PD-1–PD-1 ligand interaction contributes to immunosuppressive microenvironment of Hodgkin lymphoma

Abstract

IntroductionProgrammed death-1 (PD-1), a member of the CD28 costimulatory receptor superfamily, inhibits T-cell activity by providing a second signal to T cells in conjunction with signaling through the T-cell receptor. 1 To date, B7-H1 and B7-DC have been identified as ligands for PD-1 (PD-Ls). During chronic viral infection, PD-1 is selectively up-regulated by the exhausted T cells, and blockade of this pathway restores CD8 ϩ T-cell function and reduces viral load. 2 This signaling system has been recently highlighted in the research of human immunodeficiency virus (HIV) infection. [3][4][5][6] In addition, PD-1 is indicated to be involved in the evasion of tumor immunity. [7][8][9][10] Hodgkin lymphoma (HL) is characterized by massive reactive infiltrates surrounding Hodgkin/Reed-Sternberg (H/RS) cells. HL patients are well recognized as having defective cellular immunity; they are susceptible to bacterial, fungal, and viral infections, and in vitro studies show depressed T-cell proliferation and reduced synthesis of Th1 cytokines. 11 We report here that PD-1-PD-L signaling system is operative in patients with HL, and tumor-infiltrating T cells around H/RS cells seem to be kept in balance by this inhibitory signaling. Our findings illuminate the mechanism for deficient cellular immunity observed in HL patients, and propose a potentially effective immunologic strategy for the treatment of HL. Methods Cell lines and clinical sample preparationThe following cell lines were described previously 12,13 : HL cell lines KM-H2, L428, and HDLM-2; anaplastic large cell lymphoma (ALCL) cell line DEL; follicular lymphoma cell line FL-218; diffuse large B-cell lymphoma (DLBCL) cell line KIS-1; Burkitt lymphoma cell lines Daudi, Raji, Middle 91, Tree 92, and Ramos; adult T-cell leukemia/lymphoma cell line HUT 102; and acute T-cell leukemia cell line Jurkat. LCL-OHN is an Epstein-Barr virus (EBV)-transformed lymphoblastoid B-cell line (LCL). Peripheral blood samples were collected from 19 HL patients, 12 B-NHL patients, and 11 healthy volunteers after informed consent was obtained in accordance with the Declaration of Helsinki. This study is approved by the institutional review board of Kyoto University. After removing red blood cells using ACK lysis buffer, leukocytes were subjected to flow cytometry. For immunohistochemistry, tissue specimens were snap-frozen in OCT compound (TissueTek, Tokyo, Japan) and stored at Ϫ80°C. Reverse transcription-polymerase chain reaction, flow cytometry, and immunohistochemistryTotal RNA was isolated from cells with Trizol (Invitrogen, Carlsbad, CA), and cDNA was synthesized using MultiScribe Reverse Transcriptase (Applied Biosystems, Foster City, CA). PCR assays were performed by the conventional method using Taq polymerase (TaKaRa Biotechnology, Shiga, Japan). For flow cytometry, cells were analyzed on a FACScan (Becton Dickinson, Mansfield, MS). The following antibodies were used: PEconjugated B7-H1 and B7-DC (eBioscience, San Diego, CA), FITC-PD-1 (BD Pharmingen, San Diego, CA), PC5-CD4 a...

Increase of programmed death-1-expressing intratumoral CD8 T cells predicts a poor prognosis for nasopharyngeal carcinoma

“…13,15,33 The high PD-1 þ -CD8 rate was significantly correlated with a poor prognosis in our study. In contrast, for follicular lymphoma, in which PD-1 is highly expressed by CD4 cells, higher PD-1 expression in TILs predicts improved overall survival.…”

“…7,9,10,12 Consistent with the idea that continuous exposure to tumor antigens may also facilitate the exhaustion of infiltrating lymphocytes in tumor tissue, recent studies have reported an association between PD-1 expression and the functional impairment of TILs in some cancers. [13][14][15] Nasopharyngeal carcinoma tumors, especially those of WHO type 2 and type 3 in the endemic areas, are characterized by a prevailing Epstein-Barr virus infection in cancerous cells with intensive lymphocytic infiltration and, therefore, represent a tissue microenvironment for both tumor development and chronic viral infection. 1 PD-1 expression in the TILs suggests that T-cell exhaustion may also occur in this cancer, which is supported by previous findings that the cytotoxic activity and cytokine production of T lymphocytes in nasopharyngeal carcinoma tumors are defective even if some of the TILs exhibit activated phenotypes.…”

“…Second, patients with high PD-1 þ -CD8 expression should be carefully monitored after treatments and considered for advanced therapies. 2 The inhibitory effects of PD-1 and B7-H1 can be overcome by certain immunoactivators, 36,37 and blocking PD-1 and B7-H1 restores the anti-tumor activity of TILs in some cancers, 14,15,22 which indicates that local immunosuppression in tumors can be reversed. Therefore, we hypothesize that alleviating the strong local immunosuppression of nasopharyngeal carcinoma by counteracting PD-1 and its ligands will not only improve the outcomes of Epstein-Barr virustargeted cancer immunotherapy, but also improve the efficacy of conventional nasopharyngeal carcinoma therapy.…”

“…[9][10][11][12] Recently, elevated PD-1 expression in intratumoral lymphocytes and its association with the functional impairment of TILs have also been reported in melanoma, hepatocellular carcinoma, and Hodgkin lymphoma. [13][14][15] However, reports on the prognostic value of PD-1 expression for cancer therapy, analyzed in only a few studies, are inconsistent. Increased PD-1 expression in intratumoral immune cells correlates with a poor clinical outcome in renal cell carcinoma and classical Hodgkin lymphoma, but is associated with improved overall survival in follicular lymphoma; [16][17][18] however, it is not significantly associated with the prognosis of pancreatic cancer.…”

Anti-γδ TCR antibody-expanded γδ T cells: a better choice for the adoptive immunotherapy of lymphoid malignancies

“…37,38 The PD1 ligand/PD1 signalling pathway mediates one of the tumour immune evasion strategies. [37][38][39] Following the initial activation, PD1 expression is transiently elevated, especially on Ab-expanded cells, in the first week. Fortunately, PD1 expression gradually decreased with time and reached a considerably low level over the next 2 weeks of the culture period.…”