We established a catalog of the mouse gut metagenome comprising ∼2.6 million nonredundant genes by sequencing DNA from fecal samples of 184 mice. To secure high microbiome diversity, we used mouse strains of diverse genetic backgrounds, from different providers, kept in different housing laboratories and fed either a low-fat or high-fat diet. Similar to the human gut microbiome, >99% of the cataloged genes are bacterial. We identified 541 metagenomic species and defined a core set of 26 metagenomic species found in 95% of the mice. The mouse gut microbiome is functionally similar to its human counterpart, with 95.2% of its Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologous groups in common. However, only 4.0% of the mouse gut microbial genes were shared (95% identity, 90% coverage) with those of the human gut microbiome. This catalog provides a useful reference for future studies.

Immunotherapies targeting the programmed death 1 (PD-1) coinhibitory receptor have shown great promise for a subset of patients with cancer. However, robust and safe combination therapies are still needed to bring the benefit of cancer immunotherapy to broader patient populations. To search for an optimal strategy of combinatorial immunotherapy, we have compared the antitumor activity of the anti-4-1BB/anti-PD-1 combination with that of the anti-PD-1/anti-LAG-3 combination in the poorly immunogenic B16F10 melanoma model. Pronounced tumor inhibition occurred only in animals receiving anti-PD-1 and anti-4-1BB concomitantly, while combining anti-PD-1 with anti-LAG-3 led to a modest degree of tumor suppression. The activity of the anti-4-1BB/anti-PD-1 combination was dependent on IFNg and CD8 þ T cells. Both 4-1BB and PD-1 proteins were elevated on the surface of CD8 þ T cells by anti-4-1BB/anti-PD-1 cotreatment. In the tumor microenvironment, an effective antitumor immune response was induced as indicated by the increased CD8 þ /Treg ratio and the enrichment of genes such as Cd3e, Cd8a, Ifng, and Eomes. In the spleen, the combination treatment shaped the immune system to an effector/memory phenotype and increased the overall activity of tumor-specific CD8 þ CTLs, reflecting a long-lasting systemic antitumor response. Furthermore, combination treatment in C57BL/6 mice showed no additional safety signals, and only minimally increased severity of the known toxicity relative to 4-1BB agonist alone. Therefore, in the absence of any cancer vaccine, anti-4-1BB/anti-PD-1 combination therapy is sufficient to elicit a robust antitumor effector/memory T-cell response in an aggressive tumor model and is therefore a candidate for combination trials in patients.

Age-related macular degeneration (AMD) is a leading cause of visual dysfunction worldwide. Amyloid β (Aβ) peptides, Aβ1-40 (Aβ40) and Aβ1-42 (Aβ42), have been implicated previously in the AMD disease process. Consistent with a pathogenic role for Aβ, we show here that a mouse model of AMD that invokes multiple factors that are known to modify AMD risk (aged human apolipoprotein E 4 targeted replacement mice on a high-fat, cholesterolenriched diet) presents with Aβ-containing deposits basal to the retinal pigmented epithelium (RPE), histopathologic changes in the RPE, and a deficit in scotopic electroretinographic response, which is reflective of impaired visual function. Strikingly, these electroretinographic deficits are abrogated in a dose-dependent manner by systemic administration of an antibody targeting the C termini of Aβ40 and Aβ42. Concomitant reduction in the levels of Aβ and activated complement components in sub-RPE deposits and structural preservation of the RPE are associated with anti-Aβ40/42 antibody immunotherapy and visual protection. These observations are consistent with the reduction in amyloid plaques and improvement of cognitive function in mouse models of Alzheimer's disease treated with anti-Aβ antibodies. They also implicate Aβ in the pathogenesis of AMD and identify Aβ as a viable therapeutic target for its treatment.A ge-related macular degeneration (AMD) affects about 30% of Americans over 70 y of age (1-3) and is the leading cause of irreversible blindness in the Western world (4). It is a progressive retinal degenerative disease influenced by both environmental and genetic factors. Although the presence of a few small hard drusen is a normal, nonvision-impairing part of aging, the deposition of large diffuse drusen in the macula adversely impacts vision and is indicative of early AMD. As AMD progresses to late-stage disease, it is categorized as either dry [geographic atrophy with photoreceptor loss and extensive atrophy of the retinal pigmented epithelium (RPE)] or wet [exudative with subsequent choroidal neovascularization (CNV)] (5). Currently, there are no effective treatments for early AMD, and treatments for late-stage disease are limited to photodynamic therapy, macular translocation, and antivascular endothelial growth factor drugs (6-9).The strongest known risk factors are advanced age and cigarette smoking, with additional risk conferred by body mass index and diets high in fat (1,(10)(11)(12)(13)(14). The last decade has also yielded strong evidence that genotype, especially for genes involved in inflammation and the innate immune system, influences AMD risk and progression. Genes implicated as risk factors include complement factor H (CFH) (15-18), complement factor B (19), complement C3 (20), apolipoprotein E (APOE) (21-25), toll-like receptor 4 (26), LOC387715/ARMS2 (27, 28), HTRA1 (29, 30), ABCA4 (31), and fibulin 5 (32). Additional support for a role for chronic local inflammation in AMD comes from the discovery that protein components of drusen include activated co...

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COVID-19 is a distinctive infection characterized by elevated inter-human transmission and presenting from absence of symptoms to severe cytokine storm that can lead to dismal prognosis. Like for HIV, lymphopenia and drastic reduction of CD4+ T cell counts in COVID-19 patients have been linked with poor clinical outcome. As CD4+ T cells play a critical role in orchestrating responses against viral infections, important lessons can be drawn by comparing T cell response in COVID-19 and in HIV infection and by studying HIV-infected patients who became infected by SARS-CoV-2. We critically reviewed host characteristics and hyper-inflammatory response in these two viral infections to have a better insight on the large difference in clinical outcome in persons being infected by SARS-CoV-2. The better understanding of mechanism of T cell dysfunction will contribute to the development of targeted therapy against severe COVID-19 and will help to rationally design vaccine involving T cell response for the long-term control of viral infection.