Assuntos
Traumatismos Abdominais/microbiologia , Intestinos/lesões , Infecção dos Ferimentos , Abdome/cirurgia , Anaerobiose , Bacteroides , Sangue/microbiologia , Cefalotina/uso terapêutico , Chicago , Clindamicina/uso terapêutico , Clostridium , Eubacterium , Feminino , Humanos , Intestino Grosso/lesões , Intestino Delgado/lesões , Intestinos/microbiologia , Canamicina/uso terapêutico , Masculino , Peptostreptococcus , Propionibacterium , Estudos Prospectivos , Pseudomonas , Escarro/microbiologia , Urina/microbiologia , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
Most surface glycoproteins expressed by mammalian-stage forms of Trypanosoma cruzi are homologous to the parasite's trans-sialidase and therefore are members of the parasite's trans-sialidase superfamily. Few members of this superfamily have trans-sialidase activity. The SA85-1 family is a subfamily of the trans-sialidase superfamily whose members lack trans-sialidase activity. The function of these non-trans-sialidase members remains unknown. In this report a series of monoclonal and polyclonal antibodies to the SA85-1 glycoproteins is presented. The mAbs define distinct subgroups of SA85-1 glycoproteins, and these distinct subgroups are simultaneously expressed by individual trypomastigotes, supporting previous studies indicating that multiple SA85-1 glycoproteins and trans-sialidase superfamily glycoproteins are simultaneously expressed by each trypomastigote. In addition, the antibodies define two major subsets of the SA85-1 family (subset 1 and subset 2) based on differences in migration in SDS-PAGE; the subsets do not appear to be created by differences in glycosylation. Subset 1 migrates slower and is spontaneously released or shed preferentially from the parasite surface compared to subset 2. In addition, subset 1 is attached to the trypomastigote surface by a GPI linkage. Since these glycoprotein subsets are differentially expressed, they may have different functions.
Assuntos
Anticorpos Monoclonais/imunologia , Glicoproteínas/imunologia , Trypanosoma cruzi/imunologia , Glicoproteínas Variantes de Superfície de Trypanosoma/imunologia , Glicoproteínas Variantes de Superfície de Trypanosoma/metabolismo , Animais , Especificidade de Anticorpos , Antígenos de Protozoários/química , Antígenos de Protozoários/isolamento & purificação , Antígenos de Protozoários/metabolismo , Western Blotting , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glicoproteínas/classificação , Glicoproteínas/metabolismo , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/metabolismo , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
We examined whether human blood dendritic cells (DCs) express a functional ligand for CD40 (CD40L). Human blood DCs expressed significant amounts of cell surface CD40L identical to that expressed on activated T cells, as detected by mAb to CD40L or a chimeric CD40.Ig fusion protein (CD40.Ig). Stimulation through CD40 up-regulated protein and mRNA CD40L expression in DCs, B cells, and B cell lines. CD40-mediated CD40L expression was inhibited by a protein tyrosine kinase inhibitor, herbimycin, in a dose-dependent manner, suggesting that the induction of CD40L expression via CD40 requires protein tyrosine kinase activity. CD40L surface expression correlated with constitutive or inducible levels of CD40L-specific mRNA, as determined by reverse transcribed PCR analysis (RT-PCR) using CD40L-homologous primers. Furthermore, CD40L on DCs was functional, since CD40L+ DCs, unlike CD40L- DCs, induced B cell IgG and IgA production, and this induction could be inhibited by blocking CD40L-CD40 interactions with mAb to CD40L. Thus, CD40L on DCs and CD40L induced by crosslinking CD40 may regulate B cell activation and maturation. The importance of DC CD40L expression on B cell function is discussed.