Kinetics of interleukin-4 induction and interferon-gamma inhibition of IgE secretion by Epstein-Barr virus-infected human peripheral blood B cells.
Interleukin-4 (IL-4) acts directly on purified human peripheral blood B cells cultured in the presence of Epstein-Barr virus (EBV) to induce IgE secretion and to enhance the secretion of IgG and IgM. Interferon-gamma (IFN-gamma) inhibits IgE secretion in this system, without affecting the secretion of the other Ig isotypes. To identify the time period during which EBV-infected B cells can be induced by IL-4 to secrete IgE, we have studied the effects of delayed addition of IL-4, or the termination of IL-4 stimulation by wash out or by neutralization with anti-IL-4 antibodies, on the induction of an IgE response. To induce a maximal IgE response, IL-4 had to be added to cultures of B cells plus EBV no later than 2 days after the initiation of culture, and had to remain present through the tenth day of culture. These two time points correspond to the initiation of detectable DNA synthesis (Days 3 to 4) and the earliest detectable Ig secretion (Days 10 to 12) by EBV-stimulated B cells. No IgE response was induced if the period during which EBV-stimulated B cells were cultured with IL-4 was less than 4 days, or if IL-4 were added later than the tenth day of culture, regardless of how long the culture was continued beyond that time. In contrast, IL-4 considerably enhanced IgG and IgM secretion and B cell CD23 expression, even if it was added after the tenth day of culture. IFN-gamma strongly inhibited the IgE response of B cells cultured with IL-4 plus EBV if added within 6 days of the initiation of culture, but had little effect on the generation of IgM or IgG responses made by these cells, regardless of the time of addition. Neither IL-4 nor IFN-gamma affected ongoing IgE secretion by an established, IgE-secreting, EBV-transformed cell line. These observations suggest that: (i) IL-4 first becomes able to induce EBV-activated B cells to secrete IgE as these cells begin to synthesize DNA, must stimulate B cells for at least 4 days to induce IgE secretion, and loses its ability to induce IgE secretion as these cells differentiate into Ig-secreting cells; (ii) the ability of IFN-gamma to suppress an IgE response is limited to this same time period; and (iii) IL-4 enhancement of CD23 expression and IgM and IgG secretion are independent of IL-4 induction of an IgE response.
Thyphronitis
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Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814.
Banchereau
J
J
Heusser
C
C
Tsokos
G C
GC
Levine
A D
AD
Finkelman
F D
FD
D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology* / Q000382:microbiology; D002472:Cell Transformation, Viral / Q000276:immunology*; D002478:Cells, Cultured; D005803:Genes, Immunoglobulin; D004854:Herpesvirus 4, Human; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007371:Interferon-gamma / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D011961:Receptors, Fc / Q000032:analysis; D017455:Receptors, IgE
D000944:Antigens, Differentiation, B-Lymphocyte; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011961:Receptors, Fc; D017455:Receptors, IgE; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma