Antigenic stimuli do not influence thymic B lymphocytes: a morphological and functional study in germ-free and conventionally reared piglets.
Dev Immunol
; 6(3-4): 171-8, 1998.
Article
en En
| MEDLINE
| ID: mdl-9814590
ABSTRACT
We have recently reported that thymic B lymphocytes (TBL) are the first B-cell subpopulation undergoing isotype switching to IgG and IgA during embryonic life. The aim of this study is to analyze the influence of antigenic stimulation on TBL location and activity using a germ-free (GF) newborn pig model, in which maternal antibodies and antigens do not affect B-cell development. Immunohistological analysis showed that TBL were disseminated mainly in the thymic medulla. There were no differences in the distribution of TBL, both in GF newborn piglets before and after colonization with Escherichia coli and in older conventionally reared (CONV) piglets. The number of immunoglobulin (Ig)-secreting cells measured by the ELISPOT method was not influenced by microflora and food antigens. IgM-positive cells secreting IgM and CD45RC-positive cells spontaneously producing IgM, IgG, and IgA were detected in newborn thymus. Our findings suggest that TBL differentiation and Ig switching to IgG and IgA-secreting cells is not influenced by external antigens and that the thymic microenvironment plays an important role in this process.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Timo
/
Isotipos de Inmunoglobulinas
/
Linfocitos B
/
Vida Libre de Gérmenes
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Dev Immunol
Asunto de la revista:
ALERGIA E IMUNOLOGIA
Año:
1998
Tipo del documento:
Article