title: Rapid in vivo induction of HIV-specific CD8+ cytotoxic T lymphocytes by a 15-amino acid unmodified free peptide from the immunodominant V3-loop of GP120.
abstract: Efforts to generate a vaccine to prevent infection by human immunodeficiency virus (HIV) have focused on inducing neutralizing antibodies. However, cytotoxic T-lymphocyte (CTL) responses are a major immune defense mechanism required for recovery from many different virus infections. Since CTL epitopes can be defined by short synthetic peptides, we searched for HIV peptides that elicit a viral-specific CTL response in mice. We have developed a new method for screening CTL-inducing peptides involving a single injection into the footpad of mice to prime CTLs in the draining popliteal lymph node of mice within 10 days. Our results demonstrate that a 15-amino acid peptide (aa 315-329) derived from the V3 loop of HIV gp120 caused a rapid induction of peptide-specific and gp160-specific CD8-positive CTLs. Lysis of targets is specific since cells preincubated with unrelated peptides are resistant to lysis as are cells of a different MHC haplotype pretreated with the cognate peptide. Pretreatment of restimulated node cells with complement plus anti-CD8 but not anti-CD4 removed the lytic activity. We also successfully induced in vivo CTL activity with unmodified synthetic peptides from the influenza and Sendai virus nucleoproteins, indicating general applicability of our method for rapid screening of CTL epitopes. Because HIV replication has been reported by several labs to occur mainly in lymph nodes of infected patients, the rapid induction of HIV-specific CTLs in proximal lymph nodes by unmodified peptides emphasizes the physiological significance of our findings toward vaccine and therapeutic approaches.
authors.affiliation: Department of Molecular Pathology, University of Texas, M. D. Anderson Cancer Center, Houston 77030.
authors.forename: K J
authors.initials: KJ
authors.lastname: Sastry
authors.forename: P N
authors.initials: PN
authors.lastname: Nehete
authors.forename: S
authors.initials: S
authors.lastname: Venkatnarayanan
authors.forename: J
authors.initials: J
authors.lastname: Morkowski
authors.forename: C D
authors.initials: CD
authors.lastname: Platsoucas
authors.forename: R B
authors.initials: RB
authors.lastname: Arlinghaus
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016827:CD8 Antigens / Q000032:analysis; D006678:HIV / Q000276:immunology*; D015483:HIV Antibodies / Q000096:biosynthesis; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D009975:Orthomyxoviridae / Q000276:immunology; D010222:Parainfluenza Virus 1, Human / Q000276:immunology; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014614:Vaccines, Synthetic; D014758:Viral Core Proteins / Q000276:immunology
chemical_list: D016827:CD8 Antigens; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D010455:Peptides; D014614:Vaccines, Synthetic; D014758:Viral Core Proteins