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Published on: September 16, 2012
Flow cytometric analysis of peripheral blood lymphocyte immunophenotypes in persons infected with Treponema pallidum
1Division of Sexually Transmitted Diseases Laboratory Research, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Insights
Syphilis infection alters immune cell populations, with lower T helper (CD4+) and higher T suppressor (CD8+) cells observed in patients. These changes in lymphocyte subsets vary by syphilis stage and gender.
Area of Science:
- Immunology
- Infectious Diseases
- Hematology
Background:
- Syphilis, caused by Treponema pallidum, is a complex infection that elicits a significant host immune response.
- Understanding the dynamics of lymphocyte subpopulations during syphilis infection is crucial for characterizing immune evasion and disease progression.
Purpose of the Study:
- To investigate the impact of Treponema pallidum infection on peripheral blood lymphocyte subpopulations in individuals with varying stages of untreated syphilis.
- To analyze gender-specific differences in immune cell profiles associated with syphilis.
Main Methods:
- Flow cytometry (FACScan) was employed for dual-color analysis of lymphocyte immunophenotypes.
- Monoclonal antibodies targeting CD3 (total T cells), CD4 (T helper cells), CD8 (T suppressor cells), CD19 (B cells), and CD16+CD56 (natural killer cells) were utilized.
- Results were stratified by syphilis stage (primary, secondary, latent) and gender.
Main Results:
- Patients with syphilis exhibited significantly lower percentages of CD4+ T cells (P < 0.001) and higher percentages of CD8+ T cells (P = 0.03) compared to uninfected controls.
- Significant differences in CD3+ and CD4+ T cell percentages were observed between infected and uninfected individuals across both genders (P ≤ 0.05).
- Gender-specific immune cell differences were noted in secondary syphilis for CD3, CD4, CD8, and NK cells, but not in primary or latent stages.
Conclusions:
- Treponema pallidum infection demonstrably alters key lymphocyte subpopulations, characterized by a reduction in T helper cells and an increase in T suppressor cells.
- The immune response, particularly concerning T cell subsets and natural killer cells, shows gender-dependent variations in secondary syphilis.
- These findings contribute to a deeper understanding of the immunopathogenesis of syphilis and highlight potential gender-based differences in immune modulation during infection.
Abstract:
To characterize the human immune response to syphilis, we determined the effect of infection with Treponema pallidum on the percentage of the various lymphocyte subpopulations in the peripheral blood of infected and uninfected persons. Monoclonal antibodies labeled with either fluorescein isothiocyanate or phycoerythrin were used to perform dual color analysis on a FACScan with the following markers: CD3 for total T cells, CD4 for T helper cells, CD8 for T suppressor cells, CD19 for B cells, and CD16 plus CD56 for natural killer cells. Lymphocyte immunophenotype results were analyzed by the stage of untreated syphilis and by gender. Although they were within the ranges of the normal distribution of immunophenotypes, the percentages of CD4+ cells were significantly lower (P < 0.001) and those of CD8+ cells were higher (P = 0.03) in patients with syphilis than in the uninfected population. For infected versus uninfected subjects, both women and men, the differences in the mean percentages of CD3+ and CD4+ cells were significant (P < or = 0.05). Significant differences were noted between the sexes in secondary syphilis only in the mean percentages of cells positive for CD3, CD4, CD8, and CD16 plus CD56. Gender had no effect on lymphocyte subpopulations in subjects with primary or latent syphilis. In the control population, significant differences due to gender were observed in the percentages of cells positive for CD3, CD4, and CD16 plus CD56.
