Human cytokine ELISA assay. Analysis of human cytokines after SBCMV infection of brain vascular pericytes. A human cytokine ELISA assay was performed on supernatants from SBCMV-infected pericytes, SBCMV heat-killed pericytes and mock-infected cells. Shown are the relative amounts of TNF-alpha, IL-6 and TGF-beta in cell culture supernatants elicited 24 hours postexposure (A). Quantitative measurements IL-6 and TNF-alpha secreted from pericytes in infected cell supernatants 24 hours postinfection was based on optical density utilizing a standard curve for human IL-6 (B) and human TNF-alpha (C). Analysis was performed in triplicate and values were expressed in picograms/milliliter. IL, interleukin; SBCMV, primary HCMV isolate from a patient; TGF-beta, tumor growth factor-beta; TNF-alpha, tumor necrosis factor-alpha.