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Correlation between circulating stromal cell-derived factor 1 levels and CD4+ cell count in human immunodeficiency
C A Derdeyn1, C Costello, J M Kilby
1Department of Pathology, University of Alabama at Birmingham, 35233, USA.
Insights
Stromal cell-derived factor 1 (SDF-1) levels correlate with CD4+ cell counts in HIV-1 infection. Lower SDF-1 may indicate disease progression, but antiretroviral therapy did not alter levels in advanced cases.
Area of Science:
- Immunology
- Virology
- Molecular Biology
Background:
- Stromal cell-derived factor 1 (SDF-1) is the natural ligand for CXCR4, a coreceptor for certain HIV-1 strains.
- Understanding SDF-1's role in HIV-1 infection is crucial for disease progression insights.
Purpose of the Study:
- To investigate the relationship between plasma/serum SDF-1 protein levels and CD4+ cell counts in HIV-1-infected individuals.
- To explore potential links between SDF-1 levels and HIV-1 disease stage.
Main Methods:
- Enzyme-linked immunosorbent assay (ELISA) was used to quantify SDF-1 protein concentrations.
- Samples were analyzed from 31 HIV-1-seronegative and 79 HIV-1-infected subjects.
- SDF-1 mRNA expression was analyzed in lymph node biopsies from HIV-1-infected individuals.
Main Results:
- HIV-1-infected subjects showed a direct correlation between SDF-1 levels and CD4+ cell counts.
- Individuals with CD4+ cell counts <50 cells/µL had significantly lower mean SDF-1 levels compared to controls and those with higher CD4+ counts.
- Antiretroviral therapy did not significantly alter SDF-1 levels in nine subjects with advanced HIV-1 disease.
Conclusions:
- Lower SDF-1 levels in HIV-1-infected individuals may be associated with disease progression.
- Stromal cells in lymph node medullary cords express SDF-1 mRNA, suggesting a potential source.
- Further research is warranted to elucidate the precise role of SDF-1 in HIV-1 pathogenesis.
Abstract:
Stromal cell-derived factor 1 (SDF-1) is the natural ligand that recognizes CXCR4, which also serves as a coreceptor for some strains of HIV-1. In this study, we explored SDF-1 blood levels among HIV-1-infected individuals exhibiting a wide range of CD4+ cell counts. Plasma or serum concentrations of SDF-1 protein were measured by ELISA in samples from 31 HIV-1-seronegative individuals and 79 HIV-1-infected subjects. Although SDF-1 protein levels were stable for months among seronegative individuals (mean intrasubject variation, 17%), the absolute values varied widely (0.28 to 106.5 ng/ml; mean, 25.6 ng/ml). In HIV-1-infected subjects, there was a direct correlation between SDF-1 level and CD4+ cell count. Subjects with fewer than 50 CD4+ cells per cubic microliter of blood had significantly lower mean SDF-1 levels (+/-SD) than did either HIV-1-infected subjects with higher CD4+ cell counts or uninfected controls: CD4+ cell count <50, mean SDF-1 level of 10.7+/-33.7, 50 < CD4+ cell count <200, mean SDF-1 level of 12.9+/-19.0, 200 < CD4+ cell count <500, mean SDF-1 level of 19.3+/-36.8; CD4+ cell count >500, mean SDF-1 level of 18.5+/-25.2; uninfected control mean SDF-1 level, 25.6+/-34.7. No significant change in SDF-1 level was detected after administration of antiretroviral therapy in nine subjects with advanced disease (mean intrasubject variation, 43%). Analysis of SDF-1 mRNA expression in lymph nodes from HIV-1-infected subjects at different disease stages revealed that the medullary cords contained stromal cells that express SDF-1 mRNA. This preliminary analysis suggests a possible link between lower SDF-1 levels and disease progression.