Herpes simplex virus and human papillomavirus genital infections: new and investigational therapeutic options

REBACIN® is an optional intervention for persistent high-risk human papillomavirus infection: A retrospective analysis of 364 patients

OBJECTIVE

To evaluate the therapeutic efficacy of REBACIN® in patients with persistent high-risk HPV (hrHPV) infection. Persistent hrHPV infection is a crucial cause of cervical cancer, for which optimal pharmacological intervention remains unavailable.

METHODS

A retrospective analysis and a meta-analysis were carried out. The retrospective analysis included 364 patients who were persistently infected with HPV for at least 12 months, between September 2015 and February 2019, and only received the REBACIN® intervention. HPV DNA typing, HC2 hrHPV DNA, and ThinPrep cytologic tests were performed before and after the REBACIN® intervention, to evaluate the therapeutic efficacy. The meta-analysis included trials evaluating the therapeutic efficacy of interferons.

RESULTS

After a follow-up period of 3-6 months, the overall rate of efficacy of REBACIN® was 74.73% (272/364), which was higher than that of interferon (61.50%). The efficacy of REBACIN® was correlated with HPV type (odds ratio [OR] 0.549, 95% confidence interval [CI] 0.367-0.822, P=0.004) and pretreatment cytology (OR 0.358, 95% CI 0.173-0.739, P=0.005).

CONCLUSION

REBACIN® is potently efficacious at clearing persistent hrHPV infection; hence, it can serve as an optional intervention for persistent hrHPV infection.

PEGylated liposomes for topical vaginal therapy improve delivery of interferon alpha

Recent studies regarding mucosal drug delivery indicate that nanosystems with surface-available polyethylene glycol (PEG) are able to penetrate mucus barrier, assure closer contact with the epithelium, and improve drug delivery to vagina. In the present work, we developed the mucus-penetrating PEGylated liposomes containing interferon alpha-2b (IFN α-2b), destined to provide localized therapy for human papilloma virus (HPV) vaginal infections. The PEGylated liposomes were of a mean size of 181±8nm, bearing a negative zeta potential of - 13mV and an entrapment efficiency of 81±10%. In vitro release experiments on model membrane showed a nearly non-existent IFN α-2b release from both the control and liposomally-associated IFN α-2b. However, the ex vivo penetration studies performed on the vaginal tissue obtained from pregnant sheep, showed the clear elevated IFN α-2b penetration from PEGylated liposomes as compared to the control. Furthermore, mucin studies confirmed the absence of interaction between the PEG-modified liposomes and mucin, confirming their ability to penetrate mucus and reach the deeper epithelium. The system holds a promise in improving topical delivery of IFN α-2b through enhanced efficacy of local anti-viral therapy.

Advancements in Pharmacotherapy for Noncancerous Manifestations of HPV

Human papillomavirus (HPV) is the most common sexually transmitted disease. Via infection of the basal epithelial cells, HPV causes numerous malignancies and noncancerous cutaneous manifestations. Noncancerous cutaneous manifestations of HPV, including common, plantar, plane, and anogenital warts, are among the most common reasons for an office visit. Although there are various therapies available, they are notoriously difficult to treat. HPV treatments can be grouped into destructive (cantharidin, salicylic acid), virucidal (cidofovir, interferon-α), antimitotic (bleomycin, podophyllotoxin, 5-fluorouracil), immunotherapy (Candida antigen, contact allergen immunotherapy, imiquimod) or miscellaneous (trichloroacetic acid, polyphenon E). The mechanism of action, recent efficacy data, safety profile and recommended regimen for each of these treatment modalities is discussed.

Immune therapy for human papillomaviruses-related cancers

Human papillomaviruses (HPVs) are a large family of double strand DNA viruses comprising more than 180 types. Infection with HPV is very common and it is associated with benign and malignant proliferation of skin and squamous mucosae. Many HPVs, considered low-risk such as HPV 6 and 11, produce warts; while high-risk viruses, such as HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, and 58, induce tumors. About 5% of all cancers in men and women are associated with HPV infection. Because there are not antiviral drugs for HPV infection, current therapies for low-risk HPV infections involve physical removal of the lesion by cryotherapy, trichloracetic acid, laser, or surgical removal. Surgical procedures are effective in the treatment of pre-cancerous lesions, however after these procedures, many recurrences appear due to new re-infections, or to failure of the procedure to eliminate the HPV. In addition, HPV can inhibit recognition of malignant cells by the immune system, leading to the development of cancer lesions. When this occurs, radiotherapy and chemotherapy are then used. Unfortunately, about 50% of the HPV-cancer patients still die. In the past decade, a better knowledge of the natural history of the virus-host interaction and of the immune response against this viral infection has brought new therapeutic strategies geared to modulate the immune system to generate an efficient virus-specific cytotoxic response. Novel HPV protein-expressing vaccines have shown some significant clinical efficacy and systemic HPV-specific cytotoxic T cell responses. This review will describe the current status of the several therapeutic strategies used to treat HPV-induced lesions, and discuss the various new therapies now being tested.

Saikosaponin-d affects the differentiation, maturation and function of monocyte-derived dendritic cells

Saikosaponin-d (Ssd) is a triterpenoid saponin derived from Bupleurum falcatum L., which has been shown to exhibit a variety of pharmacological properties, including anti-inflammatory, antibacterial and antiviral properties. The aim of the present study was to investigate the effect of Ssd on the differentiation, maturation and function of human monocyte-derived dendritic cells (DCs) isolated from condylomata acuminata patients. The results of the present study demonstrated that Ssd reduced the differentiation of DCs, as evidenced by decreased expression levels of cluster of differentiation (CD)1a, CD80 and CD86 molecules and increased CD14 expression. Expression levels of the mannose receptor and CD32 were also significantly elevated, which was associated with enhanced fluorescein isothiocyanate-dextran endocytic activity. Furthermore, Ssd treatment promoted DC maturation by increasing the expression levels of CD40, CD83, CD80 and CD86. In addition, the function of mature DCs, including the secretion of IL-12 and the stimulation of lymphocyte proliferation, was significantly increased following Ssd administration. In conclusion, the present study indicated that Ssd exhibited immunomodulatory effects and may be a novel potent chemopreventive drug candidate for the treatment of condylomata acuminata.

Saikosaponin-d affects the differentiation, maturation and function of monocyte-derived dendritic cells

Saikosaponin-d (Ssd) is a triterpenoid saponin derived from Bupleurum falcatum L., which has been shown to exhibit a variety of pharmacological properties, including anti-inflammatory, antibacterial and antiviral properties. The aim of the present study was to investigate the effect of Ssd on the differentiation, maturation and function of human monocyte-derived dendritic cells (DCs) isolated from condylomata acuminata patients. The results of the present study demonstrated that Ssd reduced the differentiation of DCs, as evidenced by decreased expression levels of cluster of differentiation (CD)1a, CD80 and CD86 molecules and increased CD14 expression. Expression levels of the mannose receptor and CD32 were also significantly elevated, which was associated with enhanced fluorescein isothiocyanate-dextran endocytic activity. Furthermore, Ssd treatment promoted DC maturation by increasing the expression levels of CD40, CD83, CD80 and CD86. In addition, the function of mature DCs, including the secretion of IL-12 and the stimulation of lymphocyte proliferation, was significantly increased following Ssd administration. In conclusion, the present study indicated that Ssd exhibited immunomodulatory effects and may be a novel potent chemopreventive drug candidate for the treatment of condylomata acuminata.

Antiviral-resistant fulminant herpes hepatitis in pregnancy

Fulminant herpes hepatitis with disseminated extrahepatic involvement in pregnancy is rare and carries a high mortality risk. Although acyclovir remains standard first-line therapy, effective management of acyclovir-resistant disseminated herpes simplex virus (HSV) in pregnancy remains elusive. We present a case of disseminated HSV resistant to both acyclovir and foscarnet, the first double-agent resistant case in pregnancy reported in the literature to date. In this case, therapeutic delivery was the ultimate treatment resulting in full recovery.

Successful treatment of giant condyloma acuminatum with combination retinoid and interferon-γ therapy

Giant condyloma acuminatum, or Buschke-Löwenstein tumour, is a unique variant of anogenital warts. It is characterized by locally aggressive behaviour but rarely metastasizes. Many treatment strategies such as radical surgery, radiation and chemotherapy have been used to treat it but their efficacy is often poor and the recurrence rates are high. We report a case of 16-year-old girl who was treated with oral retinoid combined with intramuscular interferon-γ. All lesions cleared within three months. During a follow-up period of more than two years, no recurrence has developed. This relatively painless, non-scarring treatment may represent a novel therapeutic option.

Toll-like receptor 7-mediated enhancement of contextual fear memory in mice

Toll-like receptor (TLR) 7 recognizes viral single-stranded RNA and triggers production of the type I interferons (IFNs) IFN-α and IFN-β. Imiquimod, a synthetic TLR7 ligand, induces production of type I IFNs and is used clinically as an antiviral and antitumor drug. In the present study, we examined the effect of imiquimod on conditioned and innate fear behaviors in mice. Imiquimod was administered 2, 4, or 15 h before contextual fear conditioning. Imiquimod treatment 4 or 15 h before fear conditioning significantly enhanced context-dependent freezing behavior. This imiquimod-induced enhancement of fear-related behaviors was observed 120 h after fear conditioning. In contrast, imiquimod failed to enhance context-dependent freezing behavior in TLR7 knockout mice. Imiquimod had no significant effect on pain threshold or on innate fear-related behavior, as measured by the elevated plus-maze. The levels of type I IFN mRNA in the brain were significantly increased at 2 h after imiquimod treatment. Imiquimod also increased interleukin (IL)-1β mRNA expression in the brain at 4 h following administration, while mRNA expression of F4/80, a macrophage marker, was unaffected by imiquimod treatment. Our findings suggest that TLR7-mediated signaling enhances contextual fear memory in mice, possibly by inducing the expression of type I IFNs and IL-1β in the brain.

Transmission of human papillomavirus DNA from patient to surgical masks, gloves and oral mucosa of medical personnel during treatment of laryngeal papillomas and genital warts

The risk of occupational human papillomavirus (HPV) transmission from patient to medical personnel during laser vaporization procedures remains controversial. The purpose of this study was to determine the risk of HPV transmission from the patient to the protective surgical masks, gloves and oral mucosa of medical personnel during the treatment of laryngeal papillomas and genital warts. The study involved five male patients scheduled for the surgical treatment of laryngeal papillomas, and five male patients undergoing carbon dioxide (CO(2)) laser treatment for urethral warts. Oral mucosa specimens were obtained from the study patients and the employees pre- and postoperatively. Samples were collected from the HPV-infected patient tissue, and from the surgical masks and gloves used by the employees. A total of 120 samples were analyzed for the presence of HPV DNA by PCR, using the degenerated MY09/11/HMB01 primers. After the papilloma procedures, the surgeons' gloves tested HPV positive in one of the five cases and those of the surgical nurse in three of the five cases. After the treatment of genital warts, HPV DNA corresponding to the patient tissue specimens was present in all the samples obtained from the surgical gloves of the operators. All oral mucosa samples obtained from 18 different employees tested HPV negative, as did the surgical mask specimens. According to our study, HPV may contaminate protective equipment, most of all surgical gloves, but transmission of HPV DNA to medical personnel is unlikely to occur provided that protective surgical gloves and masks are applied and disposed of properly.

Evidence-based treatment and prevention of external genital warts in female pediatric and adolescent patients

External anogenital warts, or condylomata acuminata, are caused by the proliferation of squamous epithelial cells secondary to human papillomavirus infection. In sexually active adults and adolescents, anogenital warts are a common sexually transmitted disease, but in children they may be a sign of sexual abuse. There are several treatment options available for anogenital warts, but no treatment has been proven to be the most efficacious, and recurrence after clinical clearance is common. Evidence-based treatment of genital warts is challenging because of the lack of controlled trials comparing treatments, especially in pediatric and adolescent populations. This paper discusses various treatment modalities such as physical destruction, cytotoxic agents, and immunomodulating therapies. Many variables influence the selection of a treatment, such as the size, quantity, and location of the warts; and the patient and provider preference, and its availability and cost. All treatments can cause local side effects, and patient tolerability must also be factored into treatment selection. Many treatments have similar clearance and recurrence rates, and none of the treatments completely eliminates the virus. With the numerous challenges surrounding the treatment of anogenital warts, the primary prevention of HPV infection through vaccination is a key component in decreasing the incidence of the disease.

Genital human papillomavirus infections: current and prospective therapies

Infection with human papillomaviruses (HPVs) is very common and associated with benign and malignant epithelial proliferations of skin and internal squamous mucosae. A subset of the mucosal HPVs are oncogenic and associated with 5 % of all cancers in men and women. There are two licensed prophylactic vaccines, both target HPV 16 and 18, the two most pathogenic, oncogenic types and one, additionally, targets HPV 6 and 11 the cause of genital warts. The approach of deliberate immunization with oncogenic HPV E6 and/or E7 proteins and the generation of antigen-specific cytotoxic T-cells as an immunotherapy for HPV-associated cancer and their high-grade pre-cancers has been tested with a wide array of potential vaccine delivery systems in Phase I/II trials with varying success. Understanding local viral and tumour immune evasion strategies is a prerequisite for the rational design of therapeutic vaccines for HPV-associated infection and disease, progress in this is discussed. There are no antiviral drugs for the treatment of HPV infection and disease. Current therapies are not targeted antiviral therapies, but either attempt physical removal of the lesion or induce inflammation and a bystander immune response. There has been recent progress in the identification and characterization of molecular targets for small molecule antagonists of the HPV proteins E1, E2 and E6 or their interactions with their cellular targets. Lead compounds that could disrupt E1-E2 protein-protein interactions have been discovered as have inhibitors of E6-E6-AP-binding interactions. Some of these compounds showed nanomolar affinities and high specificities and demonstrate the feasibility of this approach for HPV infections. These studies are, however, at an early phase and it is unlikely that any specific anti-HPV chemotherapeutic will be in the clinic within the next 10-20 years.