising.…”

“…Experiments adhered to the principles of the current version of the National Research Council's Guide for the Care and Use of Laboratory Animals. Husbandry conditions have been previously detailed [33]. Euthanasia was performed according to the recommendations of the American Veterinary Medical Association.…”

A bioinspired and chemically defined alternative to dimethyl sulfoxide for the cryopreservation of human hematopoietic stem cells

“…Investigators adhered to the Animal Welfare Act Regulations and other Federal statues relating to the animals, and experiments involving animals, and the principles set forth in the current version of the Guide for Care and Use of Laboratory Animals, National Research Council. Mice were maintained under specific-pathogen free conditions as previously detailed [ 35 ] and euthanized according to the recommendations of the American Veterinary Medical Association. The standard diet was exchanged for irradiated Global 2018 rodent diet with 4100 ppm Uniprim (Envigo) ≥3 days before irradiation and the mice were maintained on this diet for a month.…”

Platelet EVs contain an active proteasome involved in protein processing for antigen presentation via MHC-I molecules

“…Human platelets injected into WT mice circulate less than 2h, in contrast to mouse platelets transfused into mice that can circulate for several days. 87,88 We thus used mouse PEVs in our transfusion experiments, and yet most were undetectable from the blood circulation after 15min, pointing to their rapid uptake in surrounding tissues. In blood, the main absolute cellular target was the platelets, mostly because platelets outnumber leukocytes, which might suggest that PEVs might recycle molecules back to platelets.…”