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Zurawski, S.

Publications and source records attributed to Zurawski, S..

5 recordsLinked to original sources

Dual blockade of LILRB1 and LILRB2 enhances antiviral immune responses in SIV infection

Restoring effective antiviral immunity remains a major challenge in HIV infection. Among emerging immune checkpoint molecules, the inhibitory receptors LILRB1 and LILRB2 have been proposed as therapeutic targets, yet their in vivo function remains undefined due to the lack of cross-reactive blocking antibodies for relevant preclinical models. To address this, we developed a dual-specific blocking monoclonal antibody, mac20G10, targeting cynomolgus macaque LILRB1 and LILRB2 and assessed its immunomodulatory activity in an SIV model of infection. Pharmacodynamics analyses demonstrated that mac20G10 persisted in circulation and engaged target myeloid cells for up to 14 days without detectable adverse effects. A single administration prior to SIVmac251 infection enhanced early myeloid immune activation, characterized by increased frequencies of CD80+ pDC and CD80+ monocyte/macrophage subsets in blood and lymphoid tissues. These changes were accompanied by increased plasma levels of IFN-{lambda}, IL8, and IL-1RA during acute infection. Although viral replication remained unchanged, mac20G10 treatment promoted the development of SIV-specific memory CD8 T-cell responses. Together, these findings provide in vivo evidence that LILRB1 and LILRB2 function as myeloid immune checkpoints restraining antiviral priming, supporting this pathway as a rational target for combination immunotherapeutic strategies aimed at achieving durable HIV remission during analytic treatment interruption.

immunology↗

Langerhans Cells Drive Tfh and B Cell Responses Independent of Canonical Cytokine Signals

Dendritic cells (DCs) are key regulators of adaptive immunity, guiding T helper (Th) cell differentiation through antigen presentation, co-stimulation, and cytokine production. However, in steady-state conditions, certain DC subsets, such as Langerhans cells (LCs), induce T follicular helper (Tfh) cells and B cell responses without inflammatory stimuli. Using multiple mouse models and in vitro systems, we investigated the mechanisms underlying steady-state LC-induced adaptive immune responses. We found that LCs drive germinal center Tfh and B cell differentiation and antibody production independently of interleukin-6 (IL-6), type-I interferons, and ICOS ligand (ICOS-L) signaling, which are critical in inflammatory settings. Instead, these responses relied on CD80/CD86-mediated co-stimulation. Our findings challenge the conventional three-signal paradigm by demonstrating that cytokine signaling is dispensable for LC-mediated Tfh and B cell responses in steady-state. These insights provide a framework for understanding homeostatic immunity and the immune systems role in maintaining tolerance or developing autoimmunity under non-inflammatory conditions. SUMMARY STATEMENTLangerhans cells (LCs) drive germinal center Tfh and B cell responses in steady-state conditions independently of IL-6, type-I interferons, and ICOS ligand, challenging the established cytokine-centric model of T cell differentiation.

immunology↗

Design, immunogenicity, and efficacy of a pan-sarbecovirus dendritic-cell targeting vaccine

The emergence of SARS-CoV-2 variants of concern (VOCs) that escape pre-existing antibody neutralizing responses increases the need for vaccines that target conserved epitopes and induce cross-reactive B- and T-cell responses. We used a computational approach and sequence alignment analysis to design a new-generation subunit vaccine targeting conserved sarbecovirus B- and T-cell epitopes from Spike (S) and Nucleocapsid (N) to antigen-presenting cells expressing CD40 (CD40.CoV2). We demonstrate the potency of CD40.CoV2 to elicit high levels of cross-neutralizing antibodies against SARS-CoV-2, VOCs, and SARS-CoV-1 in K18-hACE2 transgenic mice, associated with improved viral control and survival after challenge. In addition, we demonstrate the potency of CD40.CoV2 in vitro to recall human multi-epitope, functional, and cytotoxic SARS-CoV-2 S- and N-specific T-cell responses that are unaffected by VOC mutations and cross-reactive with SARS-CoV-1 and, to a lesser extent, MERS epitopes. Overall, these findings provide a framework for a pan-sarbecovirus vaccine.

immunology↗

SARS-CoV-2 mechanistic correlates of protection: insight from modelling response to vaccines

The definition of correlates of protection is critical for the development of next generation SARS-CoV-2 vaccine platforms. Here, we propose a new framework for identifying mechanistic correlates of protection based on mathematical modelling of viral dynamics and data mining of immunological markers. The application to three different studies in non-human primates evaluating SARS-CoV-2 vaccines based on CD40-targeting, two-component spike nanoparticle and mRNA 1273 identifies and quantifies two main mechanisms that are a decrease of rate of cell infection and an increase in clearance of infected cells. Inhibition of RBD binding to ACE2 appears to be a robust mechanistic correlate of protection across the three vaccine platforms although not capturing the whole biological vaccine effect. The model shows that RBD/ACE2 binding inhibition represents a strong mechanism of protection which required significant reduction in blocking potency to effectively compromise the control of viral replication. One Sentence SummaryA framework for modelling the immune control of viral dynamics is applied to quantify the effect of several SARS-CoV-2 vaccine platforms and to define mechanistic correlates of protection.

immunology↗

Targeting MOG to skin macrophages prevents EAE in macaques through TGFβ-induced peripheral tolerance

To study the effect of vaccination on tolerization to the myelin antigen MOG we used a macaque model of experimental autoimmune encephalitis (EAE) in which immunization with recombinant human myelin oligodendrocyte glycoprotein (rhMOG) elicits brain inflammation and demyelination mediated by MOG-specific autoreactive CD4+ T lymphocytes and anti-MOG IgG. For antigen targeting to tolerizing antigen presenting cells, we used a recombinant antibody directed to the Dendritic Cells (DC)-Asialoglycoprotein receptor (DC-ASGPR). The intradermal administration of an anti-DC-ASGPR-MOG fusion protein, but not a control anti-DC-ASGPR-PSA (prostate specific antigen) protein, protected monkeys committed to develop EAE. Although effective treatment did not modify anti-MOG IgG production, it prevented the CD4+ T lymphocyte activation and pro-inflammatory cytokine production. Moreover, animals treated with anti-DC-ASGPR-MOG experienced a rise of MOG-specific CD4+CD25+FOXP3+CD39+ regulatory T cells as well as a TGF{beta}1, TGF{beta}2 and IL-8 upsurge after rhMOG re-immunization. Our results indicate that the pathogenicity of autoantibodies directed to MOG is mitigated in the presence of MOG-specific regulatory lymphocytes. This vaccination scheme appears suitable to treat relapsing autoimmune diseases with identified autoantigens such as that harboring anti-MOG or anti-AQP4 autoantibodies.

immunology↗