title: Anti-HIV-1 activity of elafin depends on its nuclear localization and altered innate immune activation in female genital epithelial cells.
abstract: Elafin (E) and its precursor trappin-2 (Tr) are alarm antiproteases with antimicrobial and immunomodulatory activities. Tr and E (Tr/E) have been associated with HIV-1 resistance. We recently showed that Tr/E reduced IL-8 secretion and NF-κB activation in response to a mimic of viral dsRNA and contributed to anti-HIV activity of cervicovaginal lavage fluid (CVL) of HIV-resistant (HIV-R) commercial sex workers (CSWs). Additionally, Tr, and more so E, were found to inhibit attachment/entry and transcytosis of HIV-1 in human endometrial HEC-1A cells, acting through virus or cells. Given their immunomodulatory activity, we hypothesized that Tr/E could exert anti-HIV-1 activity at multiple levels. Here, using tagged and untagged Tr/E proteins, we comparatively evaluated their protease inhibitory, anti-HIV-1, and immunomodulatory activities, and cellular distribution. E appeared to function as an autocrine/paracrine factor in HEC-1A cells, and anti-HIV-1 activity of E depended on its unmodified N-terminus and altered cellular innate activation, but not its antiprotease activity. Specifically, exogenously added N-terminus-unmodified E was able to enter the nucleus and to reduce viral attachment/entry and transcytosis, preferentially affecting R5-HIV-1(ADA), but not X4-HIV-1(IIIB). Further, anti-HIV-1 activity of E was associated with significantly decreased HIV-1-triggered IL-8 release, attenuated NF-κB/p65 nuclear translocation, and significantly modulated mRNA expression of innate sensors TLR3 and RIG-I in HEC-1A cells. Most importantly, we found that elevated Tr/E in CVLs of HIV-R CSWs were associated with lower mRNA levels of TLRs 2, 3, 4 and RIG-I in the genital ECs from this cohort, suggesting a link between Tr/E, HIV-1 resistance and modulated innate viral recognition in the female genital mucosa. Collectively, our data indicate that unmodified N-terminus is critical for intranuclear localization and anti-HIV-1 activity of E. We also propose that E-mediated altered cellular innate activation most likely contributes to the HIV-R phenotype of these subjects.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Anna G
authors.initials: AG
authors.lastname: Drannik
authors.forename: Kakon
authors.initials: K
authors.lastname: Nag
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Yao
authors.forename: Bethany M
authors.initials: BM
authors.lastname: Henrick
authors.forename: T Blake
authors.initials: TB
authors.lastname: Ball
authors.forename: Francis A
authors.initials: FA
authors.lastname: Plummer
authors.forename: Charles
authors.initials: C
authors.lastname: Wachihi
authors.forename: Joshua
authors.initials: J
authors.lastname: Kimani
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Rosenthal
mesh_terms: D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D002584:Cervix Uteri / Q000166:cytology; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance; D053492:Elafin / Q000502:physiology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000821:virology; D005260:Female; D005786:Gene Expression Regulation; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate; D016209:Interleukin-8 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011971:Receptors, Immunologic; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000378:metabolism; D060386:Sex Workers; D051196:Toll-Like Receptor 3 / Q000235:genetics / Q000378:metabolism; D057900:Transcytosis; D014409:Tumor Necrosis Factor-alpha; D053585:Virus Attachment; D053586:Virus Internalization
chemical_list: D053492:Elafin; D016209:Interleukin-8; D016328:NF-kappa B; C506806:PI3 protein, human; D011971:Receptors, Immunologic; D051192:Receptors, Pattern Recognition; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D014409:Tumor Necrosis Factor-alpha; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases