Local accumulation of FOXP3+ regulatory T cells: evidence for an immune evasion mechanism in patients with large condylomata acuminata

Mucosal T-cell responses to chronic viral infections: Implications for vaccine design

Mucosal surfaces that line the respiratory, gastrointestinal and genitourinary tracts are the major interfaces between the immune system and the environment. Their unique immunological landscape is characterized by the necessity of balancing tolerance to commensal microorganisms and other innocuous exposures against protection from pathogenic threats such as viruses. Numerous pathogenic viruses, including herpesviruses and retroviruses, exploit this environment to establish chronic infection. Effector and regulatory T-cell populations, including effector and resident memory T cells, play instrumental roles in mediating the transition from acute to chronic infection, where a degree of viral replication is tolerated to minimize immunopathology. Persistent antigen exposure during chronic viral infection leads to the evolution and divergence of these responses. In this review, we discuss advances in the understanding of mucosal T-cell immunity during chronic viral infections and how features of T-cell responses develop in different chronic viral infections of the mucosa. We consider how insights into T-cell immunity at mucosal surfaces could inform vaccine strategies: not only to protect hosts from chronic viral infections but also to exploit viruses that can persist within mucosal surfaces as vaccine vectors.

The expression and significance of PD-L1 in condyloma acuminatum

BACKGROUND

It has been reported that programmed death-ligand 1 (PD-L1) is highly expressed in cells during viral infection, which helps the virus escape host immunity. However, the relationship between human papillomavirus (HPV) and PD-L1 in condyloma acuminatum and whether they participate in immunosuppression have not been reported. In this paper, we aimed to explore the expression and significance of PD-L1 in condyloma acuminatum.

METHODS

The expression of PD-L1 in the wart of condyloma acuminatum patients and the foreskin of healthy individuals was evaluated. Lentivirus transfection was used to introduce the HPV11-E7 gene into HaCaT cells to investigate whether HPV infection could affect the expression of PD-L1. The successfully constructed HPV11-E7 HaCaT cells were cocultured with Jurkat cells, and Jurkat cell apoptosis and proliferation as well as the Jurkat cell cycle were evaluated by flow cytometry and cell counting kit-8 (CCK-8) assays.

RESULTS

PD-L1 was highly expressed in keratinocytes of genital warts. Through the construction of a cell model, we found that HPV11-E7 could upregulate the expression of PD-L1 in HaCaT cells. Furthermore, HPV11-E7 HaCaT cells can promote the apoptosis of Jurkat cells, inhibit the proliferation of Jurkat cells and mediate the cell cycle arrest of Jurkat cells through the PD-1/PD-L1 signalling pathway.

CONCLUSIONS

HPV infection may upregulate PD-L1 expression in the keratinocytes of genital warts and participate in the inhibition of local T-cell function.

Peripheral blood CD4+ T cell count predicts recurrence of condyloma acuminatum after photodynamic therapy in HIV-positive patients

BACKGROUND

Few studies have reported postoperative relapse of condyloma acuminatum (CA) after 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in human immunodeficiency virus (HIV) positive patients.

METHODS

The clinical data of HIV-positive CA patients treated with ALA-PDT from October 2018 to December 2019 were analyzed retrospectively. Univariate and multivariate Cox regression was used to analyze the variables related to postoperative recurrence. Pearson correlation test was employed to analyze the correlation between CD4⁺ T cell count and postoperative recurrence rate. Kaplan-Meier method was used to compare the CA recurrence after ALA-PDT in low CD4 group and high CD4 group.

RESULTS

A total of 38 HIV-positive patients with CA were included in the study. Among them, 26 patients experienced CA recurrence within 6 months, and the recurrence rate was 68.4%. CD4⁺ T cell count was 187.0 (79.0-596.0) cells/μl in relapsed patients and 406.0 (89.0-612.0) cells/μl in non-relapsed patients, showing a statistically significant difference (p = .005). Pearson correlation coefficient analysis revealed a negative correlation between CD4⁺ T cell count and postoperative recurrence rate (p = .005, r = -.443). Univariate regression analysis showed that CD4⁺ T cell count was correlated with postoperative recurrence, hazard ratio (HR) was 0.99 [95% Confidence interval (CI) = 0.99-1.0, p = .012]. Multivariate Cox regression analysis showed that with the low CD4⁺ T cell count as the reference, the high CD4⁺ T cell count was negatively correlated with postoperative recurrence (HR = 0.09, 95% CI 0.01-0.87, p = .038).

CONCLUSIONS

Peripheral blood CD4⁺ T cell count can predict the CA recurrence rate after ALA-PDT in HIV-positive patients.

(Not) Home alone: Antigen presenting cell - T Cell communication in barrier tissues

Priming of T cells by antigen presenting cells (APCs) is essential for T cell fate decisions, enabling T cells to migrate to specific tissues to exert their effector functions. Previously, these interactions were mainly explored using blood-derived cells or animal models. With great advances in single cell RNA-sequencing techniques enabling analysis of tissue-derived cells, it has become clear that subsets of APCs are responsible for priming and modulating heterogeneous T cell effector responses in different tissues. This composition of APCs and T cells in tissues is essential for maintaining homeostasis and is known to be skewed in infection and inflammation, leading to pathological T cell responses. This review highlights the commonalities and differences of T cell priming and subsequent effector function in multiple barrier tissues such as the skin, intestine and female reproductive tract. Further, we provide an overview of how this process is altered during tissue-specific infections which are known to cause chronic inflammation and how this knowledge could be harnessed to modify T cell responses in barrier tissue.

Comparing the Efficacy of Chemical Cautery to Cryosurgery on CD4+ Status of HIV Patients with Condyloma Acuminata

Introduction

Condyloma acuminata (CA) is one of the sexually transmitted infections caused by human papillomavirus (HPV). Condyloma acuminata patients are usually coinfected with human immunodeficiency virus (HIV), particularly those with low CD4+ levels. Chemical cautery and cryosurgery are therapeutic modalities for CA, aiming to remove lesions and prevent recurrence, especially in patients with HIV.

Objective

To compare the efficacy of chemical cautery to cryosurgery on CD4+ status of HIV patients with CA.

Methods

A cross-sectional retrospective study was conducted in patients with CA visiting the Dermatology and Venereology outpatient clinic and the voluntary counseling and testing (VCT) clinic of Dr. Moewardi Hospital Surakarta, Indonesia from January 2018 to December 2020. The data were taken from the medical records of patients. These subjects were grouped into CA with HIV and without HIV. The data were statistically analyzed with t-tests followed by multivariate regression tests, and a p-value of <0.05 was considered significant.

Results

Seventy-eight patients with CA were included in the study, comprising 41 subjects with HIV infection and 37 subjects without HIV infection. The subjects were predominantly male (68%). Of all the subjects, 70.5% received chemical cautery, and the remaining had cryosurgery. Multivariate regression tests obtained no significant differences in CD4+ levels between chemical cautery and cryosurgery (p=0.138 vs p=0.907).

Conclusion

Either chemical cautery or cryosurgery is effective in improving the clinical condition of patients with CA. Although chemical cautery results in a higher level of CD4+ than cryosurgery, statistically both therapies have no significant difference regarding CD4+ status.

Changes in Cytokine Profile with Immunotherapy in Viral Warts using Purified Protein Derivative, Mumps Measles Rubella Vaccine, and Mycobacterium w Vaccine

Background

Immunotherapy for wart employs ability of immune system to recognize certain viral, bacterial, and fungal antigens in previously sensitized individual inducing Type IV delayed-type hypersensitivity reaction (up-regulated Th1 cytokines IL-1, TNF-α, IFN-γ; down-regulated Th2 cytokines IL-10), not only to injected antigen but also against wart virus.

Aims

To evaluate and compare the pattern of production of Th1 cytokines (IL-1, TNF-α, IFN-γ) and Th2 cytokines (IL-10) in patients receiving immunotherapy with purified-protein-derivative (PPD), Mycobacterium w (Mw), or mumps-measles-rubella (MMR) vaccine.

Methods

The cohort study conducted on patients receiving immunotherapy with PPD, Mw, or MMR which was injected intradermally at baseline, repeated every 2 weeks for 6 doses?. Five-millilit?e?r blood was collected for evaluation of cytokines at baseline and 12 weeks of treatment. Blood was centrifuged to separate serum, stored at -80°C. Cytokines were measured by ELISA using a standard kit.

Results

Nine participants in PPD group, 11 in Mw group, and 12 in MMR group completed the study. IL-1 was raised from baseline in all study arms and was significant in PPD group (P = 0.008). There was a predicted increase in IFN-γ in Mw and MMR groups but not in the PPD group. In the PPD group, IFN-γ was found to be down regulated. IL-10, a Th 2 cytokine was down regulated in all the groups at the study end from baseline, significantly so in the PPD group (P = 0.027) and MMR group (P = 0.001). TNF-α, being a Th1 cytokine was down regulated in all groups instead of an increase. In PPD group, IL-10 was significantly low at study end in patients who had complete resolution of warts.

Limitations

Longer follow-up could not be done due to logistic issues.

Conclusion

IL-1, TNF-α upregulation and IL-10 downregulation confirm that cytokine milieu plays an important role in wart immunotherapy. TNF-α has no contributory role. IL-10 can be used as a biomarker of complete response in PPD therapy.

Guidance factors orchestrating regulatory T cell positioning in tissues during development, homeostasis, and response

Over their lifetime, regulatory T cells (Treg) recalibrate their expression of trafficking receptors multiple times as they progress through development, respond to immune challenges, or adapt to the requirements of functioning in various non-lymphoid tissue environments. These trafficking receptors, which include chemokine receptors and other G-protein coupled receptors, integrins, as well as selectins and their ligands, enable Treg not only to enter appropriate tissues from the bloodstream via post-capillary venules, but also to navigate these tissues to locally execute their immune-regulatory functions, and finally to seek out the right antigen-presenting cells and interact with these, in part in order to receive the signals that sustain their survival, proliferation, and functional activity, in part in order to execute their immuno-regulatory function by altering antigen presenting cell function. Here, we will review our current knowledge of when and in what ways Treg alter their trafficking properties. We will focus on the chemokine system and try to identify specialized, non-redundant roles of individual receptors as well as similarities and differences to the conventional T cell compartment.

Macrophages participate in the immunosuppression of condyloma acuminatum through the PD-1/PD-L1 signaling pathway

BACKGROUND

The aim of this study was to investigate whether macrophages can participate in the immunosuppression of condyloma acuminatum (CA) by expressing PD-1/PD-L1.

METHODS

The infiltration of macrophages and expression of programmed death-1 (PD-1) and PD-1 ligand 1 (PD-L1) on wart lesions and in normal skin tissues were detected by immunohistochemistry assay. The amounts of M1- and M2-type macrophages derived from THP-1 cells were measured by flow cytometry. The expression of cytokines on macrophages was examined by using enzyme-linked immunosorbent assay (ELISA). The protein expression of PD-1 and PD-L1 on macrophages was detected by western blotting.

RESULTS

The macrophages were significantly increased, while PD-1 and PD-L1 were highly expressed on wart lesions compared to normal controls. More M2-like macrophages than M1-type macrophages were present on wart lesions. The M2-like macrophages in the CA groups showed high expression of interleukin-10 (IL-10), transforming growth factor (TGF-β), PD-1, and PD-L1 compared to normal controls.

CONCLUSION

Macrophages participate in the immunosuppression of CA by expressing PD-1/PD-L1.

The role of regulatory T cells in pathogenesis and therapy of human papillomavirus-related diseases, especially in cancer

Human papillomavirus (HPV) is the most common sexually transmitted agent in the world. It can cause condyloma acuminatum, anogenital malignancies, and head and neck cancers. The host immune responses to HPV involve multiple cell types that have regulatory functions, and HPV-mediated changes to regulatory T cells (Tregs) in both the local lesion tissues and the circulatory system of patients have received considerable attention. The role of Tregs in HPV infections ranges from suppression of effector T cell (Teff) responses to protection of tissues from immune-mediated injury in different anatomic subsites. In this review, we explore the influence of Tregs in the immunopathology of HPV-related diseases and therapies targeting Tregs as novel approaches against HPV.

Genital warts treatment: Beyond imiquimod

Genital warts are one of the most common sexually transmitted diseases worldwide. The disease is a result of infection with low-risk types of human papillomaviruses, mostly type 6 and 11. Current therapies for genital warts are mainly ablative, or alternatively topical application of imiquimod cream and sinecatechin (polyphenon E) ointment to the warts. However, low patient compliance and high recurrence rate are significant problems for the treatment of genital warts by imiquimod and ablative therapies. We summarise recent literature in this area and propose combining imiquimod with other therapies to increase the efficacy of imiquimod.

Therapeutic HPV vaccines

High-risk human papillomavirus (HPV) infection is known to be a necessary factor for cervical and anogenital malignancies. Cervical cancers account for over a quarter of a million deaths annually. Despite the availability of prophylactic vaccines, HPV infections remain extremely common worldwide. Furthermore, these vaccines are ineffective at clearing pre-existing infections and associated preinvasive lesions. As cervical dysplasia can regress spontaneously, a therapeutic HPV vaccine that boosts host immunity could have a significant impact on the morbidity and mortality associated with HPV. Therapeutic vaccines differ from prophylactic vaccines in that they are aimed at generating cell-mediated immunity rather than neutralising antibodies. This review will cover various therapeutic vaccine strategies in development for the treatment of HPV-associated lesions and cancers.

Functional characterization of CD4 and CD8 T cell responses among human papillomavirus infected patients with ano-genital warts

Ano-genital warts are considered one of the commonest and highly infectious sexually transmitted infections. These warts are primarily caused by the human papillomavirus (HPV) of the family Papillomaviridae, genus alpha-papillomavirus, species 10 and types 6 and 11. However the high recurrence rate of warts is a matter of serious concern to the patients and a challenge for the treating physician. The conventional treatment options are targeted only to the local site of warts. There is no systemic treatment modality as there is limited understanding of the disease immune-pathogenesis. The role of cell-mediated immunity in combating HPV infection is not clearly defined. Hence the present study is aimed at investigating the CD4⁺ T helper (Th1 and Th2) and CD8⁺ T cell responses among wart patients. In this study, we compared HPV6 and HPV11 antigen-specific T cell responses among venereal wart patients relative to healthy controls. Significant decrease in percent frequencies of IFN-γ producing CD4⁺ and CD8⁺ T cells were observed in HPV infected wart patients. On the other hand, the frequency of CD4⁺ T cells expressing IL-4 was significantly increased in these patients as compared to healthy controls. The observed functional skewing of HPV specific T cells from Th1 to Th2 response in patients indicated suppressed immunity against the HPV. Moreover, decrease in CD8 T cell function correlated with poor wart clearance. Our findings open future avenues for exploring potential immunomodulation strategies as an adjunct to standard treatment for better management of these patients and prevention of recurrence.

The Interaction Between Human Papillomaviruses and the Stromal Microenvironment

Human papillomaviruses (HPVs) are small, double-stranded DNA viruses that replicate in stratified squamous epithelia and cause a variety of malignancies. Current efforts in HPV biology are focused on understanding the virus-host interactions that enable HPV to persist for years or decades in the tissue. The importance of interactions between tumor cells and the stromal microenvironment has become increasingly apparent in recent years, but how stromal interactions impact the normal, benign life cycle of HPVs, or progression of lesions to cancer is less understood. Furthermore, how productively replicating HPV impacts cells in the stromal environment is also unclear. Here we bring together some of the relevant literature on keratinocyte-stromal interactions and their impacts on HPV biology, focusing on stromal fibroblasts, immune cells, and endothelial cells. We discuss how HPV oncogenes in infected cells manipulate other cells in their environment, and, conversely, how neighboring cells may impact the efficiency or course of HPV infection.

Both tumour cells and infiltrating T-cells in equine sarcoids express FOXP3 associated with an immune-supressed cytokine microenvironment

Bovine papillomavirus (BPV) infections of equine species have a central role in the aetiology of equine sarcoids; a common benign skin tumour of horses, zebras and donkeys. Within the lesions, all of the early papillomavirus genes are expressed and promote the excessive replication of fibroblasts which characterise these tumours. Equine sarcoids differ from BPV induced fibro-papillomas of cattle (the natural host of BPV), in that they do not produce high amounts of virus particles, do not usually regress spontaneously and do not sero-convert to BPV; features which suggest that affected horses lack an effective anti-viral immune response to BPV. Equine sarcoids contain large numbers of CD4+ CD8+ dual positive T-cells which uniformly express FOXP3, the key transcription factor of regulatory T-cells, and FOXP3 is also expressed within the BPV infected fibroblasts. Compared to healthy skin, sarcoids showed increased mRNA transcription for FOXP3 and the regulatory cytokine TGFβ. Transcription of IL17, which has been shown to have a regulatory function in human papillomavirus-associated tumours, was also elevated in equine sarcoids compared to spleen. In contrast, the levels of mRNA transcripts for effector T cell cytokines IL2, IL4 and interferon-gamma (IFNγ) were not elevated in sarcoids compared to healthy skin or spleen. Similarly neither interferon-alpha (IFNα), interferon-beta (IFNβ) nor IL12 family members were elevated in sarcoids compared to normal skin. We suggest that the regulatory cytokine micro-environment within sarcoids enables the persistence of the lesions by preventing an effective anti-viral immune response.

Immune Dysregulation in Patients Persistently Infected with Human Papillomaviruses 6 and 11

Human Papillomaviruses (HPVs) 6 and 11 are part of a large family of small DNA viruses, some of which are commensal. Although much of the population can contain or clear infection with these viruses, there is a subset of individuals who develop persistent infection that can cause significant morbidity and on occasion mortality. Depending on the site of infection, patients chronically infected with these viruses develop either recurrent, and on occasion, severe genital warts or recurrent respiratory papillomas that can obstruct the upper airway. The HPV-induced diseases described are likely the result of a complex and localized immune suppressive milieu that is characteristic of patients with persistent HPV infection. We review data that documents impaired Langerhans cell responses and maturation, describes the polarized adaptive T-cell immune responses made to these viruses, and the expression of class select II MHC and KIR genes that associate with severe HPV6 and 11 induced disease. Finally, we review evidence that documents the polarization of functional T_H2 and T-regulatory T-cells in tissues persistently infected with HPV6 and 11, and we review evidence that there is suppression of natural killer cell function. Together, these altered innate and adaptive immune responses contribute to the cellular and humoral microenvironment that supports HPV 6 and 11-induced disease.

A case of recalcitrant plantar warts associated with statin use

Background. Plantar warts are a common presenting skin complaint caused by the human papillomavirus. 1st line therapies include cryotherapy and topical salicylic acid. Where there is resistance to these treatments, consideration is made for 2nd line therapies, including intralesional bleomycin, imiquimod, 5-fluorouracil, and photodynamic therapy. We present a case of bilateral persistent plantar warts, resistant to treatment with repeated cryotherapy and topical salicylic acid over a 6-year period. Following a patient initiated decision to discontinue their statin medication, we observed rapid clearance of plantar warts without change to standard therapy or their environment. This case correlates with emerging literature demonstrating a link between statin medication and proliferation of HPV through increased levels of FOXP3+ regulatory T cells.

Pathologic and imunohistochemical characterization of tumoral inflammatory cell infiltrate in invasive penile squamous cell carcinomas: Fox-P3 expression is an independent predictor of recurrence

Penile carcinomas (PeCa) are relatively rare, but devastating neoplasms, more frequent among people of underprivileged socioeconomic status. There is mounting evidence that immune cells may trigger various mechanisms that enhance tumor growth and metastasis, but no data on the peritumoral inflammation is available for PeCa. The objectives of the present study are to evaluate the immunohistomorphology of tumoral inflammation in PeCa, and to correlate it with clinicopathological parameters, which could contribute to the prognostic evaluation. One hundred and twenty-two patients with the diagnosis of usual-type squamous cell penile carcinoma were included. Paraffin-embedded tissue was submitted to immunohistochemical evaluation of p16 protein, CD3, CD4, CD8, CD20, CD68, CD138, granzyme B, and Fox-P3. The Fisher's exact test was employed for comparison between histological variables and parameters, and the Kaplan-Meier method for the analysis of survival. Improved 5-year overall survival was significantly associated to age ≤60 years, stage I + II, tumor size T1 + T2, lymph node status N0, and absent perineural invasion. In a multivariate analysis age ≥60 years, presence of lymph node metastasis, urethral invasion, and high histologic grade retained a significantly more unfavorable outcome. Improved 5-year failure free survival was associated to stage of the disease I + II, lymph node status N0, absence of perineural, vascular, and urethral invasion, and Fox-P3 expression. In a multivariate analysis, presence of lymph node metastasis, perineural and vascular invasion, and of Fox-P3-positive lymphocytes together with low inflammatory infiltrate retained a significantly more unfavorable outcome. These results support the prognostic value of determining the levels of Fox-P3-positive lymphocytes by immunohistochemistry in PeCa, as this parameter adds value to the traditional clinicopathological features.

Neutrophils recruit regulatory T-cells into tumors via secretion of CCL17--a new mechanism of impaired antitumor immunity

The mechanisms by which tumor-associated neutrophils (TANs) affect tumor growth are to a large extent unknown. Regulatory T-cells (T-regs) are functionally immune-suppressive subsets of T-cells. Depletion or inhibition of T-regs can enhance antitumor immunity. We demonstrated both by RT-PCR and by ELISA that murine TANs secrete significant amounts of the T-regs chemoattractant, CCL17, much more than circulating or splenic neutrophils, and at a level progressively increasing during tumor development. Migration assays, both in vitro and in vivo, showed recruitment of T-regs by TANs, which was inhibited with anti-CCL17 monoclonal antibodies. Systemic neutrophil depletion in tumor-bearing mice using anti-Ly6G monoclonal antibodies reduced the migration of T-regs into the tumors. We further showed, using flow cytometry, that CCL17 secretion by TANs is not limited to mouse models of cancer but is also relevant to human TANs. Our results suggest a new indirect mechanism by which TANs may inhibit antitumor immune activity, thus promoting tumor growth. We further describe, for the first time, a clear link between TANs and T-regs acting together to impair antitumor immunity.

Mechanistic investigation of immunosuppression in patients with condyloma acuminata

Condyloma acuminatum (CA) is a common sexually transmitted disease caused by human papillomavirus (HPV) infection. Previous studies have identified that the occurrence, relapse and cancerization of CA is relevant to immune imbalance caused by immune hypofunction or immunoregulatory dysfunction. However, to date, the specific mechanisms accounting for immune imbalance in CA patients have remained elusive. In the present study, changes in the expression levels of myeloid differentiation factor 88 (MyD88) and toll‑like receptors (TLRs) were determined in lesion tissues and peripheral blood samples obtained from CA patients by fluorescence quantitative PCR and western blot analysis. The results indicated that TLRs and MyD88 expression was upregulated in the lesion tissues only. In addition, the expression of forkhead box P3, a characteristic marker of regulatory T cells (Tregs), transforming growth factor‑β1 and interleukin (IL)‑10, inhibitory factors secreted by Tregs and inhibitory costimulatory molecules, cytotoxic T-lymphocyte antigen 4, glucocorticoid-induced TNFR-related protein and programmed cell death protein 1 was observed to be upregulated, indicating that immunosuppression of Tregs was enhanced significantly. However, the expression levels of NKG2D and NKp46, natural killer (NK) cell activation receptors located on the surface of NK cells, decreased markedly indicating that HPV infection inhibits the activation of NK cells. The secretion levels of various cytokines in the peripheral blood of CA patients were detected by enzyme‑linked immunosorbent assay revealing that IL‑2, IL‑12 and interferon‑γ levels were markedly lower than that of healthy subjects. By contrast, the expression levels of tumor necrosis factor‑α, IL‑4 and IL‑10 were markedly increased in CA samples compared with the control, with the exception of IL‑6. Taken together, these results are consistent with the hypothesis of immunosuppression in CA patients. Increased expression of MyD88 and TLRs is likely to enhance immunosuppression of Tregs, leading to the imbalance of Th1/Th2, cytotoxic T cell type 1 (Tc1)/Tc2 cells and secreted cytokines.

Change in cytokines in patients with warts after contact immunotherapy with squaric acid dibutylester

BACKGROUND

A wart is a skin lesion caused by infection with human papillomavirus (HPV). Contact immunotherapy is one of the many therapeutic options that have been used to treat warts; however, the effectiveness of contact immunotherapy differs from patient to patient, and the cause of this variation in clinical response is unclear.

AIM

To assess cytokine changes in patients after contact immunotherapy with squaric acid dibutylester (SADBE).

METHODS

In total, 21 patients with warts and 9 healthy control subjects were enrolled in the study. The frequencies of CD3+ T cells expressing interleukin (IL)-4, IL-10, IL-12, tumour necrosis factor-α and interferon-γ were measured by flow cytometry analysis of peripheral blood at baseline in both patients and controls, and after SADBE treatment in patients.

RESULTS

Lower expression of IL-4 and higher expression of IL-12 in CD3+ T cells were found in patients compared with controls. The percentage of CD3+/IL-4+ T cells significantly increased after contact immunotherapy in all responders, but was significantly higher in those with an excellent response, who also had a significantly higher percentage of CD3+/IL-10+ T cells. The patients with an excellent response also had a significant decrease in the percentage of CD3+/IL-12+ T cells, and the percentage of CD3+/IL-4+ T cells normalized.

CONCLUSIONS

Response to contact immunotherapy can vary depending on the types of cytokine changes produced by treatment. An excessive shift to a Th2 pattern and increased IL-10 production after contact immunotherapy may hinder clearance of HPV.

Expression of dendritic cell lysosome-associated membrane protein and dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin in condyloma acuminatum lesions

OBJECTIVE

Retrospective, observational study to explore the role of dendritic cells (DCs) in condyloma acuminatum lesions (genital warts) and their relationship with duration of the disease.

METHODS

Condyloma acuminatum lesion samples were collected from male patients with the condition and compared with normal foreskin samples from male volunteers. Cellular locations of dendritic cell lysosome-associated membrane protein (DC-LAMP) and dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN) were detected using immunohistochemistry. Levels of both proteins were determined using Western blot analysis; levels of their corresponding mRNAs were measured using reverse transcription-polymerase chain reaction.

RESULTS

The mRNA and protein levels of DC-LAMP and DC-SIGN were both significantly higher in condyloma acuminatum lesions (n = 30 samples) compared with normal skin samples (n = 13). Levels of DC-LAMP and DC-SIGN protein and duration of disease were inversely correlated.

CONCLUSIONS

DC-LAMP and DC-SIGN may be involved in the pathogenesis of condyloma acuminatum. Their levels were inversely correlated with the duration of disease, suggesting that DCs might be involved in human papillomavirus clearance.

The immune response to papillomavirus during infection persistence and regression

Human papillomavirus (HPV) infections cause a significant global health burden, predominantly due to HPV-associated cancers. HPV infects only the epidermal cells of cutaneous and mucosal skin, without penetration into the dermal tissues. Infections may persist for months or years, contributed by an array of viral immune evasion mechanisms. However in the majority of cases immunity-based regression of HPV lesions does eventually occur. The role of the innate immune response to HPV in persistence and regression of HPV infection is not well understood. Although an initial inflammatory infiltrate may contribute to disease regression, sustained inflammation at the HPV-induced lesions, characterized by macrophage and neutrophil infiltration, has been observed in persistence. Pathogen-associated molecular patterns (PAMPs) are important in innate recognition. The double stranded DNA and an L1 and L2 capsid components of the HPV virion are potential PAMPs that can trigger signaling through cellular pattern recognition receptors, including toll-like receptors (TLR). TLR expression is increased in regressing HPV disease but is reduced in persistent lesions, suggesting a role for TLR in HPV regression. With regard to the adaptive immune response, a key indicator of regression in humans is infiltration of the lesion with both CD4 and CD8 T cells. In individuals with persistent lesions, CD8 T cell and immune suppressive regulatory T cells (Tregs) infiltrate the infection site. There is no association between persistence or regression and the presence of serum antibodies to the viral capsid antigens of HPV. There is still much to be learned about the immunological events that trigger regression of HPV disease. Understanding the viral and host factors that influence persistence and regression is important for the development of better immunotherapeutic treatments for HPV-associated disease.

Immunological and regenerative aspects of hepatic mast cells in liver allograft rejection and tolerance

The precise roles of mast cells in liver allograft rejection and tolerance are still unknown. This study aimed to explore the roles of mast cells in immune regulation and liver regeneration for tolerance induction by using rat models of orthotopic liver transplantation (OLT). Stem cell factor (SCF) and its receptor c-Kit, which are critical to the migration and development of not only stem cells but also mast cells, significantly increased in the tolerogenic livers as compared with rejected livers. The significant elevation of mast cell tryptase, high-affinity IgE receptor, and histamine suggested the activation of mast cells in liver allografts at the tolerogenic phase after OLT. Immunohistochemical analysis using confocal microscope clearly showed colocalization of mast cells, Foxp3+ Tregs, γδ T cells, and recipient-derived hepatic progenitor cells with higher expression of SCF, IL-9, IL-10, TGF-β1, and IL-17 related to immunoregulation and liver regeneration in the donor grafts of a tolerogenic OLT model. Cross-talk among mast cells and other cells was evaluated by in vitro studies demonstrating that syngeneic bone marrow-derived mast cells (BMMCs) co-cultured with naïve splenocytes or primary hepatocytes significantly increased the population of splenic γδ T cells by mitogen stimulation or by mast cell degranulation, and also significantly induced the hepatocyte proliferation, respectively. Our results suggested that mast cells in the donor grafts may play important roles in the induction/maintenance of immune tolerance and liver regeneration resulting in the replacement of hepatic cells from donor to recipient.

Adult T cell leukemia/lymphoma: FoxP3(+) cells and the cell-mediated immune response to HTLV-1

Human T-lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukaemia/lymphoma (ATLL) in ∼5% of HTLV-1-infected people. ATLL cells frequently express several molecules that are characteristic of regulatory T cells (Tregs), notably CD4, CD25 and the transcription factor FoxP3. It has therefore recently been suggested that HTLV-1 selectively infects and transforms Tregs. We show that HTLV-1 induces and maintains a high frequency of FoxP3+ T cells by inducing expression of the chemokine CCL22; the frequency is especially high in patients with chronic ATLL. In turn, the FoxP3+ T cells exert both potentially beneficial and harmful effects: they suppress the growth of autologous ATLL clones and may also suppress the host's cytotoxic T lymphocyte response, which normally limits HTLV-1 replication and reduces the risk of HTLV-1-associated diseases. Although ATLL cells may exert immune suppressive effects, we conclude that ATLL is not necessarily a tumour of classical FoxP3+ Tregs.

A novel mucosal orthotopic murine model of human papillomavirus-associated genital cancers

Cervical cancer results from infection with high-risk type human papillomaviruses (HPV). Therapeutic vaccines aiming at controlling existing genital HPV infections and associated lesions are usually tested in mice with HPV-expressing tumor cells subcutaneously implanted into their flank. However, effective vaccine-induced regression of these ectopic tumors strongly contrasts with the poor clinical results of these vaccines produced in patients with HPV-associated genital neoplasia. To assess HPV therapeutic vaccines in a more relevant setting, we have, here, established an orthotopic mouse model where tumors in the genital mucosa (GM) develop after an intravaginal instillation of HPV16 E6/E7-expressing tumor cells transduced with a luciferase-encoding lentiviral vector for in vivo imaging of tumor growth. Tumor take was 80-90% after nonoxynol-9 induced damage of the epithelium. Tumors remained localized in the genital tract, and histological analysis showed that most tumors grew within the squamous epithelium of the vaginal wall. Those tumors induced (i) E7-specific CD8 T cells restricted to the GM and draining lymph nodes, in agreement with their mucosal location and (ii) high Foxp3+ CD4+ infiltrates, similarly to those found in natural non-regressing HPV lesions. This novel genital HPV-tumor model by requiring GM homing of vaccine-induced immune responses able to overcome local immuno-suppression may be more representative of the situation occurring in patients upon therapeutic vaccination.

FOXP3+ CD4+ Tregs lose suppressive potential but remain anergic during transient inflammation in human

Tregs are crucial in controlling inflammation. Although the transcription factor FOXP3 is the most applicable phenotype marker of Tregs, it does not indisputably characterize suppressive function during T-cell activation in vitro. A question that remains is: what is the functionality of FOXP3(+) T cells during inflammation in vivo? We studied FOXP3(+) T cells in a human model of acute inflammation due to cardiac surgery. Twenty-five children who underwent cardiac surgery for correction of a septum defect were included. Following surgery, we observed a transient systemic inflammatory response accompanied by an increased proportion of CD25(bright) T cells with sustained Treg phenotype. During this transient immune activation, both the percentage of CD4(+) FOXP3(+) cells and the level of expression of FOXP3 in the CD4(+) CD25(bright) CD127(low) population increased. While Tregs remained present during systemic inflammation and continued to be anergic, the capacity to suppress effector T cells was reduced. The reduced suppressive state of Tregs could be induced in vitro by plasma obtained during the peak of inflammation after surgery. These data show that inflammation inhibits Treg function through soluble factors present in plasma. These results underscore the functional role of FOXP3(+) Tregs during inflammation in vivo.

Human T-lymphotropic virus type 1-induced CC chemokine ligand 22 maintains a high frequency of functional FoxP3+ regulatory T cells

We recently reported that human T-lymphotropic virus type 1 (HTLV-1) infection is accompanied by a high frequency of CD4(+)FoxP3(+) cells in the circulation. In asymptomatic carriers of HTLV-1 and in patients with HTLV-1-associated inflammatory and malignant diseases, a high FoxP3(+) cell frequency correlated with inefficient cytotoxic T cell-mediated killing of HTLV-1-infected cells. In adult T cell leukemia/lymphoma (ATLL), the FoxP3(+) population was distinct from the leukemic T cell clones. However, the cause of the increase in FoxP3(+) cell frequency in HTLV-1 infection was unknown. In this study, we report that the plasma concentration of the chemokine CCL22 is abnormally high in HTLV-1-infected subjects and that the concentration is strongly correlated with the frequency of FoxP3(+) cells, which express the CCL22 receptor CCR4. Further, we show that CCL22 is produced by cells that express the HTLV-1 transactivator protein Tax, and that the increased CCL22 enhances the migration and survival of FoxP3(+) cells in vitro. Finally, we show that FoxP3(+) cells inhibit the proliferation of ex vivo, autologous leukemic clones from patients with ATLL. We conclude that HTLV-1-induced CCL22 causes the high frequency of FoxP3(+) cells observed in HTLV-1 infection; these FoxP3(+) cells may both retard the progression of ATLL and HTLV-1-associated inflammatory diseases and contribute to the immune suppression seen in HTLV-1 infection, especially in ATLL.

Type-specific cervico-vaginal human papillomavirus infection increases risk of HIV acquisition independent of other sexually transmitted infections

BACKGROUND

Sexually transmitted infections (STIs) such as herpes simplex virus (HSV)-2 are associated with an increased risk of HIV infection. Human papillomavirus (HPV) is a common STI, but little is know about its role in HIV transmission. The objective of this study was to determine whether cervico-vaginal HPV infection increases the risk of HIV acquisition in women independent of other common STIs.

METHODS AND FINDINGS

This prospective cohort study followed 2040 HIV-negative Zimbabwean women (average age 27 years, range 18-49 years) for a median of 21 months. Participants were tested quarterly for 29 HPV types (with L1 PCR primers) and HIV (antibody testing on blood samples with DNA or RNA PCR confirmation). HIV incidence was 2.7 per 100 woman-years. Baseline HPV prevalence was 24.5%, and the most prevalent HPV types were 58 (5.0%), 16 (4.7%), 70 (2.4%), and 18 (2.3%). In separate regression models adjusting for baseline variables (including age, high risk partner, positive test for STIs, positive HSV-2 serology and condom use), HIV acquisition was associated with having baseline prevalent infection with HPV 58 (aHR 2.13; 95% CI 1.09-4.15) or HPV 70 (aHR 2.68; 95% CI 1.08-6.66). In separate regression models adjusting for both baseline variables and time-dependent variables (including HSV-2 status, incident STIs, new sexual partner and condom use), HIV acquisition was associated with concurrent infection with any non-oncogenic HPV type (aHR 1.70; 95% CI 1.02-2.85), any oncogenic HPV type (aHR 1.96; 95% CI 1.16-3.30), HPV 31 (aHR 4.25; 95% CI 1.81-9.97) or HPV 70 (aHR 3.30; 95% CI 1.50-7.20). Detection of any oncogenic HPV type within the previous 6 months was an independent predictor of HIV acquisition, regardless of whether HPV status at the HIV acquisition visit was included (aHR 1.95; 95% CI 1.19-3.21) or excluded (aHR 1.96; 95% CI 1.02-2.85) from the analysis.

CONCLUSIONS/SIGNIFICANCE

Cervico-vaginal HPV infection was associated with an increased risk of HIV acquisition in women, and specific HPV types were implicated in this association. The observational nature of our study precludes establishment of causation between HPV infection and HIV acquisition. However, given the high prevalence of HPV infection in women, further investigation of the role of HPV in HIV transmission is warranted.

CD4+FOXP3+ regulatory T cell depletion by low-dose cyclophosphamide prevents recurrence in patients with large condylomata acuminata after laser therapy

Condylomata acuminata (CA) caused by human papillomavirus (HPV) is a common sexually transmitted disease with half a million new cases diagnosed in the United States per year and the annual increase in incidence in China. Recurrence is a major challenge for CA treatment. Recently, we demonstrated that FOXP3(+) regulatory T (Treg) cells mediate the immunosuppression in large genital warts. Here, we further report that low-dose cyclophosphamide (CY), a conventional chemotherapy drug, can effectively prevent the recurrence of large CA in clinical patients after laser therapy. Surprisingly, although 9 out of 52 patients recur six weeks after the combination treatment, the re-administration of low-dose CY alone completely eliminates most recurred lesions. We provide evidence that low-dose CY not only depletes patients' Treg cells and enhances function of HPV-specific T cells and NK cells in the periphery, but also ameliorates the immune milieu of the lesion site, leading to the elimination of remnant viruses. These findings have important clinical significance, and potentially lead to a therapeutic breakthrough for the treatment of CA.

Mast cells mobilize myeloid-derived suppressor cells and Treg cells in tumor microenvironment via IL-17 pathway in murine hepatocarcinoma model

Tumor immunosuppression is commonly braided with chronic inflammation during tumor development. However, the relationship between immunosuppression and inflammation in tumor microenvironment is still unclear. We have demonstrated that mast cells are accumulated and exacerbate the inflammation and immunosuppression in tumor microenvironment via SCF/c-kit signaling pathway. Here, we further elucidate the underlying mechanism, which involves both myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells. Our data showed that mast cells mobilized the infiltration of MDSCs to tumor and induced the production of IL-17 by MDSCs; MDSCs-derived IL-17 indirectly attracted Treg cells, enhanced their suppressor function, and induced the IL-9 production by Treg cells; in turn, IL-9 strengthened the survival and protumor effect of mast cells in tumor microenvironment. Our findings disclose a closed loop among mast cells, MDSCs and Treg cells in tumor microenvironment, which provides a new insight into the paralleled developments of inflammation and immunosuppression in tumor microenvironment. Based on these findings, we propose that targeting tumor inflammation might be a potential strategy to reverse the immunosuppression of tumor microenvironment, thus facilitating cancer immunotherapy.

Correlation of CXCL12 expression and FoxP3+ cell infiltration with human papillomavirus infection and clinicopathological progression of cervical cancer

Human cervical cancer is an immunogenic tumor with a defined pattern of histopathological and clinical progression. Tumor-infiltrating T cells contribute to immune control of this tumor; however, cervical cancer dysregulates this immune response both through its association with human papillomavirus (HPV) infection and by producing cytokines and chemokines. Animal tumor models have revealed associations between overproduction of the chemokine stromal cell-derived factor-1 (SDF-1 or CXCL12) and dysregulation of tumor-specific immunity. We therefore proposed that CXCL12 expression by cervical precancerous and cancerous lesions correlates with histopathological progression, loss of immune control of the tumor, and HPV infection. We found a significant association between cancer stage and CXCL12 expression for squamous and glandular lesions as well as with the HPV16+ (high-risk) status of the neoplastic lesions. Cancer progression was correlated with increasing levels of FoxP3 T-cell infiltration in the tumor. FoxP3 and CXCL12 expression significantly correlated for squamous and glandular neoplastic lesions. These observations were supported by enzyme-linked immunosorbent assay and Western blotting. In addition, we demonstrated CXCL12 expression by dyskaryotic cells in ThinPrep cervical smears. This study robustly links increased CXCL12 expression and FoxP3(+)-cell infiltration to HPV infection and progression of cervical cancer. It supports the detection of CXCL12 in cervical smears and biopsies as an additional biomarker for this disease.

Loss of epidermal Langerhans cells occurs in human papillomavirus alpha, gamma, and mu but not beta genus infections

Human papillomaviruses (HPVs), which are contained in the alpha, beta, gamma, mu, and nu genera, differ in their oncogenic potential and their tropism for cutaneous or mucosal epidermis. Langerhans cells (LC), the only epidermal professional antigen-presenting cells, are readily detected in normal mucosal and cutaneous epithelium. The aim of this study is to determine whether LC loss, which has been reported for HPV16, occurs in other HPV genera and establish its significance in viral pathology. We found that, as for HPV16, LCs were reduced in lesions infected with high-risk mucosal (alpha7 and alpha9 species) and low-risk cutaneous (gamma and mu) types. Lesions infected with alpha10 low-risk genital types had reduced LC but contained epidermal LC patches, coincident with dermis-localized regulatory T cells (T-regs). In contrast to other genera, LCs were common in the epidermis, and T-regs occupied the dermis of the potentially high-risk cutaneous beta-HPV type infected lesions. Therefore, LC loss in the infected lesions occurred irrespective of tropism or oncogenic potential of the HPV type. LC depletion in the HPV-infected epidermis may create an environment that is permissive for viral persistence and in HPV lesions in which LCs are found, the presence of typically immunosuppressive T-regs may compensate for their continued presence.