Chemokine expression in melanoma metastases associated with CD8+ T-cell recruitment.
Despite the frequent detection of circulating tumor antigen-specific T cells, either spontaneously or following active immunization or adoptive transfer, immune-mediated cancer regression occurs only in the minority of patients. One theoretical rate-limiting step is whether effector T cells successfully migrate into metastatic tumor sites. Affymetrix gene expression profiling done on a series of metastatic melanoma biopsies revealed a major segregation of samples based on the presence or absence of T-cell-associated transcripts. The presence of lymphocytes correlated with the expression of defined chemokine genes. A subset of six chemokines (CCL2, CCL3, CCL4, CCL5, CXCL9, and CXCL10) was confirmed by protein array and/or quantitative reverse transcription-PCR to be preferentially expressed in tumors that contained T cells. Corresponding chemokine receptors were found to be up-regulated on human CD8(+) effector T cells, and transwell migration assays confirmed the ability of each of these chemokines to promote migration of CD8(+) effector cells in vitro. Screening by chemokine protein array identified a subset of melanoma cell lines that produced a similar broad array of chemokines. These melanoma cells more effectively recruited human CD8(+) effector T cells when implanted as xenografts in nonobese diabetic/severe combined immunodeficient mice in vivo. Chemokine blockade with specific antibodies inhibited migration of CD8(+) T cells. Our results suggest that lack of critical chemokines in a subset of melanoma metastases may limit the migration of activated T cells, which in turn could limit the effectiveness of antitumor immunity.
Harlin
Helena
H
Department of Pathology, The University of Chicago, Chicago, Illinois 60637, USA.
Meng
Yuru
Y
Peterson
Amy C
AC
Zha
Yuanyuan
Y
Tretiakova
Maria
M
Slingluff
Craig
C
McKee
Mark
M
Gajewski
Thomas F
TF
D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000276:immunology; D018925:Chemokines / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D008545:Melanoma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D005810:Multigene Family; D040081:Protein Array Analysis
D018925:Chemokines