IgE Memory Research Articles

Enumeration of antigen-specific IgE responses at the single-cell level by an ELISA plaque assay

In vitro elicitation and enumeration of antigen-specific IgE-secreting cells in antigen-primed murine lymophocyte cultures can be reproducibly and accurately quantitated. Rat anti-mouse IgE monoclonal antibodies (Mab anti-ϵ) were developed. Antigen-specific IgE-secreting cells can be detected on antigen or MAb anti-ϵ coated nitrocellulose discs pasted to 24-well cultures plates. This IgE ELISA-plaque assay (EPϵ) is more reliable than antigen capture or total IgE ELISAs in monitoring de novo induction of antigen-specific IgE memory responses in cultures of antigen-primed lymphocytes elicited with antigens.

Establishment of a memory in vitro murine IgE response to benzylpenicillin and its resistance to suppression by anti-IL-4 antibody.

Regulation of a memory IgE antibody response may be different from the induction of a primary response and may, therefore, be more relevant to the study of allergic diseases and the therapeutic manipulation of IgE antibody formation. In this paper a murine hapten-specific in vitro memory IgE antibody response to benzylpenicilloyl(BPO)-KLH is described. The response was analyzed by determining the number of antibody-producing cells (APC) in an ELISA spot assay. Of the total number of BPO-specific APC (10,000 APC/10(6) cultured spleen cells), about 1% were IgE-producing cells (100/10(6) cultured cells), as detected on day 6 of culture. The level of the antibody response is antigen dose-dependent, and the detected APC are BPO specific. The memory IgE response is not inhibited by the addition of anti-IL-4 antibody (11B11), even at a high excess. In the presence of the mitogen lipopolysaccharide, it has been shown that switch of B cells to IgE is induced by IL-4, a process which can be inhibited by anti-IL-4 antibody. Because the antigen-induced IgE response cannot be inhibited by anti-IL-4 antibody, in vitro responding cells derived from BPO-KLH-preimmunized mice may, therefore, have already switched in vivo to IgE. On the other hand, B cells switching to IgE in a situation of cognate T-B cell interaction might receive IL-4 in a transsynaptical way from T cells which might not be accessible to inhibition by anti-IL-4 antibody. The identification of the two possibilities in situations of established allergic disorders will be decisive for determining whether pharmacological inhibition of IL-4 (or IL-4-induced switch)--e.g., by putative low molecular weight compounds--will ever be a meaningful approach to suppress allergic diseases.

Difference of the IgE memory cells in SJL and BALB/c mice.

Memory cells for adoptive transfer for IgE production must be primed with Al(OH)<sub>3</sub> as adjuvant in the SJL strain of mice, but can be primed also with Freund’s complete adjuvant in the BALB/c strain.