Dextran-conjugated anti-Ig antibodies as a model for T cell-independent type 2 antigen-mediated stimulation of Ig secretion in vitro. I. Lymphokine dependence.
We have previously demonstrated that dextran-conjugated anti-IgD antibodies (anti-delta-dex) stimulate high levels of B cell proliferation at concentrations that are 1000-fold lower than that required by unconjugated anti-Ig. We now show that anti-delta-dex may provide a suitable model to study Ig secretion stimulated by soluble T cell-independent type 2 Ag exemplified by TNP-Ficoll. Thus, both TNP-Ficoll and anti-delta-dex stimulate low to undetectable levels of Ig secretion when cultured with resting B cells. Addition of IL-5 or IL-2 stimulated enhanced anti-TNP responses in the presence of TNP-Ficoll, or induced polyclonal Ig secretion in the presence of anti-delta-dex. Both TNP-Ficoll and anti-delta-dex conjugates stimulated Ig production by Percoll-separated low density (partially activated) B cells in the absence of added lymphokines. These findings point to the similarities in the activation requirements of TNP-Ficoll and anti-delta-dex and suggest that dextran-anti-Ig conjugates, which can induce B cell activation irrespective of Ag specificity, may provide a useful model for studying various parameters that characterize the responses to soluble TI type 2 Ag.
Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799.
L M
LM
Peçanha
C M
CM
Snapper
F D
FD
Finkelman
J J
JJ
Mond
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology*; D000955:Antigens, T-Independent / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology; D003911:Dextrans / Q000494:pharmacology*; D005260:Female; D007072:Immunoglobulin D / Q000276:immunology*; D007136:Immunoglobulins / Q000378:metabolism*; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D015848:Interleukin-5 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D011994:Recombinant Proteins / Q000494:pharmacology
D000888:Antibodies, Anti-Idiotypic; D000955:Antigens, T-Independent; D003911:Dextrans; D007072:Immunoglobulin D; D007136:Immunoglobulins; D007376:Interleukin-2; D015848:Interleukin-5; D008222:Lymphokines; D011994:Recombinant Proteins