The effect of dosage, gestational age and splenectomy on anti-IgM interception of prenatal B-cell development in sheep.
The administration of a single bolus of anti-IgM antibody to foetal lambs early in pregnancy produces prolonged B-cell depletion. The present study investigated this depletion by examining the effect, on B-cell development in the ileal Peyer's patches, of varying the timing and dosage of antibody administration and by supplementing anti-IgM with surgical splenectomy. The capacity of a 1 mg bolus of anti-IgM to deplete Peyer's patches of B cells was lost if its administration was deferred until two thirds of the way through pregnancy, but persisted beyond this time if weight-adjusted doses were used. Splenectomy of the foetus performed at an earlier age failed to extend the age at which a 1 mg dose of antibody remained effective. As the concentration of murine immunoglobulin in foetal serum was greatly reduced after 21 days, it is inferred that ongoing suppression of B-cell development is not dependent on the continued presence of murine immunoglobulin. The enduring nature of suppression could be attributable to a limited period during which differentiation of B cells from stem cells normally occurs, although further studies will be needed to investigate this and other possible explanations for the effect of anti-IgM treatment on prenatal B-cell development in sheep.
John Curtin School of Medical Research, Australian National University, Canberra, ACT 2600, Australia.
P
P
McCullagh
C McL
CM
Press
S J
SJ
McClure
H J
HJ
Larsen
T
T
Landsverk
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage / Q000276:immunology*; D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005333:Fetus / Q000276:immunology*; D005865:Gestational Age; D007075:Immunoglobulin M / Q000276:immunology*; D007150:Immunohistochemistry; D010581:Peyer's Patches / Q000276:immunology; D011247:Pregnancy; D012756:Sheep / Q000196:embryology / Q000276:immunology*; D013156:Splenectomy / Q000009:adverse effects / Q000662:veterinary
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D007075:Immunoglobulin M; C044203:anti-IgM