Time-dependent enhancement of mRNA vaccines by 4-1BB costimulatory antibodies
Ontology highlight
ABSTRACT: mRNA vaccines have demonstrated efficacy against COVID-19. However, concerns regarding waning immunity and breakthrough infections have motivated the development of next-generation vaccines with enhanced efficacy. In this study, we investigated the impact of 4-1BB costimulation on immune responses elicited by mRNA vaccines in mice. We first vaccinated mice with an mRNA vaccine encoding the SARS-CoV-2 spike antigen like the Moderna and Pfizer-BioNTech vaccines, followed by administration of 4-1BB costimulatory antibodies at various times post-vaccination. Administering 4-1BB costimulatory antibodies during the priming phase did not enhance immune responses. However, administering 4-1BB costimulatory antibodies after 96 hours elicited a significant improvement in CD8 T cell responses, leading to enhanced protection against breakthrough infections. A similar improvement in immune responses was observed with multiple mRNA vaccines, including vaccines against common cold coronavirus, human immunodeficiency virus (HIV), and arenavirus. These findings demonstrate a time-dependent effect by 4-1BB costimulation and provide insights for developing improved mRNA vaccines.
Project description:The activation of TLR-MyD88 (Toll like receptor- Myeloid differentiation factor 88) signaling within T cells functions as a potent costimulatory signal that boosts antitumor and antiviral responses. However, the molecular mechanisms underlying the costimulatory processes are poorly understood. We compared microarray gene analysis data between TLR1-TLR2 stimulated and unstimulated T cell receptor transgenic âpmelâ and MyD88-/-pmel CD8+ T cells and identified changes in the expression levels of several TNF family members. In particular, TLR-stimulation increased 4-1BB levels in pmel but not in MyD88-/-pmel T cells. A link between 4-1BB and TLR1-TLR2 signaling in CD8+ T cells was highlighted by in fact that 4-1BB-/- T cells exhibited suboptimal responses to TLR1-TLR2 agonist, but responded normally to CD28 or OX40 costimulation. Moreover, blocking 4-1BB signaling with antibodies also hindered the costimulatory effects of the TLR1-TLR2 agonist. The elevated levels of 4-1BB transcripts in TLR1-TLR2âstimulated cells were not due to increased mRNA stability nor increased histone activation but instead were associated with increased binding of p65 and c-Jun to two distinct 4-1BB promoter sites. Combining TLR1-TLR2 ligand with an agonistic anti-4-1BB antibody enhanced the antitumor activity in mice with established melanoma tumors. These studies reveal that the costimulatory effects of TLR1-TLR2 signaling in CD8+ T cells are in part mediated by 4-1BB and are important for mounting an effective antitumor immune response. CD8+ T cells from the B6.Cg-Thy1/Cy Tg(TcraTcrb)8Rest/J mice, referred to as âpmelâ T cells or from MyD88 knockout pmel mice (MyD88â/âpmel) were sorted. pmel and MyD88â/âpmel T cells were activated using MyD88â/â CD8 T cell-depleted splenocytes pulsed with 10ng/ml of mgp100. This was with or without 10µg/ml of Pam3CSK4. pmel or MyD88â/âpmel CD8 T cells were enriched and used for the extraction of RNA used for genomic analysis.
Project description:The activation of TLR-MyD88 (Toll like receptor- Myeloid differentiation factor 88) signaling within T cells functions as a potent costimulatory signal that boosts antitumor and antiviral responses. However, the molecular mechanisms underlying the costimulatory processes are poorly understood. We compared microarray gene analysis data between TLR1-TLR2 stimulated and unstimulated T cell receptor transgenic ‘pmel’ and MyD88-/-pmel CD8+ T cells and identified changes in the expression levels of several TNF family members. In particular, TLR-stimulation increased 4-1BB levels in pmel but not in MyD88-/-pmel T cells. A link between 4-1BB and TLR1-TLR2 signaling in CD8+ T cells was highlighted by in fact that 4-1BB-/- T cells exhibited suboptimal responses to TLR1-TLR2 agonist, but responded normally to CD28 or OX40 costimulation. Moreover, blocking 4-1BB signaling with antibodies also hindered the costimulatory effects of the TLR1-TLR2 agonist. The elevated levels of 4-1BB transcripts in TLR1-TLR2–stimulated cells were not due to increased mRNA stability nor increased histone activation but instead were associated with increased binding of p65 and c-Jun to two distinct 4-1BB promoter sites. Combining TLR1-TLR2 ligand with an agonistic anti-4-1BB antibody enhanced the antitumor activity in mice with established melanoma tumors. These studies reveal that the costimulatory effects of TLR1-TLR2 signaling in CD8+ T cells are in part mediated by 4-1BB and are important for mounting an effective antitumor immune response.
Project description:CD137 (4-1BB) is a member of the TNFR family that mediates potent T-cell costimulatory signals upon ligation by CD137L or agonist monoclonal antibodies. CD137 agonists attain immunotherapeutic antitumor effects in cancer mouse models and multiple agents of this kind are undergoing clinical trials. We show that cIAP1 and cIAP2 are physically associated with the CD137-signaling complex. Moreover, cIAPs are required for CD137 signaling towards the NF-κB and MAPK pathways and for costimulation of human and mouse T lymphocytes. Functional evidence was substantiated with SMAC-mimetics that trigger cIAPs degradation and by transfecting cIAP dominant-negative variants. Antitumor effects of agonist anti-CD137 mAbs are critically dependent on the integrity of cIAPs in cancer mouse models and cIAPs are also required for signaling from CARs encompassing CD137’s cytoplasmic tail.
Project description:Human T cells isolated from healthy donors were transduced with non-tonically signaling CARs or tonically signaling CARs, each with CD28z or 4-1BB costimulatory domains Human T cells isolated from healthy donors were transduced with non-tonically signaling CARs or tonically signaling CARs, each with CD28z or 4-1BB costimulatory domains
Project description:The choice of costimulatory domain in CAR design dictates the kinetics of in vivo anti-tumor responses, affecting potency, quality and durability. We show that 1928z results in more vigorous effector functions, whereas 19BBz design compensates for their lesser cytotoxic potency by steadily building up their numbers. Therapeutic function can be further improved by combining CD28 and 4-1BB costimulation. 1928z-41BBL was revealed to provide optimal combined costimulation, exhibiting highly therapeutic efficiency with balanced T cell effector function and accumulation. Endogenous IFN-β/IRF7 pathway activation was found in 1928z-41BBL T cell and is required for effector function acquisition. The role of the IFN-β/IRF7 pathway provides a novel mechanism through which engineering T cells improve therapeutic effect by self-providing ‘signal 3’.
Project description:Costimulation of T cells with agonist antibodies targeting 4-1BB (CD137) improves antitumor immune responses in preclinical studies, but clinical development has been hampered by on-target, off-tumor toxicity. Here, we report the development of a tumor-anchored ɑ4-1BB agonist, termed ɑ4-1BB-LAIR, which consists of an ɑ4-1BB antibody fused to the collagen binding protein mLAIR1. Combination treatment with an antitumor antibody (TA99) displayed only modest efficacy, but surprisingly cured >90% of mice upon depletion of CD4+ cells. We elucidated two mechanisms of action for this synergy: ɑCD4 increased priming and activation in the tumor draining lymph node , and TA99 + ɑ4-1BB-LAIR supported the cytotoxic program of these newly primed CD8+ T cells within the tumor microenvironment. Replacement of ɑCD4 with ɑCTLA-4, a more clinically relevant agent to enhance T cell priming, produces equivalently high cure rates while generating significantly more robust immunological memory against secondary tumor rechallenge.
Project description:Broadly protective antibodies against highly variable pathogens are very important for design of vaccines and therapeutics. We report that by administering two heterotypic influenza hemagglutinins (HAs) to mice by time difference, monoclonal antibodies can be obtained that bind strongly to both heterotypic influenza HAs. More interestingly, it was able to bind widely to the untreated subtype of HA.
Project description:We observed self-activation of SKM-CAR-T cells which target novel mesothelioma antigen. CAR-T with CD28 costimulatory domain showed signs of exhaustion while those with 4-1BB costimulatory domain did not. To elucidate molecules responsible for self-activation-induced exhaustion, we performed RNA-seq analysis of SKM-CAR-T cells with CD28 or 4-1BB and CD19-CAR-T cells with CD28 or 4-1BB.
Project description:We generated a new B7-H3 CAR-T cell costimulatory domain using TMIGD2 and found it was as good or better than the CD28.4-1BB costimulatory domain. Little is known about TMIGD2 signaling, so we examined how each CAR signals individually compared to CD19.CD28.4-1BB control CAR-T cells.