Immunoglobulin‐Secreting Cells in Cord Blood: Effects of Epstein–Barr Virus and Interleukin‐4

Abstract

Gudmundsson KO, Thorsteinsson L, Gudmundsson S, Haraldsson Á . Immunoglobulin-Secreting Cells in Cord Blood: Effects of Epstein-Barr Virus and Interleukin-4. Scand J Immunol 1999;50:21-24 The contribution of cord blood B lymphocytes to the immune response has been under considerable investigation. Cord blood B cells produce almost no antibodies except of the immunoglobulin (Ig)M isotype, indicating immaturity of the cells or the environment they reside in. The aim of this study was to investigate the number of circulating IgA-, IgM-, IgG-, and IgE-producing cells in cord blood in comparison to adult peripheral blood using the ELISPOT method. Moreover, we studied the effect of transformation with the Epstein-Barr virus (EBV) on the proportion of cells producing different isotypes with or without interleukin (IL)-4. Cord blood had IgM-producing cells circulating predominantly, but also some IgA-and IgG-producing cells, whereas adult peripheral blood contained high amounts of circulating IgA-producing cells and some IgM-and IgG-producing cells. No circulating IgE-producing cells were found in either group. Transformation by EBV caused significant expansion of IgA-, IgM-, and IgG-producing cells in adult peripheral blood, but almost only of IgM-producing cells in cord blood. A low but detectable expansion of IgA-and IgG-producing cells was found. Cells producing IgE were still not found, even after EBV transformation. However, EBV transformation in the presence of IL-4 increased the numbers of IgE-producing cells significantly both in cord blood and adult peripheral blood. These findings indicate that cord blood contains some circulating IgA-and IgG-producing cells that are expanded to some extent after EBV infection. They also indicate that cord blood B cells have a similar capacity for IgE production to adult peripheral blood B cells when appropriately stimulated.

Detection and characterization of plasma cells in peripheral blood: correlation of IgE+ plasma cell frequency with IgE serum titre

“…Especially in atopic patients with markedly elevated IgE serum titres more than 100‐fold higher frequencies than in normal donors could be detected. Our data show that the frequency of IgE producing PC correlates highly significantly with the detected IgE serum titres ( r = 0·8532; P < 0·0001), which is in accordance with data obtained by other groups using ELISPOT assays [23,24,29–32].…”

“…Apart from major sites such as bone marrow, PC or ASC have been detected in peripheral blood, e.g. by ELISPOT assays [23,24,29–32]. The cells are thought to be found transiently in the circulation and are considered to be on their way to their final destination, e.g.…”

“…Previous attempts to detect IgE + B cells using intracellular immunofluorescence of sorted and EBV‐transformed B cells were limited due to the low frequency of the cells and to complicated protocols [54,55]. Using ELISPOT assays IgE‐secreting B cells could be detected in allergic diseases with high IgE serum titres such as HIE, atopic dermatitis and others, but very rarely in normal donors [23,24,29–32].…”

“…Similarly, in hyper‐IgE syndrome extremely elevated IgE levels can be observed [26–28]. Several investigators were able to detect spontaneously IgE‐secreting cells in the blood of patients with IgE‐related diseases [23–25,29–32]. Using ELISPOT assays or ELISAs IgE‐secreting B cells were found in patients with atopic dermatitis and HIE, but only very rarely in normal donors.…”

Modification of Cɛ mRNA Expression by EBV‐Encoded Latent Membrane Protein 1

“…In in vitro studies, EBV-transformed B cells stimulated with IL-4 produce IgE in culture supernatants [3, 4], and the level of IgE secreted in culture supernatants correlates with the number of IgE-producing cells [4]. Transformation of B cells by EBV has been reported to increase the number of IgE-producing cells [5]. Clinical studies to clarify the correlation between EBV infection and serum levels of IgE, which play a pivotal role in allergic reaction, yielded however controversial and conflicting results [1, 2, 6, 7].…”