SUMMARY “Triple-defective” (3d) mice carrying a mutation in UNC93B1, a chaperone for the endosomal nucleic-acid sensing (NAS) Toll-Like Receptors TLR3, TLR7 and TLR9, are highly susceptible to Toxoplasma gondii infection. However, none of the single or even the triple NAS-TLR deficient animals recapitulated the 3d susceptible phenotype to Toxoplasma infection. Investigating this further, we find that while parasite RNA and DNA activate innate immune responses via the NAS-TLRs 7 and 9, TLR11 and TLR12 working as heterodimers are required for sensing and responding to Toxoplasma profilin. Consequently, the triple TLR7/TLR9/TLR11 deficient mice are highly susceptible to T. gondii infection, recapitulating the phenotype of 3d mice. Humans lack functional TLR11 and TLR12 genes. Consistently, human cells produce high levels of pro-inflammatory cytokines in response to parasite derived RNA and DNA, but not to Toxoplasma profilin supporting a more critical role for NAS-TLRs in human toxoplasmosis.

SUMMARY Combination antiretroviral therapy (ART) is able to suppress HIV-1 replication to undetectable levels. However, the persistence of latent viral reservoirs allows for a rebound of viral load upon cessation of therapy. Thus, therapeutic strategies to eradicate the viral latent reservoir are critically needed. Employing a targeted RNAi screen, we identified the ubiquitin ligase BIRC2 (cIAP1), a repressor of the noncanonical NF-κB pathway, as a potent negative regulator of LTR-dependent HIV-1 transcription. Depletion of BIRC2 through treatment with small molecule antagonists known as Smac mimetics enhanced HIV-1 transcription, leading to a reversal of latency in a JLat latency model system. Critically, treatment of resting CD4+ T cells isolated from ART-suppressed patients with the histone deacetylase inhibitor (HDACi) panobinostat together with Smac mimetics resulted in synergistic activation of the latent reservoir. These data implicate Smac mimetics as useful agents for shock-and-kill strategies to eliminate the latent HIV reservoir.

Background Vaccination is an important preventive health measure to protect against symptomatic and severe COVID-19. Impaired immunity secondary to an underlying malignancy or recent receipt of anti-neoplastic systemic therapies can result in less robust antibody titres following vaccination and possible risk of breakthrough infection. As clinical trials evaluating COVID-19 vaccines largely excluded patients with a history of cancer and those on active immunosuppression (including chemotherapy), limited evidence is available to inform the clinical efficacy of COVID-19 vaccination across the spectrum of patients with cancer. Patients and methods We describe the clinical features of patients with cancer who developed symptomatic COVID-19 following vaccination and compare weighted outcomes to those of contemporary unvaccinated patients, after adjustment for confounders, using data from the multi-institutional COVID-19 and Cancer Consortium (CCC19; ClinicalTrials.gov number, NCT04354701). Results Patients with cancer who develop COVID-19 following vaccination have substantial comorbidities and can present with severe and even lethal infection. Patients harboring hematologic malignancies are over-represented among vaccinated patients with cancer who develop symptomatic COVID-19. Conclusions Vaccination against COVID-19 remains an essential strategy in protecting vulnerable populations, including patients with cancer. However, patients with cancer who develop breakthrough infection despite full vaccination remain at risk of severe outcomes. A multilayered public health mitigation approach that includes vaccination of close contacts, boosters, social distancing, and mask-wearing should be continued for the foreseeable future.