Autoimmunity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66083/1/j.1365-4362.1981.tb00393.x.pd

Streptococcus iniae M-Like Protein Contributes to Virulence in Fish and Is a Target for Live Attenuated Vaccine Development

Streptococcus iniae is a significant pathogen in finfish aquaculture, though knowledge of virulence determinants is lacking. Through pyrosequencing of the S. iniae genome we have identified two gene homologues to classical surface-anchored streptococcal virulence factors: M-like protein (simA) and C5a peptidase (scpI).S. iniae possesses a Mga-like locus containing simA and a divergently transcribed putative mga-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes), scpI is located distally in the chromosome. Comparative sequence analysis of the Mgx locus revealed only one significant variant, a strain with an insertion frameshift mutation in simA and a deletion mutation in a region downstream of mgx, generating an ORF which may encode a second putative mga-like gene, mgx2. Allelic exchange mutagenesis of simA and scpI was employed to investigate the potential role of these genes in S. iniae virulence. Our hybrid striped bass (HSB) and zebrafish models of infection revealed that M-like protein contributes significantly to S. iniae pathogenesis whereas C5a peptidase-like protein does not. Further, in vitro cell-based analyses indicate that SiMA, like other M family proteins, contributes to cellular adherence and invasion and provides resistance to phagocytic killing. Attenuation in our virulence models was also observed in the S. iniae isolate possessing a natural simA mutation. Vaccination of HSB with the Delta simA mutant provided 100% protection against subsequent challenge with a lethal dose of wild-type (WT) S. iniae after 1,400 degree days, and shows promise as a target for live attenuated vaccine development.Analysis of M-like protein and C5a peptidase through allelic replacement revealed that M-like protein plays a significant role in S. iniae virulence, and the Mga-like locus, which may regulate expression of this gene, has an unusual arrangement. The M-like protein mutant created in this research holds promise as live-attenuated vaccine

Genetic Basis of Myocarditis: Myth or Reality?

n/

STREPTOCOCCAL CELL-WALLS AND SYNOVIAL CELL ACTIVATION - STIMULATION OF SYNOVIAL FIBROBLAST PLASMINOGEN-ACTIVATOR ACTIVITY BY MONOCYTES TREATED WITH GROUP-A STREPTOCOCCAL CELL-WALL SONICATES AND MURAMYL DIPEPTIDE

Group A streptococcal peptidoglycan has previously been shown to be arthritogenic in rats and has been implicated as a structure present in a class of possible etiologic agents for rheumatoid arthritis. The present study reports that conditioned medium from human monocytes, after interaction with cell wall sonicates of four group A streptococcal strains, stimulates the plasminogen activator (PA) activity of nonrheumatoid synovial fibroblasts. Low concentrations of N-acetylmuramyl-L-alanyl-D isoglutamine (muramyl dipeptide) can also generate this synovial activator (SA) activity from human monocytes. Preliminary biochemical data suggest that the SA activity is distinct from interferon-gamma, interleukin 1, and interleukin 2. These results indicate that agents that are arthritogenic in rats can modulate human synovial fibroblast functions via monocytes. The findings are proposed to have possible significance for an understanding of the cellular interactions involved in the formation and function of the rheumatoid pannus, because PA has been invoked as possibly being generally important for the processes of cell migration, tissue remodeling, and inflammation

A double-blind trial of transfer factor vs placebo in multiple sclerosis patients.

A double-blind trial of the effect of transfer factor on multiple sclerosis patients was carried out. In a series of fifty-six multiple sclerosis patients treated with monthly injections of either transfer factor or placebo for 1 year, no beneficial effect of transfer factor was noted. In addition, none of the immunological and serological parameters studied (measles migration inhibition, measles HI titre or CSF immunoglobulin) changed as a result of transfer factor therapy. Histocompatibility typing and CSF IgG/TP ratios were correlated with the disease activity. Of interest was the finding that the presence of the DW2 antigen, when unassociated with HLA-B7 antigen, appeared to correlate with the mildest form of disease activity

Marcador D8-17: implicações para a neuropsiquiatria D8/17 marker: implication to neuropsychiatry

Estudos recentes sugerem uma associação entre febre reumática (FR) e transtornos do espectro obsessivo-compulsivo, o que levou à hipótese de que alterações na resposta imune pudessem ter um papel na etiologia destes últimos. Um marcador biológico que talvez identifique maior susceptibilidade para o desenvolvimento de FR e desses transtornos neuropsiquiátricos tem causado grande interesse na literatura. Trata-se do D8/17, um anticorpo monoclonal contra um antígeno de membrana de linfócitos B. Neste artigo introduzimos conhecimentos sobre o D8/17 e discutimos suas implicações como um possível marcador biológico de transtornos neuropsiquiátricos associados ou não à FR.<br>Recent studies suggest that there is a relationship between rheumatic fever (RF) and some neuropsychiatric disorders. Thus, it has been thought that autoimmune mechanisms might be related to the etiology of these neuropsychiatric disorders. It has also been demonstrated that a B cell alloantigen associated to RF is also abnormally overexpressed in patients with such neuropsychiatric disorders. This alloantigen is recognised by a monoclonal antibody known as D8/17. The aim of this article is to introduce the recent work done about D8/17 and its possible implications to the study of neuropsychiatric disorders related or not to RF