A clonal analysis of the IgE response and its implications with regard to isotope commitment.

Abstract

In a clonal analysis of the IgE response, it was found that a small proportion of primary or nonimmune B cells in spleen and mesenteric lymph nodes can be stimulated by antigen to produce IgE-secreting clones. In addition, there appears to be no substantial difference in the frequency of such cells between the classical low and high IgE responder strains. An analysis of immune, or memory, B cells revealed substantial increases in the frequency of B cells secreting IgE as compared with primary B cells, although the actual proportion of B cells secreting IgE remained relatively low. When the IgE-secreting clones derived from either primary or secondary B cells were reanalyzed for the presence of other isotypes, it was found that all clones secreting IgE were secreting at least one other isotype, with the majority secreting two or three other isotypes in addition to IgE. This demonstrates that there is no distinct subpopulation of B cells committed to IgE expression per se.

Regulation of IgE production in pre‐sensitized animals: in vivo elimination of alveolar macrophages preferentially increases IgE responses to inhaled allergen*

“…Additionally, the secondary IgE response in the serum of these animals was not accompanied hy a detectable rise in specific IgG. Taken together with published data on clonal analysis of the IgE response to this form of priming which shows that IgE plasma cells are normally outnumbered in the order o\' 10:1 by those secreting specific IgG antibodies [16], our results suggest that the elTects of AM depletion manifest preferentially in regard to the IgE component ofthe immune response to inhaled antigen. At the T-ccll level, this may equate to preferential stimulation o\' TH-2-like (IL-4 secreting) T-helper cells which control IgE isotype switching [ 17], and this possibility will be addressed in subsequent experiments.…”

Specificity of immunoglobulin heavy chain switch correlates with activity of germline heavy chain genes prior to switching.

“…However, the 7Y2a probe detected at least five species of RNA transcribed from the non-rearranged 7Y2a gene(s) in IgM + cells (lanes 18,19), which differed in size Discussion from 7Y2a mRNAs (1.7 and 3.4 kb, shown in lane 21). Although Single clones of antigen-stimulated IgM+ B cells in spleen fragboth IgE+ and IgA+ cells have deleted the 7Y2a gene from the ment cultures (which contain helper T cells) can switch to exproductive chromosome, but still have the 72a gene on the nonpress various Ig H chains (Gearhart et al, 1975; productive chromosome, only the IgE+ cells contained Y2a 1982, 1983Teale et al, 1981;Teale, 1982Teale, , 1983. Thus, splenic RNAs.…”

Induction of IgE-Secreting Cells in the Lymphatic Drainage of the Lungs of Rats following Passive Antigen Inhalation

“…Clonal analysis of the IgE response has clearly de monstrated that parenteral allergenic stimulation leads to the generation of specific IgE secreting cells at extremely low frequencies, up to several log units below those observed for the major antibody isotypes [1], Conventional immunohistochemical techniques for the detection of the small numbers of IgE-containing cells present in tissue sections consequently re quire reagents of absolute specificity, as the slightest cross-reactivity with other isotypes would render meaningful IgE-cell counts impossible. Additionally, they require the use of state-of-the-art fixation metho dology to preserve tissue morphology in order to dis tinguish between plasma cells and cells which bind IgE, such as mast cells.…”