RESUMO
Polymorphonuclear neutrophils [PMN] have contributed only to the innate immune response, due to their phagocytosis activity. They have a short life time. Some studies of PMN cytokine production and expression of numerous cell surface proteins have suggested that PMN are likely to influence adaptive responses and may satisfy the criteria of antigen presenting cells. Flow cytometry was used in the present study for the detection of cell surface major histocompatibility complex [MHC] class II, CD80 and CD86 required for antigen presentation and subsequent T-cell activation. Human peripheral blood neutrophils were used for this purpose. In vitro stimulation of PMN with IL-2 or IL-4 for 24 h showed expression of MHC class II, CD80 and CD86. These observations, therefore, provide support to the hypothesis that human PMN have the potential to express molecules required for antigen presentation