The Journal of immunology : official journal of the American Association of Immunologists
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Sepsis is characterized by a disproportionate host response to infection that often culminates in multiple organ failure. Current concepts invoke a deregulated immune reaction involving features of hyperinflammation, as well as protracted immune suppression. However, owing to the scarcity of human data, the precise origin of a long-term suppression of adaptive immunity remains doubtful. ⋯ However, T cells from CCI patients exhibited no suppressed TCR response at the level of proximal TCR signaling (activation/phosphorylation of PLCγ, Erk, Akt, LAT), activation marker upregulation (CD69, CD25, CD154, NUR77), IL-2 production, or clonal expansion. Rather, our data illustrate an augmented response in T cells from CCI patients in response to TCR/coreceptor (CD3/CD28) challenge. Thus, the present findings reveal that CCI sepsis patients feature signs of immune suppression but that their T cells exhibit a primed, rather than a suppressed, phenotype in their TCR response, arguing against a generalized T cell paralysis as a major cause of protracted immune suppression from sepsis.