CXCR3-mediated opposite effects of CXCL10 and CXCL4 on TH1 or TH2 cytokine production.
BACKGROUND
Two variants of the CXCR3 receptor exist, one (CXCR3-A) reactive with CXCL9, CXCL10, and CXCL11 and the other (CXCR3-B) also reactive with CXCL4. Both variants are contemporarily expressed by human T cells.


OBJECTIVE
We sought to investigate the in vitro effects of CXCL10 and CXCL4 on the production of TH1 or TH2 cytokines.


METHODS
The cytokine profile of antigen-specific human CD4+ T-cell lines obtained in the absence or presence of CXCL10 or CXCL4 was evaluated by means of quantitative RT-PCR, flow cytometry, and ELISA.


RESULTS
CXCL10 upregulated IFN-gamma and downregulated IL-4, IL-5, and IL-13 production, whereas CXCL4 downregulated IFN-gamma and upregulated TH2 cytokines. Similar effects were also observed on polyclonally activated pure naive CD4+ T cells. The opposite effects of CXCL10 and CXCL4 on TH1 and TH2 cytokine production were inhibited by an anti-CXCR3 antibody able to neutralize both CXCR3-A and CXCR3-B and were apparently related to the activation of distinct signal transduction pathways. Moreover, CXCL10 upregulated mRNA levels of T-box expressed in T cells and downregulated GATA-3 expression, whereas CXCL4 downregulated T-box expressed in T cells and upregulated GATA-3. Finally, CXCL4, but not CXCL10, induced direct activation of IL-5 and IL-13 promoters.


CONCLUSIONS
CXCL10 and CXCL4 exert opposite effects on the production of human TH1 and TH2 cytokines, likely through their respective interaction with CXCR3-A or CXCR3-B and the consequent activation of different signal transduction pathways. This might represent an internal regulatory pathway of TH cell responses and might contribute to the modulation of chronic inflammatory reactions, including allergy.
Romagnani
Paola
P
Center for Research, Transfer, and High Education "DENOthe," University of Florence, Italy.
Maggi
Laura
L
Mazzinghi
Benedetta
B
Cosmi
Lorenzo
L
Lasagni
Laura
L
Liotta
Francesco
F
Lazzeri
Elena
E
Angeli
Roberta
R
Rotondi
Mario
M
Filì
Lucia
L
Parronchi
Paola
P
Serio
Mario
M
Maggi
Enrico
E
Romagnani
Sergio
S
Annunziato
Francesco
F
D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis*; D050990:GATA3 Transcription Factor / Q000235:genetics; D006801:Humans; D010978:Platelet Factor 4 / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000502:physiology*; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
C114753:CXCL10 protein, human; C515187:CXCR3 protein, human; D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D016207:Cytokines; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; C064936:PF4V1 protein, human; D012333:RNA, Messenger; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine; D010978:Platelet Factor 4