1 / 18

Genetic Restriction of HIV-1 infection and progression to AIDS by a Deletion Allele of the CKR5 Structural Gene By Esthe

Genetic Restriction of HIV-1 infection and progression to AIDS by a Deletion Allele of the CKR5 Structural Gene By Esther Valbrun.

azana
Download Presentation

Genetic Restriction of HIV-1 infection and progression to AIDS by a Deletion Allele of the CKR5 Structural Gene By Esthe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Genetic Restriction of HIV-1 infection and progression to AIDS by a Deletion Allele of the CKR5 Structural GeneBy Esther Valbrun Michael Dean, Mary Carrington, Cheryl Winkler, Gavin A. Huttley, Michael W. Smith, Rando Allikmets, James J. Goedert, Susan P. Buchbinder, Eric Vittinghoff, Edward Gomperts, Sharyne Donfield, David Vlahov, Richard Kaslow, Alfred Saah, Charles Rinaldo, Roger Detels, Hemophilia Growth and Development Study, Multicenter AIDS Cohort Study, Multicenter Hemophilia Cohort Study, San Francisco City Cohort, ALIVE Study, Stephen J. O'Brien

  2. Introduction • The HIV-1 epidemic presents a critical challenge for the application of current genetic techniques to the study of host genetic variation for infection and susceptibility to infection. • The recent demonstration that the chemokines RANTES, MIP-1 , and MIP-1 act as natural suppressors of HIV-1 infection has focused attention on the role of these chemokines during HIV-1 infection and clinical pathogenesis. • Chemokine receptor CKR5 (also called CC-CKR5, CCR5, and designated with gene symbol CMKBR5), which serves as the principal cellular receptor for RANTES.

  3. Introduction (continued)

  4. The Genotypic Markers and HIV-I Infection versus HIV-I antibody-negative individuals • Differences in the genetic profile of two populations (graph) implicated the CKR5 gene in resistance to HIV infection. • The significance value of the genotype association for each marker is plotted in physical order along each chromosome.

  5. GraphA G test showing the occurrence of genotypic association between HIV-1 infected versus HIV-1 antibody-negative of the 170 tested mapped polymorphic lociMapped polymorphic loci, includes candidate genes (for example, CD4, chemokine SCYA1, HLA-DQA1, TCRA, TCRB, and CKR5

  6. Graphical Analysis • With the exception of CKR5, none of the loci tested displayed a significant distortion of genotype frequencies among the infected versus uninfected individuals. • The genotypic distribution of the two common alleles of CKR5 [normal or wild type (+) and CKR5 32 deletion] in 738 Caucasian homosexual men displays a highly significant (P = 2.0 × 10 5) departure from genotypic equilibrium when frequencies among HIV-1-infected versus uninfected individuals are examined

  7. Mapping of CKR genes and Fusin • To genetically map the locus encoding fusin and the CKR5 locus, the gene-specific polymerase chain reaction (PCR) primers designed from the sequences of the genes to screen a panel of 90 radiation hybrid (RH) DNA samples were used. • The RH panel is designed to retain small segments of the human genome in different combinations so that the map location of new markers is implicated by their concordant occurrence in the panel with previously mapped markers.

  8. Graph

  9. Graphical Analysis • The distribution of RH results indicates that fusin maps to chromosome 2q21, proximal to the related interleukin-8 receptor (IL8RA, IL8RB) genes, and distal to the IL-1 and IL-1 receptor (IL1, IL1R) gene cluster. • These gene-mapping assignments provide additional evidence for the occurrence of chemokine receptor genes in small clusters in different regions of the human genome

  10. ChartAnalysis of CKR5 32 genotypes with reference to progression to AIDS

  11. Chart The survival distribution curves demonstrate the dependence of disease progression on CKR5 genotype in seroconverters from MHCS, SFCC, and DCG

  12. ChartThe survival distribution curves demonstrating the dependence of disease progression to AIDS on the CKR5 genotype, among 148 HIV-1-seropositive members of the SFCC with well-characterized dates of seroconversion who were seen for the study after 1987.

  13. Results • An examination of 1955 patients included among six well-characterized acquired immunodeficiency syndrome (AIDS) cohort studies revealed that 17 deletion homozygotes occurred exclusively among 612 exposed HIV-1 antibody-negative individuals (2.8 percent) and not at all in 1343 HIV-1-infected individuals. • The differential response of hemophiliacs versus homosexual men may be related to different routes of transmission, to exposure levels, or to viral load among individuals in different risk groups. • The results demonstrate that +/ 32 heterozygotes have a delayed progression to AIDS compared with CKR5 +/+ homozygotes. • The same trend (longer survival of +/ 32 individuals) was observed in all cohorts except DCG, which only contributes 43 patients. • These data suggest that the single-gene effect of CKR5 32 may be dominant and that interaction with other genes or the environment or both is necessary to prolong AIDS onset in infected patients.

  14. Results (continued) • These data suggest that the single-gene effect of CKR5 32 may be dominant and that interaction with other genes or the environment or both is necessary to prolong AIDS onset in infected patients. • Individuals homozygous for a deletion in CKR5 appear to have a greatly reduced risk of HIV-1 infection. • The simplest explanation for the gene action is that homozygous recessive 32/ 32 individuals avoid infection because of the absence of a functional CKR5 co-receptor. • A large difference in the frequency of the CKR5 32 allele was observed between Caucasians and African Americans.

  15. Conclusion • The frequency of CKR5 deletion heterozygotes was significantly elevated in groups of individuals that had survived HIV-1 infection for more than 10 years, and, in some risk groups, twice as frequent as their occurrence in rapid progressors to AIDS. • Survival analysis clearly shows that disease progression is slower in CKR5 deletion heterozygotes than in individuals homozygous for the normal CKR5 gene. • The CKR5 32 deletion may act as a recessive restriction gene against HIV-1 infection and may exert a dominant phenotype of delaying progression to AIDS among infected individuals. • It was observed that CD4+ T cells from some HIV-1-exposed individuals who have remained uninfected are relatively resistant to infection, suggesting that a defect in co-receptors or their expression may protect some individuals from infection

  16. Conclusion (continued) • No CKR5 32 homozygotes among 723 HIV-1-infected individuals were found and a rather low frequency for the CKR5 32 allele (0.054) in HIV-1-infected patients were observed. • +/ 32 heterozygotes may be less susceptible to infection than CKR5 +/+ individuals. • However, in the heterozygous state, the CKR5 32 allele does not markedly affect susceptibility to infection but does postpone progression to AIDS in infected patients.

  17. Reference • R. May and R. Anderson, Infectious Disease in Humans (Oxford Univ. Press, New York, 1995). • S. S. Morse, Ed., Emerging Viruses (Rockefeller Univ. Press, New York, 1993). • T. I. A. Sorensen, G. G. Nielsen, P. K. Andersen, T. W. Teasdale, N. Engl. J. Med.318, 727 (1988) . • A. G. Motulsky, Human Genetics: Patterns and Approaches (Springer-Verlag, Berlin, 1981). • S. Wain-Hobson, Curr. Opin. Genet. Dev.3, 878 (1993) [Medline]. • J. M. Coffin, Science267, 483 (1995) [Medline]. • E. L. Delwart et al., ibid.262, 1257 (1993) [Medline]. • R. A. Kaslow et al., Nature Med.2, 405 (1996) [Medline]; B. F. Haynes, G. Pantaleo, A. S. Fauci, Science271, 324 (1996) [Medline]. • W. A. Paxton et al., Nature Med.2, 412 (1996) [Medline]; R. Detels et al., AIDS10, 102 (1996) . • F. Cocchi et al., Science270, 1811 (1995) [Medline]; M. Baier, A. Werner, N. Bannert, K. Metzner, R. Kurth, Nature378, 563 (1995) [Medline]. • Y. Feng, C. C. Broder, P. E. Kennedy, E. A. Berger, Science272, 872 (1996) [Medline]. • B. Federsppiel et al., Genomics16, 707 (1993) [Medline]. • H. Herzog, Y. J. Hort, J. Shine, L. A. Selbie, DNA Cell Biol.12, 465 (1993) [Medline]. • H. Nomura, B. W. Nielsen, K. Matsushima, Int. Immunol.5, 1239 (1993) [Medline]. • P. J. Madden et al., Cell47, 333 (1986) . • C. Combadiere, S. K. Ahuja, H. L. Tiffany, P. M. Murphy, J. Leukocyte Biol.60, 147 (1996) [Medline]; M. Samson, O. Labbe, C. Mollereau, G. Vassart, M. Parmentier, Biochemistry35, 3362 (1996) [Medline]. • T. Dragic et al., Nature381, 667 (1996) [Medline]. • G. Alkhatib et al., Science272, 1955 (1996) [Medline]. • H. Choe et al., Cell85, 1135 (1996) [Medline]. • B. J. Doranz et al., ibid., p. 1149. • H. Deng et al., Nature381, 661 (1996) [Medline]. • P. M. Murphy, Annu. Rev. Immunol.12, 593 (1994) [Medline]. • K. Neote, D. DiGregorio, J. Y. Mak, R. Horuk, T. J. Schall, Cell72, 415 (1993) . • C. J. Raport et al., J. Leukocyte Biol.59, 18 (1996) [Medline]. • M. A. Walter, D. J. Spillett, P. Thomas, J. Weissenbach, P. Goodfellow, Nature Genet.7, 22 (1994) [Medline]. • M. White, M. Carvalho, D. Derse, S. J. O'Brien, M. Dean, Genomics12, 301 (1992) [Medline]; M. Ravnik-Glavac, D. Glavac, M. Dean, Hum. Mol. Genet.3, 801 (1994) [Medline]. • M. Orita, Y. Suzuki, T. Sekiua, K. Hayashi, Genomics5, 874 (1989) [Medline]. • M. Samson, Nature382, 722 (1996) [Medline]. • R. Liu et al., Cell86, 367 (1996) [Medline]. • Eight CKR5 variant alleles were found. These include the 32 deletion; a variant that occurred as a heterozygote in 15 individuals of 600 screened by SSCP; four variants found as heterozygous in single individuals that were HIV-1 infected, but had not progressed to AIDS after 7 to 10 years; and two variants in HIV-1-infected individuals that had not been followed for long term as yet. Preliminary sequence analysis revealed missense alterations in codons for conserved amino acids in three of the variants. • M. W. Hilgartner et al., Am. J. Pediatr. Hematol. Oncol.15, 208 (1993) [Medline]. • J. J. Goedert et al., N. Engl. J. Med.321, 1141 (1989) [Medline]. • J. J. Goedert et al., Am. J. Epidemiol.121, 629 (1985) [Medline]. • R. A. Kaslow et al., ibid.126, 310 (1987) [Medline]; J. Phair et al., J. AIDS5, 490 (1992) [Medline]; R. Detels et al., ibid.7, 1263 (1996) . • S. P. Buchbinder, AIDS8, 1123 (1994) [Medline].

  18. Reference (continued) • D. Vlahov et al., NIDA Research Monograph Series 103 (Public Health Service, Alcohol and Drug Abuse Administration, Washington, DC, 1991). • M. Deanet al., Am. J. Hum. Genet.55, 788 (1994) [Medline]. • J. C. Stephens, D. Briscoe, S. J. O'Brien, ibid., p. 809. • The G test is a likelihood ratio test that is equivalent to the 2 test but is less sensitive to very low "expected" values [J. H. Zar, Biostatistical Analysis (Prentice-Hall, Englewood Cliffs, NJ, 1984), p. 71]. With the Williams correction, G values are comparable with 2 values [R. R. Sokal and F. J. Rohlf, Biometry (Freeman, New York, 1981)]. For all significant values, a Fisher's exact test gave similar results. • The ALIVE cohort is composed of African American intravenous drug users and includes 496 homozygous (+/+) and 9 heterozygous (+/ 32) individuals. With so few individuals with the CKR5 32 allele, the ALIVE cohort was not included in subsequent computations. Although behavioral variables are probably more important, the relatively low CKR5 32 allele frequency in African Americans may contribute to a higher rate of infection in this ethnic group among intravenous drug users [ D. Vlahov et al., Am. J. Epidemiol.132, 847 (1990) [Medline]]. • M. Deanet al., data not shown. • A significant reduction in heterozygotes (+/ 32) was observed among HIV-1-seronegative individuals. This result warrants further study. • With the Bonferroni correction for multiple tests (four tests), the individual homosexual cohorts are not significant. When the two homosexual cohorts are combined, although they have different definitions of rapid progression, the result is significant (P = 0.005), even after corrections for multiple tests [B. S. Weir, Genetic Data Analysis II (Sinauer, Sunderland, MA, 1996)]. • Centers for Disease Control, Morb. Mortal. Wkly. Rep. 36 (suppl. 1) (14 August 1987). • ___, ibid. 41 (18 December 1992). This publication contains a revised classification system for HIV infection and an expanded surveillance case definition for AIDS among adolescents and adults. • J. W. Mellors et al., Science272, 1167 (1996) [Medline]. • T. R. O'Brien et al., J. Am. Med. Assoc.276, 105 (1996) . • R. L. Cann, M. Stoneking, A. C. Wilson, Nature325, 31 (1987) [Medline]. • R. Chakraborty and P. E. Smouse, Proc. Natl. Acad. Sci. U.S.A.85, 3071 (1988) [Medline]. • S. J. O'Brien, Curr. Biol.1, 209 (1991) . • Radiation hybrid DNAs, obtained from Research Genetics, were amplified for 20 min in a 10-µl PCR reaction with the following primers: for CKR5, primers CCK5F2 (5 -GGTGGAACAAGATGGATTAT-3 ) and CCK5R2 (5 -CATGTGCACAACTCTGACTG-3 ); for fusin, primers FUSF1 (5 -TGTACGTGTGTCTAGGCAGG-3 ) and FUSR1 (5 -TGTAGGTGCTGAAATCAACCC-3 ); and for CKR1, primers CKRF1 (5 -TCCCACTGCCAAGAACTTG-3 ) and CKRR1 (5 -TTCCCCAGGATTCCAAGAG-3 ). Samples were amplified with 5 units of Taq Gold (Stratagene) in the supplier's buffer in a Cetus 9600 PCR machine with a 58°C annealing temperature and loaded onto a 1.5% agarose gel. Scores for 90 radiation hybrids were recorded, and the results were analyzed by the Whitehead Mapping Server (http://www-genome.wi.mit.edu/cgi-bin/contig/rhmapper.pl) to determine significant linkages onto the framework map. RH typing data is available on request at e-mail address: dean@ncifcrf.gov. • HGDS investigators: A. Willoughby, National Institute of Child Health and Human Development, Bethesda, MD; W. Kesell, Bureau of Maternal and Child Health and Resources Development, Bethesda, MD; D. Mann, Univ. of Maryland; W. Pequegnat, National Institute of Mental Health, Bethesda, MD. The following individuals are the center directors, study coordinators, or committee chairs of the HGDS study: Childrens Hospital, Los Angeles F. Kaufman, M. Nelson, S. Pearson; The New York Hospital-Cornell Medical Ctr. M. Hilgartner, S. Cunningham-Rundles, J. Gertner, I. Goldberg; Univ. of Texas Medical Sch., Houston W. K. Hoots, K. Loveland, M. Cantini, G. Casterline; NIH, National Institute of Child Health and Human Development, Bethesda, MD A. Willoughby; New England Research Institutes, Incorporated (Data Coordinating Center), Watertown S. Donfield, M. A. Maeder; Baylor College of Medicine C. Contant Jr.; Univ. of Iowa Hospitals and Clinics, Iowa City C. T. Kisker, J. Stehbens, J. Bale, S. O'Conner; Tulane Univ. P. Sirois; Children's Hospital of Oklahoma, Oklahoma City C. Sexauer, H. Huszti, S. Hawk, F. Kiplinger; Mount Sinai Medical Ctr., New York City S. Arkin, A. Forster; Univ. of Nebraska Medical Ctr. S. Swindells, S. Richard; Univ. of Texas Health Science Ctr., San Antonio J. Mangos, A. Scott, R. Davis; Children's Hospital of Michigan, Detroit J. Lusher, I. Warrier, K. Baird-Cox; Milton S. Hershey Medical Ctr., Hershey, PA M. E. Eyster, E. Pattishall, D. Ungar, S. Neagley; Univ. of Indiana, James Whitcomb Riley Hospital for Children A. Shapiro, S. Hatcher; Univ. of California-San Diego Medical Ctr. G. Davignon, P. Rabwin; Kansas City Sch. of Medicine, Children's Mercy Hospital B. Wicklund, A. Mehrhof. MHCS investigators: M. E. Eyster, Milton S. Hershey Medical Ctr., Hershey; M. Hilgartner, Cornell Medical Ctr.; A. Cohen, Children's Hospital of Philadelphia; B. Konkle, Thomas Jefferson Univ. Hospital; G. Bray, Children's Hospital National Medical Ctr., Washington, DC; L. Aledort, Mount Sinai Medical Ctr., New York City; C. Kessler, George Washington Univ. Medical Ctr.; C. Leissinger, Tulane Medical Sch.; G. White, Univ. of North Carolina; M. Lederman, Case Western Reserve Medical School, Cleveland; P. Blatt, Christiana Hospital; M. Manco-Johnson, Univ. of Colorado. • We are indebted to the children, adolescents, adults, and parents who have volunteered to participate in this study, and to the members of the Hemophilia Treatment Centers. We thank D. Lomb, S. Edelstein, M. Malasky, T. Kissner, D. Marti, B. Gerrard, A. Hutchinson, M. Weedon, X. Wu, P. Lloyd, E. Wendel, M. McNally, R. Boaze, L. Kenefic, M. Konsavich, C. Stewart, and S. Cevario for technical assistance, and B. Weir, M. Clegg, R. Adamson, and R. Gallo for helpful discussions. Computing resources were provided by the Frederick Biomedical Supercomputing Center. Supported by the Bureau of Maternal and Child Health and Resources Development (MCJ-060570), the National Institute of Child Health and Human Development (NO1-HD-4-3200), the Centers for Disease Control and Prevention, the National Institute of Mental Health, and the National Institute of Drug Abuse (DA04334). Additional support has been provided by grants from the National Center for Research Resources (General Clinical Research Centers) of NIH to the New York Hospital-Cornell Medical Center Clinical Research Center (MO1-RR06020), the Mount Sinai General Clinical Research Center, New York (MO1-RR00071), the University of Iowa Clinical Research Center (MO1-RR00059), and the University of Texas Health Science Center, Houston (MO1-RR02558). The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.

More Related