Human Blood Chimeras

Human / Severe Combined Immunodeficient Mouse Chimeras

The ability of circulating white blood cells to enter inflamed tissues is mediated by specific cell adhesion molecules thought to be expressed in a programmed and sequential manner to form an "adhesion cascade." Because of the complexity of this process, it is becoming increasingly important to develop in vivo models. Two major problems have limited the utility of current animal models. The fir...

Human-animal chimeras in biomedical research.

Chimeras are individuals with tissues derived from more than one zygote. Interspecific chimeras have tissues derived from different species. The biological consequences of human-animal chimeras have become an issue of ethical debate. Ironically, human-animal chimeras with human blood, neurons, germ cells, and other tissues have been generated for decades. This has facilitated human biological s...

The patentability of human-animal chimeras.

Interspecies chimeras for human stem cell research.

Interspecies chimeric assays are a valuable tool for investigating the potential of human stem and progenitor cells, as well as their differentiated progeny. This Spotlight article discusses the different factors that affect interspecies chimera generation, such as evolutionary distance, developmental timing, and apoptosis of the transplanted cells, and suggests some possible strategies to addr...

Human-animal Chimeras: Human Dignity, Moral Status, and Species Prejudice

The creation of chimeras by introducing human stem cells into nonhuman animals has provoked intense concerns. Addressing objections that appeal to human dignity, I focus in this essay on stem cell research intended to generate human neurons in Great Apes and rodents. After considering samples of dignitybased objections from the literature, I examine the underlying assumption that nonhuman anima...