Boyer JD, Nelson R, Robinson T, Scott P, Weiner DB; International Conference on AIDS.
Int Conf AIDS. 2002 Jul 7-12; 14: abstract no. ThPeA7115.
University of Pennsylvania, Philadelphia, United States
BACKGROUND: More than 95% of all HIV-infected people now live in the Developing World, and 95% percent of all deaths have occurred among its people. In these countries, chronic parasitic infection adds another level of complexity to AIDS vaccine development. Helminthic and protozoan infections are common in developing countries. Approximately 1.5 billion people carry a parasitic burden. These persons are in a constant state of immune activation with a dominant Th2 type of cytokine profile, high IgE levels, and eosinophilia. Such an immune profile may have an adverse impact on the efficacy of HIV-1 vaccines. METHODS: We studied the impact of parasitic infection on the vaccine induced cellular immune response. Balb/c mice were infected with L. major. The immune response was assessed by a ELISPOT. RESULTS: A Th2 immune profile was observed two weeks post parasitic infection. Following the establishment of chronic parasitic infection the mice were immunized with a DNA HIV-1 vaccine. The level of vaccine induced CD8 and CD4 responses were assessed. We observed that the number of CD8 lymphocytes able to secrete IFN-gamma following stimulation with HIV-1 antigen decreased from approximately 200 to 20 lymphocytes. Yet, we observed a slight increase in the number of HIV-1 antigen specific CD4 lymphocytes secreting INF-gamma in the parasitically infected mice as compared to the uninfected, HIV-1 DNA vaccinated mice. Importantly, we have observed that the CD8 antigen specific cellular response to HIV-1 DNA vaccines was significantly enhanced by the addition of IL-15 independently of CD4 T cell expansion. CONCLUSIONS: It may be benificial to enhance a vaccine induced cellular immune response by co-injecting DNA plasmids that code for cytokines that enhance the CD8 immune response. And, our data indicate that IL-15 could be particularly valuable in developing countries where many individuals have a chronic parasitic infection.
Publication Types:
Keywords:
- AIDS Vaccines
- Acquired Immunodeficiency Syndrome
- Animals
- Antigens, CD4
- Antigens, CD8
- CD4-Positive T-Lymphocytes
- CD8-Positive T-Lymphocytes
- Cytokines
- HIV Infections
- HIV-1
- Humans
- Mice
- Mice, Inbred BALB C
- Parasitic Diseases
- Protozoan Infections
- Vaccines
- Vaccines, DNA
- immunology
Other ID:
UI: 102254308
From Meeting Abstracts