C5a as an Anti-HIV Microbicidal Candidate

Summary

Principal Investigator: PHILIPPE ANDRE GALLAY
Abstract: DESCRIPTION (provided by applicant): We identified a short peptide SWLRDIWDWICEVLSDFK called C5A, which represents a novel class of microbicidal candidates. C5A neutralizes HIV at an nM-M range without apparent cytotoxicity to human cells. C5A corresponds to a small (18 amino acids) N-terminal region (aa 3-20) of the hepatitis C virus (HCV) nonstructural protein 5A (NS5A) (477 amino acids). The sequence of C5A encompasses the region responsible for the anchoring of NS5A into the ER membrane. Importantly, in contrast to C5A (18 aa), full length NS5A (477 aa) does not inhibit HIV infection. We demonstrated that C5A disrupts the HIV membrane, but preserves the integrity of the cellular plasma membrane. The HIV membrane rupture is specific because C5A does not disturb the integrity of the plasma membrane of human cells even when used at high doses and because it does not inhibit the infection of other enveloped viruses such as influenza and vesicular stomatitis viruses. C5A possesses multiple attractive microbicidal properties: it i) blocks HIV infection of primary targets including T cells, macrophages and dendritic cells;ii) exhibits a broad range of antiviral activity against primary HIV isolates, multi-drug resistant HIV isolates, SIV and SHIV;iii) interrupts an ongoing T cell infection;iv) prevents transmigration of HIV through primary human genital epithelial cells;v) blocks infection of dendritic and Langerhans cells ex vivo (skin tissues);vi) prevents HIV transfer from dendritic and Langerhans cells to T cells ex vivo;vii) is extremely efficacious since less than 15 min of exposure suffices for C5A to neutralize HIV;viii) is potent for a considerable length of time both prior to (at least 1 h) and after (at least 1 h) addition of HIV to cells;ix) is potent at a low pH;x) is soluble in water at inhibitory concentrations;xi) is not toxic to commensal Lactobacilli present in the vaginal tract;xii) exhibits minimal adverse changes, inflammation and toxicity in cervicovaginal tissue in vivo;xiii) is not immunogenic;xiv) does not affect cellular signaling pathways;xv) apparently does not allow viral development resistance;xvi) efficiently blocks HIV infectivity when diluted in genital fluids;and most importantly xvii) vaginal application of C5A offers complete protection against a vaginal viral challenge in the humanized BLT mouse HIV transmission model. Thus, C5A represents the prototype of a new generation of microbicidal agents that may have promise for HIV prevention. In this application, we would like to follow up on these exciting data by fully exploring the possibility that C5A represents a true microbicidal candidate. In the first aim of this application, we propose to conduct a series of experiments aimed at identifying the component of the viral membrane to which C5A binds because the C5A ligand, which resides in the membrane of HIV, represents a potential target for the development of a novel class of anti-HIV therapies with an unusual mechanism of antiviral action. Interestingly, we obtained several lines of evidence that the sphingolipid called dihydrosphingomyelin (DHSM) represents the main target of C5A in the HIV membrane: i) DHSM, incorporated into HIV particles, is specifically pulled down by C5A beads;ii) C5A binds directly to adsorbed DHSM;iii) C5A ruptures liposomes constituted with DHSM;and most importantly iv) pre-incubation of C5A with soluble DHSM prevents HIV rupture by C5A and preserves HIV infectivity. The amphipathic property of C5A, the identity of DHSM as the C5A target in the HIV membrane, and the specific C5A rupture of DHSM-containing liposomes or HIV particles, provide the first hint for the antiviral mechanism of C5A action: C5A, which encompasses the N-terminal region responsible for the anchoring of NS5A into the ER membrane, by binding to DHSM enriched within the HIV membrane, disturbs the integrity of the viral membrane due to its amphipathic nature. In the second aim of this application, we propose to optimize the in vitro potency and in vivo safety of C5A by creating a second generation of peptides using the parental C5A peptide as the archetype. All newly synthesized peptides will be tested in genital fluids for their in vitro microbicidal properties. The most potent compounds among the newly synthesized peptides will be selected. Remarkably, we found that acetylation, amidation and glycosylation of C5A greatly enhanced C5A anti-HIV activities in genital fluids. This is the proof-of-concept for the feasibility of identifying C5A derivates with enhanced anti-HIV activities. In the third aim, the most potent C5A derivates will be assessed for safety and efficacy in the HIV vaginal transmission BLT mouse model. Kinetic administration studies will be executed to determine how long before and/or after the viral challenge C5A precludes HIV transmission. In the fourth aim, safety and efficacy pilot studies will be conducted in another SIV/HIV vaginal transmission animal model: the progesterone-treated macaque model. If similar protective results were obtained using the two transmission models, it would further validate the use of these models for the screening of microbicidal candidates. In addition, protective results would provide proof-of-concept of the usefulness of topically applied microbicides, such as C5A, to prevent genital HIV transmission.
Funding Period: 2010-06-01 - 2015-05-31
more information: NIH RePORT

Top Publications

  1. pmc A virocidal amphipathic {alpha}-helical peptide that inhibits hepatitis C virus infection in vitro
    Guofeng Cheng
    Departments of Molecular and Experimental Medicine, Chemistry, and Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
    Proc Natl Acad Sci U S A 105:3088-93. 2008
  2. pmc Correlation of naturally occurring HIV-1 resistance to DEB025 with capsid amino acid polymorphisms
    Philippe A Gallay
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla 92037, California, USA
    Viruses 5:981-97. 2013
  3. pmc Profile of alisporivir and its potential in the treatment of hepatitis C
    Philippe A Gallay
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA, USA
    Drug Des Devel Ther 7:105-15. 2013
  4. pmc Cyclophilin inhibitors: an emerging class of therapeutics for the treatment of chronic hepatitis C infection
    Sam Hopkins
    Autoimmune Technologies, LLC, 1010 Common Street, Suite 1705, New Orleans, LA 70112, USA
    Viruses 4:2558-77. 2012
  5. pmc Multiple mutations in hepatitis C virus NS5A domain II are required to confer a significant level of resistance to alisporivir
    Jose A Garcia-Rivera
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, USA
    Antimicrob Agents Chemother 56:5113-21. 2012
  6. pmc The cyclophilin inhibitor SCY-635 disrupts hepatitis C virus NS5A-cyclophilin A complexes
    Sam Hopkins
    SCYNEXIS, Inc, Research Triangle Park, North Carolina, USA
    Antimicrob Agents Chemother 56:3888-97. 2012
  7. pmc Sublimable C5A delivery provides sustained and prolonged anti-HIV microbicidal activities
    RICHARD MASKIEWICZ
    Department of Pharmaceutical Sciences, School of Pharmacy, Loma Linda University, Loma Linda, California, USA
    Antimicrob Agents Chemother 56:3336-43. 2012
  8. pmc PD 404,182 is a virocidal small molecule that disrupts hepatitis C virus and human immunodeficiency virus
    Ana Maria Chamoun
    Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas 77843, USA
    Antimicrob Agents Chemother 56:672-81. 2012
  9. pmc One percent tenofovir applied topically to humanized BLT mice and used according to the CAPRISA 004 experimental design demonstrates partial protection from vaginal HIV infection, validating the BLT model for evaluation of new microbicide candidates
    Paul W Denton
    Division of Infectious Diseases, Department of Internal Medicine, Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina 27510, USA
    J Virol 85:7582-93. 2011
  10. pmc HSV neutralization by the microbicidal candidate C5A
    Lot de Witte
    The Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
    PLoS ONE 6:e18917. 2011

Detail Information

Publications12

  1. pmc A virocidal amphipathic {alpha}-helical peptide that inhibits hepatitis C virus infection in vitro
    Guofeng Cheng
    Departments of Molecular and Experimental Medicine, Chemistry, and Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
    Proc Natl Acad Sci U S A 105:3088-93. 2008
    ..These results suggest a model in which C5A destabilizes viral membranes based on their lipid composition, offering a unique therapeutic approach to HCV and other viral infections...
  2. pmc Correlation of naturally occurring HIV-1 resistance to DEB025 with capsid amino acid polymorphisms
    Philippe A Gallay
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla 92037, California, USA
    Viruses 5:981-97. 2013
    ..The resistant HIV-1 isolates thus are CypA-independent...
  3. pmc Profile of alisporivir and its potential in the treatment of hepatitis C
    Philippe A Gallay
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA, USA
    Drug Des Devel Ther 7:105-15. 2013
    ..In conclusion, alisporivir represents an attractive candidate component of future interferon-free regimens...
  4. pmc Cyclophilin inhibitors: an emerging class of therapeutics for the treatment of chronic hepatitis C infection
    Sam Hopkins
    Autoimmune Technologies, LLC, 1010 Common Street, Suite 1705, New Orleans, LA 70112, USA
    Viruses 4:2558-77. 2012
    ....
  5. pmc Multiple mutations in hepatitis C virus NS5A domain II are required to confer a significant level of resistance to alisporivir
    Jose A Garcia-Rivera
    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, USA
    Antimicrob Agents Chemother 56:5113-21. 2012
    ..This in accordance with in vivo data that suggest that alisporivir is associated with a low potential for development of viral resistance...
  6. pmc The cyclophilin inhibitor SCY-635 disrupts hepatitis C virus NS5A-cyclophilin A complexes
    Sam Hopkins
    SCYNEXIS, Inc, Research Triangle Park, North Carolina, USA
    Antimicrob Agents Chemother 56:3888-97. 2012
    ..These specific mutations in NS5A eliminate the dependence of HCV RNA replication on the expression of host CypA...
  7. pmc Sublimable C5A delivery provides sustained and prolonged anti-HIV microbicidal activities
    RICHARD MASKIEWICZ
    Department of Pharmaceutical Sciences, School of Pharmacy, Loma Linda University, Loma Linda, California, USA
    Antimicrob Agents Chemother 56:3336-43. 2012
    ....
  8. pmc PD 404,182 is a virocidal small molecule that disrupts hepatitis C virus and human immunodeficiency virus
    Ana Maria Chamoun
    Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas 77843, USA
    Antimicrob Agents Chemother 56:672-81. 2012
    ..These qualities make PD 404,182 an attractive candidate anti-HIV microbicide for the prevention of HIV transmission through sexual intercourse...
  9. pmc One percent tenofovir applied topically to humanized BLT mice and used according to the CAPRISA 004 experimental design demonstrates partial protection from vaginal HIV infection, validating the BLT model for evaluation of new microbicide candidates
    Paul W Denton
    Division of Infectious Diseases, Department of Internal Medicine, Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina 27510, USA
    J Virol 85:7582-93. 2011
    ..Our results demonstrate that these effective topical inhibitors have excellent potential to prevent vaginal HIV transmission in humans...
  10. pmc HSV neutralization by the microbicidal candidate C5A
    Lot de Witte
    The Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
    PLoS ONE 6:e18917. 2011
    ..In conclusion, this study demonstrates that C5A represents a multipurpose microbicide candidate, which neutralizes both HIV-1 and HSV, and which may interfere with HIV-1 transmission through the genital epithelium...
  11. pmc Hepatitis C virus NS5A anchor peptide disrupts human immunodeficiency virus
    Michael D Bobardt
    Departments of Immunology and Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
    Proc Natl Acad Sci U S A 105:5525-30. 2008
    ....
  12. pmc Evaluation of PD 404,182 as an anti-HIV and anti-herpes simplex virus microbicide
    Ana M Chamoun-Emanuelli
    Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas, USA
    Antimicrob Agents Chemother 58:687-97. 2014
    ..The ability of PD to inactivate both HIV-1 and HSV, combined with its low toxicity and high stability, warrants additional studies for the evaluation of PD's microbicidal candidacy in animals and humans. ..

Research Grants31

  1. Endothelial Injury and Repair: CardioPulmonary Vascular Biology COBRE
    SHARON IRENE SMITH ROUNDS; Fiscal Year: 2013
    ..abstract_text> ..
  2. Pacific NorthWest Regional Center of Excellence (PNWRCE)
    Jay A Nelson; Fiscal Year: 2013
    ..pseudomallei host pathogen response during both the septicemic as well as the intracellular phases of the disease. ..
  3. LIAI Epitope Validation Center: Characterization of Allergen specific T Cells
    ALESSANDRO D SETTE; Fiscal Year: 2013
    ..abstract_text> ..
  4. Center for the Study of Innate Immunity to HCV Infection
    Michael J Gale; Fiscal Year: 2013
    ..Our studies are linked with the U19 Clinical Core, and Projects 2 and 3 to feature translational approaches aimed at defining the virus-host interface that controls hepatic innate immunity and HCV infection. ..