CD8+ T Lymphocyte Subsets in Bladder Tumor Draining Lymph Nodes

Document Type: Original Article

Authors

1 Cancer Immunology Group, Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Urology-Oncology Research Center,Shiraz University of Medical Sciences, Shiraz, Iran

3 Department of Urology, Shiraz University of Medical Sciences, Shiraz, Iran

4 Urology-Oncology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

5 School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

Background: Cytotoxic CD8+ T cells, as essential parts of the adaptive immune
system, play pivotal roles in anti-tumor immune responses. It is well documented that
cytokine expression profiles and activation status of these cells during anti-tumor
immune responses affect the outcome of host-tumor interaction. Objective: To
investigate the percentages of CD8+ lymphocytes and their subsets in tumor draining
lymph nodes of patients with bladder cancer. Methods: Forty-five patients with bladder
cancer, candidate for radical cystectomy, were recruited. Mononuclear cells were
isolated from draining lymph nodes using Ficoll-Hypaque gradient centrifugation, and
were activated by PMA/Ionomycin in the presence of Golgi inhibitors. The cells were
then permeabilized and stained with appropriate flourochrome conjugated antibodies
against CD3, CD8, IFN-γ, IL-17 and IL-4 molecules. Data were collected on a fourcolor
flow cytometer and analyzed by CellQuestPro software. Results: Despite no
difference in the frequency of IL-17 producing CD8+ (Tc17) lymphocytes, the mean
expression of IL-17 in this subset was significantly elevated in high-grade patients
(p=0.011). The percentage of double positive IFN-γ/IL-17 CD8+ lymphocytes was also
significantly increased in node positive patients compared to node negative ones
(p=0.046). Our results also demonstrated that the percentage of IFN-γ producing CD8+
(Tc1) lymphocytes was significantly increased in the patients with higher histological
grade compared to those with lower ones (p=0.038). Conclusion: IFN-γ and IL-17
producing CD8+ T cells may increase in advanced stages of bladder cancer, but their
correlation with tumor prognosis remains to be investigated.

Keywords