CD274 and neoplasm: On the other hand, the tumor microbiome may induce T cell dysfunction and immune suppression through cytokine production, upregulation of immune checkpoint inhibitors, and recruitment of immune-suppressive cells.625 In prostate cancer, for instance, Lactobacillus johnsonii has been shown to increase the recruitment of regulatory T cells and enhance the functions of immune-inhibitory elements like PD-L1, CCL17, and CCL18.