Abstract
Hematopoiesis requires specific interactions with the microenvironments, and VLA-4 has been implicated in these interactions based on in vitro studies. To study the role of VLA-4 in hematopoiesis in vivo, we performed in utero treatment of mice with an anti-VLA-4 monoclonal antibody. Although all hematopoietic cells in fetal liver expressed VLA-4, the treatment specifically induced anemia. It had no effect on the development of nonerythroid lineage cells, including lymphoids and myeloids. In the treated liver almost no erythroblast was detected, whereas the erythroid progenitors, which give rise to erythroid colonies in vitro, were present. These results indicate that VLA-4 plays a critical role in erythropoiesis, while it is not critical in lymphopoiesis in vivo.
MeSH terms
-
Animals
-
Antibodies, Monoclonal / administration & dosage
-
Antibodies, Monoclonal / immunology
-
Antibodies, Monoclonal / pharmacology
-
Cell Adhesion / drug effects
-
Colony-Forming Units Assay
-
Erythroid Precursor Cells / drug effects*
-
Erythroid Precursor Cells / physiology
-
Erythropoiesis / physiology*
-
Female
-
Fibronectins / physiology
-
Gestational Age
-
Hematopoiesis, Extramedullary / physiology
-
Hematopoietic Cell Growth Factors / pharmacology
-
Hematopoietic System / drug effects
-
Hematopoietic System / enzymology
-
Humans
-
Integrin alpha4beta1
-
Integrins / antagonists & inhibitors
-
Integrins / immunology
-
Integrins / physiology*
-
Liver / drug effects
-
Liver / embryology
-
Mice
-
Mice, Inbred C57BL
-
Organ Specificity
-
Pregnancy
-
Receptors, Lymphocyte Homing / antagonists & inhibitors
-
Receptors, Lymphocyte Homing / immunology
-
Receptors, Lymphocyte Homing / physiology*
-
Recombinant Proteins / pharmacology
-
Thymus Gland / drug effects
-
Thymus Gland / embryology
Substances
-
Antibodies, Monoclonal
-
Fibronectins
-
Hematopoietic Cell Growth Factors
-
Integrin alpha4beta1
-
Integrins
-
Receptors, Lymphocyte Homing
-
Recombinant Proteins