Interplay between telomere length and telomerase in human leukocyte differentiation and aging

Abstract Blood leukocytes derive from bone marrow hematopoietic stem cells anddifferentiate into multiple types of mature cells that includegranulocytes, monocytes, mast cells of myeloid lineage, and T and Blymphocytes of lymphoid lineage. Their distinctive paths ofdifferentiation and unique roles in immune response provide a model forcomparative analysis of biological parameters, such as telomere lengthand telomerase activity, in different types of leukocytes. Age has alsobeen associated with the decline in immune functions and with theattrition of telomere length in leukocytes. This review will summarizerecent progress in the study of telomere length and telomeraseexpression in leukocytes during differentiation and aging. In addition,I will attempt to shed new light on the roles of telomere andtelomerase in leukocyte function and potential clinicalinterventions.