There is growing concern about the impact of poor nutrition on honey bee health. With caged bee experiments and whole-colony field experiments, we examined the effects of supplementing bees with essential amino acids (EAA), or a control treatment of nonessential amino acids (NAA). Caged bees fed EAA developed significantly greater head weights than controls, weights that were similar to nurse bees. Caged bees fed EAA developed significantly greater thorax weights than controls, weights that were similar to foragers. Higher head and thorax weights may respectively reflect increased glandular development in nurse bees and higher flight muscle mass in forager bees. In our field study, 29% of the pollen collected by our honey bee colonies came from eucalyptus trees. Amino acid analyses revealed no EAA deficiencies for the bee-collected polyfloral pollen or for monofloral eucalyptus pollen. Colonies fed 29 g EAA supplement may have slightly increased individual bee growth and brood rearing, but this effect was not significant. A clear colony result was a correlation between nurse bee physiology and brood development: 17% increase in nurse bee weight corresponded to 100% more capped brood cells (R 2 = 0.38). We suggest that colony supplementation should target nurse bee nutrition. Nurse bees eventually become forager bees. Hence, increased glandular development may support colony brood development and greater flight muscle mass may assist colony foraging.

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited anti-viral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, ∼50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine ( Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19 ) and cytokine ( Ifn-λ and Tnf-α ) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease. Importance Understanding the immunological mechanisms contributing to both host defense and disease following viral infection of the CNS is of critical importance given the increasing number of viruses that are capable of infecting and replicating within the nervous system. With this in mind, the present study was undertaken to evaluate the role of microglia in aiding in host defense following experimental infection of the central nervous system (CNS) of K18-hACE2 with SARS-CoV-2, the causative agent of COVID-19. Neurologic symptoms that range in severity are common in COVID-19 patients and understanding immune responses that contribute to restricting neurologic disease can provide important insight into better understanding consequences associated with SARS-CoV-2 infection of the CNS.

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited anti-viral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, ∼50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine (Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19) and cytokine (Ifn-λ and Tnf-α) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease.ImportanceUnderstanding the immunological mechanisms contributing to both host defense and disease following viral infection of the CNS is of critical importance given the increasing number of viruses that are capable of infecting and replicating within the nervous system. With this in mind, the present study was undertaken to evaluate the role of microglia in aiding in host defense following experimental infection of the central nervous system (CNS) of K18-hACE2 with SARS-CoV-2, the causative agent of COVID-19. Neurologic symptoms that range in severity are common in COVID-19 patients and understanding immune responses that contribute to restricting neurologic disease can provide important insight into better understanding consequences associated with SARS-CoV-2 infection of the CNS.

Helicobacter pylori (H. pylori) infection is a major risk factor for the development of gastric cancer. The authors previously demonstrated that in mice deficient in myeloid differentiation primary response 88 (Myd88 -/-), infection with Helicobacter felis (H. felis) a close relative of H. pylori, subsequently rapidly progressed to neoplasia. The present study examined circulating tumor cells (CTCs) by measuring the expression of cytokeratins, epithelial-to-mesenchymal transition (EMT)-related markers and cancer stem cell (CSC) markers in bone marrow and peripheral blood from Myd88 -/and wild-type (WT) mice. Cytokeratins CK8/18 were detected as early as 4 months post-infection in Myd88 -/mice. By contrast, cytokeratins were not detected in WT mice even after 7 months post-infection. The expression of Mucin-1 (MUC1) was observed in both bone marrow and peripheral blood at different time points, suggesting its role in gastric cancer metastasis. Snail, Twist and ZEB were expressed at different levels in bone marrow and peripheral blood. The expression of these EMT-related markers suggests the manifestation of cancer metastasis in the early stages of disease development.LGR5, CD44 and CD133 were the most prominent CSC markers detected. The detection of CSC and EMT markers along with cytokeratins does reinforce their use as biomarkers for gastric cancer metastasis. This early detection of markers suggests that CTCs leave primary site even before cancer is well established. Thus, cytokeratins, EMT, and CSCs could be used as biomarkers to detect aggressive forms of gastric cancers. This information may prove to be of significance in stratifying patients for treatment prior to the onset of severe disease-related characteristics.

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