Toll-Like Receptors 7, 8, and 9 Expression and Function in Primary Human Cervical Cancer Langerhans Cells

• DOI: 10.1097/igc.0b013e31827a2003
• Publication Date: 2012-12-08T11:34:12Z
• Authors: Mahesh M. Kumar; Sreenivas Adurthi; Surya Ramachandran; Geetashree Mukherjee; Omana Joy; H. Krishnamurthy; Sudhir Krishna; U.D. Bafna; Devi K. Uma; R.S. Jayshree
• Keywords: Adult; Clonal Anergy; 0301 basic medicine; Primary Cell Culture; Uterine Cervical Neoplasms; Middle Aged; Ligands; 3. Good health; Gene Expression Regulation, Neoplastic; 03 medical and health sciences; Toll-Like Receptor 7; Toll-Like Receptor 8; Case-Control Studies; Langerhans Cells; Toll-Like Receptor 9; Carcinoma, Squamous Cell; Tumor Cells, Cultured; Humans; Female; Aged

Human papillomavirus oncoproteins E6 and E7 down modulate Toll-like receptor (TLR) 9 expression in infected keratinocytes. We explored the status of expression and function of TLR7, TLR8, and TLR9 in primary human Langerhans cells (LCs) isolated from cervical tumors.Single-cell suspensions were made from fresh tissues of squamous cell carcinoma (International Federation of Gynecology and Obstetrics stage IB2); myeloid dendritic cells were purified using CD1c magnetic activated cell separation kits. Langerhans cells were further flow sorted into CD1a*CD207* cells. Acute monocytic leukemia cell line THP-1-derived LCs (moLCs) formed the controls. mRNA from flow-sorted LCs was reverse transcribed to cDNA and TLR7, TLR8, and TLR9 amplified. Monocyte-derived Langerhans cells and cervical tumor LCs were stimulated with TLR7, TLR8, and TLR9 ligands. Culture supernatants were assayed for interleukin (IL) 1β, IL-6, IL-10, IL-12p70, interferon (IFN) α, interferon γ, and tumor necrosis factor (TNF) α by Luminex multiplex bead array. Human papillomavirus was genotyped.We have for the first time demonstrated that the acute monocytic leukemia cell line THP-1 can be differentiated into LCs in vitro. Although these moLCs expressed all the 3 TLRs, tumor LCs expressed TLR7 and TLR8, but uniformly lacked TLR9. Also, moLCs secreted IL-6, IL-1β, and tumor necrosis factor α to TLR8 ligand and interferon α in response to TLR9 ligand; in contrast, tumor LCs did not express any cytokine to any of the 3 TLR ligands. Human papillomavirus type 16 was one of the common human papillomavirus types in all cases.Cervical tumor LCs lacked TLR9 expression and were functionally anergic to all the 3: TLR7, TLR8, and TLR9 ligands, which may play a crucial role in immune tolerance. The exact location of block(s) in TLR7 and TLR8 signaling needs to be investigated, which would have important immunotherapeutic implications.