CCR5 : and HIV Immunity Gene Variation Works for and Against HIV Ashley Alexis & Hilda Hernandez Background 1981: Homosexuals in New York and L.A. Background 1981: Homosexuals in New York and L.A. 1983: New retrovirus is named HIV 1 Background 1981: Homosexuals in New York and L.A. 1983: New retrovirus is named HIV 1 1986: HIV 2 is isolated in West Africa Origin Earliest known infection occurred in Kinshasa, Zaire, 1959 Origin Earliest known infection occurred in Kinshasa, Zaire, 1959 Relationship between SIV and HIV is found Origin Earliest known infection occurred in Kinshasa, Zaire, 1959 Relationship between SIV and HIV is found Original transfer to humans is unknown Transmission Blood products Transmission Blood products Organ transplants Transmission Blood products Organ transplants Sexual intercourse Transmission Blood Products Organ transplants Sexual intercourse Vertical transmission What is HIV? Human Immunodeficiency Virus What is HIV? Human Immunodeficiency Virus A retrovirus What is HIV? Human Immunodeficiency Virus A retrovirus It attacks T cells What is HIV? Human Immunodeficiency Virus A retrovirus It attacks T cells Leads to opportunistic infection What is HIV? Human Immunodeficiency Virus A retrovirus It attacks T cells Leads to opportunistic infection Progresses to AIDS What is AIDS? Acquired Immunodeficiency Syndrome What is AIDS? Acquired Immunodeficiency Syndrome HIV infection confirmed What is AIDS? Acquired Immunodeficiency Syndrome HIV infection confirmed CD4 T-cell count is below 200 What is AIDS? Acquired Immunodeficiency Syndrome HIV infection confirmed CD4 T-cell count is below 200 HIV related syndrome is present The Impact of AIDS Age # of Cumulative AIDS Cases Under 5: 6,928 Ages 5 to 12: 2,066 Ages 13 to 19: 4,219 Ages 20 to 24: 27,880 Ages 25 to 29: 103,085 Ages 30 to 34: 175,343 Ages 35 to 39: 177,759 Ages 40 to 44: 131,718 Ages 45 to 49: 77,152 Ages 50 to 54: 40,972 Ages 55 to 59: 22,423 Ages 60 to 64: 12,415 Ages 65 or older: 11,065 The Impact of AIDS Race or Ethnicity # of Cumulative AIDS Cases White, not Hispanic 337,035 Black, not Hispanic 301,784 Hispanic 145,220 Asian/Pacific Islander 5,922 American Indian/Alaska Native 2,433 Race/ethnicity unknown 632 Disease Progression What is a T- “helper” Cell? The cell HIV targets What is a T- “helper” Cell? The cell HIV targets Immune regulator cells What is a T- “helper” Cell? The cell HIV targets Immune regulator cells Activates B-cells Structure of HIV HIV Lifecycle Step 1: Binding The virus binds to host cell via receptors What are Receptors? Molecules that extend from the cell membrane What are Receptors? Molecules that extend from the cell membrane Receive messages What are Receptors? Molecules that extend from the cell membrane Receive messages What Are Receptors? Molecules that extend from the cell membrane Receive messages Serve as a docking device for viruses Step 2: Entry Virus breaches cell’s outer membrane Step 2: Entry Virus breaches cell’s outer membrane Pushes core of viral proteins inside cell body Step 3: Uncoating Viral core uncoats Step 3: Uncoating Viral core uncoats Releases genetic material and enzymes Step 4: Reverse Transcription Reverse transcriptase processes viral genome Step 4: Reverse Transcription Reverse transcriptase processes viral genome Enables virus to copy its genetic structure Step 5: Nuclear Entry The viral genome is transported to cell’s nucleus Step 6: Integration Viral DNA is completely “mixed into” host cell’s genome Step 7: Transcription Proviral DNA transcribes back into viral RNA Step 7: Transcription Proviral DNA transcribes back into viral RNA Produces strands of viral proteins Step 8: Translation Protein strands are processed into chains of viral proteins Step 9: Assembly Cut proteins are assembled Step 9: Assembly Cut proteins are assembled Packages of proteins migrate to cell’s surface Step 9: Assembly Cut proteins are assembled Packages of proteins migrate to cell’s surface Begin to bud from host cell CCR5 Genetic Mutation = HIV/AIDS Immunity! N.C.I. team headed by Dr. Stephen J. O’Brien conducted a study of 1,850 subjects at high risk of HIV infection. CCR5 Genetic Mutation = HIV/AIDS Immunity! N.C.I. team headed by Dr. Stephen J. O’Brien et al. conducted a study of 1,850 subjects at high risk of HIV infection. Separated subjects into two groups: CCR5 Genetic Mutation = HIV/AIDS Immunity! N.C.I. team headed by Dr. Stephen J. O’Brien et al. conducted a study of 1,850 subjects at high risk of HIV infection. Separated subjects into two groups Compared how often allele combinations showed up in each group RESULTS Found that HIV could enter cells through CD4 receptors AND CCR5 receptors. RESULTS Found that HIV could enter cells through CD4 receptors AND CCR5 receptors. CCR5 receptor genes differed in patients RESULTS Found that HIV could enter cells through CD4 receptors AND CCR5 receptors. CCR5 receptor genes differed in patients 1 out of every 5 (3%) of the resistant individuals carried the genetic mutation and was homozygous for the deletion CCR5 gene. RESULTS Found that HIV could enter cells through CD4 receptors AND CCR5 receptors. CCR5 receptor genes differed in patients 1 out of every 5 (3%) of the resistant individuals carried the genetic mutation and was homozygous for the deletion CCR5 gene. Heterozygous individuals had an extended life span while being infected for an average of 3 to 4 years Immunity to HIV Cure Possibilities! CCR5 proteins may help protect healthy people or delay the advance of AIDS Cure Possibilities! CCR5 proteins may help protect healthy people or delay the advance of AIDS Genetic engineering can provide new genes that would stop CCR5 from serving as a docking site Cure Possibilities! CCR5 proteins may help protect healthy people or delay the advance of AIDS Genetic engineering can provide new genes that would stop CCR5 form serving as a docking site Chemotherapy and Bone Marrow transplants Bad News Other Chemokine receptors can compensate for the lack of CCR5 Bad News Other Chemokine receptors can compensate for the lack of CCR5 CCR2B and CCR3 Bad News Other Chemokine receptors can compensate for the lack of CCR5 CCR2B and CCR3 It has not been proven that CCR5 drugs/therapies improve chances of vaccination, cure, or extended survival Ethical Dilemmas Employee/ Health Insurance Screenings Ethical Dilemmas Employee/ Health Insurance Screenings CCR5 Mutation gives false hope to some Ethical Dilemmas Employee/ Health Insurance Screenings CCR5 Mutation gives false hope to some Stem cell usage for bone marrow therapy Web Sites http://critpath.org/aric/library/img005.h tm http://tthhivclinic.com/lifecycle.htm http://www.sciam.com/0997issue/0997 obrien.html Thank You