Characterization of early immunological responses in primary cultures of differentially activated human peripheral mononuclear cells

Specific immune cell activation is a hallmark of infections and autoimmune disorders. Quantification of proliferative cell responses by H-3-thymidine incorporation is a slow process and describes only one type of cellular rea ction. We here investigated early immunological responses of purified human peripheral blood mononuclear cells to the direct stimulus alpha CD3 and an tigen specific stimulation (human myelin basic protein (hMBP), tetanus toro id, and influenza vaccine) and compared them to polyclonal LPS stimulation. Cytokine mRNA levels were quantified using real-time quantitative reverse transcriptase polymerase chain reaction (RT PCR) 4 h, 16 h, and 48 h after activation. Proliferation was measured 96 h after initiation of the culture s. Antigen specific responses were detected as early as 4 h after stimulati on and followed different kinetics depending on the mode of activation. We demonstrated significant correlations of cytokine mRNA and protein expressi on for TNF alpha, IL10, and IFN gamma. Expression of IL2 mRNA at 16 h was c orrelated with proliferation indices at 96 h whereas IL4 mRNA levels were n egatively correlated. Early cytokine mRNA expression in stimulated immune c ells provides important functional data and is a powerful tool with which t o study immunological reactions. (C) 2001 Elsevier Science B.V. All rights reserved.