scholarly journals Cloning, Expression, and Characterization of the Superantigen Streptococcal Pyrogenic Exotoxin G from Streptococcus dysgalactiae

2007 ◽  
Vol 75 (4) ◽  
pp. 1721-1729 ◽  
Author(s):  
Jizi Zhao ◽  
Tomohito Hayashi ◽  
Susanna Saarinen ◽  
Anastassios C. Papageorgiou ◽  
Hidehito Kato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mononuclear Cells ◽  
The Other ◽  
Human Pbmcs ◽  
Streptococcus Dysgalactiae ◽  
Pathogenic Role ◽  
Peripheral Blood Mononuclear ◽  
Novel Variants ◽  
Blood Mononuclear Cells

ABSTRACT We identified seven novel variants of streptococcal pyrogenic exotoxin G (SPEGG), a superantigen, in Streptococcus dysgalactiae subsp. dysgalactiae or equisimilis isolates from clinical cases of infection in humans and animals. Phylogenetic analysis of the SPEGG variants indicated two clades in the dendrogram: one composed of variants derived from the bacteria isolated from the humans and the other composed of variants from the bacteria isolated from the animals. Bovine peripheral blood mononuclear cells (PBMCs) were stimulated effectively by recombinant SPEGGs (rSPEGGs) expressed in Escherichia coli, while human PBMCs were not stimulated well by any of the rSPEGGs tested. SPEGGs selectively stimulated bovine T cells bearing Vβ1,10 and Vβ4. Bovine serum showed reactivity to the rSPEGG proteins. These results indicated that SPEGGs have properties as superantigens, and it is likely that SPEGGs play a pathogenic role in animals.

scholarly journals Differential In Vitro Cytokine Induction by the Species of Cryptococcus gattii Complex

2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Patricia F. Herkert ◽  
Jessica C. dos Santos ◽  
Ferry Hagen ◽  
Fatima Ribeiro-Dias ◽  
Flávio Queiroz-Telles ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Sensu Stricto ◽  
Cryptococcus Gattii ◽  
The Other ◽  
Human Pbmcs ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α

ABSTRACT Cryptococcal species vary in capsule and cell size, thermotolerance, geographic distribution, and affected populations. Cryptococcus gattii sensu stricto and C. deuterogattii affect mainly immunocompetent hosts; however, C. bacillisporus , C. decagattii , and C. tetragattii cause infections mainly in immunocompromised hosts. This study aimed to compare the capacities of different species of the C. gattii species complex to induce cytokines and antimicrobial molecules in human peripheral blood mononuclear cells (PBMCs). Cryptococcus bacillisporus and C. deuterogattii induced the lowest levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 among the five species of the C. gattii complex. Cryptococcus deuterogattii induced higher levels of IL-22 than those induced by C. tetragattii and the environmental species C. flavescens . In addition, C. bacillisporus and C. gattii sensu stricto proliferated inside human monocyte-derived macrophages after 24 h of infection. All Cryptococcus species were able to generate reactive oxygen species (ROS) in human PBMCs, with C. bacillisporus and C. deuterogattii being more efficient than the other species. In conclusion, C. bacillisporus and C. deuterogattii induce lower levels of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and higher ROS levels than those induced by the other species. Species of the Cryptococcus gattii complex have different abilities to induce cytokine and ROS production by human PBMCs.

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