Expression of TLR4 in peripheral blood mononuclear cells and plasma concentrations of TNF-αin patients with HIV/MTB co-infection / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the expression of TLR 4 and its downstream factor TNF-αin the patients with human immunodeficiency virus and Mycobacterium tuberculosis ( HIV/MTB) co-infection. Methods A total of 119 subjects including 32 patients with HIV infection (HIV group), 30 patients with HIV/MTB co-infection (HIV/MTB group), 28 patients with MTB infection (MTB group) and 29 healthy subjects ( control group ) were recruited continuously from the Fourth People′s Hospital of Nanning City , Guangxi.The expression of TLR4 in peripheral blood mononuclear cells (PBMCs) from the patients was de-termined by flow cytometry .ELISA was performed to detect TNF-αin plasma samples .The HIV-1 viral load was determined by standard method .Results The mean fluorescence intensity ( MFI) for TLR4 expression in PBMCs from HIV, HIV/MTB, MTB and control groups were 21.62±4.67, 18.29±3.87, 16.79±4.45, and 22.85±5.80, respectively, showing significant differences among four groups (F=8.105, P<0.01). The TLR4 levels in MTB and HIV/MTB groups were significantly lower than those in control group ( both P<0.01) and HIV group (P<0.01, P=0.014).The plasma concentrations of TNF-αin HIV, HIV/MTB, MTB and control groups were 15.892 (10.494-21.646) pg/ml, 13.142 (8.014-22.038) pg/ml, 16.284 (11.916-24.005) pg/ml, and 26.657 (16.321-34.541) pg/ml, respectively, that were significantly dif-ferent from each other (F=4.350, P=0.006).The levels of TNF-αin plasma from patients with HIV and HIV/MTB infection were significantly lower than those of healthy subjects (P=0.009 and P=0.001).The viral load in patients from HIV/MTB group (5.113 ±1.018 copies/ml) was significantly higher than that from HIV group (4.416±1.020 copies/ml) (t=3.449, P=0.001).Conclusion MTB infection might promote HIV replication by inhibiting the expression of TLR 4.HIV infection might increase host′s suscepti-bility to MTB infection by reducing the production of TNF-α.Suppressed expression of TLR and TNF-αpro-duction could contribute to the occurrence of HIV /MTB co-infection .