About half of the infants congenitally infected with HIV-1 seem to acquire the virus intrapartum. Mucosal exposure during birth is likely to be an important route of infection. Our initial longterm goal had been to develop immunoprophylaxis to prevent intrapartum HIV-1 transmission. We established a primate model for mucosal infection at birth and demonstrated that SIV-delta3 (nef-, vpr-, NRE-), which acted as live attenuated virus vaccine in adult macaques, could infect rhesus monkey fetuses and neonates. However, all macaque neonates given this virus orally at birth thus far developed signs of AIDS, and half have died of disease. PCR analysis showed that the deletions in nef had not been repaired, and that SIV-delta3 had undergone further deletions after in vivo passage in some macaque neonates. These surprise findings indicate that the multiply deleted SIV mutant has retained its pathogenic potential, and that neither nef nor vpr are required for the development of AIDS. The overall goal of this (adjusted) proposal is to examine the molecular determinants for pathogenicity and avirulence in congenital SIV infection.
The Specific Aims are to: 1. Continue to evaluate the incidence and spectrum of disease following congenital SIV-delta3 infection. Animals, infected at various time points during gestation or at birth, will be followed longterm. 2. Clone virus directly from tissues of diseased offspring originally infected with SIV-delta3 and determine the DNA sequence. A replication- competent virus will be generated and tested for pathogenicity or attenuation in macaque mother/infant pairs. 3. Test whether the pathogenicity of SIV-delta3 is correlated with the initial inoculum given. 4. Clone virus directly from tissues of offspring that did not develop disease and sequence. Cloned virus from healthy, infected offspring will be tested in adults and neonates to test whether it remained avirulent. In case all offspring exposed to SIV-delta3 develop disease, other candidate attenuated SIVs will be tested in mucosally infected neonatal macaques. 5. Construct virus recombinants and search for the molecular determinants of pathogenicity. The viruses will be tested in mucosally infected neonatal macaques, which our data have shown to be sensitive indicators of the potential pathogenicity of mutant SIVs. The significance of this proposal lies in the systematic evaluation of the lentiviral genes that determine the development of AIDS.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI035533-02
Application #
2071271
Study Section
AIDS and Related Research Study Section 1 (ARRA)
Project Start
1993-11-01
Project End
1999-03-31
Budget Start
1995-04-01
Budget End
1996-03-31
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Dana-Farber Cancer Institute
Department
Type
DUNS #
149617367
City
Boston
State
MA
Country
United States
Zip Code
02215
Liska, V; Hofmann-Lehmann, R; Ruprecht, R M (2001) Infectivity of lentiviral DNA in animals. Dev Biol (Basel) 106:291-7; discussion 297-8, 317-29
Ruprecht, R M (1999) Live attenuated AIDS viruses as vaccines: promise or peril? Immunol Rev 170:135-49
Liska, V; Ruprecht, R M (1999) Isolation of high-molecular-weight genomic DNA from intact biohazardous mammalian tissues. Biotechniques 26:62-4, 66
Baba, T W; Liska, V; Khimani, A H et al. (1999) Live attenuated, multiply deleted simian immunodeficiency virus causes AIDS in infant and adult macaques. Nat Med 5:194-203
Liska, V; Lerche, N W; Ruprecht, R M (1997) Simultaneous detection of simian retrovirus type D serotypes 1, 2, and 3 by polymerase chain reaction. AIDS Res Hum Retroviruses 13:433-7
Ruprecht, R M; Baba, T W; Rasmussen, R et al. (1996) Murine and simian retrovirus models: the threshold hypothesis. AIDS 10 Suppl A:S33-40
Montefiori, D C; Baba, T W; Li, A et al. (1996) Neutralizing and infection-enhancing antibody responses do not correlate with the differential pathogenicity of SIVmac239delta3 in adult and infant rhesus monkeys. J Immunol 157:5528-35
Baba, T W; Koch, J; Mittler, E S et al. (1994) Mucosal infection of neonatal rhesus monkeys with cell-free SIV. AIDS Res Hum Retroviruses 10:351-7