Purification, and biochemical and biological characterization of an immunosuppressive and lymphocyte mitogenic protein secreted by Streptococcus sobrinus

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Ferreira, P (Author) ICBAS; Bras, A (Author) Other; Tavares, D (Author) Other; Vilanova, M (Author) ICBAS; Ribeiro, A (Author) Other; Videira, A (Author) ICBAS; AralaChaves, M (Author) Other

Journal

Title: International Immunology

Vol. 9

Pages: 1735-1743

ISSN: 0953-8178

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 17 Citations

Scopus - 16 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-001-AC3

Abstract (EN): An immunosuppressive/mitogenic (ISM) protein was purified from the supernatants of cultures of Streptococcus sobrinus with an isoelectric point of 4.75 and a relative molecular mass of 38 kDa (p38), Treatment of C57BL/6 mice with p38 induced an increase in the numbers of non-specific splenic Ig-secreting plaque-forming cells (PFC) with peak responses on day 3 for IgM-secreting PFC and on day 5 for IgG-secreting PFC, with an isotype pattern consisting predominantly of IgG2a and IgG2b, This increase was accompanied by a lymphocyte blastogenic response of both T and B lymphocytes, The in vitro effects of p38 on pure B, T and total splenic lymphocytes indicated that this ISM protein was primarily a B cell mitogen, being T cells activated subsequently by the generation of B blasts, Suppression of the murine primary immune response against sheep red blood cells was observed in C57BL/6 mice treated 4 days before with p38, The amino acid sequence of the N-terminus of p38 has a significant similarity with several enolases: particularly with rabbit enolase, However, the biological effects ascribed to p38 have not been detected after in vivo treatment with that enolase. The immunosuppressive effect of p38 was abrogated by depletion of IL-10 but not of IL-4, In agreement with this observation IL-10 was the only cytokine detected in serum of C57BL/6 mice after p38 treatment and the peak of serum levels was observed as soon as 2 h after treatment.

Language: English

Type (Professor's evaluation): Scientific