In vitro Synthesis of IgE by Human Peripheral Blood Leucocytes

Abstract

The assessment of IgE production in cultures of T- and B-cells from peripheral blood is proving a useful tool to probe IgE immunoregulation in human atopies. The present study contrasts secretion and synthesis as indices of IgE production, and demonstrates that these measures yield comparable data upon the magnitude and direction of regulatory T-cell effects (help vs. suppression) in severe atopies. The majority of peripheral blood B-cell samples from the atopies in this study exhibited spontaneous IgE synthesis and secretion, and in vitro T-cell help and suppression were observed with equal frequency within the sample population. Repeated testing of individual atopies indicated that the direction of T-cell effects remained stable in some (but not all) atopies over periods as long as 3 years.

Ultrastructural Localization of IgE in Peripheral Blood Monocytes from Atopies

“…In this context, the average serum content of IgG in these patients was 11.8 mg/ ml, which represents a 10,000-fold excess over their serum IgE levels (1.01 qg/ml). However, when cellassociated levels of lg were calculated as described by Turner et al [18], the content of IgG in 6 samples (23.8 ± 8.8, range 15.37 ng/ml) was in excess of that of IgE (688 ±591, range 127-1,731 pg/ml) by only a fac tor of 34.6. Consequently, uptake of the IgE isotype by monocytes is unlikely to be via random pinocytosis, but must instead involve a highly selective mechanism.…”

“…We have recently reported that enriched pop ulations of human monocytes/B cells from atopies contain significant levels of acid-extractable IgE [18][19][20], which is secreted in active form during in vitro culture. Much of this is performed and does not arise by de novo synthesis in vitro by B cells, and thus presumably represents IgE released from the mono cyte pool (as shown in figure 1) via exocytosis.…”

In vitro Synthesis of Human IgE: Reappraisal of a 5-Year Study

“…Several at tempts have also been made to establish whether the spontaneously IgE-producing cells detected in the cir culation of atopies are still sensitive to the influence of modulatory signals delivered in vitro. The addition of lectins, such as pokeweed mitogen (PWM), to cul tures of MNC from atopies and, more consistently, to B cell enriched populations induced suppression of the spontaneous IgE production [8,11,12], Likewise, pre-incubation of cells from grass-sensitive or mitesensitive patients with grass or mite antigen, respec tively, as well as the addition to cultures of anti-IgE monoclonal antibodies, appeared to be consistently inhibitory on the spontaneous IgE production in vitro [13][14][15], The effect of autologous or allogeneic T cells on the spontaneous IgE production in vitro by atopic B cells has also been investigated. In some patients with severe atopic disease T cells had inhibitory activity on the IgE production by autologous B cells; in some pa tients the inhibitory activity exerted by autologous T cells was radioresistant, while in other patients it was radiosensitive.…”

Festschrift In vitro synthesis of IgE by human peripheral blood leucocytes: VI Seasonal variations in synthesis of rye pollen (Lolium perenne) specific IgE

“…IgE determinations were performed as described by Turner et al (9), modified by the use of a polyclonal rabbit anti-IgE as the capture antibody on the paper discs and a mouse monoclonal anti-IgE (2.1.5) as the radiolabelled detector antibody. Both antisera were prepared in our laboratory.…”

“…vitro correlate with these in vivo observations, utilizes in vitro synthesis of IgE by peripheral blood leucocytes (PBL) from atopic donors (6)(7)(8)(9). A number of authors (4,(10)(11)(12)) demonstrated with this model that while de novo synthesis, as opposed to secretion (13), of pollen-specific IgE, was relatively low, it only occurred in cultures of PBL collected during the pollen season.…”