IL-10 and TNF-alpha expression in THP-1 cells in response to stimulation with LPS, CML and CLA

Abstract

IL-10 and TNF-a are immunoregulatory cytokines with antagonistic roles within the immune system, IL-10 is a potent anti-inflammatory mediator needed to control over exuberant immune responses and prevent self reactivity and TNF-α is a pro-inflammatory cytokine necessary for wound healing and pathogen removal. The purpose of this investigation was to determine whether stimulating THP-1 cells with LPS, CML or CLA over different time periods would alter IL-10 and TNF-α expression. The hypothesis was that LPS, CML and CLA would induce IL-10 and TNF-α secretion in THP-1 cells and that cytokine expression would be greatest in cells exposed for the maximum duration of time (72hrs) to the stimuli. THP-1 cells were grown in suspension, sub-cultured and differentiated using PMA in order to induce macrophage receptor expression. Cells were then incubated with LPS, CML or CLA over 24hr, 48hr or 72hr periods and the levels of IL-10 and TNF-α determined using DuoSet ELISA's. The results indicated that LPS, CML and CLA had no significant effect on IL-10 expression, whereas LPS considerably increased TNF-α secretion, particularly at 24hrs. CML stimulation produced a small increase in TNF-α expression although stimulation with CLA had no effect. The hypothesis was disproved because not all of the stimuli induced cytokine production and greatest levels were not generated at 72hrs. Evidence suggests that the optimum incubation times for IL-10 and TNF-α are below 12hrs, therefore it is possible that peak IL-10 and TNF-α concentrations were missed.