Blood, Vol. 94 No. 1 (July 1), 1999:
pp. 348-358
Incomplete T-Cell Immune Reconstitution in Two Major Histocompatibility
Complex Class II-Deficiency/Bare Lymphocyte Syndrome Patients
After HLA-Identical Sibling Bone Marrow Transplantation
Barbara C. Godthelp,
Marja C.J.A. van Eggermond,
Ad Peijnenburg,
Ilhan Tezcan,
Stefaan van Lierde,
Maarten J.D. van Tol,
Jaak M. Vossen, and
Peter J. van den Elsen
From the Departments of Pediatrics and Immunohematology and Blood
Bank, Leiden University Medical Center, Leiden, The Netherlands; the
Immunology Unit, Haceteppe University Childrens Hospital, Ankara,
Turkey; and the Heilig Hart Hospital Tienen, Tienen,
Belgium.
To study the effects of major histocompatibility complex (MHC) class
II expression on T-cell development, we have investigated T-cell immune
reconstitution in two MHC class II-deficiency patients after
allogeneic bone marrow transplantation (allo-BMT). Our study showed
that the induction of MHC class II antigen expression on BM
graft-derived T cells in these allo-BMT recipients was hampered upon
T-cell activation. This reduction was most striking in the CD8+ T-cell subset. Furthermore, the peripheral T-cell
receptor (TCR) repertoire in these graft-derived MHC class
II-expressing CD4+ and in the CD8+ T-cell
fractions was found to be restricted on the basis of TCR complementarity determining region 3 (CDR3) size profiles.
Interestingly, the T-cell immune response to tetanus toxoid (TT) was
found to be comparable to that of the donor. However, when comparing
recipient-derived TT-specific T cells with donor-derived T cells,
differences were observed in TCR gene segment usage and in the
hydropathicity index of the CDR3 regions. Together, these results
reveal the impact of an environment lacking endogenous MHC class II on
the development of the T-cell immune repertoire after allo-BMT.
