1 / 19

Genetic Restriction of HIV-1 Infection and Progression to AIDS by a Deletion Allele of the CKR5 Structural Gene

Genetic Restriction of HIV-1 Infection and Progression to AIDS by a Deletion Allele of the CKR5 Structural Gene.

melia
Télécharger la présentation

Genetic Restriction of HIV-1 Infection and Progression to AIDS by a Deletion Allele of the CKR5 Structural Gene

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 Gene 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. 1996. Science Magazine 273:1858-1862.   By Jacinta Gaitor

  2. Introduction • Persons in a population respond to diseases differently due to the phenotypic variations of resistance. • It is proposed that inheritance factors play a major role in mortality rates. • HIV-1 epidemic has evoked the study of genetic variation and susceptibility to infections in different hosts. • Research has shown a specific allele of the HLA locus to be associated with different rates of progression from infection to AIDS.

  3. Chemokine Receptors • Chemokine receptors are G-protein-linked serpentine receptors • Also used as co-receptors for the binding of immunodeficiency viruses (eg HIV) to leucocytes. • Chemokines RANTES, MIP-1 , and MIP-1 role as natural HIV-1 suppressors are being studied. • The chemokine co-receptor and receptors associated with the above mentioned are fusin, CD4, CKR2B, CKR3 and CKR5 (principal cellular receptor). • Individuals at high risk for the HIV-1 infection have been observed to have CD4+T cells that have been relatively resistant to infection.

  4. The Genetic mapping of CKR5 and Fusin • The locus encoding fusin and the CKR5 are genetically mapped using the polymerase chain reaction (PCR). • PCR screens a panel of 90 radiation hybrid (RH) DNA samples of the human genome. • The allocation of RH results indicates that fusin is positioned on chromosome 2q21 and CKR5 on chromosome 3p21. • These loci are mapped in small clusters along different locations in the human genome (represented in the subsequent graph).

  5. Representation of Chemokine Receptor clusters in the Human Genome

  6. Determination of Genotype Frequency among HIV-1 Infected versus Non-infected Individuals • Genomic DNA was screened by using 170 mapped polymorphic loci. • Distortion of allele and geneotype frequency among HIV-1 positive vs high risked HIV-1 negative persons were determined.

  7. A Graph Showing Genotypic markers and HIV-1 infection [G test ]

  8. Analysis of Graph • According to the data displayed in the graph, CKR5 show a significant distortion of genotype frequencies among the infected vs uninfected. • The other loci (CD4, chemokine SCYAL, HLADQAL, TCRA,TCRB) on the other hand did not show such a significance.

  9. Further Examination of CKR5 Allele • Distribution of alleles and genotypes with genomic DNA were determined in 1955 patients in order to find important variables in HIV-1 infection and its progression • Subjects used for the experiment were high risk HIV-1 type ndividuals. • The experiment also included HIV-1-exposed seronegative individuals, HIV-1-infected AIDS patients, and HIV-1-infected individuals who have not yet progressed to AIDS. • CKR5 frequency was found to be greatest in high risk HIV-1 individuals and less in those cosidered to be of low risk. • CKR5 frequency was found least in African Americans.

  10. HIV-1 infected vs non infected • CKR5 frequencies were found to be relatively the same in HIV-! Infected and non infected individuals. • A significant difference of CKR5 was found in the genotypic distribution between infected and non infected individuals. • High risk HIV-I antibody negative individuals were found to have 17 homozygous CKR5 32 genes which is highly significant (G=35.0, p=2.5*10-8). • Therefore, the CKR5 32 gene seem to have a recessive phenotype associated with HIV-1 infection resistance and antibody production. • Homozygous CKR5 32 allele was non existent in HIV-1 infected patients but the Heterozygote gene was found. • In homosexual HIV-1 infected long term non progressors heterozygotes were twice the percentage compared to rapid progressors. • In Hemophilia individuals the heterozygote frequency differences between rapid progressors and non progressors were insignificant.

  11. Hemophiliacs vs Homosexuals • There is a difference in response in hemophiliacs vs homosexuals due to : • 1) transmission • 2)exposure level • 3)viral load • Hemophiliacs consist of large doses of HIV-1 contaminating clotting factors. • Homosexuals sexual transmission involve HIV-1 mucosal epithelium infection.

  12. Analysis of CKR5 Heterozygote frequency

  13. Homozygotes vs Heterozygotes for CKR5 32 gene • Multiple tests in 1987 and 1992 for AIDS definition show that heterozygotes for CKR5 show a delayed progression to AIDS ic comparison with homozygotes (x2 =8.1, p=0.0045). • Probability is >0.01 therefore difference is significant. • Hence single-gene CKR5 32 may be dominant and due to interaction with other genes/environment it may prolong AIDS in infected persons.

  14. Results of Investigation • Persons homozygous (recessive) for CKR5 have greater reduced risk of HIV-1 infection due to absence of functional CKR5 co-receptor. • Heterozygotes can be infected but due to CKR5 HIV-1 co –receptor limiting viral spreading in infected persons ultimately delaying AIDS. • Large differences in frequencies of CKR5 were found amongst Caucasians (0.11) compared to African Americans (0.017) which may be because CKR5 is a recent recessive mutation.

  15. Conclusion A Genetic restriction experiment including HIV-1-infected individuals vs. HIV-1-antibody-negative individuals were performed on 1955 patients. The study includes the chemokine receptor 5 (CKR5) protein. CKR5 (structural Gene) is a deletion allele found at a frequency of ~0.1 in Caucasian Americans. Cohort study show 17 deletion homozygotes occurring exclusively in HIV-1-antibody-negative individuals.

  16. Deletion Allele – CKR5 • Deletion allele absent in HIV-1-infected individuals • CKR5 heterozygote allele found to be more frequent in individuals who have carried the HIV-1-infection for more than 10 yrs opposed to rapid progression AIDS victims. • Results prove that CKR5 heterozygotes progression to AIDS is slower than CKR5 homozygotes for normal gene. • Hence, it is proposed that the CKR5 allele may act as a recessive restriction gene. • CKR5 – An alternative antiviral therapy????

  17. References • 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].

  18. 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]. • 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.

  19. 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