Interleukin-6 expression in human neutrophil and eosinophil peripheral blood granulocytes

Abstract

Human peripheral blood granulocytes were analyzed for expression of interleukin-6 (IL-6) using reverse-transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization. Neutrophil granulocytes from healthy donors were shown to express variable levels of IL-6. This expression was rapidly down-regulated after the removal of the cells from the circulating blood. In vitro culture of neutrophils abolished IL-6 expression, which could be reactivated by addition of GM-CSF to the culture medium. Constitutive expression of IL-6 was instead demonstrated in eosinophil granulocytes purified from normal donors and from a hypereosinophilic patient. In situ hybridization of unstimulated granulocytes confirmed that IL-6 expression occurs both in eosinophils and in neutrophils from peripheral blood. These findings show that granulocytes can actively contribute to cytokine expression in the peripheral blood and suggest their role in the afferent limb of the immune response, since by IL-6 production they might modulate T- and B- lymphocyte functions, granulocyte self-priming, and endothelial interaction.

Differential interleukin‐6 mRNA expression in Nippostrongylus brasiliensis infection of susceptible and resistant strains of mice

“…The role of eosinophilia in parasite infection is problematic, because both pathogenesis and protection have been attributed to their activities 10 . Based on our findings in the gut and reports that eosinophils 3 and mast cells 4 can also produce IL‐6 mRNA, we speculate that some of these IL‐6 mRNA + cells in the gut are eosinophils and/or mast cells. Whether IL‐6 is an autocrine or paracrine factor in this leucocytosis is currently being investigated.…”

“…Interleukin‐6 plays an important role in host defence mechanisms regulating both inflammatory and immune responses. The expression of IL‐6 has been reported in eosinophils, neutrophils 3 and mast cells; 4 it has been implicated in granulocyte recruitment, 5 self‐priming 6 and regulation 7 and may be necessary for optimal granulocyte function. Intestinal eosinophilia and mastocytosis are consistent features of host immunity to gastrointestinal parasite infection.…”

Target site search and effective inhibition of leukaemic cell growth by a covalently closed multiple anti-sense oligonucleotide to c-myb

“…C-myb is important in the proliferation of leukocytes. AS-oligos to c-myb have been observed to inhibit leukaemic cell growth [2][3][4][5][6][7]. We examined the inhibition of leukaemic cell growth by the c-myb CMAS-oligo.…”

“…The result shown here demonstrates the rationale for this approach in locating a good target site. In many anti-sense studies, the region encompassing the translational start site has been adopted for a target site [2,24]. However, in the c-myb mRNA is a quartet of G residues on the 3h side of the translational start codon.…”

“…Anti-sense oligonucleotides (AS-oligos) have been valuable in the functional study of genes by decreasing gene expression in a sequence-specific manner [1][2][3]. Intense efforts have also been made to develop molecular anti-cancer agents by ablating the aberrant expression of genes involved in tumour initiation and progression [4][5][6][7][8][9][10].…”