Quantitative analysis of the immune cells in the anal mucosa

The immunological effects of intradermal particle-based vaccine delivery using a novel microinjection needle studied in a human skin explant model

For intradermal (ID) immunisation, novel needle-based delivery systems have been proposed as a better alternative to the Mantoux method. However, the penetration depth of needles in the human skin and its effect on immune cells residing in the different layers of the skin has not been analyzed. A novel and user-friendly silicon microinjection needle (Bella-mu^TM) has been developed, which allows for a perpendicular injection due to its short needle length (1.4-1.8 mm) and ultrashort bevel. We aimed to characterize the performance of this microinjection needle in the context of the delivery of a particle-based outer membrane vesicle (OMV) vaccine using an ex vivo human skin explant model. We compared the needles of 1.4 and 1.8 mm with the conventional Mantoux method to investigate the depth of vaccine injection and the capacity of the skin antigen-presenting cell (APC) to phagocytose the OMVs. The 1.4 mm needle deposited the antigen closer to the epidermis than the 1.8 mm needle or the Mantoux method. Consequently, activation of epidermal Langerhans cells was significantly higher as determined by dendrite shortening. We found that five different subsets of dermal APCs are able to phagocytose the OMV vaccine, irrespective of the device or injection method. ID delivery using the 1.4 mm needle of a OMV-based vaccine allowed epidermal and dermal APC targeting, with superior activation of Langerhans cells. This study indicates that the use of a microinjection needle improves the delivery of vaccines in the human skin.

Differences in the Immune Microenvironment of Anal Cancer Precursors by HIV Status and Association With Ablation Outcomes

Background

Anal high-grade squamous intraepithelial lesions (HSILs) are the precursors to anal cancer and frequently persist or recur following electrocautery ablation (EA). Impaired mucosal immunity may facilitate anal carcinogenesis. We characterized the immune microenvironment of anal HSILs in correlation with human immunodeficiency virus (HIV) serostatus and ablation outcomes.

Methods

Using immunohistochemistry, mucosa-infiltrating CD4+ and CD8+ lymphocytes were quantified in HSILs and benign mucosa from 70 HIV+ and 45 HIV- patients. Clinicopathological parameters were compared.

Results

Anal HSILs harbored more T lymphocytes than benign mucosa regardless of HIV status (P ≤ .03). Total T lymphocyte count and CD8+ subset were significantly higher in HIV+ HSILs versus HIV- HSILs (median cell count, 71 vs 47; 47 vs 22/high power field [HPF]; P < .001), whereas the CD4+ subset was comparable between groups (median, 24 vs. 25; P = .40). Post EA, HSILs persisted in 41% of HIV+ and 19% of HIV- patients (P = .04). Unadjusted analysis showed trends toward EA failures associated with HIV seropositivity (incidence rate ratio [IRR], 2.0; 95% CI, .8-4.9) and increased CD8+ cells (IRR, 2.3; 95% CI, .9-5.3).

Conclusions

Human immunodeficiency virus is associated with alterations of the immune microenvironment of anal HSILs manifested by increased local lymphocytic infiltrates, predominately CD8+. Human immunodeficiency virus seropositivity and excess mucosa-infiltrating CD8+ cells may be associated with ablation resistance.

Local Impairment of Immunoreactivity in Hiv-infected Women with Hpv-related Squamous Intraepithelial Lesions of the Cervix

Aims and background

The aim of this study was to compare the local immune response in two groups of patients with high-grade cervical intraepithelial squamous lesions (SIL): one with HIV infection and the other with HPV infection alone.

Materials and methods

16 conization specimens (8 from HIV-infected and 8 from non-HIV-infected patients) of HPV-related, high-grade SIL were selected. The specimens from non-HIV patients were considered as controls. The total number of Langerhans cells, CD4 and CD8 cells present in 10 field areas (3.120 mm2) was recorded in each case. In HIV patients CD4 and CD8 peripheral counts were performed immediately before surgery.

Results

The CD4/CD8 ratio never exceeded 0.71, whereas the lowest ratio in controls was 0.81: this difference was statistically significant (P=0.0009). The mean number of Langerhans cells was markedly reduced in the high-grade SILs in the HIV patients in comparison with controls (P=0.001). The number of CD4 cells and the CD4/CD8 ratio correlated with the peripheral CD4 count (P=0.001 and 0.02).

Conclusions

In our study a marked local impairment of cervical immunoreactivity was observed, which may play a major role in the progression of these lesions in HIV-infected women.

Langerhans cells and sexual transmission of HIV and HSV

Langerhans cells (LCs) situated in stratified squamous epithelium of the skin and mucosal tissue are amongst the first cells that sexually transmitted pathogens encounter during transmission. They are potent antigen presenting cells and play a key role in the host mounting an appropriate immune response. As such, viruses have evolved complex strategies to manipulate these cells to facilitate successful transmission. One of best studied examples is HIV, which manipulates the natural function of these cells to interact with CD4 T cells, which are the main target cell for HIV in which rapid replication occurs. However, there is controversy in the literature as to the role that LCs play in this process. Langerhans cells also play a key role in the way the body mounts an immune response to HSV, and there is also a complex interplay between the transmission of HSV and HIV that involves LCs. In this article, we review both past and present literatures with a particular focus on a few very recent studies that shed new light on the role that LCs play in the transmission and immune response to these 2 pathogens.

A randomized, double-blind, placebo-controlled trial of a Chinese herbal Sophora flower formula in patients with symptomatic haemorrhoids: a preliminary study

Dried flowers and buds of Sophora japonica (Huaihua) are used in China, Japan and Korea for treating haematemesis and bleeding haemorrhoids. This study compared the clinical safety and efficacy of a Sophora flower formula with a placebo for the conservative treatment of symptomatic haemorrhoids. The study was a prospective, double-blind, randomized placebo-controlled trial. The clinical effective rate, symptom score and the incidence of important clinical events were used as observation indices to evaluate the effect of the Sophora flower formula. The results showed that after 7 days of treatment, improvement was observed in 87.0% of the patients' major symptoms in the Sophora flower formula group compared with 81.8% of those in the placebo group. After 14 days, 78.2% patients in the Sophora flower formula group were asymptomatic, whereas 40.9% of those in the placebo group exhibited residual symptoms. However, the difference between both groups was not statistically significant. As the bowel habits of the patients improved and as the patients took sitz baths, their symptoms improved drastically, regardless of the use of the Sophora flower formula. These findings indicate that the traditional Chinese Sophora flower formula is clinically safe; however, its effects on haemorrhoids need to be studied in a larger sample size and with different dosages. The present study results may be a potential clinical reference for physicians prescribing medications for patients with symptomatic haemorrhoids.

Intradermal immunization triggers epidermal Langerhans cell mobilization required for CD8 T-cell immune responses

The potential of the skin immune system for the generation of both powerful humoral and cellular immune responses is now well established. However, the mechanisms responsible for the efficacy of skin antigen-presenting cells (APCs) during intradermal (ID) vaccination still remain to be elucidated. We have previously demonstrated in clinical trials that preferential targeting of Langerhans cells (LCs) by transcutaneous immunization shapes the immune response toward vaccine-specific CD8 T cells. Others have shown that ID inoculation of a vaccine, which targets dermal APCs, mobilizes both the cellular and humoral arms of immunity. Here, we investigated the participation of epidermal LCs in response to ID immunization. When human or mouse skin was injected ID with a particle-based vaccine, we observed significant modifications in the morphology of epidermal LCs and their mobilization to the dermis. We further established that this LC recruitment after ID administration was essential for the induction of antigen-specific CD8 T cells, but was, however, dispensable for the generation of specific CD4 T cells and neutralizing antibodies. Thus, epidermal and dermal APCs shape the outcome of the immune responses to ID vaccination. Their combined potential provides new avenues for the development of vaccination strategies against infectious diseases.

FoxP3 overexpression and CD1a+ and CD3+ depletion in anal tissue as possible mechanisms for increased risk of human papillomavirus-related anal carcinoma in HIV infection

AIM

We analysed local cellular and humoral immunity factors in the anal mucosa in an attempt to explain how HIV infection increases the risk of anal cancer in HPV-infected patients.

METHOD

HIV-positive cases and matched HIV-negative controls with more than one recurrence of condylomas were included in a prospective study following treatment of the initial lesions. Patients were followed every 3 to 6 months for the development of anal intraepithelial neoplasia (AIN3) and cancer for up to 60 months. Tissue CD1a(+), CD3(+), CD4(+), CD8(+) cells and mRNAs of selected cytokines and chemokines were quantified and compared in patients with or without AIN3 or cancer using morphometric or immunohistochemistry analysis and qRT-PCR.

RESULTS

Sixty-six individuals (22 patients and 44 controls) were included. In the case group, CD1a(+) and CD3(+) cell counts were significantly lower in biopsies from AIN3 and cancer specimens compared with those from AIN 1-2 or normal biopsies (P < 0.0001). A CD1a(+) count of < 10/mm was predictive of AIN3 and cancer (Odds ratio = 9.4, 95% CI: 5.4-18.3, P < 0.0001). IL-8 and IL23 levels were significantly higher in cancer than in non-cancer tissues regardless of HIV status (P = 0.02). FoxP3 expression was significantly higher in HIV-infected cases than in controls with AIN3/cancer (P < 0.04).

CONCLUSION

Depletion of CD1a(+) and CD3(+) cells and overexpression of FoxP3 in the anal mucosa appear likely to contribute to the risk of HPV-related anal cancer in HIV-infected patients. Furthermore, overexpression of IL-8 and IL-23 in the anal mucosa might be responsible for the development of this cancer regardless of HIV status.

Current understanding and potential immunotherapy for HIV-associated squamous cell carcinoma of the anus (SCCA)

Squamous cell carcinoma of the anus (SCCA) is a rare disease in the average population but is an increasing concern among immunocompromised individuals, such as the HIV-seropositive. Coinfection with human papillomavirus (HPV) in this population is common. HPV infection is difficult to clear with a compromised immune system, which results in a greater risk of tumor development and a more aggressive progression of the disease. The recent approval of a prophylactic HPV vaccine for cervical cancer has sparked an interest in a search for improved immunotherapeutic multimodality therapies to combat anogenital tumors associated with the virus. In this review, we discuss the known mechanisms of action of HIV-associated SCCA, examine the current treatments for the disease, and focus on the potential of an immunotherapeutic vaccine approach for both prophylactic and therapeutic application.

Anal carcinoma: incidence and effect of cumulative infections

INTRODUCTION

Human papilloma virus (HPV) causes anal condyloma that is a risk factor for anal carcinoma. The incidence and mechanism of invasive anal carcinoma in patients with anal condyloma are prospectively determined.

PATIENTS AND METHODS

From 1993 to 2002, 228 consecutive patients (164 HIV positive) with anal canal condylomas were included in the study, after curing of their lesions. They were asked to attend follow-up visits at 3- or 6-month intervals. We checked for anal co-infection with syphilis, gonococci, viruses (Epstein-Barr virus, cytomegalovirus, herpes simplex, HPV types), and quantified Langerhans' cells (LC) in anal mucosa at baseline and during follow up. We cured and analysed relapsed condylomas during follow up (3-112 months; median 26). Serum HIV loads and CD4 T-lymphocyte counts were determined at each visit and the densities of LC in consecutive specimens from patients with cancers were compared with that for a matched control group (n = 23).

RESULTS

Analysis of 199 patients showed high-grade dysplasia (HGD) in 13.6% of patients, more in HIV-positive (16%) than in HIV-negative (6%) patients at baseline. During follow up, 3.5% (7/199; six HIV positive) patients developed invasive carcinoma after 13-108 months and 112 (56%) patients relapsed condylomas. HIV and anal co-infection were identified as independent risk factors (P < 0.01) for HGD and cancer: odd ratio (95% confidence interval) of 9.4 (2.4-37.4) and 3.67 (0.95-14.2), respectively. LC densities in anal mucosa were lower in patients with invasive carcinoma than in controls.

CONCLUSION

The risk of invasive carcinoma in HPV-infected patients is increased by HIV and anal co-infection. Decreases in LC numbers in anal mucosa may favour this outcome.

Prevalence of high-grade dysplasia and cancer in the anal canal in human papillomavirus-infected individuals

BACKGROUND & AIMS

The incidence of anal cancer is higher in patients with anal canal condyloma, a sexually transmitted disease, than in the general population. We determined the prevalence of anal dysplasia and cancer in patients with anal canal condyloma with respect to human immunodeficiency virus (HIV) status, immunity status, and human papillomavirus types.

METHODS

In 174 consecutive patients (114 HIV positive, 60 HIV negative) with anal canal condyloma, lesions were cured, and the patients were then followed up prospectively. Langerhans cells (LCs) in normal anal mucosa were quantified, and viruses (Epstein-Barr virus, cytomegalovirus, human simplex virus 1, and various human papillomavirus [HPV] types) were characterized on inclusion. During follow-up (median 26 months), relapsed condylomas were resected and examined histologically. HIV load and CD4 T-lymphocyte counts in serum were determined at each visit.

RESULTS

Several factors differed significantly between HIV-positive and HIV-negative patients: LCs/mm anal tissue (15 vs. 30), oncogenic HPV (27% vs. 13%), other current anal infections (44% vs. 0%), and sex ratio (93% vs. 73% male). During follow-up, condylomas relapsed in 75% of the HIV-positive patients, with 19 high-grade dysplasias (HGDs) and 1 invasive carcinoma, but in only 6% of HIV-negative patients, with 1 HGD. Male sex, HIV positivity, and <15 LCs/mm tissue were independent risk factors for condyloma relapse. HIV positivity, HGD before inclusion, and condyloma relapse were independent risk factors for HGD and cancer. Serum HIV load was associated with relapse, whereas CD4 T-lymphocyte counts were not.

CONCLUSIONS

The prevalence of HGD and carcinoma is higher in HIV-positive than in HIV-negative patients, probably because of HPV activity. HIV-positive patients with high serum HIV load and/or a history of anal dysplasia should be examined by anoscopy, and condylomas should be analyzed histologically.

Reduced number of Langerhans cells in oesophageal mucosa from AIDS patients

AIMS

The oesophageal mucosa is a frequent target of opportunistic infections in human immunodeficiency virus (HIV) infection. Langerhans cells (LC) are known as a target and reservoir of HIV in the skin. The aim of this study was to characterize oesophageal LC in HIV-infected patients.

METHODS AND RESULTS

Thirty oesophageal biopsies were obtained from 29 patients (median age 35.5), all in stage IV of the HIV Center of Disease Control Classification. We performed histological assessment of the oesophageal mucosa and immunohistochemical detection of oesophageal LC using an anti-CD1a antibody, followed by morphometric analysis. Biopsies from 17 noninfected patients were studied using the same procedure. LC in oesophageal mucosa of the HIV positive patients showed a significantly and dramatically decreased number (LC(N) median = 5.85/mm2) and surface/epithelial surface (LC (S) ratio = 0.09) when compared with HIV-negative controls (LC(N) median = 29.7/mm2, LC(S) ratio = 1.83) with P = 0.003 for LC(N) and P < 0.0001 for LC(S).

CONCLUSION

These data suggest that oesophageal LC are, like their epidermal counterparts, a preferential target for HIV infection. Their alterations may provide a clue to the pathogenesis of the decreased local oesophageal immunity and to the occurrence of opportunistic infections.

Langerhans' cells are depleted in chronic graft versus host disease

AIMS

To measure Langerhans' cells in skin of patients treated by bone marrow transplantation who developed chronic graft versus host disease (GvHD); to determine whether the reduction in Langerhans' cells resulted directly from the GvHD or from other factors, such as the immunosuppressive regimens used in bone marrow transplant patients.

PATIENTS AND METHODS

Lesional and nonlesional skin specimens from nine patients with lichen planus-like lesions and three patients with sclerodermoid lesions were studied. Control skin specimens were taken from three patients undergoing breast reduction surgery. The number of Langerhans' cells/mm2 and the area of Langerhans' cells as a percentage of total epidermis were measured by counting cells labelled with antihuman CD1a.

RESULTS

A significant reduction in Langerhans' cell area and number were found in specimens with lesions (area 3.5%; number 507/mm2) compared with specimens without lesions (8.42%; 2375/mm2). In contrast, Langerhans' cell area and number in skin without lesions were similar to controls (10.26%; 2968/mm2).

CONCLUSIONS

Langerhans' cells were significantly reduced in skin with lesions of chronic GvHD but not in skin without lesions from the same patient, suggesting that the reduction is a direct consequence of GvHD and not linked to immunosuppressive drugs or late effects of conditioning regimens. In long term bone marrow transplant recipients, Langerhans' cells are derived mainly from the donor cells; therefore, this result suggests the occurrence of autoreactive phenomenon in chronic GvHD.