Novel method to characterize immune cells from human prostate tissue

Background: Benign prostatic hyperplasia (BPH) is the most common benign adenoma and prostate cancer is the most frequent malignancy in men over 50 years of age in the Western world, where it remains a significant health problem. Prostate lesions are known to contain immune cells, which may contribute to the immune control of tumor progression. However, due to their low numbers and restricted access to necessary material it is difficult to isolate immune cells from prostate tissue to characterize their immunological features.

Methods: An efficient and robust method was developed to process prostate tissue and isolate immune cells for phenotypic analysis by multicolor flow cytometry as downstream application. Fresh prostate tissue from 11 patients undergoing surgery for bladder outlet obstruction due to BPH was processed to evaluate the number, viability, yield, and frequency of various immune cell types.

Results: The presented method does not include enzymatic digestion nor incubation steps at 37 °C, increasing cellular viability and avoiding possible phenotypic modification. Various immune cell populations were detected in all patient samples and the median cellular viability was 90%. The number of detected events of individual cell populations varied between patients. The median frequency of different immune cell populations also varied, being 87% for the CD3- and 15% for the CD3+ cell population.

Conclusions: This novel method will allow the phenotypic characterization of immune cell populations present in tumor tissue of prostate cancer patients and promote development of novel approaches to immunotherapy of the disease.