Expression of HLA‐DR antigens in nasopharyngeal carcinoma: An immunohistological analysis of the tumour cells and infiltrating lymphocytes

Abstract

A panel of conventional and monoclonal antibodies was used to examine the immunohistological characteristics of malignant epithelial cells and infiltrating lymphocytes in frozen sections of nasopharyngeal carcinoma (NPC) biopsies from 10 Tunisian patients. Three main categories of cells were identified. (1) Tumour cells which were positive for Epstein-Barr nuclear antigen, HLA-ABC and keratin determinants. In most samples, the tumour cells also expressed variable amounts of HLA-DR antigens. The presence of HLA-DR antigens has not been previously reported in NPC and may be a contributory factor in effecting the transfer of Epstein-Barr virus to the epithelial cells. (2) Infiltrating lymphocytes which were mainly composed of T inducer (T4+) and T suppressor/cytotoxic (T8+) cells although one sample contained predominantly immature T cells expressing the HTA-I+ cortical thymocyte phenotype. Few B cells or natural killer cells were demonstrated. (3) Large HTA-I+ dendritic cells which were invariably present within the tumour masses. These were morphologically and phenotypically similar to antigen presenting Langerhans cells which are usually located in the skin but also found in other epithelial sites. These cells may be a residual population from the normal nasopharynx or represent part of a specific immunological response to the presence of Epstein-Barr virus in the epithelial cells.

Epstein-Barr Virus-specific Transcription in Normal and Malignant Nasopharyngeal Biopsies and in Lymphocytes from Healthy Donors and Infectious Mononucleosis Patients

“…It is therefore conceivable that differences in virus gene expression may correlate with different EBV-associated diseases, particularly in the case of NPC which seems to be the only pathological instance in which EBV is found in a cell type other than Bqymphoid. Although NPC tissue is heavily infiltrated with 0000-7424 © 1987 SGM lymphocytes, these are predominantly T cells which are resistant to infection by EBV (Lemon et al, 1977 ;Thomas et al, 1984) and viral DNA is present only in the epithelial cells (Wolf et al, 1973).…”

Potential Selection of LMP1 Variants in Nasopharyngeal Carcinoma

“…Patients have elevated titers of antibodies to multiple EBV proteins, and T cells infiltrate the tumor without apparent cytotoxicity (29,30,50,59,68,88). It is possible that this immune evasion may be due to changes in CTL-recognized viral epitopes, since MHC-I and transporter-associated proteins (TAP-1 and -2) are still expressed within tumors and may be upregulated by LMP1 (44,51,65).…”

CTL Control of EBV in Nasopharyngeal Carcinoma (NPC): EBV-Specific CTL Responses in the Blood and Tumors of NPC Patients and the Antigen-Processing Function of the Tumor Cells

“…Equally, it is important to determine whether such effectors can access and function at the tumor site. NPC is characterized by a large lymphocytic infiltrate comprised mainly of T cells, including both CD4 ϩ and CD8 ϩ cells (22), although the antigenic specificity of these lymphocytes is unknown. A further requirement for an effective CTL-based therapy is that the tumor must be capable of processing and presenting the target Ag to a CTL through the TAP-dependent HLA class I processing pathway.…”