Long V. Ly

Detection of M2-Macrophages in Uveal Melanoma and Relation with Survival

PURPOSE The presence of a high number of infiltrating macrophages in uveal melanoma is associated with a bad prognosis. However, there are several known types of macrophages, of which the M2 is considered to be proangiogenic and tumor-promoting. This study was conducted to determine whether the tumor-infiltrating macrophages in uveal melanoma are of this M2 subtype. METHODS Macrophages were identified in sections from 43 uveal melanomas by immunofluorescence histochemistry, using monoclonal antibodies directed against CD68 and CD163. The immunopositive cell density was measured visually and with a confocal microscope and calculated per square millimeter. Results were compared with clinical and tumor characteristics. RESULTS Infiltrating macrophages in uveal melanoma were predominantly CD68(+)CD163(+), thus of the M2 phenotype. The density of CD68(+), CD163(+), and CD68(+)CD163(+) cells was significantly increased in uveal melanomas with monosomy 3 compared with cases with disomy of chromosome 3 and was associated with ciliary body involvement. High CD68(+)CD163(+) staining was associated with an increased microvascular density. Survival was significantly better among patients with low CD68(+) and CD68(+)CD163(+) staining. CONCLUSION The main type of macrophage present in uveal melanoma was the M2 type. Tumors with monosomy of chromosome 3 contained a higher number of M2-macrophages than tumors with disomy of chromosome 3. Infiltration of M2-type macrophages gives a worse prognosis for survival. As M2-type macrophages are proangiogenic, a high density of these cells may contribute to the previously noticed positive association between the density of CD68(+) macrophages and blood vessels.

Monosomy of chromosome 3 and an inflammatory phenotype occur together in uveal melanoma.

PURPOSE In uveal melanoma, different predictors of poor prognosis have been identified, including monosomy of chromosome 3, HLA expression, and the presence of infiltrating leukocytes and macrophages. Each of these parameters can be used to differentiate prognostically the favorable tumors from the unfavorable ones, and thus the hypothesis for the present study was that they are related, and that monosomy of chromosome 3 occurs in the same tumors as the unfavorable inflammatory phenotype. METHODS Tumor tissue was obtained from 50 cases of uveal melanoma treated between 1999 and 2004. After enucleation, nuclei were isolated from paraffin-embedded tissue for fluorescence in situ hybridization, to determine the chromosome 3 copy number. Each tumor-containing globe was further processed for conventional histopathologic examination and for immunohistochemical analysis with HLA class I and II-specific antibodies and with macrophage marker CD68. RESULTS Of 50 uveal melanomas, 62% (31/50) were categorized as having monosomy of chromosome 3. Monosomy 3 was associated with the presence of epithelioid cells, an increased density of tumor-infiltrating macrophages, and a higher HLA class I and II expression. Survival analyses showed a correlation between monosomy 3 and decreased survival and identified monosomy 3, ciliary body involvement, and largest basal tumor diameter as the best prognostic markers. CONCLUSIONS Monosomy 3 in uveal melanoma is associated with the presence of an inflammatory phenotype, consisting of a high HLA class I and II expression as well as an increased number of tumor-infiltrating macrophages. In a multivariate Cox regression analysis, the presence of monosomy 3 was one of the best prognostic markers of metastatic disease and survival, although the follow-up time was short.

In Aged Mice, Outgrowth of Intraocular Melanoma Depends on Proangiogenic M2-Type Macrophages

Macrophages are part of the tumor microenvironment and have been associated with poor prognosis in uveal melanoma. We determined the presence of macrophages and their differentiation status in a murine intraocular melanoma model. Inoculation of B16F10 cells into the anterior chamber of the eye resulted in rapid tumor outgrowth. Strikingly, in aged mice, tumor progression depended on the presence of macrophages, as local depletion of these cells prevented tumor outgrowth, indicating that macrophages in old mice had a strong tumor-promoting role. Immunohistochemistry and gene expression analysis revealed that macrophages carried M2-type characteristics, as shown by CD163 and peroxisome proliferator-activated receptor γ expression, and that multiple angiogenic genes were heavily overrepresented in tumors of old mice. The M2-type macrophages were also shown to have immunosuppressive features. We conclude that tumor-associated macrophages are directly involved in tumor outgrowth of intraocular melanoma and that macrophages in aged mice have a predisposition for an M2-type profile.

Peptide Vaccination after T-Cell Transfer Causes Massive Clonal Expansion, Tumor Eradication, and Manageable Cytokine Storm

Adoptive T-cell transfer (ACT) is successfully applied as a cancer treatment that is based on the activation and effector functions of tumor-specific T cells. Here, we present results from a mouse model in which ACT is combined with a long peptide-based vaccine comprising gp100 T-cell epitopes. Transferred CD8(+) T cells expanded up to 1,000-fold after peptide vaccination, leading to a 3-fold increase in white blood cell count and a very high frequency in the generation of antigen-specific memory T cells, the generation of which tended to correlate with effective antitumor responses. An enormous pool of effector T cells spread widely to different tissues, including the skin and the immune-privileged eye, where they mediate tumor eradication. Importantly, these striking T-cell dynamics occurred in immunocompetent mice without prior hematologic conditioning. Continued activation of the specific T-cell pool by vaccination led to strong T-cell-mediated cytokine storm and lethality due to multi-organ failure. However, this immunopathology could be prevented by controlling the rapid biodistribution of the peptide or by using a weakly agonistic peptide. Together, these results identify a peptide vaccination strategy that can potently accentuate effective ACT in non-lymphodepleted hosts.

Inflammatory cytokines in eyes with uveal melanoma and relation with macrophage infiltration.

PURPOSE The presence of an inflammatory phenotype, characterized by an increased expression of HLA antigens and an immunologic infiltrate, carries a bad prognosis in uveal melanoma. This study was conducted to determine whether the aqueous humor (AqH) from eyes with uveal melanoma contains inflammatory cytokines and whether their presence is associated with inflammation. METHODS Immediately after enucleation, AqH was obtained from 37 eyes containing uveal melanoma. Samples were stored at -80°C until use. Fifteen different cytokines were measured with a multiplex bead array. Intratumoral macrophages were analyzed by immunohistochemistry and immunofluorescence staining. The presence of specific cytokines was compared with histopathologic, genetic, and clinical tumor characteristics, as well as patient survival. RESULTS Several cytokines showed significantly higher expression in the AqH of uveal melanoma-containing eyes than in the AqH of eyes undergoing cataract surgery. MCP-3 was associated with the presence of CD68(+) macrophages. Correlations were found between some cytokine levels and a few known prognostic factors of uveal melanoma, but cytokine levels were not of predictive value for survival. CONCLUSIONS Uveal melanoma-containing eyes often carry increased levels of inflammation-related cytokines in their AqH. However, the presence of most specific cytokines was not related to the presence of macrophages, clinical or histopathologic parameters, or prognosis.

Evidence for Natural Killer Cell-Mediated Protection from Metastasis Formation in Uveal Melanoma Patients

PURPOSE In uveal melanoma, low human leukocyte antigen (HLA) class I expression on primary tumors is associated with a decreased risk of metastasis. Consequently, it has been suggested that natural killer (NK) cells, which detect decreased expression of HLA class I, are involved in the immune control of metastases. In this study, three novel lines of evidence were identified that support a role for NK cells. METHODS Uveal melanoma cell lines were used to determine the expression of NK cell receptor ligands (MICA, MICB, ULBP1-3, CD112, CD155, and HLA class I) and to examine sensitivity to lysis by human NK cell lines. Because interactions between polymorphic killer immunoglobulin receptors (KIRs) and HLA regulate NK cell function, KIR and HLA genotyping was performed on 154 patients with uveal melanoma and 222 healthy control subjects. RESULTS First, all 11 uveal melanoma cell lines tested expressed ligands for activating as well as inhibitory NK cell receptors. Second, such cell lines were lysed efficiently by human NK cells in vitro. Finally, the HLA-C genotype was related to the risk of metastasis-related death in patients with uveal melanoma: The patients carrying HLA-C alleles encoding ligands for KIR2DL1 and KIR2DL2/3 (HLA-C group 1/group 2 heterozygous patients), both inhibitory NK receptors, had a longer metastasis-free survival than did those carrying HLA-C ligands for either KIR2DL1 (HLA-C group 2 homozygotes) or KIR2DL2/3 (HLA-C group 1 homozygotes). CONCLUSIONS Together, the data support a role for NK cells in the prevention of uveal melanoma metastases.

Impact of Tumor-Associated Macrophages in LHBETATAG Mice on Retinal Tumor Progression: Relation to Macrophage Subtype

PURPOSE To determine the distribution of tumor-associated macrophages (TAMs) during retinoblastoma tumor development, examine the contribution of bone marrow-derived TAMs in retinoblastoma tumors, and evaluate the supportive role of TAMs in tumor growth in a transgenic retinoblastoma mouse model. METHODS The time course of macrophage infiltration in transgenic retinoblastoma tumors was assessed by immunohistochemistry at different time points in tumorigenesis. The origin of TAMs in transgenic retinoblastoma tumors was determined by transplanting 10(7) bone marrow cells from green fluorescent protein (GFP)-positive 16-week-old mice into age-matched, irradiated LH(BETA)T(AG) mice via tail vein injections. Macrophage depletion was performed by subconjunctival (SC) delivery of liposomal clodronate. RESULTS The density of TAMs increased from 4 to 12 weeks of age in mice with small to medium tumors (P = 0.037) and remained stable in the later stages of disease (i.e., 16 weeks old with large tumors; P = 0.20). In 16-week-old mice, 38% (2.5 +/- 3.2 cells per 400x high-power field) of TAMs were GFP-positive, bone marrow-derived macrophages. Total TAM depletion was associated with a significant decrease in the expression levels of MMP-9 (P = 0.014) and mature vessels (P < 0.001) and a nonsignificant decrease in the density of neovessels (P = 0.94). The density of M2-polarized TAMs did not change significantly after TAM depletion (P = 0.68). After M1-polarized TAM depletion, the tumor burden increased (P = 0.056). CONCLUSIONS This work extends understanding of the complex role that macrophages play in retinoblastoma. Macrophage modulation in the tumor microenvironment is a critical factor in retinoblastoma tumor progression.

Three Generations of Eminent American Chinese: Lives Intertwined With History

This article describes the lives of 3 generations of a remarkable American Chinese family, who all excelled in their achievements. Grandfather Chan Loon Teung was the first Chinese Harvard graduate; the father, Eugene Chan, and his wife, Winifred Mao, were famous ophthalmologists, working in the United States and in China, and their daughter, Chi-Chao Chan, is a specialist in ophthalmic pathology and uveitis at the National Institutes of Health in the United States. Although the different generations all encountered dramatic situations caused by political turmoil, such as the Xinhai Revolution, World War II, and the cultural revolution in China, this did not prevent them from making major contributions to their home countries and ophthalmology. The history of this family as depicted in this article illustrates what perseverance and passion can achieve.