Human Ig production and isotype switching in severe combined immunodeficient-human mice

Autor: Bart Vandekerckhove, Jones D, Punnonen J, Schols D, Hc, Lin, Duncan B, Bacchetta R, Je, Vries, Mg, Roncarolo
Přispěvatelé: Vandekerckhove, Bae, Jones, D, Punnonen, J, Schols, D, Lin, Hc, Duncan, B, Bacchetta, R, Devries, Je, Roncarolo, MARIA GRAZIA
Rok vydání: 1993
Předmět:
Zdroj: ResearcherID
Europe PubMed Central
ISSN: 0022-1767
Popis: Severe combined immunodeficient (SCID) mice were transplanted with different human fetal organs (SCID-hu mice), including thymus, liver, spleen, and omentum, and the serum levels of human IgM, IgG, IgE, and IgA were measured. In all SCID-hu mice significant levels (up to 590 ng/ml) of IgM were detected, irrespective of the organs transplanted. In contrast, IgG was present (up to 530 ng/ml) only when the fetal thymus was transplanted together with the fetal liver, indicating that the presence of human T cells is a prerequisite for in vivo isotype switching by human B cells in SCID-hu mice. Additional transplantation of fetal spleen did not significantly increase IgG levels. Human IgA and IgE were never detected in the serum of these SCID-hu mice. The peak of IgM and IgG production was observed 4 months after transplantation. At that time, analysis by IEF showed that human IgG present in SCID-hu serum was at least oligoclonal. Furthermore, all IgG subclasses were represented in the human IgG pool. Human B cells were undetectable in the peripheral blood, spleen, and bone marrow of-these SCID-hu mice; in contrast, B cells expressing CD19 could be isolated from the SCID-hu thymus. Considerable proportions of the CD19+ B cells coexpressed CD5, CD7, CD10, CD40, and CD2. These B cells spontaneously produced IgM and IgG in vitro and could be induced to switch to IgE-producing cells when cocultured with cloned activated CD4+ T cells in the presence of IL-4. Collectively, these data demonstrate that functionally mature B cells able to produce IgM and IgG in vivo, and IgE in vitro, are present in the SCID-hu human thymus.
Databáze: OpenAIRE
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