T-cell subsets and Langerhans cells in wart lesions

Dermatologists' Impressions of Spontaneously Regressing Verruca Plana Histopathology

ABSTRACT

Verruca plana in its regressing phase exhibits clinical and histological features distinct from classic verruca plana, but the ways in which these features should inform treatment plans are still under investigation. We conducted a retrospective single-center analysis of 25 patients with features of classic verruca plana, or plane warts, who exhibited self-remission within 4 weeks of skin biopsy. Measures included lesion sites, clinical findings preceding regression, and histological analysis. Histological analysis involved review by 2 dermatologists followed by impressions given by 4 board-certified dermatologists who were blinded to the clinical characteristics of the patients. Histopathological findings of regressing plane warts showed superficial perivascular infiltration (96%), spongiosis and exocytosis (84%), basal vacuolization (64%), parakeratosis (64%), apoptotic keratinocytes (60%), and lichenoid infiltration (44%). These findings were more compatible with the histological patterns of pityriasis lichenoides, lichen planus, and spongiotic eczema, rather than classic verruca plana. This suggests that regressing verruca plana may be included in the differential diagnosis of lesions exhibiting a lichenoid or spongiotic reaction, and observation may be a favorable treatment plan in these patients.

Recurrent respiratory papillomatosis: altered CD8(+) T-cell subsets and T(H)1/T(H)2 cytokine imbalance

Human papillomaviruses (HPVs) cause benign papillomas and squamous cell carcinomas in the genital and respiratory tracts. Recurrent respiratory papillomas (RRP) generate a high level of morbidity and significant mortality because of their location, resistance to treatment, and relentless recurrence that can vary in frequency in a given patient and between patients. We have found that T-cells from these patients, when exposed to or isolated from autologous papilloma tissue, have an elevated percentage of CD8(+), CD28(-) T-cells, and that T-cells from many of these patients express an increase in T(H)2-like cytokine mRNA in response to autologous papilloma tissue. Furthermore, both of these immunologic findings correlate with disease severity. These observations suggest that patients with RRP, and possibly others with refractory HPV-induced lesions, are unable to manage their disease with an appropriate and effective HPV-specific, T-cell response. This immune imbalance may be responsible for the development and severity of HPV-induced respiratory papillomatosis.

Enriched HLA-DQ3 phenotype and decreased class I major histocompatibility complex antigen expression in recurrent respiratory papillomatosis

Respiratory papillomas, caused by human papillomaviruses, are benign tumors that recur following removal. We evaluated immune function and major histocompatibility complex (MHC) phenotype and expression in these patients. MHC-independent immune function appeared normal. The frequency of peripheral blood MHC class II phenotypes was highly enriched for DQ3 and DR11, one split of DR5. Class I MHC antigen expression on papilloma tissue was markedly reduced. Together, these phenomena may facilitate papillomavirus evasion of the cellular immune response.

Expression of immune associated surface antigens of keratinocytes in human papillomavirus-derived lesions

The expression of immune associated surface antigens of keratinocytes was studied in human papillomavirus (HPV) derived lesions in order to determine whether HPV types have a regulatory role in the pathogenesis of papillomas. A series of cutaneous and mucosal lesions were immunolabeled with monoclonal antibodies to the major histocompatibility complex class 1 (beta 2-microglobulin) and 2 (HLA-DR antigens), intercellular adhesion molecule (ICAM-1) and glycoprotein CD36 (OKM5) as well as CD1a (Langerhans cells), CD4, CD8 (T cells) and CD11a (LFA1 antigen). Testing for the presence of HPV was carried out by in situ hybridization with biotinylated probes for viral DNA detection and typing. We observed a drastic reduction or a loss of beta 2-microglobulin by keratinocytes from cutaneous lesions in correlation with the disappearance of Langerhans cells. Only mild alterations were observed in mucosal lesions. HLA-DR expressed by keratinocytes was only detected in condylomas and laryngeal papillomas and was usually associated with a dense inflammatory reaction. This HLA-DR expression may be correlated with an up-regulation of ICAM-1 and the presence of LFA1 positive leukocytes, mainly of CD8 phenotype, in the epithelium. CD36 was detected on differentiated keratinocytes of all lesions; its expression seems related to the proliferation state of the lesions and probably does not represent an immune marker. The different reactivity patterns observed in cutaneous and mucosal lesions may reflect: 1. different roles for mucosal and cutaneous HPV types in the induction of immunoregulatory surface antigens of keratinocytes, or 2. the changing nature of the cytokines released by mononuclear cells and infected keratinocytes in these lesions.

Role of Langerhans cells and other dendritic cells in viral diseases

Langerhans cells are part of a vast system of potent antigen-presenting cells known under the name of dendritic cells. During the last decade, much has been learned on dendritic cell involvement in the immune response to infectious diseases. This review briefly summarizes our current understanding of the role played by Langerhans cells and other dendritic cells in the pathogenesis of DNA and RNA virus infections. These data may form the basis for the development of innovative approaches in the diagnosis, prevention, and treatment of viral diseases.

Epidermotropism of T cells correlates with intercellular adhesion molecule (ICAM1) expression in human papillomavirus (HPV)-induced lesions

Adhesion molecules play an important role in inflammatory reactions. Among them, ICAM1, a ligand for the lymphocyte function-associated antigen (FLA1) of leucocytes, may be expressed by antigen-presenting cells and keratinocytes in various inflammatory disorders. As cell-mediated immune responses play a great role in HPV infections, we investigated the expression of ICAM1 and correlated it with the presence of LFA1-positive cells by immunohistochemistry on serial frozen sections of a series of non-regressing cutaneous and mucosal HPV-induced lesions. ICAM1 expression by keratinocytes was observed only in intensely infiltrated lesions of condylomas and laryngeal papillomas. Its induction was usually correlated with the presence of LFA1-positive cells (mainly CD8-positive cells) which were in close apposition to ICAM1-positive proliferative epithelial cells expressing also, in some cases, HLA-DR antigen. ICAM1 was not correlated with the presence of HPV DNA or viral antigen. In moderately infiltrated lesions, keratinocytes did not express ICAM1, and LFA1-positive cells were not observed in the epidermis. In all lesions, ICAM1 was more intense on endothelial cells than in normal skin; infiltrating cells (lymphocytes and dendritic cells) may also express this antigen but intraepithelial Langerhans cells were devoid of any labelling. These studies provide further evidence that T-lymphocyte mechanisms are important in the host response to HPV-induced lesions. ICAM1 expression correlates with a lesional infiltrate but not with HPV infection and probably results in a more efficient initiation of the immune reaction.

A placebo controlled observer blind immunocytochemical and histologic study of epithelium adjacent to anogenital warts in patients treated with systemic interferon alpha in combination with cryotherapy or cryotherapy alone

OBJECTIVE

To examine biopsy specimens of tissue immediately adjacent to anogenital (AG) warts which had been treated with either cryotherapy plus subcutaneous interferon (IFN) alpha 2a or cryotherapy alone, for histological features of (a) human papilloma virus (HPV) infection (b) localised cellular immune responses, to further characterise any cellular immune infiltrates with tissue immunocytochemistry, and to relate any histological, immunocytochemical findings to the treatment response of nearby AG warts.

DESIGN

A randomised placebo controlled observer blind study.

SETTING

Genitourinary Medicine clinic, Department of Immunopathology, Royal Victoria Hospital, Belfast, N. Ireland.

SUBJECTS

Thirty patients with AG warts; 16 treated with IFN alpha 2a plus cryotherapy, and 14 treated with cryotherapy alone.

OUTCOME MEASURES

(1) Light microscopic features associated with HPV infection and local cellular immune responses. (2) Indirect immunofluorescence detection of the following cell surface markers: HLA DR, alpha one antitrypsin, CD1, CD3, CD4, CD8, CD22. (3) Clinical response of AG warts to treatment.

RESULTS

In pre-treatment biopsies only non specific indicators of HPV infection (acanthosis, 29/30 biopsies, and hyperkeratosis, 7/30 biopsies) were seen on light microscopy. Mononuclear cells were seen both throughout the upper dermis and centred around dermal blood vessels in 19/30 (63.3%) biopsies, and infiltrating into the epidermis in 12/30 (40%) biopsies. On indirect immunofluorescence CD3, CD8, CD4 antigen was detected on the surface of cells throughout the upper dermis in 24/29 (82.7%), 15/29 (51.7%), and 3/29 (10.3%), of biopsy specimens respectively. CD3 antigen, CD8 antigen and CD4 antigen was detected on the surface of cells infiltrating into the epidermis in 18/29 (62%), 7/29 (24.1%), and 6/29 (20.7%) of biopsy specimens respectively. CD1 antigen was seen on the surface of dendritic cells throughout the epidermis in all specimens; CD1 positive cells infiltrated into the upper dermis in 5/29 (17.2%). HLA DR was detected on the surface of dendritic cells throughout the epidermis in 22/29 (75.9%) of specimens, and on the surface of cells scattered both diffusely throughout the upper dermis and centred around dermal blood vessels in all specimens. Alpha one antitrypsin (A1AT) antigen was seen on the surface of cells in the upper dermis in 6/29 (20.7%) of biopsy specimens; no cells expressing CD22 surface antigen were seen. The nature of this local cellular immune response was not altered by treatment of nearby warts with either cryotherapy alone or cryotherapy plus systemic IFN alpha 2a, or related to the therapeutic outcome of these warts.

CONCLUSIONS

(1) No convincing histological evidence of HPV infection was seen in epithelium surrounding AG warts. (2) A predominantly T cell-mediated immune response (the target of which is uncertain) was seen in this perilesional epithelium. (3) In the dosage regimens used in this study, treatment of AG warts with either systemic IFN alpha 2a plus cryotherapy or cryotherapy alone did not appear to augment localised cellular immune responses (against any presumed subclinical HPV infection) in epithelium surrounding AG warts.

An immunohistological study of condylomata acuminata

Using an indirect immunoperoxidase method and a panel of monoclonal antibodies, anogenital warts removed from 86 individuals (28 heterosexual men, 47 homosexual men and 11 women) were studied. A constant feature was the presence of a stromal infiltrate of lymphocytes, in which CD4+ and CD8+ cells appeared in a ratio of about 5:1. Cells expressing interleukin-2 receptors were found in the stroma, amounting to 10% of the CD3+ cells. Leu 6+ epidermal dendritic cells (Langerhans' cells) were present in each wart; their density and morphology were similar to that in adjacent, apparently normal, skin. The mean number of Langerhans' cells that expressed HLA-DQ was lower than that of HLA-DR + cells. In 40 warts, HLA-DR was expressed on the surface of keratinocytes. Leu 7+ and Leu 11b+ cells were found in the epidermis of 17 and five warts, respectively. B-cells were noted in only five warts. These results are discussed in relation to persistence of wart virus infection.

Effect of aging on epidermal dendritic cell populations in C57BL/6J mice

The density and function of epidermal dendritic cell populations were investigated in aged C57BL/6J mice. The densities of both Langerhans cells (LC) and Thy-1+ dendritic epidermal cells were found to decrease with age. Epidermal cell suspensions from aged mice showed impaired immunologic function as assessed in vitro by the skin-lymphocyte reaction assay and by measuring the ability of epidermal cell suspensions to stimulate the proliferation of sensitized T cells in the presence of the sensitizing antigen. However, the capacity of LC to transport antigen from the skin to the draining lymph nodes was found in vivo to be comparable to that of young mice. Results of transplantation of bone marrow cells from young and old donors into irradiated recipients indicate that the decreased Langerhans cell density found in old mice may result from a deficiency in Langerhans cell bone marrow progenitors.

Role of epidermal Langerhans cells in viral infections

Langerhans cells function as highly potent antigen-presenting cells in the epidermis. In the last few years, their role in viral infections has been studied in various experimental systems. They have been shown to be involved in the pathogenesis of a number of infections of viral origin. These include vaccinia virus, human papilloma virus, herpes simplex virus, foot and mouth disease virus and human retrovirus infections. Studies on the effect of various factors, that are known to modulate the activity and density of Langerhans cell in the epidermis, may lead in the future to the development of new strategies aimed at inhibiting virus infections or even eradicating latent infection.

Epidermal Langerhans cells, dermal dendritic cells, and keratinocytes in viral lesions of skin and mucous membranes: an immunohistochemical study

We wanted to evaluate the eventual expression of viral antigens and MHC class II products by keratinocytes as well as the alterations of epidermal Langerhans cells and dermal dendritic cells in viral lesions of skin and mucous membranes. Therefore we investigated 68 biopsy specimens of protracted viral lesions, such as warts, condylomas, and mollusca contagiosa, and of rapidly resolving viral lesions such as herpes simplex virus infection. For this we used immunohistochemical staining techniques and several monoclonal and polyclonal antisera. In most cases investigated viral antigens (human papilloma virus antigens or herpes simplex virus type 1 antigens) could be demonstrated in keratinocytic nuclei. Except for a few viral lesions in which epidermal Langerhans cells were rather numerous, epidermal Langerhans cells were reduced in number or absent in almost all viral lesions. Moreover, epidermal Langerhans cells and dermal dendritic cells showed changes in morphology, distribution, and immunophenotype. These alterations may be caused by a toxic effect of the virus on dendritic cells. HLA-DR+ keratinocytes could be identified in few viral lesions only; HLA-DQ+ keratinocytes were not seen. Possible explanations for this lack of MHC class II expression by keratinocytes are discussed.

Epithelial expression of HLA-DR antigens in laryngeal papillomas with a dense inflammatory reaction

Thirty six laryngeal papillomas taken from 11 children and 10 adults were investigated with an indirect immunofluorescence technique for the occurrence of T cell subsets, Langerhans cells and HLA-DR antigen using specific monoclonal antibodies. A mild local cellular immune response was preferentially associated with juvenile laryngeal papillomas, whereas a more intense inflammatory reaction with T8 cell infiltration and large amounts of Langerhans cells in the chorion and the epithelium was observed in adult lesions. Some lesions either from adults or children characterized by high densities of lymphoid and dendritic cells exhibited the expression of DR antigen by epithelial cells. This result may suggest either a role of lymphokines released by activated T cells or a direct effect of viral infection on epithelial cells inducing DR antigen in laryngeal papillomas.

Virus expression. EGF and transferrin receptors in human papillomas

Thirty five non regressing cutaneous and mucosal human papillomas were studied for the expression of EGF and transferrin receptors by indirect immunofluorescence on frozen sections. The lesions were also examined for the presence of human papillomavirus (HPV) DNA by in situ-hybridization with biotinylated probes and viral capsid antigen. The mapping of EGF and transferrin receptors was modified in cutaneous lesions with drastic viral cytopathic effects and was enhanced in mucosal lesions mainly in laryngeal papillomas, which are poor virus producers. The greatest increase in EGF and transferrin receptor reactivity was observed in the group of mucosal lesions in which viral DNA was more frequently detected than viral antigen. This suggests that viral DNA may play a role in basal cell stimulation. Moreover some of these lesions with dense inflammatory reactions showed DR antigen expression by epithelial cells. Our findings indicate that epithelial cell activation in papillomas might be modulated by other factors than HPV such as mediators of the local immune response.

Langerhans cells in human warts

Seventy-six warts (15 plantar, 38 hand, 16 miscellaneous and seven anogenital lesions) taken from 55 patients, were studied by indirect immunofluorescence with monoclonal antibodies specific for T-cell subsets, Langerhans cells (LC) and HLA-DR antigen. The results were related to the presence of viral antigen. Approximately 80% of the lesions showed an infiltrate. Only 19 lesions contained helper/inducer or suppressor/cytotoxic T cells. The distribution of LC was abnormal in 65% of biopsies which contained LC in the dermis, and 29% were devoid of LC in the epidermis. Many lesions had reduced numbers of LC in the epidermis. The disappearance of LC from the epidermis was related to the presence of viral antigen, but not to the presence of particular T-cell subsets. Infiltrating cells were sometimes HLA-DR-positive, whereas basal cells did not express HLA-DR antigen, irrespective of the density of the infiltrate.

Laryngeal papillomas: local cellular immune response, keratinization and viral antigen

Various parameters of the local cellular response have been studied in 16 laryngeal papillomas from ten patients with recurrent papillomas as well as normal control laryngeal and tracheal tissue by indirect immunofluorescence on frozen sections using monoclonal antibodies specific for T-cell subsets, Langerhans cells (LC) and HLA-DR antigens. Keratinization was investigated with a monoclonal antibody KL1 recognizing an acidic 56.5 Kd keratin, which is a marker of suprabasal cells in stratified squamous epithelium and is absent from the basal layer. The presence of viral antigen was detected with a rabbit antiserum raised against SDS-dissociated purified virus. A mild inflammatory response was observed in most biopsies. Cytotoxic/suppressor T-cells were the predominant cells found in the lesions. Compared with normal epithelium, the number of LC was dramatically reduced in the papillomatous epithelium. High densities of HLA-DR-positive cells were found mainly in the corium. The keratinization process was disturbed in most specimens in that both basal and suprabasal compartments reacted positively with the KL1 monoclonal antibody. Viral antigen was present in the nucleus of very occasional epithelial cells in some samples.

Human epidermal Langerhans cells and peripheral blood monocytes. Accessory cell function, autoactivating and alloactivating capacity and ETAF/IL-1 production

We compared the functional capacities of human epidermal Langerhans cells (LC) and peripheral blood monocytes. Epidermal sheets were obtained by a suction blister device. After enzymatic treatment LC were enriched by attaching them to IgG-located erythrocyte monolayers. On a per cell basis, LC were several times more efficient accessory cells than monocytes in augmenting nickel-and tuberculin (PPD)-induced T-cell proliferation. In mixed cell cultures LC stimulated both autologous and allogeneic T cells, whereas monocytes stimulated only allogeneic cells. In addition, LC were significantly more potent allogeneic stimulators than monocytes. Although monocytes were weaker accessory cells and allogeneic stimulators than LC, they induced higher interleukin 1 (IL-1) activities than LC-enriched or LC-depleted cells. These results indicate that there are functional differences between LC and monocytes and that antigen presentation and mediator secretion are not correlated.

Enrichment of human epidermal Langerhans cells by attachment to erythrocyte monolayers

The present investigation introduces a method for purification of human epidermal Langerhans cells (LC). The method is based on the attachment of LC to IgG-coated sheep erythrocyte monolayers via their Fc receptors. To optimize the enrichment assay, several variables were tested. The best results were obtained when epidermal cells were centrifuged against erythrocyte monolayers; the purification procedure was performed at 4 degrees C in the presence of 5% fetal calf serum, using about 6 X 10(6) epidermal cells per erythrocyte plate (diameter 5 cm). The average purity of the recovered LC was 80.9% and LC-depleted fractions contained an average of 0.5% DR-positive cells. LC were able to enhance significantly leukoagglutinin- and purified protein derivative-induced T lymphocyte proliferation and leukocyte migration inhibitory factor production.

Immunophenotypes of lymphocytes in prospectively followed up human papillomavirus lesions of the cervix

From 1981 286 women were prospectively followed up for a mean (SD) of 16 (14) months for established infection with human papillomavirus (HPV) with or without coexistent cervical intraepithelial neoplasia (CIN). The in situ immunocompetent cell infiltrates in 263 cervical punch biopsy specimens from these women were phenotypically identified by the avidinbiotin peroxidase complex (ABC) technique using monoclonal antibodies Leu-10, OKT-3, OKT-4, and OKT-8. Leu-10+ B lymphocytes far outnumbered the OKT-3+ T lymphocytes in all types of HPV lesions (flat, inverted, and papillomatous condylomas of the cervix). The ratio of OKT-4+ to OKT-8+ (T helper to T suppressor cells) was slightly reduced in HPV lesions with more severe CIN and correlated positively with the intensity of the immunocompetent cell infiltrate. The ratio of OKT-4+ to OKT-8+ cells was highest in the 47 (28.8%) patients with HPV lesions that regressed during follow up, somewhat lower in the 85 (52.1%) with persistent lesions, and lowest in the 31 (19.1%) with lesions showing clinical progression. The results are discussed in terms of the proposed immune surveillance functions attributed to immunocompetent cells in situ according to the mucosal associated lymphatic tissue (MALT) concept. The conclusion drawn is that a dynamic balance between the immunoregulatory cells and their subtypes is a prerequisite for the proper handling of intracellular infections of the mucosa, including that with HPV.

Langerhans cells in human papillomavirus (HPV) lesions of the uterine cervix identified by the monoclonal antibody OKT-6

The local inflammatory cell infiltrates in 263 cervical punch biopsies of the women followed-up since 1981 (16 +/- 14 months, mean +/- S.D.) for an established human papillomavirus (HPV) lesion with or without concomitant cervical intraepithelial neoplasia (CIN) were analysed for occurrence of Langerhans cells, defined by the monoclonal antibody OKT-6 using the avidin-biotin peroxidase complex (ABC) technique. OKT-6+ cells remained at the constant low level (1.5-1.9% of the inflammatory cells) in the different types of HPV lesions (flat, inverted or papillomatous condylomas), their percentages (range 0.8-2.1% of the cells) being slightly affected by the grade of HPV-associated CIN, however, (P less than 0.05 between HPV-CIN I and HPV-CIS). Although cervical HPV lesions characteristically are a disease of young females, the relative levels of in situ Langerhans cells did not show any age-dependence. Furthermore, the intensity of the inflammatory cell infiltrate did not correlate with the relative levels of OKT-6+ cells in the biopsies. Practically identical (1.6%) levels of OKT-6+ cells were found in the first biopsies of the HPV lesions shown to regress during the follow-up period (28.8% of cases), when compared with those (1.7%) in the lesions persisted (52.1% of cases) or progressed (19.1% of lesions). The results are discussed in terms of the proposed immune surveillance function against viral infections, attributed to Langerhans cells in the SALT/MALT concept.(ABSTRACT TRUNCATED AT 250 WORDS)

Human papilloma virus (HPV) antigens and local immunologic reactivity in oral squamous cell tumors and hyperplasias

A series of 191 oral mucosal tumors including those with suspected HPV (Human Papilloma Virus) etiology; squamous cell papilloma (SQP), condyloma acuminatum (CA), focal epithelial hyperplasia (FEH), as well as those regarded as unrelated to HPV; fibrous hyperplasia (FH), papillary hyperplasia (PH), and true fibroma (TF), were analyzed for HPV structural proteins (by indirect immunoperoxidase IP-PAP technique), for the presence of epithelial dysplasia, and for the cellular composition (B and T lymphocytes, mononuclear phagocytes, (MPS cells] of their local inflammatory cell infiltrates using ANAE-(acid alpha-naphthyl acetate esterase) stain. HPV structural proteins were disclosed in 85% of FEH, in 75% of CA, and in 41% of SQP. These three lesions significantly differed from PH and FH with regard to the intensity and cellular composition of the local infiltrates, being most intense and B cell predominated in the latter two. Mild dysplasia was found in 20% of both CA and SQP lesions, the former also showing moderate dysplasia in 12% of cases. The HPV antigen positivity was negatively correlated with dysplasia in CA and SQP, the intensity of the infiltrate showing positive association with dysplasia. The results are discussed in terms of HPV etiology of CA, SQP and FEH, of the host immunologic reactivity against these lesions, as well as of the possible role of HPV in human squamous cell carcinogenesis.

Occurrence of papillomavirus structural antigens in oral papillomas and leukoplakias

Six oral papillomas and 7 oral leukoplakias were studied with genus-specific antibodies against detergent-disrupted papillomaviruses. Indirect immunofluorescence staining was applied to frozen sections. Distinct nuclear staining of superficial keratinocytes was seen in 5 of 6 oral papillomas, 2 of 5 homogenous leukoplakias, and in 2 cases of nodular leukoplakia, one of these showing transition into an invasive carcinoma. Papillomavirus antibodies offer a new way to detect and localize papillomaviruses in epithelial hyperplasias. The relevance of the immunomorphological identification of papillomavirus-associated antigens is discussed with special reference to the molecular hybridization technique.