Defective interferon-augmented natural killer cell activity in patients with metastatic malignant melanoma

Impaired Perforin-Dependent NK Cell Cytotoxicity and Proliferative Activity of Peripheral Blood T Cells is Associated with Metastatic Melanoma

Aims and Background

Patients with metastatic melanoma often have defects in the percentage and function of peripheral blood NK cells, which are involved in the non-specific innate antitumor immune response, and T cells, which participate in the specific acquired antitumor immune response. The aim of this study was to investigate in more detail not only the percentage but also the activation status and function of NK and T cells in patients with metastatic melanoma prior to therapy.

Methods

The percentage of peripheral blood CD56+ NK cells, CD3+ T cells and their CD4+ and CD8+ subsets, as well as the expression of the activation antigens CD69, CD38 and HLA-DR were analyzed by flow cytometry. The functional capacity of NK cells was evaluated by the 51-chromium release cytotoxicity assay, while the proliferative activity of T cells was estimated by the lymphocyte transformation test to mitogen phytohemagglutinin.

Results

The results obtained in this study have revealed a new aspect of NK and T cell dysfunction that is not, as commonly reported, associated with a decrease in their percentage. Moreover, a significant number of the investigated patients had a higher percentage of NK cells that did not lead to improved NK ceil cytotoxicity as a result of the detected defect in the NK cell perforin-mediated cytotoxic mechanism of tumor cell lysis. The impaired proliferative response of T cells was associated with a decreased expression of the activation antigen HLA-DR.

Conclusion

The novel finding in this study of melanoma patients with metastatic disease is the impaired perforin-depen-dent NK cell cytotoxic mechanism, which was recently shown to be primarily responsible for preventing metastasis. Another interesting finding was the generally hyporeactive status of T cells, possibly resulting from persistent antigenic stimulation. The observed dysfunction of NK and T cells in patients with metastatic melanoma prior to therapy point to the need to supplement chemotherapy with appropriate immunotherapeutic agents in order to overcome the immunosuppression associated with advanced malignancy.

Malignant melanoma and HIV infection -- aggressive course despite immune reconstitution

BACKGROUND

Highly active antiretroviral therapy (HAART) has altered the course of most AIDS-related malignancies. There is some evidence that cellular immunity plays an important role in the progression of metastatic melanoma.

CASE REPORT

We report on a patient suffering from metastatic melanoma and HIV infection. The 53-year-old man received HAART in order to use both its anti-tumor efficacy and its stimulating effect on cellular and humoral immune functions. Furthermore, our patient was treated with interleukin-2, a drug which has shown efficacy in metastatic melanoma and HIV infection.

RESULTS

Although the CD4 and CD8 cell count increased significantly, a fulminant progression of melanoma in the liver and spleen was noted, and the patient died subsequently.

CONCLUSION

This case describes that neither immune reconstitution through HAART nor interleukin-2 treatment were able to lead into an anti-tumor response. HIV-infected patients should be monitored routinely for an early diagnosis of this potentially lethal disease.

Malignant melanoma in an HIV-infected man: a case report and literature review

Although it is not proven by causative association, several studies indicate that patients with acquired immune deficiency syndrome (AIDS) have a high risk for developing cutaneous malignancies, especially lymphoma and Kaposi's sarcoma. Other malignant cutaneous lesions seen in this patient population include basal-cell carcinoma, squamous-cell cancer, Bowen's disease, and rarely, malignant melanoma. We review the clinical course of a human immunodeficiency virus (HIV)-infected man with a superficial spreading melanoma of the scapula treated with wide local excision. Ten years later, he was diagnosed as having metastatic and widespread disease. By placing our patient's experience in context with other case reports, we sought to determine whether malignant melanoma in the HIV-infected population presents atypically or has a more aggressive natural history. The appearance of malignant melanoma in homosexual men may be coincidental or reflective of the expanding spectrum of HIV-associated diseases. Of the 22 patients reported to have malignant melanoma and HIV, approximately one-third had metastatic disease at the time of initial examination, and those with a decreased CD4+ cell count were most likely to have systemic symptoms. Melanomas among patients with HIV infection were often atypical in appearance, being multiple or metastatic, as is the case in other well-defined immunosuppressed groups. Further epidemiological and clinical studies are required to determine whether melanoma occurs more frequently or is more likely to metastasize in persons with HIV disease. Laboratory investigators must also concentrate on those factors in the setting of HIV disease that may contribute to melanocyte activation. Our patient's fulminant clinical course should alert clinicians to carefully evaluate patients with HIV infection and unusual pigmented cutaneous lesions, or who have a prior history of malignant melanoma.

Human autologous tumor-specific T cells in malignant melanoma

T cell lines and clones with autologous tumor-specific activity have been developed in malignant melanoma by stimulating peripheral blood lymphocytes (PBL), lymph node lymphocytes or tumor-infiltrating lymphocytes (TIL) with autologous melanoma cells in the presence of recombinant interleukin 2 (rIL2). T-cell lines and clones have been developed with specific cytotoxicity and/or proliferative responses for autologous melanoma targets but not for allogeneic melanoma tumor cells, autologous normal cells or natural killer (NK)-sensitive targets. The concentration of rIL2 is critical for the generation of autologous tumor-specific T-cell lines, with low rIL2 concentrations (up to 800 IU/ml) facilitating the growth of T-cell lines with tumor-specific activity. The alpha beta T-cell receptor (TCR) and the CD3 antigen are involved in specific cytotoxicity and/or proliferative responses of these T-cell lines and clones. An oligoclonal pattern of beta-chain TCR gene rearrangements was observed on T-cell lines and clones with autologous tumor-specific cytotoxicity, suggesting that they are comprised of T cells that have undergone a clonal expansion in response to particular antigen. Autologous tumor-specific cytotoxic T cells are HLA-restricted and recognize on the melanoma tumor cells HLA Class I or possibly Class II antigens plus a tumor-specific determinant. TIL from patients with metastatic melanoma have unique characteristics in comparison with PBL and lymph node lymphocytes and they appear to contain substantial proportions of T cells that have been locally sensitized to autologous tumor cells. Single stimulation of TIL with autologous tumor cells in the presence of rIL2 is sufficient for the generation of T cell lines with autologous tumor-specific activity, whereas, multiple stimulation of PBL and lymph node lymphocytes was required to achieve the same purpose. TIL-derived T cell lines have been expanded in rIL2 in vitro by at least 1,500-fold without losing their activity. Approximately, 40% of the patients exhibited complete or partial responses to adoptive immunotherapy with melanoma TIL and rIL2.