Grant-funded Project Nr. 071/2001/C/3.LF
Final Report

Project title:Influence of stress on the course of HIV infection model and its pharmacological intervention
Research leader:MUDr. Miroslav Starec, CSc.
Co-researcher: Doc. MUDr. Jozef Rosina; Mgr. Gabriela Ditteová; MUDr. Marek Prùcha; MUDr. Jana Hrmová; RNDr. Petr Kodym, CSc.
Period of project:2001-2003
Overall grant:784 000 CZK

Project Results

Project GAUK 71/2001 focused on the effect of stress and some immunomodulators on the course of Friend virus infection in mice. In addition, we studied the effect of selected drugs – namely alpha and D2 receptors antagonists - on immune parameters compromised by stress.
DBA/2 male mice were inoculated i.v. with 0,2 ml (approximately 5 focus forming units, ffu)  of Friend virus suspension. The polycythemia-inducing Friend virus is a mixture of helper Friend murine leukemia virus and defective spleen focus-forming virus. Immobilization stress: infected mice were immobilized in small sufficiently aerated chambers four times for 24 hours over14 days (on days 3, 5, 8 and 11 from infection). Swimming stress:  Mice were forced to swim in water at 24°C in a transparent tank 20 x 30 cm for 1 h four times over 14 days (on the same days as indicated for immobilization). Insulin shock: After 24-hour starving, mice were given insulin intraperitoneally at a dose of 20 IU/kg on experimental days 5 and 14. An immunostimulatory agent norAbu-MDP was administered i.p. at a dose of 200 nmol/mouse 24 h prior to and 24 h after virus inoculation. Survival of animals, subpopulations of lymphocytes, cytotoxicity of NK cells and blastic transformation of lymphocytes were monitored.
Results: 1. Different stressors had different effects on the course of Friend virus infection in mice. Insulin shock clearly reduced survival of mice. Repeated immobilization was associated with longer survival. Forced swimming had practically no effect on survival. 2. A statistically significant difference in the survival was found between infected mice given norAbu-MDP and infected controls given saline. This indicates that the immunomodulatory agent norAbu-MDP of the group of muramyl glycopeptide analogs significantly prolongs survival of infected mice within month 1 after virus inoculation. Another MDP derivative also yielded promising results (positive effect on survival and functional immune parameters – blastic transformation of lymphocytes, cytotoxicity of NK cells). However, these results cannot be published before the agent is patented.
3. Experiments with non-infected animals: Agroclavine enhanced the cytotoxicity of NK cells under „normal“ conditions but reduced the cytotoxicity under immobilization-immersion stress conditions in rats Wistar Kyoto. 12h immobilization stress caused a decrease in spleen weights and spleen mononuclear cell numbers in mice CBA/J. Administration of phentolamine (alpha antagonist) or sulpiride (D2 antagonist) before stress exposure antagonized the negative effects of immobilization on both parameters mentioned above. Immobilization stress caused significant decrease in the number of NK cells. Administration of alpha antagonist enhanced the number of NK cells in both stressed and non-stressed animals. Sulpiride did not influence the ratio of NK cells to spleen mononuclear cells in non-stressed animals, but significantly enhanced the total number of NK cells and activated NK cells in stressed mice. Cytotoxicity of NK cells appeared clearly reduced by stress. Phentolamine caused an increase in cytotoxicity in both stressed and non-stressed mice. Sulpiride decreased this parameter in non-stressed animals, but significantly increased NK cell cytotoxicity in immobilized animals. These results together with those presented previously (cytokines production, phentolamine and sulpiride effects on the expression of alpha subunits of G-protein in brain and spleen cells) are suggestive of the role of alpha-adrenergic and dopamine D2 receptors played during immobilization stress. These receptors seem to inhibit cytotoxic activity of NK cells under stress conditions.