Development of an mRNA-based therapeutic vaccine mHTV-03E2 for high-risk HPV-related malignancies.

Human papillomavirus (HPV) 16 and 18 infections are related to many human cancers. Despite several preventive vaccines for high-risk (hr) HPVs, there is still an urgent need to develop therapeutic HPV vaccines for targeting pre-existing hrHPV infections and lesions. In this study, we developed a lipid nanoparticle (LNP)-formulated mRNA-based HPV therapeutic vaccine (mHTV)-03E2, simultaneously targeting the E2/E6/E7 of both HPV16 and HPV18. mHTV-03E2 dramatically induced antigen-specific cellular immune responses, leading to significant CD8+ T cell infiltration and cytotoxicity in TC-1 tumors derived from primary lung epithelial cells of C57BL/6 mice expressing HPV E6/E7 antigens, mediated significant tumor regression, and prolonged animal survival, in a dose-dependent manner. We further demonstrated significant T cell immunity against HPV16/18 E6/E7 antigens for up to 4 months post-vaccination in immunological and distant tumor rechallenging experiments, suggesting robust memory T cell immunity against relapse. Finally, mHTV-03E2 synergized with immune checkpoint blockade to inhibit tumor growth and extend animal survival, indicating the potential in combination therapy. We conclude that mHTV-03E2 is an excellent candidate therapeutic mRNA vaccine for treating malignancies caused by HPV16 or HPV18 infections.

Lymph node-targeted STING agonist nanovaccine against chronic HBV infection.

Chronic hepatitis B virus (HBV) infection is a global health problem that substantially increases the risk of developing liver disease. The development of a novel strategy to induce anti-HB seroconversion and achieve a long-lasting immune response against chronic HBV infection remains challenging. Here, we found that chronic HBV infection affected the signaling pathway involved in STING-mediated induction of host immune responses in dendritic cells (DCs) and then generated a lymph node-targeted nanovaccine that co-delivered hepatitis B surface antigen (HBsAg) and cyclic diguanylate monophosphate (c-di-GMP) (named the PP-SG nanovaccine). The feasibility and efficiency of the PP-SG nanovaccine for CHB treatment were evaluated in HBV-carrier mice. Serum samples were analyzed for HBsAg, anti-HBs, HBV DNA, and alanine aminotransferase levels, and liver samples were evaluated for HBV DNA and RNA and HBcAg, accompanied by an analysis of HBV-specific cellular and humoral immune responses during PP-SG nanovaccine treatment. The PP-SG nanovaccine increased antigen phagocytosis and DC maturation, efficiently and safely eliminated HBV, achieved a long-lasting immune response against HBV reinjection, and disrupted chronic HBV infection-induced immune tolerance, as characterized by the generation and multifunctionality of HBV-specific CD8+ T and CD4+ T cells and the downregulation of immune checkpoint molecules. HBV-carrier mice immunized with the PP-SG nanovaccine achieved partial anti-HBs seroconversion. The PP-SG nanovaccine can induce sufficient and persistent viral suppression and achieve anti-HBs seroconversion, rendering it a promising vaccine candidate for clinical chronic hepatitis B therapy.

Alternating Arenavirus Vector Immunization Generates Robust Polyfunctional Genotype Cross-Reactive Hepatitis B Virus-Specific CD8 T-Cell Responses and High Anti-Hepatitis B Surface Antigen Titers.

Hepatitis B Virus (HBV) is a major driver of infectious disease mortality. Curative therapies are needed and ideally should induce CD8 T cell-mediated clearance of infected hepatocytes plus anti-hepatitis B surface antigen (HBsAg) antibodies (anti-HBs) to neutralize residual virus. We developed a novel therapeutic vaccine using non-replicating arenavirus vectors. Antigens were screened for genotype conservation and magnitude and genotype reactivity of T cell response, then cloned into Pichinde virus (PICV) vectors (recombinant PICV, GS-2829) and lymphocytic choriomeningitis virus (LCMV) vectors (replication-incompetent, GS-6779). Alternating immunizations with GS-2829 and GS-6779 induced high-magnitude HBV T cell responses, and high anti-HBs titers. Dose schedule optimization in macaques achieved strong polyfunctional CD8 T cell responses against core, HBsAg, and polymerase and high titer anti-HBs. In AAV-HBV mice, GS-2829 and GS-6779 were efficacious in animals with low pre-treatment serum HBsAg. Based on these results, GS-2829 and GS-6779 could become a central component of cure regimens.

Peptide Vaccine Against ADAMTS-7 Ameliorates Atherosclerosis and Postinjury Neointima Hyperplasia.

BACKGROUND: The metalloprotease ADAMTS-7 (a disintegrin and metalloproteinase with thrombospondin type 1 motif 7) is a novel locus associated with human coronary atherosclerosis. ADAMTS-7 deletion protects against atherosclerosis and vascular restenosis in rodents. METHODS: We designed 3 potential vaccines consisting of distinct B cell epitopic peptides derived from ADAMTS-7 and conjugated with the carrier protein KLH (keyhole limpet hemocyanin) as well as aluminum hydroxide as an adjuvant. Arterial ligation or wire injury was used to induce neointima in mice, whereas ApoE-/- and LDLR-/- (LDLR [low-density lipoprotein receptor]) mice fed a high-fat diet were applied to assess atherosclerosis. In addition, coronary stent implantation was performed on vaccine-immunized Bama miniature pigs, followed by optical coherence tomography to evaluate coronary intimal hyperplasia. RESULTS: A vaccine, ATS7vac, was screened out from 3 candidates to effectively inhibit intimal thickening in murine carotid artery ligation models after vaccination. As well, immunization with ATS7vac alleviated neointima formation in murine wire injury models and mitigated atherosclerotic lesions in both hyperlipidemic ApoE-/- and LDLR-/- mice without lowering lipid levels. Preclinically, ATS7vac markedly impeded intimal hyperplasia in swine stented coronary arteries, but without significant immune-related organ injuries. Mechanistically, ATS7vac vaccination produced specific antibodies against ADAMTS-7, which markedly repressed ADAMTS-7-mediated COMP (cartilage oligomeric matrix protein) and TSP-1 (thrombospondin-1) degradation and subsequently inhibited vascular smooth muscle cell migration but promoted re-endothelialization. CONCLUSIONS: ATS7vac is a novel atherosclerosis vaccine that also alleviates in-stent restenosis. The application of ATS7vac would be a complementary therapeutic avenue to the current lipid-lowering strategy for atherosclerotic disease.

Prevention and treatment of HPV-related cancer through a mRNA vaccine expressing APC-targeting antigen.

Persistent human papillomavirus (HPV) infection is associated with multiple malignancies. Developing therapeutic vaccines to eliminate HPV-infected and malignant cells holds significant value. In this study, we introduced a lipid nanoparticle encapsulated mRNA vaccine expressing tHA-mE7-mE6. Mutations were introduced into E6 and E7 of HPV to eliminate their tumourigenicity. A truncated influenza haemagglutinin protein (tHA), which binds to the CD209 receptor on the surface of dendritic cells (DCs), was fused with mE7-mE6 in order to allow efficient uptake of antigen by antigen presenting cells. The tHA-mE7-mE6 (mRNA) showed higher therapeutic efficacy than mE7-mE6 (mRNA) in an E6 and E7+ tumour model. The treatment resulted in complete tumour regression and prevented tumour formation. Strong CD8+ T-cell immune response was induced, contributing to preventing and curing of E6 and E7+ tumour. Antigen-specific CD8+ T were found in spleens, peripheral blood and in tumours. In addition, the tumour infiltration of DC and NK cells were increased post therapy. In conclusion, this study described a therapeutic mRNA vaccine inducing strong anti-tumour immunity in peripheral and in tumour microenvironment, holding promising potential to treat HPV-induced cancer and to prevent cancer recurrence.

An engineered Accum-E7 protein-based vaccine with dual anti-cervical cancer activity.

Worldwide prevalence of cervical cancer decreased significantly with the use of human papilloma virus (HPV)-targeted prophylactic vaccines. However, these multivalent antiviral vaccines are inert against established tumors, which leave patients with surgical ablative options possibly resulting in long-term reproductive complications and morbidity. In an attempt to bypass this unmet medical need, we designed a new E7 protein-based vaccine formulation using Accum™, a technology platform designed to promote endosome-to-cytosol escape as a means to enhance protein accumulation in target cells. Prophylactic vaccination of immunocompetent mice using the Accum-E7 vaccine (aE7) leads to complete protection from cervical cancer despite multiple challenges conducted with ascending C3.43 cellular doses (0.5-, 1.0-, and 2.0 × 106 cells). Moreover, the humoral response induced by aE7 was higher in magnitude compared with naked E7 protein vaccination and displayed potent inhibitory effects on C3.43 proliferation in vitro. When administered therapeutically to animals with pre-established C3.43 or Tal3 tumors, the vaccine-induced response synergized with multiple immune checkpoint blockers (anti-PD-1, anti-CTLA4, and anti-CD47) to effectively control tumor growth. Mechanistically, the observed therapeutic effect requires cross-presenting dendritic cells as well as CD8 T cells predominantly, with a non-negligible role played by both CD4+ and CD19+ lymphocytes. good laboratory practice (GLP) studies revealed that aE7 is immunogenic and well tolerated by immunocompetent mice with no observed adverse effects despite the use of a fourfold exceeding dose. In a nutshell, aE7 represents an ideal vaccine candidate for further clinical development as it uses a single engineered protein capable of exhibiting both prophylactic and therapeutic activity.

Phase Ib/IIa randomized study of heterologous ChAdOx1-HBV/MVA-HBV therapeutic vaccination (VTP-300) as monotherapy and combined with low-dose nivolumab in virally-suppressed patients with CHB.

BACKGROUND & AIMS: The induction of effective CD8+ T cells is thought to play a critical role in the functional cure of chronic hepatitis B (CHB). Additionally, the use of checkpoint inhibitors is being evaluated to overcome T-cell dysfunction during CHB. METHODS: A chimpanzee adenoviral vector (ChAdOx1-HBV) and a Modified vaccinia Ankara boost (MVA-HBV) encoding the inactivated polymerase, core, and S region from a consensus genotype C HBV were studied. Fifty-five patients with virally suppressed CHB and HBsAg <4,000 IU/ml were enrolled. Group 1 received MVA-HBV intramuscularly on Day 0 and 28, Group 2 received ChAdOx1-HBV on Day 0 and MVA-HBV on Day 28 (VTP-300), Group 3 received VTP-300 + low-dose nivolumab (LDN) on Day 28, and Group 4 received VTP-300 plus LDN with both injections. RESULTS: VTP-300 alone and in combination with LDN was well tolerated with no treatment-related serious adverse events. Reductions of HBsAg were demonstrated in Group 2: 3 of 18 patients with starting HBsAg <50 IU/ml had durable log10 declines of >0.7 log10 at 2 months after the last dose. Group 3 (n = 18) had mean reductions in HBsAg of 0.76 log10 and 0.80 log10 (p <0.001) at 2 and 7 months after the last dose. Two patients developed persistent non-detectable HBsAg levels. CD4+ and CD8+ antigen-specific T-cell responses were generated and there was a correlation between IFN-γ ELISpot response and HBsAg decline in Group 2. CONCLUSIONS: VTP-300 induced CD4+ and CD8+ T cells and lowered HBsAg in a subset of patients with baseline values below 100 IU/ml. The addition of LDN resulted in significant reduction in surface antigen. VTP-300 is a promising immunotherapeutic that warrants further development alone or in combination therapies. IMPACT AND IMPLICATIONS: The induction of potent, durable CD8+ T cells may be critical to achieving a functional cure in chronic HBV infection. A prime-boost immunotherapeutic consisting of an adenoviral-vector encoding hepatitis B antigens followed by a pox virus boost was shown to induce CD8+ T cells and to lower HBsAg, either alone or more impactfully when administered in conjunction with a checkpoint inhibitor, in patients with chronic hepatitis B. The use of immunotherapeutics in this setting warrants further evaluation. CLINTRIALS: NCT047789.

Therapeutic vaccine-induced plasma cell differentiation is defective in the presence of persistently high HBsAg levels.

BACKGROUND & AIMS: Mechanisms behind the impaired response of antigen-specific B cells to therapeutic vaccination in chronic hepatitis B virus (HBV) infection remain unclear. The development of vaccines or strategies to overcome this obstacle is vital for advancing the management of chronic hepatitis B. METHODS: A mouse model, denominated as E6F6-B, was engineered to feature a knock-in of a B-cell receptor (BCR) that specifically recognizes HBsAg. This model served as a valuable tool for investigating the temporal and spatial dynamics of humoral responses following therapeutic vaccination under continuous antigen exposure. Using a suite of immunological techniques, we elucidated the differentiation trajectory of HBsAg-specific B cells post-therapeutic vaccination in HBV carrier mice. RESULTS: Utilizing the E6F6-B transfer model, we observed a marked decline in antibody-secreting cells 2 weeks after vaccination. A dysfunctional and atypical pre-plasma cell population (BLIMP-1+ IRF4+ CD40- CD138- BCMA-) emerged, manifested by sustained BCR signaling. By deploying an antibody to purge persistent HBsAg, we effectively prompted the therapeutic vaccine to provoke conventional plasma cell differentiation. This resulted in an enhanced anti-HBs antibody response and facilitated HBsAg clearance. CONCLUSIONS: Sustained high levels of HBsAg limit the ability of therapeutic hepatitis B vaccines to induce the canonical plasma cell differentiation necessary for anti-HBs antibody production. Employing a strategy combining antibodies with vaccines can surmount this altered humoral response associated with atypical pre-plasma cells, leading to improved therapeutic efficacy in HBV carrier mice. IMPACT AND IMPLICATIONS: Therapeutic vaccines aimed at combatting HBV encounter suboptimal humoral responses in clinical settings, and the mechanisms impeding their effectiveness have remained obscure. Our research, utilizing the innovative E6F6-B mouse transfer model, reveals that the persistence of HBsAg can lead to the emergence of an atypical pre-plasma cell population, which proves to be relevant to the potency of therapeutic HBV vaccines. Targeting the aberrant differentiation process of these atypical pre-plasma cells stands out as a critical strategy to amplify the humoral response elicited by HBV therapeutic vaccines in carrier mouse models. This discovery suggests a compelling avenue for further study in the context of human chronic hepatitis B. Encouragingly, our findings indicate that synergistic therapy combining HBV-specific antibodies with vaccines offers a promising approach that could significantly advance the pursuit of a functional cure for HBV.

HPV16 mutant E6/E7 construct is protective in mouse model.

BACKGROUND: Human papillomavirus type 16 (HPV-16) infection is strongly associated with considerable parts of cervical, neck, and head cancers. Performed investigations have had moderate clinical success, so research to reach an efficient vaccine has been of great interest. In the present study, the immunization potential of a newly designed HPV-16 construct was evaluated in a mouse model. RESULTS: Initially, a construct containing HPV-16 mutant (m) E6/E7 fusion gene was designed and antigen produced in two platforms (i.e., DNA vaccine and recombinant protein). Subsequently, the immunogenicity of these platforms was investigated in five mice) C57BL/6 (groups based on several administration strategies. Three mice groups were immunized recombinant protein, DNA vaccine, and a combination of them, and two other groups were negative controls. The peripheral blood mononuclear cells (PBMCs) proliferation, Interleukin-5 (IL-5) and interferon-γ (IFN-γ) cytokines, IgG1 and IgG2a antibody levels were measured. After two weeks, TC-1 tumor cells were injected into all mice groups, and subsequently further analysis of tumor growth and metastasis and mice survival were performed according to the schedule. Overall, the results obtained from in vitro immunology and tumor cells challenging assays indicated the potential of the mE6/E7 construct as an HPV16 therapeutic vaccine candidate. The results demonstrated a significant increase in IFN-γ cytokine (P value < 0.05) in the Protein/Protein (D) and DNA/Protein (E) groups. This finding was in agreement with in vivo assays. Control groups show a 10.5-fold increase (P value < 0.001) and (C) DNA/DNA group shows a 2.5-fold increase (P value < 0.01) in tumor growth compared to D and E groups. Also, a significant increase in survival of D and E (P value < 0.001) and C (P value < 0.01) groups were observed. CONCLUSIONS: So, according to the findings, the recombinant protein could induce stronger protection compared to the DNA vaccine form. Protein/Protein and DNA/Protein are promising administration strategies for presenting this construct to develop an HPV-16 therapeutic vaccine candidate.

Boosting of vaginal HSV-2-specific B and T cell responses by intravaginal therapeutic immunization results in diminished recurrent HSV-2 disease.

Boosting herpes simplex virus (HSV)-specific immunity in the genital tissues of HSV-positive individuals to increase control of HSV-2 recurrent disease and virus shedding is an important goal of therapeutic immunization and would impact HSV-2 transmission. Experimental therapeutic HSV-2 vaccines delivered by a parenteral route have resulted in decreased recurrent disease in experimental animals. We used a guinea pig model of HSV-2 infection to test if HSV-specific antibody and cell-mediated responses in the vaginal mucosa would be more effectively increased by intravaginal (Ivag) therapeutic immunization compared to parenteral immunization. Therapeutic immunization with HSV glycoproteins and CpG adjuvant increased glycoprotein-specific IgG titers in vaginal secretions and serum to comparable levels in Ivag- and intramuscular (IM)-immunized animals. However, the mean numbers of HSV glycoprotein-specific antibody secreting cells (ASCs) and IFN-γ SCs were greater in Ivag-immunized animals demonstrating superior boosting of immunity in the vaginal mucosa compared to parenteral immunization. Therapeutic Ivag immunization also resulted in a significant decrease in the cumulative mean lesion days compared to IM immunization. There was no difference in the incidence or magnitude of HSV-2 shedding in either therapeutic immunization group compared to control-treated animals. Collectively, these data demonstrated that Ivag therapeutic immunization was superior compared to parenteral immunization to boost HSV-2 antigen-specific ASC and IFN-γ SC responses in the vagina and control recurrent HSV-2 disease. These results suggest that novel antigen delivery methods providing controlled release of optimized antigen/adjuvant combinations in the vaginal mucosa would be an effective approach for therapeutic HSV vaccines. IMPORTANCE HSV-2 replicates in skin cells before it infects sensory nerve cells where it establishes a lifelong but mostly silent infection. HSV-2 occasionally reactivates, producing new virus which is released back at the skin surface and may be transmitted to new individuals. Some HSV-specific immune cells reside at the skin site of the HSV-2 infection that can quickly activate and clear new virus. Immunizing people already infected with HSV-2 to boost their skin-resident immune cells and rapidly control the new HSV-2 infection is logical, but we do not know the best way to administer the vaccine to achieve this goal. In this study, a therapeutic vaccine given intravaginally resulted in significantly better protection against HSV-2 disease than immunization with the same vaccine by a conventional route. Immunization by the intravaginal route resulted in greater stimulation of vaginal-resident, virus-specific cells that produced antibody and produced immune molecules to rapidly clear virus.

Repeated immunization with ATRA-containing liposomal adjuvant transdifferentiates Th17 cells to a Tr1-like phenotype.

In many autoimmune diseases, autoantigen-specific Th17 cells play a pivotal role in disease pathogenesis. Th17 cells can transdifferentiate into other T cell subsets in inflammatory conditions, however, there have been no attempts to target Th17 cell plasticity using vaccines. We investigated if autoantigen-specific Th17 cells could be specifically targeted using a therapeutic vaccine approach, where antigen was formulated in all-trans retinoic acid (ATRA)-containing liposomes, permitting co-delivery of antigen and ATRA to the same target cell. Whilst ATRA was previously found to broadly reduce Th17 responses, we found that antigen formulated in ATRA-containing cationic liposomes only inhibited Th17 cells in an antigen-specific manner and not when combined with an irrelevant antigen. Furthermore, this approach shifted existing Th17 cells away from IL-17A expression and transcriptomic analysis of sorted Th17 lineage cells from IL-17 fate reporter mice revealed a shift of antigen-specific Th17 cells to exTh17 cells, expressing functional markers associated with T cell regulation and tolerance. In the experimental autoimmune encephalomyelitis (EAE) mouse model of MS, vaccination with myelin-specific (MOG) antigen in ATRA-containing liposomes reduced Th17 responses and alleviated disease. This highlights the potential of therapeutic vaccination for changing the phenotype of existing Th17 cells in the context of immune mediated diseases.

Engineered ClearColi™-derived outer membrane vesicles as functional carriers for development of HIV-1 therapeutic vaccine candidate.

Bacteria-derived outer membrane vesicles (OMVs) can be engineered to incorporate foreign antigens. This study explored the potential of ClearColi™-derived OMVs as a natural adjuvant and a carrier (recombinant OMVs or rOMVs) for development of an innovative therapeutic vaccine candidate harboring HIV-1 Nef and Nef-Tat antigens. Herein, the rOMVs containing CytolysinA (ClyA)-Nef and ClyA-Nef-Tat fusion proteins were isolated from ClearColi™ strain. The presence of Nef and Nef-Tat proteins on their surface (rOMVNef and rOMVNef-Tat) was confirmed by western blotting after proteinase K treatment. Immune responses induced by Nef and Nef-Tat proteins emulsified with Montanide® ISA720 or mixed with OMVs, and also rOMVNef and rOMVNef-Tat were investigated in BALB/c mice. Additionally, the potency of splenocytes exposed to single-cycle replicable (SCR) HIV-1 virions was assessed for the secretion of cytokines in vitro. Our findings showed that the rOMVs as an antigen carrier (rOMVNef and rOMVNef-Tat) induced higher levels of IgG2a, IFN-γ and granzyme B compared to OMVs as an adjuvant (Nef + OMV and Nef-Tat + OMV), and also Montanide® ISA720 (Nef + Montanide and Nef-Tat + Montanide). Moreover, IFN-γ level in splenocytes isolated from mice immunized with rOMVNef-Tat was higher than other regimens after exposure to SCR virions. Generally, ClearColi™-derived rOMVs can serve as potent carriers for developing effective vaccines against HIV-1 infection.

cccDNA epigenetic regulator as target for therapeutical vaccine development against hepatitis B.

Chronic hepatitis B virus infection (CHB) remains a global health concern, with currently available antiviral therapies demonstrating limited effectiveness in preventing hepatocellular carcinoma (HCC) development. Two primary challenges in CHB treatment include the persistence of the minichromosome, covalently closed circular DNA (cccDNA) of the hepatitis B virus (HBV), and the failure of the host immune response to eliminate cccDNA. Recent findings indicate several host and HBV proteins involved in the epigenetic regulation of cccDNA, including HBV core protein (HBc) and HBV x protein (HBx). Both proteins might contribute to the stability of the cccDNA minichromosome and interact with viral and host proteins to support transcription. One potential avenue for CHB treatment involves the utilization of therapeutic vaccines. This paper explores HBV antigens suitable for epigenetic manipulation of cccDNA, elucidates their mechanisms of action, and evaluates their potential as key components of epigenetically-driven vaccines for CHB therapy. Molecular targeted agents with therapeutic vaccines offer a promising strategy for addressing CHB by targeting the virus and enhancing the host's immunological response. Despite challenges, the development of these vaccines provides new hope for CHB patients by emphasizing the need for HBV antigens that induce effective immune responses without causing T cell exhaustion.

Role of HIV-1 Tat Protein Interactions with Host Receptors in HIV Infection and Pathogenesis.

Each time the virus starts a new round of expression/replication, even under effective antiretroviral therapy (ART), the transactivator of viral transcription Tat is one of the first HIV-1 protein to be produced, as it is strictly required for HIV replication and spreading. At this stage, most of the Tat protein exits infected cells, accumulates in the extracellular matrix and exerts profound effects on both the virus and neighbor cells, mostly of the innate and adaptive immune systems. Through these effects, extracellular Tat contributes to the acquisition of infection, spreading and progression to AIDS in untreated patients, or to non-AIDS co-morbidities in ART-treated individuals, who experience inflammation and immune activation despite virus suppression. Here, we review the role of extracellular Tat in both the virus life cycle and on cells of the innate and adaptive immune system, and we provide epidemiological and experimental evidence of the importance of targeting Tat to block residual HIV expression and replication. Finally, we briefly review vaccine studies showing that a therapeutic Tat vaccine intensifies ART, while its inclusion in a preventative vaccine may blunt escape from neutralizing antibodies and block early events in HIV acquisition.

Vaccine a promising immunotherapy option for head and neck cancer patients.

Head and neck cancer (HNC) is a diversified group of tumors arising from the upper aerodigestive tract, encompassing the oral cavity, larynx, and pharynx. Globally, this particular cancer ranks sixth in prevalence, resulting in an annual mortality rate above 325,000 individuals. Surgery, radiation, and chemotherapy are the primary therapeutic options for HNC, which are frequently used in combination. Despite their extensive use, these treatments are typically unsuccessful and can significantly impair patient quality of life. Therapeutic vaccinations are administered to cancer patients instead of preventative immunizations administered to a healthy population. The efficacy of this modality has considerably transformed the application and success of cancer management by providing an additional and effective therapeutic option for patients. Cancer treatment has been revolutionized by introducing Immune Checkpoint receptors inhibitors (ICR), such as anti-CTLA4, anti-PD-1, and anti-PD-L1.3. ICR have also established immunity against self-generated cancerous cells. Cancer vaccines have shown extraordinary synergistic potential with checkpoint inhibitors to maximize tumor-specific CD8+ expansion and activity, which detects and destroys tumor cells. Personalized neoantigen vaccination therapies can potentially combat the heterogeneity of each patient's tumor. The findings of this review suggest that recent advances in cancer immunology and genetics imply that cancer vaccination can be a promising alternative treatment for head and neck cancer patients. This review conducted a comprehensive literature search to identify relevant studies on immunotherapy options for head and neck cancer patients. The search strategy was designed to capture a wide range of peer-reviewed articles, conference proceedings, and grey literature from 2013 to 2023. The databases searched to ensure comprehensive coverage of the literature included PubMed, Web of Science, and Google Scholar; to include grey literature and articles not indexed in traditional databases.

Activation of CD4 T cells during prime immunization determines the success of a therapeutic hepatitis B vaccine in HBV-carrier mouse models.

BACKGROUND & AIMS: We recently developed a heterologous therapeutic vaccination scheme (TherVacB) comprising a particulate protein prime followed by a modified vaccinia-virus Ankara (MVA)-vector boost for the treatment of HBV. However, the key determinants required to overcome HBV-specific immune tolerance remain unclear. Herein, we aimed to study new combination adjuvants and unravel factors that are essential for the antiviral efficacy of TherVacB. METHODS: Recombinant hepatitis B surface and core antigen (HBsAg and HBcAg) particles were formulated with different liposome- or oil-in-water emulsion-based combination adjuvants containing saponin QS21 and monophosphoryl lipid A; these formulations were compared to STING-agonist c-di-AMP and conventional aluminium hydroxide formulations. Immunogenicity and the antiviral effects of protein antigen formulations and the MVA-vector boost within TherVacB were evaluated in adeno-associated virus-HBV-infected and HBV-transgenic mice. RESULTS: Combination adjuvant formulations preserved HBsAg and HBcAg integrity for ≥12 weeks, promoted human and mouse dendritic cell activation and, within TherVacB, elicited robust HBV-specific antibody and T-cell responses in wild-type and HBV-carrier mice. Combination adjuvants that prime a balanced HBV-specific type 1 and 2 T helper response induced high-titer anti-HBs antibodies, cytotoxic T-cell responses and long-term control of HBV. In the absence of an MVA-vector boost or following selective CD8 T-cell depletion, HBsAg still declined (mediated mainly by anti-HBs antibodies) but HBV replication was not controlled. Selective CD4 T-cell depletion during the priming phase of TherVacB resulted in a complete loss of vaccine-induced immune responses and its therapeutic antiviral effect in mice. CONCLUSIONS: Our results identify CD4 T-cell activation during the priming phase of TherVacB as a key determinant of HBV-specific antibody and CD8 T-cell responses. IMPACT AND IMPLICATIONS: Therapeutic vaccination is a potentially curative treatment option for chronic hepatitis B. However, it remains unclear which factors are essential for breaking immune tolerance in HBV carriers and determining successful outcomes. Our study provides the first direct evidence that efficient priming of HBV-specific CD4 T cells determines the success of therapeutic hepatitis B vaccination in two preclinical HBV-carrier mouse models. Applying an optimal formulation of HBV antigens that activates CD4 and CD8 T cells during prime immunization provided the foundation for an antiviral effect of therapeutic vaccination, while depletion of CD4 T cells led to a complete loss of vaccine-induced antiviral efficacy. Boosting CD8 T cells was important to finally control HBV in these mouse models. Our findings provide important insights into the rational design of therapeutic vaccines for the cure of chronic hepatitis B.

Prophylactic and therapeutic vaccination protects sperm health from Chlamydia muridarum-induced abnormalities.

Chlamydia is the most common bacterial sexually transmitted infection worldwide and it is widely acknowledged that controlling the rampant community transmission of this infection requires vaccine development. In this study, for the first time, we elucidate the long-term response to male mouse chlamydial vaccination with chlamydial major outer membrane protein (MOMP) and ISCOMATRIX (IMX) both prophylactically and in a novel therapeutic setting. Vaccination significantly reduced and, in some cases, cleared chlamydial burden from the prostates, epididymides, and testes, which correlates with high IgG and IgA tires in tissues and serum. Important markers of sperm health and fertility were protected including sperm motility and proteins associated with fertility in men. Within splenocytes, expression of IFNγ, TNFα, IL17, IL13, IL10, and TGFß were changed by both infection and vaccination within CD4 and CD8 T cells and regulatory T cells. Within the testicular tissue, phenotypic and concentration changes were observed in macrophages and T cells (resident and transitory). This revealed some pathogenic phenotypes associated with infection and critically that vaccination allows maintenance of testicular homeostasis, likely by preventing significant influx of CD4 T cells and promoting IL10 production. Finally, we demonstrated the testes contained immature (B220+) B cells and mature (CD138+) Chlamydia-specific plasma cells. Thus, through vaccination, we can maintain the healthy function of the testes, which is vital to protection of male fertility.

Intranasal therapeutic vaccine containing HBsAg and HBcAg for patients with chronic hepatitis B; 18 months follow-up results of phase IIa clinical study.

AIMS: HBsAg loss with anti-HBs acquisition is considered a functional cure and ideal treatment goal for patients with CHB. Our group have reported the efficacy of therapeutic vaccine with HBsAg and HBcAg (NASVAC) by intranasal and subcutaneous injection. In this study, we investigated the safety and efficacy of newly developed CVP-NASVAC, which contained NASVAC with mucoadhesive carboxyl vinyl polymer (CVP) in the dedicated device. METHODS: A single dose, open-label, phase IIa clinical trial of CVP-NASVAC was conducted. Patients with CHB treated with nucleoside/nucleotide analogs (NAs) and HBV carriers not undergoing anti-HBV treatment were enrolled. CVP-NASVAC was injected through the nose for, in total, 10 times. Participants were followed-up for 18 months, and their HBsAg reduction and anti-HBs induction assessed as endpoints. RESULTS: Among the patients with CHB treated with NAs (n = 27) and HBV carriers without NAs (n = 36), 74.1% and 75.0% exhibited reductions in their baseline HBsAg, and the mean reductions were -0.1454 log10  IU/ml (p < 0.05) and -0.2677 log10  IU/ml (p < 0.05), respectively. Anti-HBs antibody was detected in 40.7% and 58.3% of patients treated with and without NAs, respectively. Six of 71 (9.5%) patients were functionally cured after the CVP-NASVAC treatment. CONCLUSIONS: Anti-HBs induction and HBsAg reduction was observed after CVP-NASVAC treatment in some patients with CHB. The CVP-NASVAC is a safe treatment, which might expect to achieve functional cure for patients with CHB.

LL-37 antimicrobial peptide and heterologous prime-boost vaccination regimen significantly induce HIV-1 Nef-Vpr antigen- and virion-specific immune responses in mice.

OBJECTIVES: HIV infection still remains a leading cause of morbidity and mortality worldwide. The inability of highly-active antiretroviral therapy in HIV-1 eradication led to development of therapeutic vaccines. Exploiting effective immunogenic constructs and potent delivery systems are important to generate effective therapeutic vaccines, and overcome their poor membrane permeability. Among HIV-1 proteins, the Nef and Vpr proteins can be considered as antigen candidates in vaccine design. METHODS: In this study, the immunogenicity of Nef-Vpr antigen candidate in different regimens along with antimicrobial peptide LL-37 (as a DNA carrier) and Montanide 720 (as an adjuvant) was studied in mice. Moreover, the secretion of cytokines was assessed in virion-exposed mice lymphocytes in vitro. RESULTS: Our data indicated that groups immunized with the homologous protein + Montanide regimen (group 1), and also the heterologous DNA + LL-37 prime/protein + Montanide boost regimen (group 2) could significantly generate strong immune responses as compared to groups immunized with the DNA constructs (groups 3 & 4). Moreover, immunization of mice with the homologous DNA + LL-37 regimen in low dose of DNA (5 µg) could induce higher immune responses than the homologous naked DNA regimen in high dose of DNA (50 µg) indicating the role of LL-37 as a cell penetrating peptide. Additionally, the heterologous DNA + LL-37 prime/protein + Montanide boost regimen (group 2) induced significantly IFN-gamma secretion from virion-exposed lymphocytes in vitro. CONCLUSION: Generally, the use of LL-37 for DNA delivery, Montanide 720 as an adjuvant, and heterologous DNA prime/protein boost strategy could significantly increase IgG2a, IFN-gamma, and Granzyme B, and maintain cytokine secretion after exposure to virions. Indeed, the heterologous DNA + LL-37 prime/protein + Montanide boost regimen can be considered as a potent strategy for development of therapeutic HIV vaccines.

A Therapeutic DNA Vaccine Targeting HPV16 E7 in Combination with Anti-PD-1/PD-L1 Enhanced Tumor Regression and Cytotoxic Immune Responses.

Persistent infection of high-risk human papillomavirus (HPV) and the expression of E6 and E7 oncoproteins are the main causes of cervical cancer. Several prophylactic HPV vaccines are used in the clinic, but these vaccines have limited efficacy in patients already infected with HPV. Since HPV E7 is vital for tumor-specific immunity, developing a vaccine against HPV E7 is an attractive strategy for cervical cancer treatment. Here, we constructed an HPV16 E7 mutant that loses the ability to bind pRb while still eliciting a robust immune response. In order to build a therapeutic DNA vaccine, the E7 mutant was packaged in an adenovirus vector (Ad-E7) for efficient expression and enhanced immunogenicity of the vaccine. Our results showed that the Ad-E7 vaccine effectively inhibited tumor growth and increased the proportion of interferon-gamma (IFN-γ)-secreting CD8+ T cells in the spleen, and tumor-infiltrating lymphocytes in a mouse cervical cancer model was achieved by injecting with HPV16-E6/E7-expressing TC-1 cells subcutaneously. Combining the Ad-E7 vaccine with the PD-1/PD-L1 antibody blockade significantly improved the control of TC-1 tumors. Combination therapy elicited stronger cytotoxic T lymphocyte (CTL) responses, and IFN-γ secretion downregulated the proportion of Tregs and MDSCs significantly. The expressions of cancer-promoting factors, such as TNF-α, were also significantly down-regulated in the case of combination therapy. In addition, combination therapy inhibited the number of capillaries in tumor tissues and increased the thickness of the tumor capsule. Thus, Ad-E7 vaccination, in combination with an immune checkpoint blockade, may benefit patients with HPV16-associated cervical cancer.