Natural killer (NK) and T cell-associated surface marker expression following allogeneic and autologous bone marrow transplantation (BMT)

Natural killer (NK) and T cell development was studied after allogeneic and autologous BMT. We determined the phenotypic expression and lytic ability of these subpopulations after BMT. Following T cell-depleted (TCD) BMT, the number of CD16⁺ and CD56⁺ cells peaked at 39 and 46 days, respectively, and constituted the majority of peripheral blood lymphocytes (PBL). Coexpression of CD3 and CD16 was <10% up to 14.5 weeks after transplant. Following allogeneic non-T cell-depleted (NTCD) BMT, the number of CD16⁺ and CD56⁺ cells peaked at 6 weeks. CD3 expression was normal (70%-80%), % CD8⁺ cells was high (40%), and % CD4⁺ cells was low (20%). Following autologous BMT (ABMT), % CD3⁺ T cells was 80%, of which 70% expressed the CD8 marker. In contrast, CD4 expression was low (20%). CD16⁺ cells appeared 2.5-3 weeks after ABMT but with low frequency (20%), at which point 20%-30% of the CD3⁺ cells coexpressed CD16. A positive correlation was found between CD16 expression and cytotoxic capability. In conclusion, a marked difference was observed in NK and T cell-associated markers following TCD BMT, NTCD BMT, and ABMT. Following NTCD or ABMT, but not TCD BMT, a high percentage of cells coexpress CD16 and CD3, which may indicate the possibility of a common NK and T cell progenitor.