Innate resistance to HIV

A small proportion of humans show partial or apparently complete innate resistance to HIV, the virus that causes AIDS.[1] The main mechanism is a mutation of the gene encoding CCR5, which acts as a co-receptor for HIV. It is estimated that the proportion of people with some form of resistance to HIV is under 1%.[2][3][4]

History

In 1994, Stephen Crohn became the first person discovered to be completely resistant to HIV in all tests performed.[5][6] In early 2000, researchers discovered a small group of prostitutes in Nairobi, Kenya who were estimated to have sexual contact with 60 to 70 HIV positive clients a year without signs of infection.[7] Researchers from Public Health Agency of Canada have identified 15 proteins unique to those virus-free prostitutes.[8] Later, however some prostitutes were discovered to have contracted the virus, leading Oxford University researcher Sarah Rowland-Jones to believe continual exposure is a requirement for maintaining immunity.[9]

CCR5 deletion

C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines. This is the process by which T cells are attracted to specific tissue and organ targets. Many strains of HIV use CCR5 as a co-receptor to enter and infect host cells. A few individuals carry a mutation known as CCR5-Δ32 in the CCR5 gene, protecting them against these strains of HIV.

In humans, the CCR5 gene that encodes the CCR5 protein is located on the short (p) arm at position 21 on chromosome 3. Certain populations have inherited the Delta 32 mutation resulting in the genetic deletion of a portion of the CCR5 gene. Homozygous carriers of this mutation are resistant to M-tropic strains of HIV-1 infection.[10][11][12][13][14][15]

See also

References

  1. ↑ Susan Scutti (2014-11-20). "Why Some People Are Naturally Immune To HIV". Medical Daily. Retrieved 2015-01-20.
  2. ↑ Trudy Ring (2012-09-07). "Is Anyone Immune to HIV?". HIVPlusMag. Retrieved 2015-01-20.
  3. ↑ Stephanie Nolen (2007-05-27). "Staying alive: the women who are immune to Aids". the Guardian. Retrieved 2015-01-20.
  4. ↑ Amber Angelle (2010-07-21). "Immune to HIV: How Do They Do It?". LiveScience. Retrieved 2015-01-20.
  5. ↑ Maanvi Singh (21 September 2013). "In Life, Man Immune To HIV Helped Scientists Fight Virus". NPR.org. Retrieved 2015-01-20.
  6. ↑ Jesse Green (2014-06-13). "The Man Who Was Immune to AIDS". NYMag.com. Retrieved 2015-01-20.
  7. ↑ Altman, Lawrence K. (3 February 2000). "A New AIDS Mystery: Prostitutes Who Have Remained Immune". NYTimes. Retrieved 2015-01-20.
  8. ↑ Blackwell, Tom (2012-02-13). "Blackwell on Health: Montreal researchers discover why some prostitutes evade HIV". National Post. Retrieved 2015-01-20. Public Health Agency of Canada have identified 15 proteins unique to those virus-free prostitutes
  9. ↑ "Prostitutes lose HIV immunity". BBC News. 1999. Retrieved 2015-01-20.
  10. ↑ de Silva E, Stumpf MP (2004). "HIV and the CCR5-Delta32 resistance allele". FEMS Microbiol. Lett. 241 (1): 1–12. doi:10.1016/j.femsle.2004.09.040. PMID 15556703.
  11. ↑ Hütter G, Nowak D, Mossner M, Ganepola S, Müssig A, Allers K, Schneider T, Hofmann J, Kücherer C, Blau O, Blau IW, Hofmann WK, Thiel E (2009). "Long-term control of HIV by CCR5 Delta32/Delta32 stem-cell transplantation". N. Engl. J. Med. 360 (7): 692–8. doi:10.1056/NEJMoa0802905. PMID 19213682.
  12. ↑ Allers K, Hütter G, Hofmann J, Loddenkemper C, Rieger K, Thiel E, Schneider T (2011). "Evidence for the cure of HIV infection by CCR5Δ32/Δ32 stem cell transplantation". Blood. 117 (10): 2791–9. doi:10.1182/blood-2010-09-309591. PMID 21148083.
  13. ↑ Zhen A, Kitchen S (2014). "Stem-cell-based gene therapy for HIV infection". Viruses. 6 (1): 1–12. doi:10.3390/v6010001. PMC 3917429Freely accessible. PMID 24368413.
  14. ↑ Kay MA, Walker BD (2014). "Engineering cellular resistance to HIV". N. Engl. J. Med. 370 (10): 968–9. doi:10.1056/NEJMe1400593. PMID 24597871.
  15. ↑ Tebas P, Stein D, Tang WW, Frank I, Wang SQ, Lee G, Spratt SK, Surosky RT, Giedlin MA, Nichol G, Holmes MC, Gregory PD, Ando DG, Kalos M, Collman RG, Binder-Scholl G, Plesa G, Hwang WT, Levine BL, June CH (2014). "Gene editing of CCR5 in autologous CD4 T cells of persons infected with HIV". N. Engl. J. Med. 370 (10): 901–10. doi:10.1056/NEJMoa1300662. PMC 4084652Freely accessible. PMID 24597865.

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