RESUMO
The IgE serum levels and IgE FcR-positive lymphocytes (Fc epsilon R) in the spleen and mesenteric lymph nodes (MLN) of normal and immunologically mutant strains of mice were determined before and 14 days after infection with Nippostrongylus brasiliensis (Nbr) parasites. By IgE rosetting of cells immunofluorescently stained for sIg. Thy-1.2, Lyt-2, and L3T4, only sIg+ IgE rosetting lymphocytes were detected in both normal and Nbr-infected mice. IgE high responder mice had the same percentage of Fc epsilon R+ spleen and MLN lymphocytes as low responder mice. After Nbr infection, the percentages of splenic and MLN Fc epsilon R+ cells increased in parallel to a similar increase of sIg+ B cells. Athymic C57BL/6J-nu mice had 62% Fc epsilon R+ spleen and 85% Fc epsilon R+ MLN cells before and after Nbr infection, but IgE serum levels were less than 5 ng IgE/ml. C57BL/6J mice with the viable moth-eaten mutation mev which have almost exclusively Ly-1+ B cells, had less than 1% Fc epsilon R+ lymphocytes and formed only small amounts of IgE. C57BL/6J mice with the lymphoproliferation (lpr) or generalized lymphoproliferative disease (gld) mutations had low numbers of Fc epsilon R+ cells but formed 15 to 30 times more IgE after Nbr infection than control C57BL/6J mice. The IgE response of mice with the beige mutation (bg) did not differ from control mice. Mice with the xid mutation had few Fc epsilon R+ and sIg+ cells but showed high IgE responses. These data demonstrate that Fc epsilon R are typical cell surface markers for approximately 90% of murine Ly-1-, sIg+ B cells and that the number of Fc epsilon R+ cells does not correlate with the capacity of the mice to form IgE. The IgE response to Nbr infection is normal in mice homozygous for the bg mutation, elevated in mice homozygous for the xid, lpr, and gld mutations, and decreased in mice homozygous for the mev and nu mutations.
Assuntos
Doenças Autoimunes/imunologia , Imunoglobulina E/biossíntese , Síndromes de Imunodeficiência/imunologia , Linfócitos/metabolismo , Infecções por Nematoides/imunologia , Receptores Fc/análise , Animais , Doenças Autoimunes/metabolismo , Separação Celular , Feminino , Imunoglobulina E/análise , Imunoglobulina G/classificação , Imunoglobulina M/análise , Síndromes de Imunodeficiência/metabolismo , Linfócitos/classificação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Infecções por Nematoides/sangue , Infecções por Nematoides/metabolismo , Nippostrongylus , Fenótipo , Receptores de IgE , Formação de Roseta/métodosRESUMO
The immunoglobulin (Ig)E, IgG subclass, and IgM formation in vivo and in vitro were measured by radioimmunoassays in normal and immunodeficient mice infected with the parasite Nippostrongylus brasiliensis (Nbr). High IgE responder mice had higher IgE serum levels than low responder mice both before (100 to 250 vs 2 to 20 ng of IgE/ml) and after (17,000 to 27,000 vs 1,000 to 5,000 ng of IgE/ml) infection. In vitro, mesenteric lymph node cells formed 5- to 10-fold more IgE than the spleen cells. Nu/nu mice had less than 1 ng before and 5 ng of IgE/ml serum after Nbr infection; no IgE was detectable in cell supernatants. There was no difference in the in vivo and in vitro IgE formation between C57BL/6 and C57BL/6-beige mice. Both in vivo and in vitro Nbr-infected Xid+ mice (CBA/N; (CBA/N X BALB/c) F1 male) formed approximately twice the amount of IgE than Xid- mice. Concomitant with the rise of the IgE serum levels, the IgG1 serum level increased by 100 to 1,500 micrograms/ml over preinfection levels in all strains except nu/nu+ mice. The IgM serum level increased by 100 to 500 micrograms/ml. In contrast, the IgG2a and IgG2b levels decreased in most strains, and the IgG3 levels remained unchanged. Nu/nu+ mice showed an increase of all IgG subclasses after Nbr infection. The antibodies to an Nbr extract were predominantly of IgM and IgG1, except in SJL mice which also had IgG2b and nude mice which only had IgM antibodies. The concomitant increase of IgE and IgG1 formation in all but the nude strains suggests that the regulation of these two Ig isotypes may be linked via regulatory T helper cells, which corroborates recent data on the simultaneous induction of IgG1 and IgE synthesis in vitro by the B cell stimulatory factor 1.