RESUMO
Allogeneic hematopoietic stem cell transplantation represents the most effective form of immunotherapy for chemorefractory diseases. However, animal models have been missing that allow evaluation of donor-patient-specific graft-versus-leukemia effects. Thus, we sought to establish a patient-tailored humanized mouse model that would result in long-term engraftment of various lymphocytic lineages and would serve as a donor-specific surrogate. Following transfer of donor-derived peripheral blood stem cells into NOD/SCID/IL-2Rgamma(null) (NSG) mice with supplementation of human IL-7, we could demonstrate robust engraftment and multilineage differentiation comparable to earlier studies using cord blood stem cells. Phenotypical and functional analyses of lymphoid lineages revealed that >20 wk posthematopoietic stem cell transplantation, the majority of T lymphocytes consisted of memory-type CD4(+) T cells capable of inducing specific immune functions, whereas CD8(+) T cells were only present in low numbers. Analysis of NSG-derived NK cells revealed the expression of constitutively activated CD56(bright)CD16(-) killer Ig-like receptor(negative) NK cells that exhibited functional impairments. Thus, the data presented in this study demonstrate that humanized NSG mice can be successfully used to develop a xenotransplantation model that might allow patient-tailored treatment strategies in the future, but also highlight the need to improve this model, for example, by coadministration of differentiation-promoting cytokines and induction of human MHC molecules to complement existing deficiencies in NK and CD8(+) T cell development.
Assuntos
Antígenos CD34/biossíntese , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/imunologia , Transplante de Células-Tronco Hematopoéticas/métodos , Subunidade gama Comum de Receptores de Interleucina/deficiência , Células Matadoras Naturais/imunologia , Transplante Heterólogo/imunologia , Adulto , Animais , Morte Celular/genética , Morte Celular/imunologia , Linhagem da Célula/imunologia , Efeito Enxerto vs Leucemia/imunologia , Humanos , Subunidade gama Comum de Receptores de Interleucina/genética , Células K562 , Células Matadoras Naturais/patologia , Teste de Cultura Mista de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Camundongos Transgênicos , Transplante Heterólogo/métodos , Transplante Heterólogo/patologiaRESUMO
Trials of immune-modulating drugs in septic patients have mostly failed to demonstrate clinical efficacy. Thus, we sought to generate a surrogate model of myelomonocytic lineage differentiation that would potentially allow sepsis induction and preclinical testing of anti-inflammatory drugs. Comparing transplantation of cord blood-derived stem cells in neonatal NOD/SCID/IL2Rγ(null) (neonatal huNSG) mice with transplantation of adult peripheral mobilized stem cells into adult NSG (adult huNSG) recipients, we demonstrate that myelomonocytic lineage differentiation in neonatal huNSG mice is retarded and monocytes are phenotypically immature with respect to HLA-DR expression and the emergence of CD80(+)CD86(+) monocytes. Functionally, neonatal huNSG mice were less sensitive toward interferon-γ-induced upregulation of CD86 and exhibited a reduced T-cell stimulating capacity when compared with adult huNSG mice, whereas the phagocytic activity and the ability for cytokine secretion were mature. However, comparison of these data with data obtained from human neonates indicate that absence of the CD80(+)CD86(+) population and the reduced T-cell stimulating capacity of neonatal huNSG monocytes resemble functional immaturities observed in human neonatal monocytes. Thus, these two mouse models might well serve as 2 independent surrogate models for studying the neonatal myelomonocytic lineage differentiation or for testing the efficacy of immunomodulatory drugs on functionally mature monocytes.