Retrocyclin: A primate peptide that protects cells from infection by T- and M-tropic strains of HIV-1

Cole, Alexander M.; Hong, Teresa; Boo, Lee Ming; Nguyen, Tam; Zhao, Chengquan; Bristol, Gregory; Zack, Jerome A.; Waring, Alan J.; Yang, Otto O.; Lehrer, Robert I.

doi:10.1073/pnas.052706399

Cited by 270 publications

(325 citation statements)

References 28 publications

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“…The theta defensin pseudogene has been found in human bone marrow, but the peptide has not been identified in humans. 34 Of the four human beta defensins, only HBD-1 is constitutively expressed in the human epidermis and sweat gland ducts. 35-37 HBD 2-3 are inducible by bacterial infection, cytokines IL-1α, IL-1β, TNF-α, and differentiation.…”

Section: Defensinsmentioning

confidence: 99%

Antimicrobial Peptides, Skin Infections, and Atopic Dermatitis

Hata

Gallo²

2008

Seminars in Cutaneous Medicine and Surgery

106

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The innate immune system evolved over 2 billion years ago to first recognize pathogens then eradicate them. Several distinct defects in this ancient but rapidly responsive element of human immune defense account for the increased incidence of skin infections in atopics. These defects include abnormalities in the physical barrier of the epidermis, alterations in microbial pattern recognition receptors such as toll receptors and NOD, and a diminished capacity to increase the expression of antimicrobial peptides during inflammation. Several antimicrobial peptides are affected including; cathelicidin, HBD-2, and HBD-3, which are lower in lesional skin of atopics compared to other inflammatory skin diseases, and dermcidin, which is decreased in sweat. Other defects in the immune defense barrier of atopics include a relative deficiency in plasmacytoid dendritic cells. In the future, understanding the cause of these defects may allow therapeutic intervention to reduce the incidence of infection in atopic individuals and potentially decrease the severity of this disorder.

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Section: Defensinsmentioning

confidence: 99%

Antimicrobial Peptides, Skin Infections, and Atopic Dermatitis

Hata

Gallo²

2008

Seminars in Cutaneous Medicine and Surgery

106

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“…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 structure.…”

Section: Introductionmentioning

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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“…α-and β-defensins are found in humans, while θ -defensin is not, although a human orthologue of this defensin has been described [44]. The defensins are cysteine-rich peptides that have six cysteine residues with three disulphide bonds ( Table 1).…”

Section: Defensinsmentioning

confidence: 99%

Innate defences against methicillin‐resistant Staphylococcus aureus (MRSA) infection

Komatsuzawa

Ouhara

Yamada

et al. 2005

The Journal of Pathology

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The innate immune system is the primary defence against bacterial infection. Among the factors involved in innate defence, anti-microbial peptides produced by humans have recently attracted attention due to their relevance to some diseases and also to the development of new chemotherapeutic agents. Staphylococcus aureus is one of the major human pathogens, causing a variety of infections from suppurative disease to food poisoning. Methicillin-resistant S. aureus (MRSA) is a clinical problem and with the recent emergence of a vancomycin-resistant strain, this will pose serious problems in the near future. In investigating the molecular biology of S. aureus infections to develop new chemotherapeutic agents against MRSA infections, knowledge of the interaction of innate anti-microbial peptides with S. aureus is important. In vitro and in vivo experiments demonstrate that exposure of S. aureus to host cells can induce the anti-microbial peptides β-defensin-2 (hBD2), hBD3, and LL37/CAP18. The induction level of these peptides differs among strains, as does the susceptibility of the strains, with MRSA strains exhibiting lower susceptibility. In summary, the susceptibility of S. aureus strains, including MRSA strains, to components of the innate immune system varies, with the MRSA strains showing more resistance to both innate immune factors and chemotherapeutic agents.

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Retrocyclin: A primate peptide that protects cells from infection by T- and M-tropic strains of HIV-1

Cited by 270 publications

References 28 publications

Antimicrobial Peptides, Skin Infections, and Atopic Dermatitis

Antimicrobial Peptides, Skin Infections, and Atopic Dermatitis

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

Innate defences against methicillin‐resistant Staphylococcus aureus (MRSA) infection

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