CC Chemokines Induce Neutrophils to Chemotaxis, Degranulation, and α-Defensin Release

Jan, Ming‐Shiou; Huang, Yi-Hsien; Shieh, Biehuoy; Teng, Ru-Hsiu; Yan, Yao-Pei; Lee, Yuan‐Ti; Liao, Ko-Kaung; Li, Ching

doi:10.1097/01.qai.0000188336.94090.14

Cited by 36 publications

(33 citation statements)

References 37 publications

(55 reference statements)

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“…Interestingly, a recent work suggests that ␣-defensins can trigger the release of LTB 4 from alveolar macrophages (19), indicating that ␣-defensins and LTB 4 , through positive feedback loops, can influence each other's formation and release. Even more recently, CC chemokines (RANTES, MIP-1␣, and MIP-1␤) were reported to induce PMN degranulation and ␣-defensin release (39). Considering that LTB 4 also induces the release of human MIP-1␤ under in vivo conditions (29) and that ␤-chemokines trigger the release of ␣-defensins, additive and possibly synergistic effects between LTB 4 and CC-chemokines on ␣-defensin release are expected.…”

Section: Discussionmentioning

confidence: 99%

Leukotriene B4 Triggers the In Vitro and In Vivo Release of Potent Antimicrobial Agents

Flamand

Tremblay

Borgeat

2007

The Journal of Immunology

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Leukotriene B4 (LTB4) is a bioactive lipid derived from the metabolism of arachidonic acid. Mainly produced by polymorphonuclear leukocytes (PMN) and macrophages, LTB4 triggers several functional responses important in host defense, including the secretion of lysosomal enzymes, the activation of NADPH oxidase activity, NO formation, and phagocytosis. We report that LTB4, but not structural analogs thereof, stimulates primed human PMN to release molecules having potent antimicrobial activities. Exposure of bacteria (Escherichia coli and Staphylococcus aureus) or viruses (herpes simplex virus type 1 and HIV type 1) to supernatants of LTB4-activated PMN lead to ≥90% reduction in infectivity. ELISA and mass spectroscopy analysis of proteins released from LTB4-activated PMN have identified several antimicrobial proteins, including α-defensins, cathepsin G, elastase, lysozyme C, and LL-37, that are likely to participate in the killing of microorganisms. In addition to these in vitro observations, i.v. injections of LTB4 (50 μg/kg) to monkeys led to an increase in α-defensin plasmatic levels and enhanced ex vivo antimicrobial activities of plasma. These results demonstrate the ability of LTB4 to cause the release of potent antimicrobial agents from PMN in vitro as well as in vivo and add further support to the important role of LTB4 in host defense.

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Section: Discussionmentioning

confidence: 99%

Leukotriene B4 Triggers the In Vitro and In Vivo Release of Potent Antimicrobial Agents

Flamand

Tremblay

Borgeat

2007

The Journal of Immunology

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“…45 Neutrophils release massive quantities of ␣-defensins upon degranulation in response to cytokines or, as recently reported, CC chemokines. 46 Recent studies have reported elevated levels of CC chemokines in the genital tracts of women who are exposed to HIV-1 and yet remain uninfected. 47 Furthermore, ␣-defensins may play an important role as natural antagonists of HIV-1 entry at the intestinal mucosal level.…”

Section: Discussionmentioning

confidence: 99%

α-defensins block the early steps of HIV-1 infection: interference with the binding of gp120 to CD4

Furci¹,

Sironi²,

Tolazzi³

et al. 2006

Blood

102

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␣-defensins are antibiotic peptides that act as natural inhibitors of HIV-1 infection. However, the mechanisms of such inhibition are still unclear. Here we demonstrate that ␣-defensins block the earliest steps in the viral infectious cycle, as documented using an HIV-1 envelopemediated cell-fusion assay. A broad-spectrum inhibitory activity was observed on primary and laboratory-adapted HIV-1 isolates irrespective of their coreceptor specificity and genetic subtype. A primary mechanism of such inhibition was identified as the ability of ␣-defensins to bind specifically both to the primary HIV-1 cellular receptor, CD4, and to the viral envelope glycoprotein, gp120. Moreover, treatment of CD4 ؉ T cells with ␣-defensins caused a dramatic downmodulation of CD4 expression. By monoclonal antibody competition, the regions of interaction with ␣-defensins were mapped to the D1 domain of CD4 and to a surface contiguous to the CD4-and coreceptorbinding sites of gp120. Consistent with these findings, ␣-defensins inhibited the binding of gp120 to CD4. These data demonstrate that ␣-defensins specifically block the initial phase of the HIV infectious cycle and modulate the expression of CD4, a critical receptor in the physiology of T-cell activation. IntroductionEvidence suggests that a concerted action of innate and adaptive immune responses is essential for the effective containment and, ultimately, the clearance of invading microorganisms. 1 The innate immune system is phylogenetically more archaic and constitutes the first line of antimicrobial defense, characterized by a rapid response time; however, it is limited in its target specificity. By contrast, the adaptive immune system has evolved refined molecular devices for the recognition of a wide variety of specific epitopes, but a lag time is required for its functional activation. Once activated, most of the cells involved in both innate and cognate immune responses secrete soluble factors, including cytokines, chemokines, antibiotic peptides, and others, which can directly antagonize infectious microorganisms and/or contribute to the recruitment and activation of other immune cells, thereby amplifying the cascade of defense mechanisms and bolstering their effectiveness. 2,3 In HIV infection, various host-derived soluble factors with antiviral activity have been described, which act by both specific and nonspecific mechanisms. These include chemokines such as RANTES, MIP-1␣, and MIP-1␤ 4 ; cytokines such as the interferons, IL-10, IL-13, IL-16, transforming growth factor-␤, and others 5 ; as well as, more recently, defensins. [6][7][8][9] Defensins are natural antibiotic peptides that play an important role in innate immune responses by acting as broad-spectrum antibacterial, antifungal, and antiviral effector molecules 10 as well as by enhancing certain adaptive immune responses. 11 ␣-defensins 1 to 3 are 3-to 4-kDa cationic peptides (29 to 30 amino acids [aa]) characterized by a conserved 6-cysteine motif, with 3 disulfide bonds that impose a characteristic ␤-sheet ...

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“…It promotes leukocyte recruitment and activation (41). RANTES activates human neutrophil to release antimicrobial peptide ␣-defensins and promote neutrophil phagocytic capacity (42). These effects likely contribute to its host defense against P. aeruginosa infection.…”

Section: Figurementioning

confidence: 99%

A Role of Toll-IL-1 Receptor Domain-Containing Adaptor-Inducing IFN-β in the Host Response to Pseudomonas aeruginosa Lung Infection in Mice

Power¹,

Li²,

Yamamoto

et al. 2007

The Journal of Immunology

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Toll-IL-1R domain-containing adaptor-inducing IFN-β (TRIF) is an adaptor molecule that mediates a distinct TLR signaling pathway. Roles of TRIF in the host defense have been primarily associated with virus infections owing to the induction of IFN-αβ. In this study, we investigated a role of TRIF in Pseudomonas aeruginosa infection. In vitro, TRIF-deficient mouse alveolar and peritoneal macrophages showed a complete inhibition of RANTES (CCL5) production, severely impaired TNF and KC (CXCL1) production, and reduced NF-κB activation in response to P. aeruginosa stimulation. In vivo, TRIF-deficient mice showed a complete inhibition of RANTES production, a severely impaired TNF and KC production, and an efficient MIP-2 and IL-1β production in the lung following P. aeruginosa infection. This outcome was associated with a delayed recruitment of neutrophils into the airways. These results suggest that TRIF mediates a distinct cytokine/chemokine profile in response to P. aeruginosa infection. P. aeruginosa-induced RANTES production is completely dependent on TRIF pathway in mice. Importantly, TRIF deficiency leads to impaired clearance of P. aeruginosa from the lung during the initial 24–48 h of infection. Thus, TRIF represents a novel mechanism involved in the development of host response to P. aeruginosa infection.

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CC Chemokines Induce Neutrophils to Chemotaxis, Degranulation, and α-Defensin Release

Cited by 36 publications

References 37 publications

Leukotriene B4 Triggers the In Vitro and In Vivo Release of Potent Antimicrobial Agents

Leukotriene B4 Triggers the In Vitro and In Vivo Release of Potent Antimicrobial Agents

α-defensins block the early steps of HIV-1 infection: interference with the binding of gp120 to CD4

A Role of Toll-IL-1 Receptor Domain-Containing Adaptor-Inducing IFN-β in the Host Response to Pseudomonas aeruginosa Lung Infection in Mice

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