Conserved multiepitope vaccine constructs: A potent HIV-1 therapeutic vaccine in clinical trials

Abstract Despite the success of Antiretroviral Therapy (ART) in preventing HIV-1-associated clinical progression to AIDS, it is unable to eliminate the viral reservoirs and eradicate the HIV-1 infection. Therapeutic vaccination is an alternative approach to alter the HIV-1 infection course. It can induce effective HIV-1-specific immunity to control viremia and eliminate the need for lifelong ART. Immunological data from spontaneous HIV-1 controllers have shown that cross-reactive T-cell responses are the key immune mechanism in HIV-1 control. Directing these responses toward preferred HIV-1 epitopes is a promising strategy in therapeutic vaccine settings. Designing novel immunogens based on the HIV-1 conserved regions containing a wide range of critical T- and B-cell epitopes of the main viral antigens (conserved multiepitope approaches) supplies broad coverage of global diversity in HIV-1 strains and Human Leukocyte Antigen (HLA) alleles. It can also prevent immune induction to undesirable decoy epitopes theoretically. The efficacy of different novel HIV-1 immunogens based on the conserved and/or functional protective site of HIV-1 proteome has been evaluated in multiple clinical trials. Most of these immunogens were generally safe and able to induce potent HIV-1-specific immunity. However, despite these findings, several candidates have demonstrated limited efficacy in viral replication control. In this study, we used the PubMed and ClinicalTrial.gov databases to review the rationale of designing curative HIV-1 vaccine immunogens based on the conserved favorable site of the virus. Most of these studies evaluate the efficacy of vaccine candidates in combination with other therapeutics and/or with new formulations and immunization protocols. This review briefly describes the design of conserved multiepitope constructs and outlines the results of these vaccine candidates in the recent clinical pipeline.

Therapeutic use of human papillomavirus vaccines in cervical lesions

ABSTRACT Human papillomavirus (HPV) has been associated with the development of precancerous lesions of the cervix and cervical cancer (CC). Prophylactic HPV vaccination induces the development of a specific memory immune response that facilitates HPV elimination once the natural infection occurs. At present, in addition to the prophylactic vaccine, therapeutic vaccines are being developed and researched with the aim of inducing an immune response that allows the elimination of HPV-infected cells. The purpose of this study is to describe the current evidence on the use of therapeutic vaccines and their effect on cervical precancerous lesions, to establish recommendations on their clinical use. So far, the studies that have generated results have described a marginal beneficial effect of the prophylactic vaccine in the management of infection and pre-invasive lesions. Based on the evidence, continuing research on the efficacy and safety of therapeutic vaccines for the treatment of cervical intraepithelial lesions is recommended. The use of the HPV prophylactic vaccine as treatment for pre-existing lesions is not advised, but it is recommended to prevent new lesions.

Dynamics of Hepatitis B Virus Surface Antigen Level with Peripheral Blood Lymphocytes in Chronic Hepatitis B Infection

Background:Peripheral blood mononuclear cells containing an aggregate of immune competent cells,such as T lymphocytes, B cells and natural killer cells, play an important role in control or persistence of the hepatitis B virus(HBV) infection. Similarly, the expression of hepatitis B viral antigens on the surface of infected hepatocytes can invoke a cytotoxic T–cell response.Objective:To investigate the dynamic changes in hepatitis B surface antigen (HBsAg) and peripheral lymphocyte subsets of healthy donors and chronic hepatitis B patients. Methodology:Serum HBsAg was quantified by enzyme-linked immunosorbent assayaccording to the manufacturer’s guidelines. Peripheral blood lymphocyte cell phenotyping was carried out by flow cytometry for all chronic hepatitis B patients and healthy blood donors Results:The results of this study showed a significant correlation between HBsAg level and percentage of T and NK cells (r=0.366; P=0.01, r=-0.462; P=0.01,respectively). On the other hand, significance variation in peripheral blood lymphocyte percentage of T lymphocyte subsets in patients were found to be directly proportional to T cell subsets CD4+and CD8+ (P=0.001)compared with healthy blood donor controls. Conclusion:In conclusion this study highlighted the role of the HBsAg level in supressing the immune cells of the innate and adaptive immune system. Understanding the interactions between HBsAg and peripheral blood cells serves as a basis for development of HBV therapeutic vaccines and a prognostic biomarker in persistent HBV infection

Vacuna terapéutica racotumomab en un anciano con cáncer avanzado de pulmón / Racotumomab therapeutic vaccine in an elderly with advanced lung cancer

Se presenta el caso clínico de un anciano de 84 años de edad, fumador, con diagnóstico de cáncer de pulmón en etapa IV, quien fue incluido en el ensayo clínico de fase III para ser tratado con racotumumab. Se observó mejoría clínica y del estado general del paciente, pues según la escala funcional concluyó el estudio con ECOG 0. Por tanto, es oportuno destacar que esta vacuna incrementa la supervivencia de los afectados por cáncer de pulmón de células no pequeñas recurrentes o en estadios avanzados.

The case report of a 84 years elderly smoker, is presented with diagnosis of lung cancer in stage IV who was included in the phase III clinical trial to be treated with racotumomab. Clinical improvement and recovery of the patient's general state was observed, because according to the functional scale the study concluded with ECOG 0. Therefore, it is opportune to highlight that this vaccine increases the survival of those affected by recurrent non-small cells lung cancer or in advanced stages.

Hepatitis B vaccination and immunotherapies: an update

Perspectives on the clinical development of immunotherapy in prostate cancer / 亚洲男科学杂志(英文版)

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. Sipuleucel-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. Reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomarkers, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.

Hepatitis B surface antigen and functional cure of chronic hepatitis B / 复旦学报（医学版）

Functional cure of viral hepatitis B is currently the main target of scientists worldwide.The definition of functional cure is durable loss of HBsAg (with or without HBsAg sero-conversion),undetectable serum HBV DNA,persistence of cccDNA in an inactive state and the absence of spontaneous relapse after treatment cessation.In this article,the knowns and unknowns of HBsAg have been shortly reviewed,and current immunotherapies for chronic hepatitis are introduced.Among these,the experimental and clinical application of HBsAg-HBIG immunotherapy developed by our group is presented.Based on the current data,as anti-HBV drugs can eliminate or decrease viral load,neutralizing HBsAg antibody can provide passive immunity,and HBsAg-HBIG complexes can trigger potent immune responses,a "sandwich" protocol for functional cure of chronic hepatitis B is proposed.Namely,first use anti-HBV drugs for decrease or elimination of viral load;second,use passive immune therapy,by neutralizing anti-HBs antibody for decrease or clearance of serum HBsAg;and lastly,use active immunization,by HBsAg-HBIG complex vaccination to induce long term and effective immune responses to HBsAg.This approach may keep cccDNA in an inactive state,and reach the goal of functional cure.

Enhancing T Cell Immune Responses by B Cell-based Therapeutic Vaccine Against Chronic Virus Infection

Chronic virus infection leads to the functional impairment of dendritic cells (DCs) as well as T cells, limiting the clinical usefulness of DC-based therapeutic vaccine against chronic virus infection. Meanwhile, B cells have been known to maintain the ability to differentiate plasma cells producing antibodies even during chronic virus infection. Previously, alpha-galactosylceramide (alphaGC) and cognate peptide-loaded B cells were comparable to DCs in priming peptide-specific CD8+ T cells as antigen presenting cells (APCs). Here, we investigated whether B cells activated by alphaGC can improve virus-specific T cell immune responses instead of DCs during chronic virus infection. We found that comparable to B cells isolated from naive mice, chronic B cells isolated from chronically infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13) after alphaGC-loading could activate CD1d-restricted invariant natural killer T (iNKT) cells to produce effector cytokines and upregulate co-stimulatory molecules in both naive and chronically infected mice. Similar to naive B cells, chronic B cells efficiently primed LCMV glycoprotein (GP) 33-41-specific P14 CD8+ T cells in vivo, thereby allowing the proliferation of functional CD8+ T cells. Importantly, when alphaGC and cognate epitope-loaded chronic B cells were transferred into chronically infected mice, the mice showed a significant increase in the population of epitope-specific CD8+ T cells and the accelerated control of viremia. Therefore, our studies demonstrate that reciprocal activation between alphaGC-loaded chronic B cells and iNKT cells can strengthen virus-specific T cell immune responses, providing an effective regimen of autologous B cell-based therapeutic vaccine to treat chronic virus infection.

CLINICAL EXPERIENCE WITH TABLETED V5 THERAPEUTIC VACCINE DERIVED FROM HYDROLYZED BLOOD OF DONORS WITH HEPATITIS B AND C / Шинэ санаа Шинэ нээлт

V5 is derived from pooled blood of donors with hepatitis B and C, which was hydrolyzed, autoclaved and foFWHlrtted into ordinary tablets. The principle of V5 action is similar to the first generation hepatitis B vaccine derived from plasma of hepatitis carriers. Preclinical studies have shown that V5 is safe - no acute or chronic toxicity in vitro or animals was seen at 1,882-fold higher doses than recommended once-per-day pill regimen. Safety Phase 1 two-month study has not demonstrated any adverse effects. Several clinical Phase II trials of V5 were conducted in past 5 years since its approval as a biologically active immunomodulator. Post-marketing survey in Mongolia assessed in 240 individuals with hepatitis B and C revealed that levels of liver damage biomarkcrs: ALT; bilirubin and alkaline phosphatase decreased from mean 104.9192 to 63.2 • 51 (P« 0.0001); 14. I±12 to 9.9±7 (P=0.0001); 319±190 to 242±145 (P=0.049), respectively. The efficacy ofV5 based on ALT decrease in each individual was observed in 84.1% of patients. During trial in Ukraine on hepatitis C patients who also had tuberculosis it was accidentally discovered that V5 can clear Mycobacterium tuberculosis. Subsequent trials, including randomized placebo controlled phase II Mai, conducted in over 300 patients with TB has demonstrated that V5 has potent anti-TB activity r4iardless whether patients had drug sensitive TB, MDR-TB or TB with HIV. On average the c'crrance rate was observed in over 85% of TB patients after just one month. Recently wc have slJHed seeing patients with hepatocellular carcinoma who seemed to benefit from V5. The case rcR)rt from one patient will be presented to illustrate this effect. In conclusion. V5 appears to have kfSad spectrum activity against unrelated diseases. This needs to be verified in further clinical studies

Vacinas terapêuticas para a hipertensão / Therapeutic vaccines for hypertension

A hipertensão arterial (HA) é uma doença crônica, não transmissível, de natureza multifatorial, assintomática, que constitui um dos principais fatores de risco cardiovascular. Apesar do sucesso do arsenal farmacológico disponível para o tratamento da HA, sabe-se que a adesão ao tratamento é um dos fatores limitantes do controle efetivo da pressão arterial. O objetivo deste trabalho foi realizar uma revisão da literatura sobre os tratamentos atuais da HA, com foco na modulação imunológica do sistema renina-angiotensina-aldosterona. O sistema renina-angiotensina-aldosterona (SRAA) é um dos principais reguladores das funções cardiovascular e renal, foco de várias intervenções terapêuticas cujo objetivo é controlar os níveis pressóricos. A crescente compreensão da farmacologia do SRAA levou ao desenvolvimento de abordagens imunológicas na inibição do SRAA para o tratamento da HA. A imunização contra componentes do sistema poderia evitar a necessidade da administração diária de drogas a pacientes com hipertensão e poderiam melhorar o controle dessa doença. As pesquisas que envolvem a imunização ativa ou passiva contra os componentes do SRAA incluíram o desenvolvimento de vacinas contra a renina, a angiotensina I e II, além dos receptores de angiotensina II. Há inúmeras etapas em que o sistema pode ser interrompido por vacinação. Contudo, a eficácia da vacinação varia, dependendo da etapa que estiver sendo interrompida. Apesar de promissora, a ideia de tratar uma doença crônica com vacinas contra antígenos, endógenos, deve ser encarada com cautela.

Hypertension is a chronic, multifactorial and asymptomatic disease which is a major cardiovascular risk factor. Despite the success of the pharmacological tools available to the treatment of hypertension, it is known that patient compliance is a limiting step of effective control of high blood pressure. The aim of this study was a review of current treatments for hypertension, focusing on immune modulation of the renin-angiotensin-aldosterone system. The renin-angiotensin-aldosterone system (RAAS) is a key regulator of cardiovascular and renal functions, focus of several therapeutic interventions aimed at controlling blood pressure levels. The increasing understanding of the pharmacology of RAAS led to the development of immunological approaches to inhibit the RAAS. The immunization against components of the system could avoid the need for daily drugs administration to patients with hypertension and could improve the control of this disease. The research involving the active or passive immunization against the components of RAAS included the development of vaccines against renin, angiotensin I and II, and angiotensin II receptors. There are several steps in which the system can be blocked by vaccination; however, the effectiveness of vaccines varies depending on the stage being interrupted. Despite promising, the idea of treating a chronic disease with vaccines against endogenous antigens should be viewed with caution.

HPV vaccination: the beginning of the end of cervical cancer? - A Review

Human papillomavirus (HPV) is responsible for all cases of cervical cancer, as well as a great percentage of other anogenital tumors and oropharyngeal tumors. Since the main etiologic factor for these diseases is a virus, prophylactic measures are the best way to reduce the burden caused by the infection and associated disease. This review brings up to date information on the two commercially available prophylactic HPV vaccines against HPV, as well as presenting the ongoing research on HPV peptide, protein and dendritic cell based therapeutic vaccines.

Recent Concepts of Human Papillomavirus Vaccine

Two prophylactic human papillomavirus (HPV) vaccines against types 6, 11, 16 and 18 have shown great promise in clinical trials with recent results demonstrating 100% efficacy against persistent HPV infection and development of cervical intraepithelial neoplasia up to five years of follow-up. Published data from the phase-IIb and III trials thus far indicate that the prophylactic HPV L1 virus-like particle vaccine is safe and well-tolerated. It offers HPV-naive women a very high level of protection against HPV persistent infection and cervical intraepithelial lesions associated with the types included in the vaccine. HPV vaccination should be also offered to girls before onset of sexual activity. But there are still questions about several issues of HPV prophylactic vaccination. Prolonged clinical trials should be performed for demonstration of these remaining questions. Finally, prophylactic vaccines against HPV will certainly reduce the incidence of the risk of developing cervical cancer.

Human Papillomavirus Type 16 E5 Protein as a Therapeutic Target

Cervical cancer is a progressive disease with an onset of one to two decades on average. During the productive replication stage, the Human papillomavirus (HPV) genome is maintained episomally in the infected cervical epithelium and early gene products, including E5, are expressed. Therefore, E5 has a potential to contribute to the HPV-associated carcinogenic process. In invasive malignancies, the HPV genomes are commonly integrated into the host genome, and E6 and E7 genes remain intact. However, the E5 is lost or, if present, under-expressed as compared with the E6 and E7 proteins. This suggests that E5 may play a critical role in the genesis of cervical cancer but less of a role in its persistence or progression. In the initiation of neoplasia and the premalignant stage, there are fewer malignant cells than in the invasive malignancies. Moreover, cells in the invasive malignant stage are found to have a very low level of MHC class I and II, which could hamper the presentation of the antigen and lead to a decreased immune response. Since the E5 protein is likely to play a role during the early tumorigenesis stage, a therapeutic vaccine to target and eliminate the E5-expressing cells may be a good strategy to prevent premalignant lesions from progressing toward invasive cervical cancers. This paper provides an overview of HPV-induced cervical carcinogenesis and strategies for designing prophylactic and therapeutic vaccines to prevent and cure the cervical cancer. In particular, focus will be on the rationale of targeting the E5 protein to develop therapeutic vaccines.

The Construction, Expression and Purification of Therapeutic Adjuvant-free Protein Vaccine——HPV16z-Hsp65-E6/E7 / 中国生物工程杂志

Objective: To develop a therapeutic adjuvantfree protein vaccine against HPV16 which is closely related to cervical cancer of China. Method: First the E6/E7 gene by PCR technology from HPV16z virus strain was isolated in the highrisk cervical cancer area of Shanxi province of China in1990s, and again got the gene segment of Hsp65 from BCG by the same method, mutated the transforming codes in sequences of HPV 16 E6/E7 genes and thus constructed the expression vector pET28aHsp65E6/E7, expressed the Hsp65E6/E7 fusion protein in E.coli BL21(DE3) strain and researched optimal protein purification procedures. Results: The expression vector pET28aHsp65E6/E7 was constructed successfully and E6/E7 gene was mutated correctly. Hsp65E6/E7 fusion protein was renatured and purified on the affinity chromatography column simultaneously. The protein purity achieved 95% after the anionic exchange chromatograph purification. conclusions: This research laid a foundation for further functional study of the therapeutic adjuvantfree protein vaccine——Hsp65E6/E7.

Study of therapeutic adjuvant-free protein vaccine-HPV16Z-Hsp65-E6/E7 / 中国肿瘤生物治疗杂志

Objective: To study the biological effects of the HPV16Z-Hsp65-E6/E7 fusion protein vaccine on the tumor associated with HPV16 infection. Methods: We tested the cellular immune responsive intensity to the vaccine by the lymphocyte proliferation and CTL response, and studied the therapeutic effect of the vaccine on mouse TC-1 cell transplanted cancer in vivo and the influence on mouse lifetime. Results: The spleen lymphocytes from the C57BL/6 mouse immunized by the Hsp65-E6/E7 vaccine could proliferate obviously in the presence of the protein and TC-1 tumor cell could be lysed specifically by immune activated lymphocytes in vitro. This animal therapeutic experiment in vivo showed that the vaccine suppressed the growth of TC-1 cell transplanted tumor remarkably. Conclusion: The recombined vaccine can induce specific cellular immune response in vitro and suppress HPV16 positive TC-1 tumor cell growth obviously in vivo.