Why do cultured transplanted myoblasts die in vivo? DNA quantification shows enhanced survival of donor male myoblasts in host mice depleted of CD4+ and CD8+ cells or Nk1.1+ cells.
Overcoming the massive and rapid death of injected donor myoblasts is the primary hurdle for successful myoblast transfer therapy (MTT), designed as a treatment for the lethal childhood myopathy Duchenne muscular dystrophy. The injection of male myoblasts into female host mice and quantification of surviving male DNA using the Y-chromosome-specific (Y1) probe allows the speed and extent of death of donor myoblasts to be determined. Cultured normal C57BL/10Sn male donor myoblasts were injected into untreated normal C57BL/10Sn and dystrophic mdx female host mice and analyzed by slot blots using a 32P-labeled Y1 probe. The amount of male DNA from donor myoblasts showed a remarkable decrease within minutes and by 1 h represented only about 10-18% of the 2.5 x 10(5) cells originally injected (designated 100%). This declined further over 1 week to approximately 1-4%. The host environment (normal or dystrophic) as well as the extent of passaging in tissue culture (early "P3" or late "P15-20" passage) made no difference to this result. Modulation of the host response by CD4+/CD8+ -depleting antibodies administered prior to injection of the cultured myoblasts dramatically enhanced donor myoblast survival in dystrophic mdx hosts (15-fold relative to untreated hosts after 1 week). NK1.1 depletion also dramatically enhanced donor myoblast survival in dystrophic mdx hosts (21-fold after 1 week) compared to untreated hosts. These results provide a strategic approach to enhance donor myoblast survival in clinical trials of MTT.
Hodgetts
S I
SI
Department of Anatomy and Human Biology, The University of Western Australia, Nedlands, Perth. hodgetts@cyllene.uwa.edu.au
Beilharz
M W
MW
Scalzo
A A
AA
Grounds
M D
MD
D000818:Animals; D000941:Antigens / Q000032:analysis; D000950:Antigens, Ly; D000954:Antigens, Surface; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002470:Cell Survival; D017690:Cell Transplantation; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D005260:Female; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008212:Lymphocyte Depletion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D009132:Muscles / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation; D009137:Muscular Dystrophy, Animal / Q000628:therapy; D020388:Muscular Dystrophy, Duchenne / Q000628:therapy; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins / Q000032:analysis; D014998:Y Chromosome / Q000235:genetics
D000941:Antigens; D000950:Antigens, Ly; D000954:Antigens, Surface; C527211:Klrb1c protein, mouse; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins; D004247:DNA