TLR3\TLR7 as Differentially Expressed Markers Among Viral, Nonviral, and Autoimmune Diseases in Egyptian Patients

Abstract

Toll-like receptors (TLRs) represent the immune link between the innate and the adaptive immune signals against various pathogens. This study aimed to evaluate the TLRs3 and 7 as immune-markers in differentiating between hepatitis C virus (HCV)-infected and -uninfected patients. Also, the use of the TLR3 and TLR7 as immune markers was compared with the prevalent bio and immune markers for autoimmune diseases in HCV-infected or -uninfected patients. The levels of GPT, GOT, B cell activated factors, tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-10 were measured in plasma, while the levels of TLR3 and TLR7 were quantified in lysates of peripheral blood mononuclear cells from healthy donors, HCV-infected patients, nonalcoholic fatty liver (NAFL) patients without autoimmune diseases and with autoimmune diseases (HCV-infected patients with autoimmune diseases [HCV+auto], nonalcoholic fatty liver patients with autoimmune diseases [NAFL+auto]), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) patients. The relative expression of TLR3, TLR7, TNF, and IL-10 in cell lysates was assessed against glyceraldehyde 3-phosphate dehydrogenase (GAPDH) by quantitative real time-polymerase chain reaction (qRT-PCR). Results showed that TLRs 3 and 7 levels were significantly higher in SLE, RA, HCV, HCV+auto, and the NAFL patients compared to the normal control. The cell lysates from SLE patients expressed TLR3 at relatively significantly higher mRNA levels compared to normal subjects or other patient groups. The NAFL+auto patients expressed TLR7 at relatively significantly high mRNA levels compared to normal subjects or other patients. The RA patients expressed TLR7 at relatively significantly higher mRNA levels when compared to HCV, HCV+auto, and NAFL+auto patients. Conclusions: At the protein level, TLR7 can differentiate between HCV and NAFL patients. In addition, both TLRs3 and 7 can serve as potent markers in differentiating between NAFL and NAFL+auto.

Keywords: Toll-like receptors; autoimmune diseases; hepatitis C virus; nonalcoholic fatty liver disease.