Autologous dendritic cell vaccination against HIV-1 induces changes in natural killer cell phenotype and functionality

Immunostimulatory effects of Hsp70 fragments-modified DCs: A computational and experimental study in HIV vaccine design

BACKGROUND

Dendritic cells (DCs) loaded with HIV-1 antigens have been explored as a promising therapeutic approach to overcome HIV-1 infection. Heat shock proteins (Hsps) can improve cross-presentation of linked antigens by DCs. Our aim was a comprehensive in silico, in vitro, and in vivo evaluation of fusion proteins comprising the N- and C-terminal regions of Hsp70 (i.e., NT-Hsp70 and CT-Hsp70) as an adjuvant linked to HIV-1 Nef antigen in development of DCs-based vaccine candidates.

METHODS

Computational analyses of the NT-Hsp70-Nef and CT-Hsp70-Nef fusion constructs were performed, and their structural features and docking ability with toll-like or endocytic receptors were evaluated. The effectiveness of DCs loaded with the fusion proteins in eliciting immunity was assessed in mice. Cytokine secretion levels from splenocytes exposed to single-cycle replicable (SCR) HIV-1 were also measured in vitro.

RESULTS

The DCs pulsed with the fusion constructs induced robust cellular and humoral immune responses in mice and infected splenocytes. The CT-Hsp70 region showed better docking scores with immune receptors and superior adjuvanticity for inducing Nef-specific immune responses (Th1 and CTL activity) compared to the NT-Hsp70 region in DC-based immunization.

CONCLUSIONS

The CT-Hsp70-Nef protein demonstrated promising results in both computational and experimental analyses compared to the NT-Hsp70-Nef protein.

From natural defenders to therapeutic warriors: NK cells in HIV immunotherapy

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells both play essential roles in controlling viral infections by eliminating virus-infected cells. Unlike CTLs, which require priming and activation by antigen-presenting cells, NK cells possess a remarkable capacity to mount a rapid antiviral immune response immediately after infection. Additionally, they can bolster the adaptive immune system by secreting cytokines and directly interacting with other immune cells. However, during chronic human immunodeficiency virus (HIV) infection, various immune cells, including NK cells, experience functional impairments. This has led to the exploration of NK cell-based immunotherapy as a promising strategy to reverse these dysfunctions and contribute to the pursuit of a functional cure for HIV. Building on the success of NK cell therapies in cancer treatment, these approaches offer significant potential for transforming the HIV cure field. This review provides a comprehensive overview of the latest advances in NK cell-based immunotherapy for HIV, outlining the progress made and the key challenges that must be overcome to achieve a functional cure for people living with HIV.

Navigating the Roadblocks: Progress and Challenges in Cell-Based Therapies for Human Immunodeficiency Virus

Cell-based therapies represent a major advancement in the treatment and management of HIV/AIDS, with a goal to overcome the limitations of traditional antiretroviral therapy (ART). These innovative approaches not only promise a functional cure by reconstructing the immune landscape but also address the persistent viral reservoirs. For example, stem cell therapies have emerged from the foundational success of allogeneic hematopoietic stem cell transplantation in curing HIV infection in a limited number of cases. B cell therapies make use of genetically modified B cells constitutively expressing broadly neutralizing antibodies (bNAbs) against target viral particles and infected cells. Adoptive cell transfer (ACT), including TCR-T therapy, CAR-T cells, NK-CAR cells, and DC-based therapy, is adapted from cancer immunotherapy and repurposed for HIV eradication. In this review, we summarize the mechanisms through which these engineered cells recognize and destroy HIV-infected cells, the modification strategies, and their role in sustaining remission in the absence of ART. The review also addresses the challenges to cell-based therapies against HIV and discusses the recent advancements aimed at overcoming them.

Leveraging oncovirus-derived antigen against the viral malignancies in adoptive cell therapies

Adoptive cell therapies (ACTs) have revolutionized cancer immunotherapy, prompting exploration into their application against oncoviruses. Oncoviruses such as human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), and Epstein-Barr virus (EBV) contribute significantly (12-25%) to human malignancies through direct or indirect oncogenic mechanisms. These viruses persistently or latently infect cells, disrupt cellular homeostasis and pathways, challenging current antiviral treatment paradigms. Moreover, viral infections pose additional risks in the setting of long-term cancer therapy and lead to morbidity and mortality. Virally encoded oncoproteins, which are tumor-restricted, immunologically foreign, and even uniformly expressed, represent promising targets for patient-tailored ACTs. This review elucidates the rationale for leveraging viral antigen-specific ACTs in combating viral-associated malignancies. On this basis, ongoing preclinical studies consolidate our understanding of harnessing ACTs against viral malignancies, underscoring their potential to eradicate viruses implicated in cancer progression. Furthermore, we scrutinize the current landscape of clinical trials focusing on virus-specific ACTs and discuss their implications for therapeutic advancement.

Natural killer cells at the forefront of cancer immunotherapy with immune potency, genetic engineering, and nanotechnology

Natural killer (NK) cells are vital components of the human immune system, acting as innate lymphocytes and playing a crucial role in immune surveillance. Their unique ability to independently eliminate target cells without antigen contact or antibodies has sparked interest in immunological research. This review examines recent NK cell developments and applications, encompassing immune functions, interactions with target cells, genetic engineering techniques, pharmaceutical interventions, and implications in cancers. Insights into NK cell regulation emerge, with a focus on promising genetic engineering like CAR-engineered NK cells, enhancing specificity against tumors. Immune checkpoint inhibitors also enhance NK cells' potential in cancer therapy. Nanotechnology's emergence as a tool for targeted drug delivery to improve NK cell therapies is explored. In conclusion, NK cells are pivotal in immunity, holding exciting potential in cancer immunotherapy. Ongoing research promises novel therapeutic strategies, advancing immunotherapy and medical interventions.

Unlocking Dendritic Cell-Based Vaccine Efficacy through Genetic Modulation-How Soon Is Now?

The dendritic cell (DC) vaccine anti-cancer strategy involves tumour-associated antigen loading and maturation of autologous ex vivo cultured DCs, followed by infusion into the cancer patient. This strategy stemmed from the idea that to induce a robust anti-tumour immune response, it was necessary to bypass the fundamental immunosuppressive mechanisms of the tumour microenvironment that dampen down endogenous innate immune cell activation and enable tumours to evade immune attack. Even though the feasibility and safety of DC vaccines have long been confirmed, clinical response rates remain disappointing. Hence, the full potential of DC vaccines has yet to be reached. Whether this cellular-based vaccination approach will fully realise its position in the immunotherapy arsenal is yet to be determined. Attempts to increase DC vaccine immunogenicity will depend on increasing our understanding of DC biology and the signalling pathways involved in antigen uptake, maturation, migration, and T lymphocyte priming to identify amenable molecular targets to improve DC vaccine performance. This review evaluates various genetic engineering strategies that have been employed to optimise and boost the efficacy of DC vaccines.

Multimeric immunotherapeutic complexes activating natural killer cells towards HIV-1 cure

BACKGROUND

Combination antiretroviral therapy (cART) has dramatically extended the life expectancy of people living with HIV-1 and improved their quality of life. There is nevertheless no cure for HIV-1 infection since HIV-1 persists in viral reservoirs of latently infected CD4+ T cells. cART does not eradicate HIV-1 reservoirs or restore cytotoxic natural killer (NK) cells which are dramatically reduced by HIV-1 infection, and express the checkpoint inhibitors NKG2A or KIR2DL upregulated after HIV-1 infection. Cytotoxic NK cells expressing the homing receptor CXCR5 were recently described as key subsets controlling viral replication.

METHODS

We designed and evaluated the potency of "Natural killer activating Multimeric immunotherapeutic compleXes", called as NaMiX, combining multimers of the IL-15/IL-15Rα complex with an anti-NKG2A or an anti-KIR single-chain fragment variable (scFv) to kill HIV-1 infected CD4+ T cells. The oligomerization domain of the C4 binding protein was used to associate the IL-15/IL-15Rα complex to the scFv of each checkpoint inhibitor as well as to multimerize each entity into a heptamer (α form) or a dimer (β form). Each α or β form was compared in different in vitro models using one-way ANOVA and post-hoc Tukey's tests before evaluation in humanized NSG tg-huIL-15 mice having functional NK cells.

RESULTS

All NaMiX significantly enhanced the cytolytic activity of NK and CD8+ T cells against Raji tumour cells and HIV-1+ ACH-2 cells by increasing degranulation, release of granzyme B, perforin and IFN-γ. Targeting NKG2A had a stronger effect than targeting KIR2DL due to higher expression of NKG2A on NK cells. In viral inhibition assays, NaMiX initially increased viral replication of CD4+ T cells which was subsequently inhibited by cytotoxic NK cells. Importantly, anti-NKG2A NaMiX enhanced activation, cytotoxicity, IFN-γ production and CXCR5 expression of NK cells from HIV-1 positive individuals. In humanized NSG tg-huIL-15 mice, we confirmed enhanced activation, degranulation, cytotoxicity of NK cells, and killing of HIV-1 infected cells from mice injected with the anti-NKG2A.α NaMiX, as compared to control mice, as well as decreased total HIV-1 DNA in the lung.

CONCLUSIONS

NK cell-mediated killing of HIV-1 infected cells by NaMiX represents a promising approach to support HIV-1 cure strategies.