TLR8 and complement C5 induce cytokine release and thrombin activation in human whole blood challenged with Gram‐positive bacteria

ABSTRACT The reliability of an in vitro pyrogen test system based on proinflammatory cytokine release from human monocytic cells was assessed by comparison with a test system based on a human whole blood culture as well as with the conventional rabbit pyrogen test. The human cells used as the pyrogen indicator cells were newly selected by subcloning of a human monocytic cell line, Mono-Mac-6. The selected cells, named MM6-CA8, responded to various pyrogens, including endotoxin, peptidoglycan (PG), Staphylococcus aureus Cowan 1 (SAC), and poly(I · C), with a high sensitivity and produced proinflammatory cytokines, such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor alpha. Among these cytokines, IL-6 was produced most sensitively in response to traces of the pyrogens and detected in the largest quantities in the culture medium. The cytokine-producing responses of MM6-CA8 cells correlated significantly with the responses of cultured human whole blood, which represents an ex vivo culture test system reproducing pyrogen-induced cytokine production in the human body. In terms of cytokine inducibility, the pyrogens were ranked in the order endotoxin > PG > poly (I · C) > SAC in both culture systems, a ranking which almost agreed with the ranking of their pyrogenicity as assessed by the rabbit pyrogen test. These results suggest that the in vitro responsiveness of MM6-CA8 cells to various pyrogens is highly relevant for human pyrogenic reactions. Therefore, the in vitro test system is useful and reliable for detecting the presence of materials that are pyrogenic for humans.

Download Full-text

Production of tumor necrosis factor-α and interleukin-6 in whole blood stimulated by live Gram-negative and Gram-positive bacteria

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.1998.tb00375.x ◽

1998 ◽

Vol 4 (3) ◽

pp. 129-134 ◽

Cited By ~ 6

Author(s):

Peter Kragsbjerg ◽

Bo Söderquist ◽

Hans Holmberg ◽

Tomas Vikerfors ◽

Dan Danielsson

Keyword(s):

Tumor Necrosis Factor ◽

Interleukin 6 ◽

Whole Blood ◽

Tumor Necrosis ◽

Tumor Necrosis Factor Α ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Factor Α ◽

Necrosis Factor

Download Full-text

Combined C5aR1 and CD14 inhibition significantly reduced cytokine release induced by both viable and heat inactivated bacteria in human whole blood

Molecular Immunology ◽

10.1016/j.molimm.2017.06.147 ◽

2017 ◽

Vol 89 ◽

pp. 169-170

Author(s):

Dorte Christiansen ◽

Espen Waage Skjeflo ◽

Anne Landsem ◽

Hilde Fure ◽

Judith K. Ludviksen ◽

...

Keyword(s):

Whole Blood ◽

Cytokine Release ◽

Human Whole Blood

Download Full-text

Molecular Characterization of the Acute Inflammatory Response to Infections with Gram-Negative versus Gram-Positive Bacteria

Infection and Immunity ◽

10.1128/iai.71.10.5803-5813.2003 ◽

2003 ◽

Vol 71 (10) ◽

pp. 5803-5813 ◽

Cited By ~ 137

Author(s):

Robert J. Feezor ◽

Caroline Oberholzer ◽

Henry V. Baker ◽

Daniela Novick ◽

Menachem Rubinstein ◽

...

Keyword(s):

Whole Blood ◽

Inflammatory Responses ◽

Ex Vivo ◽

Interleukin 1 ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Blood Leukocytes ◽

Necrosis Factor Alpha ◽

Gram Negative ◽

Gram Positive Bacteria

ABSTRACT Sepsis caused by gram-negative bacteria and that caused by gram-positive bacteria often manifest similar clinical features. We investigated plasma proinflammatory cytokine profiles in patients with sepsis due to gram-positive and gram-negative bacteria and studied the cytokine production and differential gene regulation of leukocytes stimulated ex vivo with Escherichia coli lipopolysaccharide or heat-killed Staphylococcus aureus. Concentrations of tumor necrosis factor alpha, interleukin 1 receptor antagonist (IL-1Ra), IL-8, IL-10, IL-18 binding protein, procalcitonin, and protein C in plasma did not differ between patients with sepsis due to gram-negative and gram-positive bacteria. However, plasma IL-1β, IL-6, and IL-18 concentrations were significantly higher in patients with sepsis due to gram-positive bacteria. Ex vivo stimulation of whole blood with heat-killed S. aureus markedly increased IL-1β and IL-18 levels more than E. coli lipopolysaccharide stimulation. Microarray analysis revealed at least 359 cross-validated probe sets (genes) significant at the P < 0.001 level whose expression discriminated among gram-negative-organism-stimulated, gram-positive-organism-stimulated, and unstimulated whole-blood leukocytes. The host inflammatory responses to gram-negative and gram-positive stimuli share some common response elements but also exhibit distinct patterns of cytokine appearance and leukocyte gene expression.

Download Full-text