Classification of cytokines into T helper type 1 (Th1) and T helper type 2 (Th2) has helped in the elucidation of the mechanisms of resistance or susceptibility to infections. HIV infection causes CD4$\sp+$ T cell dysfunction and depletion by indirect mechanisms; for example: inhibition of immunoregulatory cytokines. Interleukin (IL-10), the subject of this study, is secreted mostly by CD4$\sp+$ human Th2-like, but also by Th0,Th1-like, and by a proportion of CD8$\sp+$ T cell clones. HIV sero-positive patients exhibit depressed cell mediated immune responses, B cell hyperplasia, and hypergammaglobulinemia which may result from downregulation of Th1 and upregulation of Th2 class responses respectively. In this study, the expression of interferon$\gamma$ (IFN$\gamma$) and IL-10 which mediate Th1 and Th2 responses respectively, in unstimulated peripheral blood lymphocytes (PBLs) from HIV$\sp+$ patients were investigated. IL-10 expression as observed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis was significantly upregulated in patients with less than 400 CD4$\sp+$ T cells in comparison with HIV$\sp+$ patients with more than 400 CD4$\sp+$ T cells and normal controls. A semi-quantitative RT-PCR analysis of unstimulated PBLs further demonstrated IL-10 upregulation was inversely associated with IFN$\gamma$ downregulation in the same individuals. Similar results were observed as determined by measuring IL-10 and IFN$\gamma$ production in the supernatants of unstimulated PBLs by employing enzyme immunoassay techniques. These results suggest that HIV infected individuals express predominately Th2 type cytokines in their PBLs.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/6527 |
| Date | January 1994 |
| Creators | Karimi, Sepideh. |
| Contributors | Diaz-Mitoma, Francesco, |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 119 p. |
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