T-Cell Distribution and Adhesion Receptor Expression in Metastatic Melanoma

Abstract

Purpose: Metastatic malignant melanoma is a devastating disease with a poor prognosis. Recent therapeutic trials have focused on immunotherapy to induce development of endogenous antitumor immune responses. To date, such protocols have shown success in activation of tumor-specific CTL but no overall improvement in survival. To kill tumor, antigen-specific CTL must efficiently target and enter tumor tissue.The purpose of this study was to examine the pathway of leukocyte migration to metastatic melanoma. Experimental design: Peripheral blood and metastatic melanoma tissues (n = 65) were evaluated for expression of adhesion molecules using immunohistochemistry of tumor sections and flow cytometry of tumor-associated and peripheral blood CTL and compared with healthy controls. CTL expressing T-cell receptors for the melanoma antigen MART-1 were identified in a subset of samples by reactivity with HLA-A2 tetramers loaded with MART-1peptide. Results: Results show that the majority of metastatic melanoma samples examined do not express the vascular adhesion receptors E-selectin (CD62E), P-selectin (CD62P), and intercellular adhesion molecule-1 (CD54) on vessels within the tumor boundaries. Strong adhesion receptor expression was noted on vessels within adjacent tissue. Tumor-associated T lymphocytes accumulate preferentially in these adjacent areas and are not enriched for skin-or lymph node^homing receptor phenotype. Conclusion: Expression of leukocyte homing receptors is dysregulated on the vasculature of metastatic melanoma. This results in a block to recruitment of activated tumor-specific CTL to melanoma metastases and is a likely factor limiting the effectiveness of current immunotherapy protocols.Despite significant effort and investment in clinical care and research, effective therapeutic options for treatment of metastatic malignant melanoma remain elusive. Because trials of chemotherapeutic drugs have not been satisfactory, significant interest has been directed toward immunotherapy protocols designed to induce or augment an endogenous immune response to the tumor. A variety of such clinical trials have been published, including infusions of ex vivo expanded melanoma-specific CTL (1 -4); vaccination with melanoma antigen -loaded antigen presenting cells (5 -8); transfection of tumor cells with granulocyte macrophage colony-stimulating factor (9); treatment with granulocyte macrophage colony-stimulating factor plus FLt3 ligand (10), interleukin 12 (11, 12), or IFN-g (13); and, most recently, transfection of CTL with a MART-1 -specific T-cell receptor (14). Although activation of tumor-specific CTL and occasional complete clinical responses have been documented in many of these trials, they have not, in general, altered the mean survival times for the majority of patients.CTL recruitment to and infiltration of metastatic tumors is an essential component of an effective immune response to melanoma. Prior studies have shown that lymphocyte infiltration is associated with spontaneous regression of primar...

Targeted regulation of a lymphocyte-endothelial-interleukin-6 axis by thermal stress

“…Moreover, intratumoral vessels in murine tumor models (e.g., RIP-Tag5 pancreatic tumors, EMT6 mammary tumors, CT26 colon tumors, B16 melanoma) poorly express primary adhesion molecules (e.g., E-selectin), chemokines (e.g., CXCL9, CXCL10) or prototypical arrest molecules such as intercellular adhesion molecule-1 (ICAM-1) or vascular adhesion molecule-1 (VCAM-1) [23,25,26,[42][43][44][45][46][47][48]. These observations in murine tumors correspond with histologic studies showing limited expression of adhesion molecules and chemokines in the intratumoral region of human tumors [23,25,26,42,45,[49][50][51].…”

IL-6 trans-signaling licenses mouse and human tumor microvascular gateways for trafficking of cytotoxic T cells

“…We further determined that the moderate intravascular density of ICAM-1 detected on tumor vessels was not sufficient to support efficient extravasation of CD8 + Teffs. These findings provide a functional explanation for the modest steadystate level of infiltration observed for endogenous or adoptively transferred CD8 + T cells in murine tumors (B16, RIP-Tag5) (27,28,36,38) or patient tumors (metastatic melanoma, squamous cell skin carcinoma) (39,40) in regions where vessels were weakly immunostained for E-selectin, ICAM-1, or VCAM-1. When the function of tumor-reactive T cells was monitored after bolus infusion under conditions commonly used in preclinical and clinical protocols to boost circulating Teff populations (3), we found that basal trafficking of CD8 + Teffs across tumor vessels was insufficient to mediate apoptosis of tumor targets.…”

The Role of the Tumor Vasculature in the Host Immune Response: Implications for Therapeutic Strategies Targeting the Tumor Microenvironment

“…However, this inflammatory environment appears to fail to induce the expression of vascular adhesion molecules on intratumoral vessels. This has been demonstrated in experimental models of melanoma and carcinoma (81), as well as in human cutaneous squamous cell carcinoma, Merkel cell carcinoma, and metastatic melanoma tissue (74, 75, 82). This lack of responsiveness to inflammatory signals has been termed endothelial anergy (83) and may play an important role in the exclusion of antitumor immune effector cells from the tumor microenvironment.…”