The Effect of Mating with
Neanderthals and Denisovans
on our Immune system
Group A10
Gerald Duncan, Olivia Lahay, Madeline
Lionberger, Kyle Sledge, Heather Yutko
Introduction
• HLA (human leukocyte antigen): Genes important in immune
system response
• Haplotype: Combination of alleles transmitted together
• Ligand: binds to receptors
• Natural Killer Cells: Integral part of immune system
• Denisovans: group similar to Neanderthals
• Balancing selection: Multiple alleles maintained in population
• Introgression: Gene flow between hybrids and parental
populations
• Admixture: Mixing formerly unexposed populations
Data/Results
• Study led by Stanford University
• Human migration from Africa occurred 67,500 years ago
• Maximum of 4% of modern Eurasian genomes can be traced
back to Neanderthals
• Maximum of 4-6% of modern Melanesian genomes can be
traced back to Denisovans
• Thousands of alleles per HLA
http://images.dailytech.com/nimage/21570_large_HLA_B_Protein.jpg
Model of a HLA-B Protein
Data/Results (Cont’d)
• Percentage of HLA-A deviations believed (Abi-Rached) to be
from sexual activity with extinct races:
I. European: 50%
II. Chinese: 70%
III. Papua New Guinean: 95%
• 50-60 % of Chinese inhabitants possess A*11
• Very rare in African regions
http://www.sciencemag.org/content/334/6052/89/F2.large.jpg
http://www.sciencemag.org/content/334/6052/89/F3.large.jpg
Discussion
• The findings suggest:
I.
II.
• HLA:
I.
II.
III.
IV.
Interbreeding between archaic humans and Homo
sapiens.
Adaptive introgression of HLA genes.
Control NK cells
T cell immunity
Highly polymorphic---different alleles
Vital immune system component
Conclusion
•
•
Some HLA alleles in modern humans may have
originated from extinct human species.
These alleles may contribute to defending against
locally prevalent diseases.
Literature Cited
•
•
•
•
•
•
•
•
•
•
Abi-Rached, Jobin, Kulkami, McWhinnie, Dalva, Gragert, Babrzadeh, Gharizadeh, Luo, Plummer, Kimani, Carrington,
Middleton, Rajalingam, Beksac, Marsh, Maiers, Guethlein, Tavoularis, Little, Green, Norman & Parham. 2011.
“The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans.” Science
Mag, online. http://www.sciencemag.org/content/334/6052/89.full
Freeman, Scott. Biological Science. 4th ed. San Francisco: Person Education, Inc, 2011. Print.
Handbook of Statistical Genetics. 3rd ed. Eds. D.J. Balding, M. Bishop., C. Cannings. Chichester: John Wiley & Sons, Ltd,
2007. Print.
“Haplotype.” genome.gov. National Human Genome Research Institute. Web. 17 November 2012.
http://www.genome.gov/Glossary/index.cfm?id=99
McGrath, Matt. “Neanderthal sex boosted immunity in modern humans.” BBC News, online.
http://www.bbc.co.uk/news/science-environment-14673047
Mick, Jason. “Neanderthal Sex Gave Europeans and Asians Stronger Immune Systems.” Daily Tech, online.
http://www.dailytech.com/Neanderthal+Sex+Gave+Europeans+and+Asians+Stronger+Immune+Systems/article22
555.htm
Rhymer, Judith M and Daniel Simberloff. “Extinction by Hybridization and Introgression.” Annual Reviews Inc., 1996. Web.
17 November 2012. http://www.annualreviews.org/doi/pdf/10.1146/annurev.ecolsys.27.1.83
Sample, Ian. “The Downside of Sex with Neanderthals.” The Guardian, online.
http://www.guardian.co.uk/science/blog/2011/aug/25/neanderthal-denisovan-genes-human-immunity
Vivier E, Tomasello E, Baratin M, Walzer T, Ugolini S. “Functions of natural killer cells.” Nat Immunol, May 2008. Web. 17
November 2012. http://www.ncbi.nlm.nih.gov/pubmed/18425107
Young, Ed. “Did sex with Neanderthals and Denisovans shape our immune system? The jury’s still out.” Discover Magazine,
online. http://blogs.discovermagazine.com/notrocketscience/2011/08/25/did-sex-with-neanderthals-anddenisovans-shape-our-immune-systems-the-jury%E2%80%99s-still-out/