RESUMEN DE LOS AVANCES EN INVESTIGACIÓN BÁSICA

RESUMEN DE LOS AVANCES EN INVESTIGACIÓN BÁSICA
Observamos una fuerte transactivación del promotor de CXCL12 tanto en linfocitos como en células Jurkatt por la expresión transitoria de la proteína Tax. De acuerdo con estos resultados, la expresión tanto de mRNA y como de proteína se encontró en una línea celular infectada con HTLV-I (MT2) por RT-PCR, citometría de flujo e inmunohistoquimica. CXCL12 también se detecto en sobrenadantes de cultivo de células MT2 por ELISA. Las biopsias de pacientes infectados con HTLV-I fueron positivas para CXCL12 en linfocitos CD3 positivos mientras que la quimiocina no fue detectada en nódulos linfoides de pacientes no infectados con HTLV-I. La proteína Tax del HTLV-I induce la expresión de SDF-1/CXCL12 a nivel transcriptional Encontramos producción aberrante de SDF-1/CXCL12 en líneas infectadas con HTLV-I y biopsias de linfomas HTLV-I. Este incremento en la expresión de SDF-1/CXCL12 por Tax podria contribuir a la patogenesis de HTLV-I a través del reclutamiento de linfocitos hacia zonas infectadas por HTLV-I aumentando de esta manera la propagación del HTLV-I. I.P. Pepe Alcami Unidad de Inmunopatologia del SIDA Instituto de SaIud Carlos III

Nuevos mecanismos de entrada Latencia Reactivación Inmunologia
I.P. Virologia Factores celulares Nuevos mecanismos de entrada Latencia Reactivación Inmunologia Celulas T reguladoras Vacunas Casos especiales Titulo: Interacción virus-hospedador Comentario: Para comprender la interacción virus-hospedador es necesario situarse en un doble contexto: El microcosmos de interacción entre una partícula vírica y una célula que supone el estudio de los mecanismos de adaptación celular del virus. b. El macrocosmos que representa la interacción entre poblaciones virales con una dinámica de cuasiespecies y un sistema inmunológico que es a la vez diana de la infección y principal defensa frente a la misma. Esto supone estudiar los efectores de respuesta antiviral y los mecanismos de escape viral. CD4

CICLO BIOLOGICO DEL VIH
CXCR4/CCR5 CD4 Actin filaments Reverse transcription complex (RTC) Microtubular network Linear dscDNA Nuclear import Integration Cellular DNA Nuclear membrane Circular non-integrated DNA Provirus Post-integration latency Pre-integration latency Full- and short-length dscDNA Proviral DNA synthesis Reverse transcriptase Viral RNA Integrase Pre-integration complex (PIC) Matrix protein Nuclear pore complex (NPC) NF-B, Sp1, NF-AT Transcription Tat Efficient elongation Rev Unspliced mRNA Multiple spliced mRNA Structural proteins Regulatory proteins Ribosomal traslation Genomic RNA Assembly Budding Maturation gp120/gp41 Vpr

CICLO BIOLOGICO DEL VIH
CXCR4/CCR5 CD4 Actin filaments Reverse transcription complex (RTC) Microtubular network Linear dscDNA Nuclear import Integration Cellular DNA Nuclear membrane Circular non-integrated DNA Provirus Post-integration latency Pre-integration latency Full- and short-length dscDNA Proviral DNA synthesis Reverse transcriptase Viral RNA Integrase Pre-integration complex (PIC) Matrix protein Nuclear pore complex (NPC) NF-B, Sp1, NF-AT Transcription Tat Efficient elongation Rev Unspliced mRNA Multiple spliced mRNA Structural proteins Regulatory proteins Ribosomal traslation Genomic RNA Assembly Budding Maturation gp120/gp41 Vpr Membrana celular Barrera de actina APOBEC Niveles de nucleótidos Membrana nuclear EMERIN LEDGF Transcripcion Nucleosoma

FACTORES QUE FAVORECEN LA INTEGRACIÓN
EMERIN, LEDGF The LEM domain proteins emerin and LAP2alpha are dispensable for human immunodeficiency virus type 1 and murine leukemia virus infections. Mulky A, Cohen TV, Kozlov SV, Korbei B, Foisner R, Stewart CL, KewalRamani VN. J Virol Jun;82(12): Epub 2008 Apr 9. Wild-type levels of human immunodeficiency virus type 1 infectivity in the absence of cellular emerin protein. Shun MC, Daigle JE, Vandegraaff N, Engelman A. J Virol Jan;81(1): Epub 2006 Oct 11. Related Articles Free article in PMC | at journal site Virology: HIV goes nuclear. Li M, Craigie R. Nature Jun 1;441(7093): No abstract available. The inner-nuclear-envelope protein emerin regulates HIV-1 infectivity. Jacque JM, Stevenson M. Nature Jun 1;441(7093): Epub 2006 May 7. When we describe HIV infection very often we talk with warlike terms: words as fight, strugle, challenge, war, battle...are part of our vocabulary and actually this reflects a reality and during this Conference it has been frequently said that AIDS is a war against humanity. These terms reminded me the Charles Dicken´s novel “A Tale of two cities” and I will use this image to summarize the contribution of Basic Science Track to the Conference. We can consider the city of the virus and the city of the immune system. In summary what we try to do as scientists is to understand the two players of this battle: the HIV and the immune system. On one hand we try to understand how HIV adapts to the cell and the mechanisms involved in cell killing. On the other hand we study how the immune system fights against the virus and why the immune response is not sufficient to control viral replication and achieve virus eradication.

FACTORES QUE FAVORECEN LA INTEGRACIÓN
EMERIN, LEDGF Affinities between the binding partners of the HIV-1 integrase dimer/lens epithelium derived growth factor (in dimer/LEDGF) complex. Tsiang M, Jones GS, Hung M, Mukund S, Han B, Liu X, Babaoglu K, Lansdon E, Chen X, Todd J, Cai T, Pagratis N, Sakowicz R, Geleziunas R. J Biol Chem Sep 28. [Epub ahead of print] Barrier-to-autointegration factor proteome reveals chromatin-regulatory partners. Montes de Oca R, Shoemaker CJ, Gucek M, Cole RN, Wilson KL. PLoS One Sep 16;4(9):e7050.

Tetherin inhibits retrovirus release and is antagonized by HIV-1 Vpu.
Neil SJ, Zang T, Bieniasz PD. Nature Jan 24;451(7177): Epub 2008 Jan 16. PMID: [PubMed - indexed for MEDLINE] Related Articles

HIV-1 accessory protein Vpu internalizes cell-surface BST-2/tetherin through transmembrane interactions leading to lysosomes. Iwabu Y, Fujita H, Kinomoto M, Kaneko K, Ishizaka Y, Tanaka Y, Sata T, Tokunaga K. J Biol Chem Oct 16. [Epub ahead of print] 2: Effect of Calcium Modulating Cyclophilin Ligand (CAML) on HIV-1 particle release and Tetherin cell-surface expression. Bego MG, Dubé M, Mercier J, Cohen EA. J Virol Sep 30. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] Related Articles 3: Antagonism and intracellular sequestration of human tetherin by the HIV-2 envelope glycoprotein. Le Tortorec A, Neil SJ. J Virol Sep 9. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 4: The formation of cysteine-linked dimers of BST-2/tetherin is important for inhibition of HIV-1 virus release but not for sensitivity to Vpu. Andrew AJ, Miyagi E, Kao S, Strebel K. Retrovirology Sep 8;6:80. PMID: [PubMed - indexed for MEDLINE] Related Articles Free article in PMC | at journal site 5: HIV-1 Vpu neutralizes the antiviral factor Tetherin/BST-2 by binding it and directing its beta-TrCP2-dependent degradation. Mangeat B, Gers-Huber G, Lehmann M, Zufferey M, Luban J, Piguet V. PLoS Pathog Sep;5(9):e Epub 2009 Sep 4. PMID: [PubMed - in process] 6: Evolutionary Trajectories of Primate Genes Involved in HIV Pathogenesis. Ortiz M, Guex N, Patin E, Martin O, Xenarios I, Ciuffi A, Quintana-Murci L, Telenti A. Mol Biol Evol Sep 2. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 7: SIMIAN IMMUNODEFICIENCY VIRUS FROM AFRICAN GREEN MONKEYS (SIVAGM) DOES NOT ANTAGONIZE ENDOGENOUS LEVELS OF AFRICAN GREEN MONKEY TETHERIN/BST-2. Lim E, Emerman M. J Virol Sep 2. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 8: Molecular mechanism of BST2/tetherin downregulation by K5/MIR2 of Kaposi's sarcoma-associated herpesvirus. Mansouri M, Viswanathan K, Douglas JL, Hines J, Gustin J, Moses AV, Früh K. J Virol Oct;83(19): Epub 2009 Jul 15. PMID: [PubMed - indexed for MEDLINE] 9: A New World primate deficient in tetherin-mediated restriction of human immunodeficiency virus type 1. Wong SK, Connole M, Sullivan JS, Choe H, Carville A, Farzan M. J Virol Sep;83(17): Epub 2009 Jun 24. PMID: [PubMed - indexed for MEDLINE] 10: Vpu directs the degradation of the human immunodeficiency virus restriction factor BST-2/Tetherin via a {beta}TrCP-dependent mechanism. Douglas JL, Viswanathan K, McCarroll MN, Gustin JK, Früh K, Moses AV. J Virol Aug;83(16): Epub 2009 Jun 10. PMID: [PubMed - indexed for MEDLINE] 11: Nef proteins from simian immunodeficiency viruses are tetherin antagonists. Zhang F, Wilson SJ, Landford WC, Virgen B, Gregory D, Johnson MC, Munch J, Kirchhoff F, Bieniasz PD, Hatziioannou T. Cell Host Microbe Jul 23;6(1): Epub 2009 Jun 4. PMID: [PubMed - indexed for MEDLINE] 12: Comparative study on the effect of human BST-2/Tetherin on HIV-1 release in cells of various species. Sato K, Yamamoto SP, Misawa N, Yoshida T, Miyazawa T, Koyanagi Y. Retrovirology Jun 2;6:53. PMID: [PubMed - indexed for MEDLINE] 13: Vpu antagonizes BST-2-mediated restriction of HIV-1 release via beta-TrCP and endo-lysosomal trafficking. Mitchell RS, Katsura C, Skasko MA, Fitzpatrick K, Lau D, Ruiz A, Stephens EB, Margottin-Goguet F, Benarous R, Guatelli JC. PLoS Pathog May;5(5):e Epub 2009 May 29. PMID: [PubMed - indexed for MEDLINE] 14: The transmembrane domain of BST-2 determines its sensitivity to down-modulation by human immunodeficiency virus type 1 Vpu. Rong L, Zhang J, Lu J, Pan Q, Lorgeoux RP, Aloysius C, Guo F, Liu SL, Wainberg MA, Liang C. J Virol Aug;83(15): Epub 2009 May 27. PMID: [PubMed - indexed for MEDLINE] 15: Mutation of a single residue renders human tetherin resistant to HIV-1 Vpu-mediated depletion. Gupta RK, Hué S, Schaller T, Verschoor E, Pillay D, Towers GJ. PLoS Pathog May;5(5):e Epub 2009 May 22. PMID: [PubMed - indexed for MEDLINE] 16: Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2. Jia B, Serra-Moreno R, Neidermyer W, Rahmberg A, Mackey J, Fofana IB, Johnson WE, Westmoreland S, Evans DT. PLoS Pathog May;5(5):e Epub 2009 May 15. PMID: [PubMed - indexed for MEDLINE] 17: HIV-1 antagonism of CD317 is species specific and involves Vpu-mediated proteasomal degradation of the restriction factor. Goffinet C, Allespach I, Homann S, Tervo HM, Habermann A, Rupp D, Oberbremer L, Kern C, Tibroni N, Welsch S, Krijnse-Locker J, Banting G, Kräusslich HG, Fackler OT, Keppler OT. Cell Host Microbe Mar 19;5(3): PMID: [PubMed - indexed for MEDLINE] 18: Suppression of Tetherin-restricting activity upon human immunodeficiency virus type 1 particle release correlates with localization of Vpu in the trans-Golgi network. Dubé M, Roy BB, Guiot-Guillain P, Mercier J, Binette J, Leung G, Cohen EA. J Virol May;83(9): Epub 2009 Feb 25. PMID: [PubMed - indexed for MEDLINE] 19: Species-specific activity of HIV-1 Vpu and positive selection of tetherin transmembrane domain variants. McNatt MW, Zang T, Hatziioannou T, Bartlett M, Fofana IB, Johnson WE, Neil SJ, Bieniasz PD. PLoS Pathog Feb;5(2):e Epub 2009 Feb 13. PMID: [PubMed - indexed for MEDLINE] 20: Vpu enhances HIV-1 virus release in the absence of Bst-2 cell surface down-modulation and intracellular depletion. Miyagi E, Andrew AJ, Kao S, Strebel K. Proc Natl Acad Sci U S A Feb 24;106(8): Epub 2009 Feb 5. PMID: [PubMed - indexed for MEDLINE] HIV-1 accessory protein Vpu internalizes cell-surface BST-2/tetherin through transmembrane interactions leading to lysosomes. Iwabu Y, Fujita H, Kinomoto M, Kaneko K, Ishizaka Y, Tanaka Y, Sata T, Tokunaga K. J Biol Chem Oct 16. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] Related Articles Free article at journal site 2: Effect of Calcium Modulating Cyclophilin Ligand (CAML) on HIV-1 particle release and Tetherin cell-surface expression. Bego MG, Dubé M, Mercier J, Cohen EA. J Virol Sep 30. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] Related Articles 3: Antagonism and intracellular sequestration of human tetherin by the HIV-2 envelope glycoprotein. Le Tortorec A, Neil SJ. J Virol Sep 9. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 4: The formation of cysteine-linked dimers of BST-2/tetherin is important for inhibition of HIV-1 virus release but not for sensitivity to Vpu. Andrew AJ, Miyagi E, Kao S, Strebel K. Retrovirology Sep 8;6:80. PMID: [PubMed - indexed for MEDLINE] Related Articles Free article in PMC | at journal site 5: HIV-1 Vpu neutralizes the antiviral factor Tetherin/BST-2 by binding it and directing its beta-TrCP2-dependent degradation. Mangeat B, Gers-Huber G, Lehmann M, Zufferey M, Luban J, Piguet V. PLoS Pathog Sep;5(9):e Epub 2009 Sep 4. PMID: [PubMed - in process] 6: Evolutionary Trajectories of Primate Genes Involved in HIV Pathogenesis. Ortiz M, Guex N, Patin E, Martin O, Xenarios I, Ciuffi A, Quintana-Murci L, Telenti A. Mol Biol Evol Sep 2. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 7: SIMIAN IMMUNODEFICIENCY VIRUS FROM AFRICAN GREEN MONKEYS (SIVAGM) DOES NOT ANTAGONIZE ENDOGENOUS LEVELS OF AFRICAN GREEN MONKEY TETHERIN/BST-2. Lim E, Emerman M. J Virol Sep 2. [Epub ahead of print] PMID: [PubMed - as supplied by publisher] 8: Molecular mechanism of BST2/tetherin downregulation by K5/MIR2 of Kaposi's sarcoma-associated herpesvirus. Mansouri M, Viswanathan K, Douglas JL, Hines J, Gustin J, Moses AV, Früh K. J Virol Oct;83(19): Epub 2009 Jul 15. PMID: [PubMed - indexed for MEDLINE] 9: A New World primate deficient in tetherin-mediated restriction of human immunodeficiency virus type 1. Wong SK, Connole M, Sullivan JS, Choe H, Carville A, Farzan M. J Virol Sep;83(17): Epub 2009 Jun 24. PMID: [PubMed - indexed for MEDLINE] 10: Vpu directs the degradation of the human immunodeficiency virus restriction factor BST-2/Tetherin via a {beta}TrCP-dependent mechanism. Douglas JL, Viswanathan K, McCarroll MN, Gustin JK, Früh K, Moses AV. J Virol Aug;83(16): Epub 2009 Jun 10. PMID: [PubMed - indexed for MEDLINE] 11: Nef proteins from simian immunodeficiency viruses are tetherin antagonists. Zhang F, Wilson SJ, Landford WC, Virgen B, Gregory D, Johnson MC, Munch J, Kirchhoff F, Bieniasz PD, Hatziioannou T. Cell Host Microbe Jul 23;6(1): Epub 2009 Jun 4. PMID: [PubMed - indexed for MEDLINE] 12: Comparative study on the effect of human BST-2/Tetherin on HIV-1 release in cells of various species. Sato K, Yamamoto SP, Misawa N, Yoshida T, Miyazawa T, Koyanagi Y. Retrovirology Jun 2;6:53. PMID: [PubMed - indexed for MEDLINE] 13: Vpu antagonizes BST-2-mediated restriction of HIV-1 release via beta-TrCP and endo-lysosomal trafficking. Mitchell RS, Katsura C, Skasko MA, Fitzpatrick K, Lau D, Ruiz A, Stephens EB, Margottin-Goguet F, Benarous R, Guatelli JC. PLoS Pathog May;5(5):e Epub 2009 May 29. PMID: [PubMed - indexed for MEDLINE] 14: The transmembrane domain of BST-2 determines its sensitivity to down-modulation by human immunodeficiency virus type 1 Vpu. Rong L, Zhang J, Lu J, Pan Q, Lorgeoux RP, Aloysius C, Guo F, Liu SL, Wainberg MA, Liang C. J Virol Aug;83(15): Epub 2009 May 27. PMID: [PubMed - indexed for MEDLINE] 15: Mutation of a single residue renders human tetherin resistant to HIV-1 Vpu-mediated depletion. Gupta RK, Hué S, Schaller T, Verschoor E, Pillay D, Towers GJ. PLoS Pathog May;5(5):e Epub 2009 May 22. PMID: [PubMed - indexed for MEDLINE] 16: Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2. Jia B, Serra-Moreno R, Neidermyer W, Rahmberg A, Mackey J, Fofana IB, Johnson WE, Westmoreland S, Evans DT. PLoS Pathog May;5(5):e Epub 2009 May 15. PMID: [PubMed - indexed for MEDLINE] 17: HIV-1 antagonism of CD317 is species specific and involves Vpu-mediated proteasomal degradation of the restriction factor. Goffinet C, Allespach I, Homann S, Tervo HM, Habermann A, Rupp D, Oberbremer L, Kern C, Tibroni N, Welsch S, Krijnse-Locker J, Banting G, Kräusslich HG, Fackler OT, Keppler OT. Cell Host Microbe Mar 19;5(3): PMID: [PubMed - indexed for MEDLINE] 18: Suppression of Tetherin-restricting activity upon human immunodeficiency virus type 1 particle release correlates with localization of Vpu in the trans-Golgi network. Dubé M, Roy BB, Guiot-Guillain P, Mercier J, Binette J, Leung G, Cohen EA. J Virol May;83(9): Epub 2009 Feb 25. PMID: [PubMed - indexed for MEDLINE] 19: Species-specific activity of HIV-1 Vpu and positive selection of tetherin transmembrane domain variants. McNatt MW, Zang T, Hatziioannou T, Bartlett M, Fofana IB, Johnson WE, Neil SJ, Bieniasz PD. PLoS Pathog Feb;5(2):e Epub 2009 Feb 13. PMID: [PubMed - indexed for MEDLINE] 20: Vpu enhances HIV-1 virus release in the absence of Bst-2 cell surface down-modulation and intracellular depletion. Miyagi E, Andrew AJ, Kao S, Strebel K. Proc Natl Acad Sci U S A Feb 24;106(8): Epub 2009 Feb 5. PMID: [PubMed - indexed for MEDLINE]

SUCEPTIBILIDAD A LA INFECCIÓN Y REPLICACIÓN VIRAL
Linfocito en reposo Linfocito activado Resistencia a la infección Susceptible a infección Latencia Replicación masiva

Kreisberg JF, Yonemoto W, Greene WC.
Apobec3 encodes Rfv3, a gene influencing neutralizing antibody control of retrovirus infection. Santiago ML, Montano M, Benitez R, Messer RJ, Yonemoto W, Chesebro B, Hasenkrug KJ, Greene WC. Science Sep 5;321(5894):1343-6 Endogenous factors enhance HIV infection of tissue naive CD4 T cells by stimulating high molecular mass APOBEC3G complex formation. Kreisberg JF, Yonemoto W, Greene WC. J Exp Med Apr 17;203(4): Epub 2006 Apr 10

E) Formación estructura Exposición del dominio de unión al correceptor
de fusión 2 trímeros env E) Formación estructura 6-hélices. Fusión de las membranas D) Liberación del dominio de fusión y anclaje en las membranas viral y celular. A) Envuelta VIH CD4 Exposición del dominio de unión al correceptor C) Interacción con los coreceptores B) Interacción con CD4 y cambio conformacional de la gp120 gp120 gp41 HR1 HR2 correceptor Dinámica del proceso de fusión Figura 7. Dinámica del proceso de fusión. A) Estructura trimérica de la envuelta del VIH. B) Interacción con CD4 y cambios conformacionales en la gp120 que exponen el dominio de interacción con los coreceptores. C) Interacción con los coreceptores virales. D) Desplegamiento del péptido de fusión y anclaje en la membrana celular. E) Formación de la estructura de “arpón” que fusiona las membranas viral y celular.

Pero las cosas no son fáciles…

Trogocytosis… Intercellular exchange of antigens/membranes.
Active process of cellular communication, different from proteolitic cleavage or exosome transfer.

Box 2. Mechanisms for generation of HIV-1 latency.
Transcriptional interference due to the site and orientation of the provirus within the cell chromosome. Epigenetic silencing by posttranscriptional modifications of the histone tails that form the nucleosome core and modulate the chromatin structure (e.g. hypoacetylation, trimethylation). Absence of nuclear host transcription activators for HIV-1 expression (e.g. NF-B, NF-AT, Sp1). Presence of cellular transcriptional repressors (e.g. YY1, LSF, CBF-1, APOBEC3G, IB, COMMD1). Inefficient elongation of HIV-1 transcripts due to the absence of the viral protein Tat and Tat-associated viral factors. Unproductive control of viral RNA splicing due to the absence of the viral protein Rev. Innate host antiviral processes (siRNA, miRNA).

RNA DE INTERFERENCIA E INFECCION VIH
Host cell DNA Provirus AAAA Target mRNA 21-23nt miRNA duplex P Tat DICER RISC TRBP Ago2 PACT TAR HIV-1 RNA Active RISC Nuclear membrane Cytosol Degradation of target mRNA Translational repression Multiple spliced viral mRNA Inactive RISC Tat/Rev mRNAs miR-28 miR-125b miR-150 miR-223 miR-382 viRNA Pri-miRNA transcription miRNA precursors Inactive miRISC Viral-derived miRNAs (viRNAs) DGCR8 DROSHA Exportin5 1 4 2 Cellular miRNAs 3 Cellular factor involved in HIV-1 expression RNA DE INTERFERENCIA E INFECCION VIH

HIGH-LEVEL VIREMIA RESIDUAL VIREMIA
VIRAL REPLICATION IN NAIVE PATIENTS IM-SUP POTENTIAL SOURCES OF RESIDUAL VIREMIA IN HAART Homeostatic cell division Latently infected lymphocytes REACT HAART + HIGH-LEVEL VIREMIA Reactivation RESIDUAL VIREMIA Activated lymphocytes IM-SUP Replenishment of reservoirs Low level ongoing replication Lymphocyte destruction Robust replication HAART INT New cycles of infection (?) Viral propagation Infection of new targets (?) Other infected cell types Persistent replication Persistent replication ?

LATENCIA Y REACTIVACION
Analysis of human immunodeficiency virus type 1 viremia and provirus in resting CD4+ T cells reveals a novel source of residual viremia in patients on antiretroviral therapy. Brennan TP, Woods JO, Sedaghat AR, Siliciano JD, Siliciano RF, Wilke . J Virol Sep;83(17): Treatment intensification does not reduce residual HIV-1 viremia in patients on highly active antiretroviral therapy. Dinoso JB, Kim SY, Wiegand AM, Palmer SE, Gange SJ, Cranmer L, O'Shea A, Callender M, Spivak A, Brennan T, Kearney MF, Proschan MA, Mican JM, Rehm CA, Coffin JM, Mellors JW, Siliciano RF, Maldarelli F. Proc Natl Acad Sci U S A Jun 9;106(23): HIV reservoir size and persistence are driven by T cell survival and homeostatic proliferation. Chomont N, El-Far M, Ancuta P, Trautmann L, Procopio FA, Yassine-Diab B, Boucher G, Boulassel MR, Ghattas G, Brenchley JM, Schacker TW, Hill BJ, Douek DC, Routy JP, Haddad EK, Sékaly RP. Nat Med Aug;15(8): Epub 2009 Jun 21 Understanding HIV-1 latency provides clues for the eradication of long-term reservoirs. Coiras M, López-Huertas MR, Pérez-Olmeda M, Alcamí J. Nat Rev Microbiol Nov;7(11):

Tipos de anticuerpos neutralizantes. Dominios de neutralización
 dominio interacción coreceptores  dominios variables 2G12 b12 gp120  dominio interacción CD4 CD4bs 2F5 gp41  dominio de fusión 4E10/Z13 Viral envelope (Burton D. Human neutralizing antibodies and a vaccine for HIV-1. XIV International AIDS Conference [Abstract nº201])

Patient 1: Neutralizing HIV Antibody Titers of Sequential Plasma Specimens against Autologous Virus
Dates Virus (months) 3 6 9 12 15 18 21 25 9/2/99 26 219 675 1403 2670 2089 2190 2363 2411 11/29/99 29 179 1024 2151 3733 3152 2808 2953 3086 2/29/00 27 35 78 358 1769 1939 2247 3112 4345 5/31/00 36 67 82 200 795 1078 1371 2208 3375 8/30/00 19 48 64 76 166 556 937 1407 11/22/00 43 90 119 374 721 1234 2/14/01 42 65 61 152 117 134 122 289 526 5/30/01 41 66 84 85 113 107 296 9/11/01 62 56 77 55 95 Control NL43 17 138 294 956 1172 953 1584 1868 2143 JRCSF 24 37 60 87 97 105 209 Plasma (months) (D.Richman Rapid evolution of the neutralizing antibody response following primary HIV infection. XIV International AIDS Conference . [Abstract nº1051])

EL GRAN DESAFIO: OBTENER ANTICUERPOS NEUTRALIZANTES
Karlsson et al. Nat.Rev.Microbiol 2008

Antibody induction Reverse Vaccinology
(Burton D. Human neutralizing antibodies and a vaccine for HIV-1. XIV International AIDS Conference [Abstract nº201])

ESTRATEGIAS DE MODIFICACIÓN DE LA ENVUELTA
PARA INCREMENTAR SU INMUNOGENICIDAD Inmunizar con envueltas triméricas Estabilizar la envuelta mediante la unión a otras proteínas: IgG Direccionar la envuelta fusionandola a otras proteínas: CD40 Acoplarla a nanopartículas que la dirijan a las células dendríticas. Generar envueltas truncadas que expongan los dominios de interacción con los receptores

ANTICUERPOS NEUTRALIZANTES ¿QUE TIENEN QUE NO TENGAN LOS OTROS?
4E10 Anticuerpo frente a gp41: estructura de bucle 2F5 Anticuerpo frente a gp41: estructura helicoidal b12 Anticuerpo frente al dominio de interacción con CD4 447-52D Anticuerpo frente al dominio V3-lamina beta que interacciona con el receptor CCR5 17b Anticuerpo frente a un epitopo inducido tras el desplegamiento de gp120 por CD4 (CD4i) 2g12 Anticuerpo dirigido frente a estructuras glicano

Structure of b12 neutralising antibody
(Burton D. Human neutralizing antibodies and a vaccine for HIV-1. XIV International AIDS Conference [Abstract nº201])

ESTRATEGIAS DE DISEÑO DE INMUNÓGENOS
4E10, 2F5 anticuerpos frente a gp41 En fase de definición a nivel atómico Acoplamiento en lisosomas b12 Anticuerpo frente al dominio de interacción con CD4 Investigación sobre anticuerpos de camélidos ¿Posible inducirlos en humanos? Base genética 447-52D Anticuerpo frente al dominio V3-lamina beta que interacciona con el receptor CCR5 Potenciar su inmunogenicidad 17b Anticuerpo frente a un epitopo inducido tras el desplegamiento de gp120 por CD4 (CD4i) Desplegar la gp120 con anticuerpos bivalentes, CD4 soluble o acoplamiento del epitopo a otras estructuras

ESTRATEGIAS DE DISEÑO DE INMUNÓGENOS
2G12 Anticuerpo dirigido frente a estructuras glicano Se une con igual afinidad a Candida Albicans que a gp120 Identificación de dichos epítopos/anticuerpos en el Sindrome de Guillain-Barré Sistemas de produccion de mann-8 en Sacharomices Cerevisiae: inmunización en conejos induce anticuerpos neutralizantes similares a 2G12 que neutralizan el VIH Modificacion para aumentar su inmunogenicidad. Acoplamiento a nanoparticulas para aumentar la estabilidad del epítopo.

¿Qué podemos esperar de una vacuna frente al VIH?
MAS POLEMICAS: EL PROBLEMA DE LA REDUCCION DE OBJETIVOS ¿Qué podemos esperar de una vacuna frente al VIH? Protección completa de la infección Protección parcial Infección con cargas virales a un nivel más bajo Los riesgos de la reducción de objetivos UTILIZAR VACUNAS NO PROTECTORAS UTILIZAR VACUNAS CON BAJO GRADO DE PROTECCIÓN

Microbicidas Fracaso ensayos fase II y III
Nueva generacion demicrobicidas Nuevos mecanismos de liberacion Microbicida oral Walker B. NEJM. 1998 Pilcher CD. J Clin Invest

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RESUMEN DE LOS AVANCES EN INVESTIGACIÓN BÁSICA

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