Premium
Correlation between Specific Immunosuppression and Polyclonal B Cell Activation Induced by a Protein Secreted by Streptococcus mutans
Author(s) -
FERREIRA P.,
SOARES R.,
RIBEIRO A.,
ARALACHAVES M.
Publication year - 1988
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1988.tb02382.x
Subject(s) - polyclonal antibodies , spleen , immunosuppression , immunization , in vivo , microbiology and biotechnology , priming (agriculture) , cytotoxic t cell , streptococcus mutans , biology , t cell , immunology , in vitro , immune system , antibody , chemistry , biochemistry , bacteria , botany , germination , genetics
The relationship between polyclonal B cell activation and immunosuppressor effects induced by F5'EP‐Sm, a non‐cytotoxic protein secreted by Streptococcus mutans , was studied in C57BL/6 mice. Mice created with F5'EP‐Sm exhibited a considerable increase in splenic nonspecific Ig plaque‐forming cells (PFC) compared with untreated mice. The isotypic pattern of non‐specific PFC responses favours IgG2a∼IgG2b>IgG3>IgG1∼IgM, when taken as a ratio between treated and untreated animals. When F5'EP‐Sm was administered 2 days before immunization with sheep red blood cells (SRBC), the non‐specific PFC production was accompanied by an ephemeral increase in specific PFC against SRBC 1 day after immunization, which was quickly replaced by a strong immunosuppression. In contrast, when F5'EP‐Sm was injected after priming, there was little or no demonstrable suppression of specific PFC, and the increase of non‐specific PFC was much less evident. The kinetic curves representing increase or decrease in relation to controls of specific and non‐specific PFC are almost mirror images in each of the isotypes. The in vivo suppressor effect was abrogated in thymectomized mice, although the involvement of the T cell compartment is probably secondary to the B cell mitogen effect, since T‐depleted spleen cells proliferate and synthesize non‐specific Ig when stimulated in vitro with F5'EP‐Sm.