Recombinant gamma interferon induces HLA-DR expression on squamous cell carcinoma, trichilemmoma, adenocarcinoma cell lines, and cultured human keratinocytes

Treatment of Basal Cell Carcinoma with Intralesional Interferon Alpha-2b

We report a series of 11 basal cell carcinomas of various types treated with nine intra-lesional injections of 1.5 million units of interferon alpha-2b. The diagnosis was confirmed histologically in each case.

After 3 months' follow-up six tumours had resolved both clinically and histologically. In three cases the tumour size was reduced. One tumour grew larger. Side effects were well tolerated except by one subject who was withdrawn. Those cases which responded have now been followed-up for between 12 and 26 months with no clinical or histological evidence of tumour recurrence.

This is the longest period of follow-up so far reported for this novel treatment. The results are encouraging and, if maintained in future series, may indicate a useful role for interferon alpha in the management of this common cutaneous malignancy.

Immunisation with modified HPV16 E7 genes against mouse oncogenic TC-1 cell sublines with downregulated expression of MHC class I molecules

Human papillomavirus type 16 (HPV16)-transformed mouse TC-1 cells are extensively used in the evaluation of efficacy of experimental vaccines against tumours induced by HPVs. As these cells strongly express MHC class I molecules and downregulation of MHC class I surface expression is one of the important mechanisms that enable tumour escape from the host immune system, we undertook to derive TC-1 clones with reduced expression of MHC class I antigens. TC-1 cells were inoculated into mice preimmunised with an E7 gene-based DNA vaccine and from tumours developing in a portion of the animals, cell clones with downregulated MHC class I surface expression were isolated. Treatment with IFN-gamma resulted in an upregulation of MHC class I molecules in these cells, but after IFN-gamma removal, their expression gradually dropped again. When the expression of some components of the antigen-processing machinery (APM; LMP-2, TAP-1, and TAP-2) was tested, a reduced TAP-1 production was detected in cell lines with downregulated MHC class I expression. An enhanced immunoresistance of TC-1-derived clones with reduced MHC class I expression was observed in animals immunised with plasmids carrying modified E7 genes. Apart from the previously described fusion gene Sig/E7/LAMP-1, a new construct, Sig/E7GGG/LAMP-1, with a mutated Rb-binding site, was also used for immunisation. No significant change of immunogenicity was recorded for Sig/E7GGG/LAMP-1. Cell lines with downregulated MHC class I expression derived from TC-1 cells may represent a useful model for testing therapeutic anti-HPV vaccines in settings more relevant to clinical requirements.

1 alpha,25-dihydroxy vitamin D3 modulation of HLA-DR mRNA induced by gamma-interferon in cultured epithelial tumor cell lines

Using three cultured epithelial tumor cell lines, we investigated and analyzed the effects of gamma-interferon (gamma-IFN) and 1 alpha,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on the levels of HLA-DR (alpha) mRNA and HLA-DR (beta) mRNA by Northern blot analysis. After treatment with gamma-IFN alone, the levels of the mRNA increased. Treatment with both gamma-IFN and 1,25-(OH)2D3 at the same time resulted in a significant decrease in the levels of mRNA in K-TL-1, IK-TL-2, and M-TL cells as compared to those induced by gamma-IFN alone.

Common histopathological processes of phenytoin drug eruption

Fifteen patients (6 males and 9 females) with phenytoin drug eruptions which ultimately resulted in various skin manifestations were analyzed histopathologically. The following types of skin manifestations were noted; 2 cases of toxic epidermal necrolysis, 2 cases of mucocutaneous ocular syndrome, 6 cases of erythema exudative multiform, 3 cases of lichenoid, and 2 cases of the maculopapular type. All of the biopsied specimens from these different skin manifestations exhibited some of the more common histopathological findings: 1) adhesion of the infiltrated cells to the basal layer of the epidermis, 2) cell infiltration into the epidermis, 3) vacuolation of the basal cells, 4) dyskeratotic cells in the epidermis, and epidermal necrosis. Immunohistopathological examinations in 5 typical cases with different skin manifestations revealed that epidermal cells and infiltrating cells were HLA-DR antigen positive. The infiltrating cells in the dermis consisted of almost equal numbers of CD4+ and CD8+ cells; CD8+ cells were predominant in the cells infiltrating into the epidermis. These findings suggest a possibility that the various clinical features in phenytoin drug eruptions may share some common mechanisms.

Evidence for accessory cell function by class II MHC antigen-expressing airway epithelial cells

Expression of major histocompatibility complex (MHC) class II antigens is a requirement for accessory cell function in antigen presentation. Recent reports have demonstrated the presence of class II antigens on human bronchial epithelial cells. In the present study, immunohistochemical staining revealed HLA-DR on human airway epithelial cells obtained from two different mucosal sites (lobar bronchus and nasal turbinates). To determine whether airway epithelial cells bear functional class II molecules that allow for their cognate interaction with T lymphocytes, cells isolated from these sites were used in mixed lymphocyte cultures (MLR), as an in vitro model of accessory cell function. Freshly isolated cells (11 bronchi/3 turbinates) stimulated allogeneic T lymphocytes (stimulation index [S.I.] = 9.3 [mean]; P less than 0.001 compared to T cells alone). In order to assess the potential role of contaminating conventional accessory cells, bronchial epithelial cell isolates were first preincubated in a serum-free, growth factor-supplemented medium that functionally eliminates potential non-epithelial stimulators prior to MLR culture. Conventional accessory cell-depleted epithelial cells were still capable of stimulating allogenic T lymphocytes in 18 of 23 MLR cultures (S.I. = 5.5 [mean]; P less than 0.0005 compared to T cells alone). The addition of an anti-class II monoclonal antibody (VG2.2) at the onset of culture completely inhibited the MLR response (n = 10). No shift in the CD4+/CD8+ ratio was detected between lymphocytes harvested from airway epithelial cell MLR (1.42 +/- 1.29) and the ratio from T lymphocytes cultured alone (1.3 +/- 0.75), suggesting that both CD4+ and CD8+ T lymphocytes were proliferating in response to stimulation from alloepitopes recognized on airway epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of Sneddon's syndrome with positive ANA and anti-cardiolipin antibodies: primary anti-phospholipid syndrome?

A 22-year-old woman developed ulcerative lesions on the lower extremities which usually exacerbated during the summer. Histological analysis revealed a micro-thrombotic lesion in the deep dermis without inflammatory cell infiltration or fibrinoid degeneration of blood vessels. Magnetic resonance imaging revealed multiple cerebral infarctions. Abnormal laboratory findings included an elevated anti-cardiolipin antibody titer and positive speckled pattern ANA (x80), but without other manifestations or signs of SLE. FACS analysis revealed that the patient's serum reacted with ethanol fixed endothelial cells in addition to keratinocytes and peripheral blood neutrophils. This case was thought to be livedo reticularis and cerebral thrombotic lesions (Sneddon's syndrome) associated with atrophie blanche or livedo(id) vasculitis and may be one clinical subset of primary anti-phospholipid syndrome.

Interferons in dermatology

Interferons are a large family of proteins and glycoproteins, naturally occurring or artificially produced by recombinant biotechnology. Their antiviral, antiproliferative, antitumoral, and immunomodulatory activities are induced by alterations in cell metabolism after binding to specific membrane receptors. Interferons have been used for the treatment of viral papillomas (e.g., verruca vulgaris and condyloma acuminatum), human immunodeficiency virus (HIV)-associated Kaposi's sarcoma and cutaneous tumors (e.g., melanoma, cutaneous T cell lymphoma, and basal cell carcinoma), and inflammatory dermatoses (e.g., Behçet's syndrome and psoriatic arthropathy). Clinical trials have been performed worldwide with various regimens and have not always led to conclusive results. In our experience long-term therapy with high doses of subcutaneously injected, recombinant interferon-alpha-2a in patients with HIV-associated Kaposi's sarcoma induces a remission or stabilization of the disease. In malignant melanoma a low response rate is obtained in metastatic disease with the use of interferon as a single therapeutic agent. Combined with other antitumor agents, however, interferon seems to be a useful drug. Excellent control of Behçet's disease has been obtained, and the treatment of condylomata acuminata has been effective.

Interferons modulate the expression of hormone receptors on the surface of murine melanoma cells

The effects of IFN-alpha, IFN-beta, and IFN-gamma on the differentiation of murine melanoma cells has been studied, in the presence and absence of melanocyte-stimulating hormone (MSH); the cells were highly responsive to treatment with MSH, which increased the rate of melanin production 25-fold and tyrosinase activity 6-fold within 4 d. Treatment of melanoma cells with IFN-alpha, IFN-beta, or IFN-gamma alone had no stimulatory effect on melanin production, but when the cells were cultured with IFN in the presence of MSH, pigment production was significantly and synergistically increased relative to cells cultured with MSH only. Flow cytometric analysis revealed that levels of tyrosinase in the cells were not affected by MSH or by IFN, which suggests that stimulation of melanogenic activity occurred by activation of a preexisting cellular enzyme. Scatchard analyses showed that the number of MSH receptors on IFN-treated cells was significantly increased (approximately 2.5-fold) relative to untreated cells (approximately 61,000/cell). These findings demonstrate that IFN stimulate differentiation (that is, pigmentation) of melanocytes by increasing the expression of surface MSH receptors; this in turn suggests that such a mechanism may in part be responsible for postinflammatory skin pigmentation, and provides an additional basis for action in the clinical responses of melanoma to IFN treatment.

Gamma interferon-induced expression of class II major histocompatibility complex antigens by human keratinocytes. Effects of conditions of culture

Normal human keratinocytes grown in MCDB 153 plus bovine pituitary extract and treated with recombinant gamma interferon (rIFN-gamma) express HLA-DR, DP and DQ antigens. The expression of these class II MHC antigens is time dependent: DR and DP appear before DQ. The delay in HLA-DQ expression is not due to the effects of trypsinization of cultures prior to analysis. Increasing the calcium ion concentration from 0.1 to 1.8 mM does not alter the expression of these antigens. Keratinocytes grown without serum proteins or bovine pituitary extract exhibited markedly delayed expression of DR. By contrast, keratinocytes grown in Dulbecco's modified Eagle's medium (DMEM) plus 10% fetal calf serum express DR and DP but only very small amounts of DQ after treatment with rIFN-gamma. Expression of HLA-DR occurs at doses of rIFN-gamma that are too low to cause growth inhibition. The cells of the squamous cell carcinoma cell line SCL-1, whether grown in MCDB 153 plus bovine pituitary extract or DMEM plus 10% fetal calf serum, express HLA-DQ and DP on only small numbers of cells after treatment with the lymphokine. Thus, the conditions of culture, possibly the presence of a serum factor(s), influence the expression of class II antigens in normal keratinocytes. Furthermore, rIFN-gamma does not induce DP and DQ antigens readily in transformed squamous cells cultured in either serum-containing or serum-free medium.