Optimization of an imaging cytometry protocol to observe the cellular distribution of haemoglobin F in F-erythrocytes

Abstract

Haemoglobin (Hb) contains two α-like and two β-like globin chains. Around birth, a shift from γ- to β-globin gene expression causes a switch from foetal haemoglobin (HbF) to adult haemoglobin (HbA). Residual amounts of HbF are synthesized throughout life, in some erythrocytes termed F-cells. Carriers of mutations for hereditary persistence of foetal haemoglobin (HPFH) show variably elevated (10-40%) HbF levels; they are otherwise normal. Increased HbF levels ameliorate symptoms of β-haemoglobinopathies (β-thalassaemia, sickle cell anaemia). Krüppel-like factor 1 (KLF1) plays a central role in the developmental globin gene switching mechanism; KLF1 haploinsufficiency is one cause of HPFH. The exact cellular mechanism of HPFH and the variation in HbF levels expressed are as yet unexplained; the latter may be due to differential expression of modifier genes acting in concert with KLF1 to regulate the switch. The KLF1 interactome can be further defined by identifying potential molecular targets and observing their expression at the cellular level in comparison with HbF expression and distribution in F-cells.