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Lipopolysaccharide (LPS) and lipooligosaccharide (LOS) are inflammatory response inducers triggering downstream inflammatory signals by binding to the TLR4-MD2 complex. LPS/LOS exposure through TLR4 receptor on dendritic cells (DC) causes an increase in interferon (IFN)-β expression via an increase in interferon regulatory factor (IRF)3 expression and a decrease in nuclear factor (NF)-κβ, which result in HIV replication inhibition. This study aimed to compare the binding affinity between Escherichia coli LPS and Neisseria gonorrhoeae LOS toward TLR4-MD2 in silico and the production of NF-κβ, IRF3, and IFN-β from naive-HIV monocyte-derived dendric cells (MDDCs) after LPS and LOS exposure in vitro, to find a deeper understanding of host immune response, disease pathogenesis, and trends of drug development in the future. Molecular docking and dynamics were analyzed using AutoDock Vina and YASARA, respectively. The naive-HIV DC culture was exposed to LPS at 50, 100, and 200 ng/mL, or LOS at concentrations of 2.5, 5, and 10% for 24-h. Levels of NF-κβ, IRF3, and IFN- β were measured by Enzyme-linked Immunosorbent Assay (ELISA). The results showed that LOS demonstrated higher binding affinity to TLR4-MD2 complex than LPS, although the docking between LOS and TLR4-MD2 complex involved fewer amino acids. Inversely, LPS exposure significantly increased IRF3 and IFN-β production (P < 0.01). Production of IFN-β was significantly increased with higher doses of LOS (P < 0.01). Different doses of LPS induced significant differences in NF-κβ and IFN-β levels (P < 0.01 and P < 0.05, respectively). Despite LOS showing higher binding affinity to TLR4- MD2 complex, LPS exposure induced higher production of IRF3 and IFN-β from MDDCs. These findings provided information for deeper apprehension of immune responses and disease pathogenesis during HIV co-infections. [ABSTRACT FROM AUTHOR]

Background: The innate immune response to tuberculosis infection may involve the increased production of nitric oxide and cathelicidin due to the up-regulated expression of the vitamin D receptor (VDR), though this proposed mechanism remains controversial. The aim of this study was to determine how the exposure of human monocytes to Mycobacterium tuberculosis (M. tuberculosis) DNA affects the production of nitric oxide and cathelicidin, as well as the expression of VDR. Methods: This study was performed using monocytes obtained from healthy donors. After 24 h incubation, monocytes were stimulated with M. tuberculosis DNA for 18 h to determine the expression of VDR mRNA and the production of nitric oxide and cathelicidin versus non-stimulated cells (the control group). Results: The expression of VDR mRNA was higher in the monocytes exposed to M. tuberculosis DNA compared to the control group (P = 0.020). Monocytes exposed to M. tuberculosis DNA also showed significantly increased production of nitric oxide and cathelicidin compared to the control group (P = 0.0001; P = 0.028). Conclusion: The stimulation of human monocytes with M. tuberculosis DNA increases the expression of the VDR mRNA and the production of nitric oxide and cathelicidin. [ABSTRACT FROM AUTHOR]