Significance High adjuvant doses are generally required to induce strong CD8 + T-cell immunity with subunit vaccines. Here we codeliver an antigen and an adjuvant coupled on separate ultrasmall polymeric nanoparticles. Because both payloads are attached to similarly sized nanoparticles, and as size is the principle determinant of nanoparticle drainage, this enhanced the dual uptake of antigen and adjuvant by cross-presenting dendritic cells resident in the draining lymph nodes. This cotargeting induced potent effector CD8 + T cells and a more powerful memory recall of these cytotoxic T cells compared with nanoparticle-conjugated antigen with free adjuvant. As such, nanoparticle conjugation enhanced the immunogenicity of adjuvants while maintaining a low dose, and thus limiting toxicity, affecting the design of future subunit vaccine formulations.

The ability of vaccines to induce memory cytotoxic T-cell responses in the lung is crucial in stemming and treating pulmonary diseases caused by viruses and bacteria. However, most approaches to subunit vaccines produce primarily humoral and only to a lesser extent cellular immune responses. We developed a nanoparticle (NP)-based carrier that, upon delivery to the lung, specifically targets pulmonary dendritic cells, thus enhancing antigen uptake and transport to the draining lymph node; antigen coupling via a disulfide link promotes highly efficient cross-presentation after uptake, inducing potent protective mucosal and systemic CD8 + Tcell immunity. Pulmonary immunization with NP-conjugated ovalbumin (NP-ova) with CpG induced a threefold enhancement of splenic antigen-specific CD8 + T cells displaying increased CD107a expression and IFN-γ production compared with immunization with soluble (i.e., unconjugated) ova with CpG. This enhanced response was accompanied by a potent Th17 cytokine profile in CD4 + T cells. After 50 d, NP-ova and CpG also led to substantial enhancements in memory CD8 + T-cell effector functions. Importantly, pulmonary vaccination with NP-ova and CpG induced as much as 10-fold increased frequencies of antigen-specific effector CD8 + T cells to the lung and completely protected mice from morbidity following influenza-ova infection. Here, we highlight recruitment to the lung of a long-lasting pool of protective effector memory cytotoxic T-cells by our disulfide-linked antigen-conjugated NP formulation. These results suggest the reduction-reversible NP system is a highly promising platform for vaccines specifically targeting intracellular pathogens infecting the lung.adjuvant | antigen trafficking | T lymphocyte | prophylactic | antigen conjugation

The sentinel or tumor-draining lymph node (tdLN) serves as a metastatic niche for many solid tumors and is altered via tumor-derived factors that support tumor progression and metastasis. tdLNs are often removed surgically, and therapeutic vaccines against tumor antigens are typically administered systemically or in nontumor-associated sites. Although the tdLN is immune-suppressed, it is also antigen experienced through drainage of tumor-associated antigens (TAA), so we asked whether therapeutic vaccines targeting the tdLN would be more or less effective than those targeting the non-tdLN. Using LN-targeting nanoparticle (NP)-conjugate vaccines consisting of TAA-NP and CpG-NP, we compared delivery to the tdLN versus non-tdLN in two different cancer models, E.G7-OVA lymphoma (expressing the nonendogenous TAA ovalbumin) and B16-F10 melanoma. Surprisingly, despite the immune-suppressed state of the tdLN, tdLN-targeting vaccination induced substantially stronger cytotoxic CD8 þ T-cell responses, both locally and systemically, than non-tdLN-targeting vaccination, leading to enhanced tumor regression and host survival. This improved tumor regression correlated with a shift in the tumor-infiltrating leukocyte repertoire toward a less suppressive and more immunogenic balance. Nanoparticle coupling of adjuvant and antigen was required for effective tdLN targeting, as nanoparticle coupling dramatically increased the delivery of antigen and adjuvant to LN-resident antigen-presenting cells, thereby increasing therapeutic efficacy. This work highlights the tdLN as a target for cancer immunotherapy and shows how its antigen-experienced but immune-suppressed state can be reprogrammed with a targeted vaccine yielding antitumor immunity. Cancer Immunol Res; 2(5); 436-47. Ó2014 AACR.

Highlights COVID-19 patients with total loss of smell have more olfactory bulb abnormalities at the magnetic resonance imaging than patients without loss of smell. The olfactory bulb MRI abnormalities may be objectified through a signal intensity ratio measurement that is calculated between the average signals of the olfactory bulb and the frontal white matter. The loss of smell is probably due to olfactory bulb inflammation related to virus spread.

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Background High levels of serum interleukin-6 (IL-6) correlate with disease severity in COVID-19. We hypothesized that tocilizumab (a recombinant humanized anti-IL-6 receptor) could improve outcomes in selected patients with severe worsening COVID-19 pneumonia and high inflammatory parameters. Methods The TOCICOVID study included a prospective cohort of patients aged 16–80 years with severe (requiring > 6 L/min of oxygen therapy to obtain Sp02 > 94%) rapidly deteriorating (increase by ≥ 3 L/min of oxygen flow within the previous 12 h) COVID-19 pneumonia with ≥ 5 days of symptoms and C-reactive protein levels > 40 mg/L. They entered a compassionate use program of treatment with intravenous tocilizumab (8 mg/kg with a maximum of 800 mg per infusion; and if needed a second infusion 24 to 72 h later). A control group was retrospectively selected with the same inclusion criteria. Outcomes were assessed at D28 using inverse probability of treatment weighted (IPTW) methodology. Results Among the 96 patients included (81% male, mean (SD) age: 60 (12.5) years), underlying conditions, baseline disease severity, and concomitant medications were broadly similar between the tocilizumab ( n = 49) and the control ( n = 47) groups. In the IPTW analysis, treatment with tocilizumab was associated with a reduced need for overall ventilatory support (49 vs. 89%, wHR: 0.39 [0.25–0.56]; p < 0.001). Albeit lacking statistical significance, there was a substantial trend towards a reduction of mechanical ventilation (31% vs. 45%; wHR: 0.58 [0.36–0.94]; p = 0.026). However, tocilizumab did not improve overall survival (wHR = 0.68 [0.31–1.748], p = 0.338). Among the 85 (89%) patients still alive at D28, patients treated with tocilizumab had a higher rate of oxygen withdrawal (82% vs. 73.5%, wHR = 1.66 [1.17–2.37], p = 0.005), with a shorter delay before being weaned of oxygen therapy (mean 11 vs. 16 days; p < 0.001). At D28, the rate of patients discharged from hospital was higher in the tocilizumab group (70% vs. 40%, wHR = 1.82 [1.22–2.75]; p = 0.003). The levels of CRP and fibrinogen post therapy ( p < 0.001 for both variables) were significantly lower in the tocilizumab group (interaction test, mixed model). Rates of neutropenia (35% vs. 0%; p < 0.001) were higher in the tocilizumab group, yet rates of infections (22% vs. 38%, p = 0.089) including ventilator-acquired pneumonia (8% vs. 26%, p = 0.022) were higher in the control group. Conclusion These data could be helpful for the design of future trials aiming to counter COVID-19-induced inflammation, especially before patients require admission to the intensive ca...

An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy.

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