Transferrin is required for early T‐cell differentiation

MF Macedo, M De Sousa, RM Ned… - …, 2004 - Wiley Online Library
MF Macedo, M De Sousa, RM Ned, C Mascarenhas, NC Andrews, M Correia‐Neves
Immunology, 2004Wiley Online Library
Transferrin, the major plasma iron carrier, mediates iron entry into cells through interaction
with its receptor. Several in vitro studies have demonstrated that transferrin plays an
essential role in lymphocyte division, a role attributed to its iron transport function. In the
present study we used hypotransferrinaemic (Trfhpx/hpx) mice to investigate the possible
involvement of transferrin in T lymphocyte differentiation in vivo. The absolute number of
thymocytes was substantially reduced in Trfhpx/hpx mice, a result that could not be attributed …
Summary
Transferrin, the major plasma iron carrier, mediates iron entry into cells through interaction with its receptor. Several in vitro studies have demonstrated that transferrin plays an essential role in lymphocyte division, a role attributed to its iron transport function. In the present study we used hypotransferrinaemic (Trfhpx/hpx) mice to investigate the possible involvement of transferrin in T lymphocyte differentiation in vivo. The absolute number of thymocytes was substantially reduced in Trfhpx/hpx mice, a result that could not be attributed to increased apoptosis. Moreover, the proportions of the four major thymic subpopulations were maintained and the percentage of dividing cells was not reduced. A leaky block in the differentiation of CD4 CD8 CD3 CD44 CD25+ (TN3) into CD4 CD8 CD3 CD44 CD25 (TN4) cells was observed. In addition, a similar impairment of early thymocyte differentiation was observed in mice with reduced levels of transferrin receptor. The present study demonstrates, for the first time, that transferrin itself or a pathway triggered by the interaction of transferrin with its receptor is essential for normal early T‐cell differentiation in vivo.
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