Leukemia is characterized by oncogenic lesions that result in a block of differentiation, whereas phenotypic plasticity is retained. A better understanding of how these two phenomena arise during leukemogenesis in humans could help inform diagnosis and treatment strategies. Here, we leveraged the well-defined differentiation states during T-cell development to pinpoint the initiation of T-cell acute lymphoblastic leukemia (T-ALL), an aggressive form of childhood leukemia, and study the emergence of phenotypic plasticity. Single-cell whole genome sequencing of leukemic blasts was combined with multiparameter flow cytometry to couple cell identity and clonal lineages. Irrespective of genetic events, leukemia-initiating cells altered their phenotypes by differentiation and dedifferentiation. The construction of the phylogenies of individual leukemias using somatic mutations revealed that phenotypic diversity is reflected by the clonal structure of cancer. The analysis also indicated that the acquired phenotypes are heritable and stable. Together, these results demonstrate a transient period of plasticity during leukemia initiation, where phenotypic switches seem unidirectional. Significance: A method merging multicolor flow cytometry with single-cell whole genome sequencing to couple cell identity with clonal lineages uncovers differentiation-state plasticity in leukemia, reconciling blocked differentiation with phenotypic plasticity in cancer.
©2024 The Authors; Published by the American Association for Cancer Research.

An effective HIV-1 vaccine remains a critical unmet need for ending the AIDS epidemic. Vaccine trials conducted to date have suggested the need to increase the durability and functionality of vaccine-elicited antibodies to improve efficacy. We hypothesized that a conjugate vaccine based on the learned response to immunization with hepatitis B virus could be utilized to expand T cell help and improve antibody production against HIV-1. To test this, we developed an innovative conjugate vaccine regimen that used a modified vaccinia virus Ankara (MVA) co-expressing HIV-1 envelope (Env) and the hepatitis B virus surface antigen (HBsAg) as a prime, followed by two Env-HBsAg conjugate protein boosts. We compared the immunogenicity of this conjugate regimen to matched HIV-1 Env-only vaccines in two groups of 5 juvenile rhesus macaques previously immunized with hepatitis B vaccines in infancy. We found expansion of both HIV-1 and HBsAg-specific circulating T follicular helper cells and elevated serum levels of CXCL13, a marker for germinal center activity, after boosting with HBsAg-Env conjugate antigens in comparison to Env alone. The conjugate vaccine elicited higher levels of antibodies binding to select HIV Env antigens, but we did not observe significant improvement in antibody functionality, durability, maturation, or B cell clonal expansion. These data suggests that conjugate vaccination can engage both HIV-1 Env and HBsAg specific T cell help and modify antibody responses at early time points, but more research is needed to understand how to leverage this strategy to improve the durability and efficacy of next-generation HIV vaccines.
© 2023. The Author(s).

Infants and children infected with human immunodeficiency virus (HIV)-1 have been shown to develop neutralizing antibodies (nAbs) against heterologous HIV-1 strains, characteristic of broadly nAbs (bnAbs). Thus, having a neonatal model for the induction of heterologous HIV-1 nAbs may provide insights into the mechanisms of neonatal bnAb development. Here, we describe a neonatal model for heterologous HIV-1 nAb induction in pathogenic simian-HIV (SHIV)-infected rhesus macaques (RMs). Viral envelope (env) evolution showed mutations at multiple sites, including nAb epitopes. All 13 RMs generated plasma autologous HIV-1 nAbs. However, 8/13 (62%) RMs generated heterologous HIV-1 nAbs with increasing potency over time, albeit with limited breadth, and mapped to multiple nAb epitopes, suggestive of a polyclonal response. Moreover, plasma heterologous HIV-1 nAb development was associated with antigen-specific, lymph-node-derived germinal center activity. We define a neonatal model for heterologous HIV-1 nAb induction that may inform future pediatric HIV-1 vaccines for bnAb induction in infants and children.
Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.

Harnessing innate immunity is emerging as a promising therapeutic approach in cancer. We report here the design of tetraspecific molecules engaging natural killer (NK) cell-activating receptors NKp46 and CD16a, the β-chain of the interleukin-2 receptor (IL-2R), and a tumor-associated antigen (TAA). In vitro, these tetraspecific antibody-based natural killer cell engager therapeutics (ANKETs) induce a preferential activation and proliferation of NK cells, and the binding to the targeted TAA triggers NK cell cytotoxicity and cytokine and chemokine production. In vivo, tetraspecific ANKETs induce NK cell proliferation and their accumulation at the tumor bed, as well as the control of local and disseminated tumors. Treatment of non-human primates with CD20-directed tetraspecific ANKET leads to CD20+ circulating B cell depletion, with minimal systemic cytokine release and no sign of toxicity. Tetraspecific ANKETs, thus, constitute a technological platform for harnessing NK cells as next-generation cancer immunotherapies.
Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.

The prognosis of hepatocellular carcinoma (HCC) is extremely poor, of which hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) accounts for the majority in China. Immune checkpoint inhibitors have become an effective immunotherapy method for the treatment of HCC, but they are mainly used for T cells. NK cells play a vital role as the first line of defense against tumors. Therefore, we explored the characteristic expression pattern of immune checkpoints on NK cells of HBV-HCC patients. We analyzed the correlation between the co-expression of TIGIT and TIM-3 and the clinical progress of patients with HBV-HCC. The co-expression of TIGIT and TIM-3 on NK cells is elevated in patients with HBV-HCC. TIGIT+TIM-3+NK cells showed exhausted phenotypic characteristics and displayed dysfunction manifested as weakened killing function, reduced cytokine production, and proliferation function. TIGIT+TIM-3+NK cells participate in NK cells function exhaustion and are closely related to the disease progression of patients with HBV-HCC, suggesting a new target for future immunotherapy.
© 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.