The effects of retinoic acid on immunoglobulin synthesis by human cord blood mononuclear cells.
Derivatives of vitamin A have attracted considerable attention as agents which have immune potentiating properties and possibly tumor-suppressive effects. Recent investigations have shown that retinoic acid (RA) can augment immunoglobulin production of B-cell hybridomas from patients with immune deficiency. In this study we examined the ability of RA to modify the mitogen-induced polyclonal immunoglobulin synthesis of cord blood mononuclear cells (CBMC). RA in concentrations ranging from 10(-5) to 10(-7) M augmented IgM synthesis of CBMC in response to formalinized Cowans I strain Staphylococcus aureus (SAC) up to 45.6-fold which was greater at suboptimal responses to SAC. There were no changes in IgG or IgA synthesis and minimal effects on SAC-induced proliferative responses. RA did not produce similar changes in IgM synthesis of SAC-stimulated adult peripheral blood mononuclear cells (PBMC), and RA had no effect on the immunoglobulin synthesis of Epstein-Barr virus (EBV)-stimulated CBMC or adult PBMC. Time course studies showed that peak enhancement occurred when RA was added between 4 and 24 hr after culture initiation and required prior activation by SAC for augmentation of IgM synthesis. Cell separation experiments showed that prior incubation (18 hr) of an enriched T-cell fraction with RA enhanced the IgM synthesis of a T-cell-depleted B-cell fraction. These experiments and the findings that RA-induced augmentation of IgM production in response to SAC, but not to EBV suggest that the immunoregulatory effects of RA may be mediated by either T cells or T-cell products. Further studies will be necessary to understand the mechanism by which RA augments IgM synthesis of CBMC.
Israel
H
H
Department of Pediatrics, Children's Hospital, State University of New York, Buffalo 14222.
Odziemiec
C
C
Ballow
M
M
D000328:Adult; D005312:Fetal Blood / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis*; D007231:Infant, Newborn; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013211:Staphylococcus aureus / Q000276:immunology; D013601:T-Lymphocytes / Q000502:physiology; D014212:Tretinoin / Q000494:pharmacology*
D007075:Immunoglobulin M; D014212:Tretinoin