AEGiS-14IAC: Interferon-[gamma] production by human lymphocytes treated with regulatory RNA from mice immunized with a synthetic peptide of HIV-1: role of the RNA-dependent protein kinase.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Interferon-[gamma] production by human lymphocytes treated with regulatory RNA from mice immunized with a synthetic peptide of HIV-1: role of the RNA-dependent protein kinase.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10082)

Lucca FL, Sales VS, Souza LR, Watanabe MA
School of Medicine University of Sao Paulo, Ribeirao Preto - SP, Brazil

BACKGROUND: Recent studies indicate that regulatory RNAs are involved in the regulation of gene expression. We previously showed that p9-RNA isolated from animals immunized with the synthetic peptide p9 of HIV-1 induces immunological effects and acts as a regulatory RNA. In this study, we examined the ability of p9-RNA to induce the production of IFN-γ in human lymphocytes. We also investigated whether this effect is mediated by the RNA-dependent protein kinase (PKR) since this kinase is involved in the regulation of IFN-γ gene.

METHODS: Mice were immunized with the synthetic peptide p9 (pol:476-484) of HIV-1. RNA was extracted from lymph nodes of immunized (p9-RNA) and nonimmunized (N-RNA) mice. The production of IFN-γ was measured by ELISA. PKR was assayed using [[gamma]-32P]ATP, purifed with poly[I:C]-agarose and analyzed by SDS-PAGE followed by autoradiography.

RESULTS: The N-RNA was used as control in all experiments. We found that only human lymphocytes incubated with p9-RNA are able to produce IFN-γ. Our results also indicated that p9-RNA activates PKR from human lymphocytes whereas N-RNA had no effect.

CONCLUSIONS: It is known that PKR activates the nuclear factor-kappa B (NF-~B) and that the promotor of IFN-γ gene contains binding site for the transcription factor NF-~B. Thus, it is possible that this effect of p9-RNA is mediated by PKR through NF-~B activation, suggesting that p9-RNA acts as a regulatory RNA. Our previous results showed that p9-RNA induces HIV-specific human cytotoxic T lymphocytes. Taken together, these findings support the use of p9-RNA as a immunomodulator in HIV infection. Supported by FAPESP (00/09491-7) and CNPq (523412/95-9).

Keywords: AEGIS, eIF-2 Kinase, Interferon Type II, Lymphocytes, RNA, NF-kappa B, Peptides, Transcription Factors, T-Lymphocytes, Cytotoxic, Promoter Regions (Genetics), Poly I-C, Mice, Human, Animal, genetics

020707
A10082