Introduction: This study was designed to explore the role of acetylcholine (ACh) in pulmonary viral infection and recovery. Inflammatory control is critical to recovery from respiratory viral infection. ACh secreted from non-neuronal sources, including lymphocytes, plays an important, albeit underappreciated, role in regulating immune-mediated inflammation. Methods: ACh and lymphocyte cholinergic status in the lungs were measured over the course of influenza infection and recovery. The role of ACh was examined by inhibiting ACh synthesis in vivo. Pulmonary inflammation was monitored by Iba1 immunofluorescence, using a novel automated algorithm. Tissue repair was monitored histologically. Results: Pulmonary ACh remained constant through the early stage of infection and increased during the peak of the acquired immune response. As the concentration of ACh increased, cholinergic lymphocytes appeared in the BAL and lungs. Cholinergic capacity was found primarily in CD4 T cells, but also in B cells and CD8 T cells. The cholinergic CD4⁺ T cells bound to influenza-specific tetramers and were retained in the resident memory regions of the lung up to 2 months after infection. Histologically, cholinergic lymphocytes were found in direct physical contact with activated macrophages throughout the lung. Inflammation was monitored by ionized calcium-binding adapter molecule 1 (Iba1) immunofluorescence, using a novel automated algorithm. When ACh production was inhibited, mice exhibited increased tissue inflammation and delayed recovery. Histologic examination revealed abnormal tissue repair when ACh was limited. Conclusion: These findings point to a previously unrecognized role for ACh in the transition from active immunity to recovery and pulmonary repair following respiratory viral infection.

Background: Vaping is touted as a safer alternative to traditional cigarette smoking, but the full spectrum of harm reduction versus comparable risk remains unresolved. Elevated bioavailability of nicotine in vape aerosol together with known risks of nicotine exposure may result in previously uncharacterized cardiovascular consequences of vaping. The objective of this study is to assess the impact of nicotine exposure via vape aerosol inhalation upon myocardial response to infarction injury. Methods and Results: Flavored vape juice containing nicotine (5 mg/mL) or vehicle alone (0 mg) was delivered using identical 4‐week treatment protocols. Mice were subjected to acute myocardial infarction injury and evaluated for outcomes of cardiac structure and function. Findings reveal that nicotine exposure leads to worse outcomes with respect to contractile performance regardless of sex. Nonmyocyte interstitial cell accumulation following infarction significantly increased with exposure to vape aerosol alone, but a comparable increase was not present when nicotine was included. Conclusions: Myocardial function after infarction is significantly decreased after exposure to nicotine vape aerosol irrespective of sex. Comparable loss of contractile function was not observed in mice exposed to vape aerosol alone, highlighting the essential role of nicotine in loss of contractile function. Increased vimentin immunoreactivity was observed in the vape alone group compared with control and vape nicotine. The correlation between vaping, interstitial cell responses, and cardiac remodeling leading to impaired contractility warrants further investigation. Public health experts seeking to reduce vaping‐related health risks should consider messaging that highlights the increased cardiovascular risk especially with nicotine‐containing aerosols.

Generating long-lived mucosal and systemic antibodies through respiratory immunization with protective antigens encapsulated in nanoscale biodegradable particles could potentially decrease or eliminate the incidence of many infectious diseases, but requires the incorporation of a suitable mucosal immunostimulant. We previously found that respiratory immunization with a model protein antigen (LPS-free OVA) encapsulated in PLGA 50:50 nanoparticles (~380 nm diameter) surface-modified with complement peptide-derived immunostimulant 02 (CPDI-02; formerly EP67) through 2 kDa PEG linkers increases mucosal and systemic OVA-specific memory T-cells with long-lived surface phenotypes in young, naïve female C57BL/6 mice. Here, we determined if respiratory immunization with LPS-free OVA encapsulated in similar PLGA 50:50 microparticles (~1 μm diameter) surface-modified with CPDI-02 (CPDI-02-MP) increases long-term OVA-specific mucosal and systemic antibodies. We found that, compared to MP surface-modified with inactive, scrambled scCPDI-02 (scCPDI-02-MP), intranasal administration of CPDI-02-MP in 50 μL sterile PBS greatly increased titers of short-term (14 days post-immunization) and long-term (90 days post-immunization) antibodies against encapsulated LPS-free OVA in nasal lavage fluids, bronchoalveolar lavage fluids, and sera of young, naïve female C57BL/6 mice with minimal lung inflammation. Thus, surface modification of ~1 μm biodegradable microparticles with CPDI-02 is likely to increase long-term mucosal and systemic antibodies against encapsulated protein antigen after respiratory and possibly other routes of mucosal immunization.

Background and Aim: Donepezil is a front-line treatment for Alzheimer’s disease. Donepezil treatment is associated with decreased risk of all-cause mortality. Specific protection is observed in pneumonia and cardiovascular disease. We hypothesized that donepezil treatment would improve mortality among Alzheimer’s patients following infection with COVID-19. The objective of this study is to assess the influence of ongoing donepezil treatment on survival in Alzheimer’s disease patients after polymerase chain reaction (PCR)-confirmed COVID-19 infection. Methods: This is a retrospective cohort study. We conducted a national survey of Veterans with Alzheimer’s disease to assess the influence of ongoing donepezil treatment on survival in Alzheimer’s disease patients after PCR-confirmed COVID-19 infection. We assessed all-cause 30-day mortality stratified by COVID-19 infection and donepezil use, estimating odds ratios using multivariate logistic regression. Results: Among people with Alzheimer’s disease and COVID-19, all-cause 30-day mortality was 29% (47/163) for people taking donepezil compared with 38% (159/419) for those who were not. Among people with Alzheimer’s disease without COVID-19, all-cause 30-day mortality was 5% (189/4189) for people taking donepezil compared with 7% (712/10,241) for those who were not. Adjusting for covariates, the decrease in mortality associated with donepezil did not differ between people with and without COVID-19 (interaction p = 0.710) Conclusion: The known survival benefits of donepezil were retained but not found to be specific to COVID-19 among people with Alzheimer’s disease.

Inflammatory control is critical to recovery from respiratory viral infection. Acetylcholine (ACh) secreted from non-neuronal sources, including lymphocytes, plays an important, albeit underappreciated, role in regulating immune-mediated inflammation. This study was designed to explore the role of ACh in acute viral infection and recovery. Using the murine model of influenza A, cholinergic status in the lungs and airway was examined over the course of infection and recovery. The results showed that airway ACh remained constant through the early stage of infection and increased during the peak of the acquired immune response. As the concentration of ACh increased, cholinergic lymphocytes appeared in the airway and lungs. Cholinergic capacity was found primarily in CD4 T cells, but also in B cells and CD8 T cells. The cholinergic CD4+ T cells bound to influenza-specific tetramers at the same frequency as their conventional (i.e., non-cholinergic) counterparts. In addition, they were retained in the lungs throughout the recovery phase and could still be detected in the resident memory regions of the lung up to two months after infection. Histologically, cholinergic lymphocytes were found in direct physical contact with activated macrophages throughout the lung. When ACh production was inhibited, mice exhibited increased tissue inflammation, altered lung architecture, and delayed recovery. Together, these findings point to a previously unrecognized role for ACh in the transition from active immunity to recovery and pulmonary repair following respiratory viral infection.

Age-related chronic, low-grade inflammation, known as inflammaging, contributes to tissue damage and disease. In the lungs, inflammaging leads to abnormal tissue remodeling, reduced function, and decreased immunity. A key factor in inflammaging is declining acetylcholine signaling, which normally suppresses inflammation and promotes tissue repair. We tested whether increasing acetylcholine responsiveness could reverse age-related lung damage. Aged mice were treated with donepezil to increase acetylcholine availability. After six months, blood oxygen saturation and voluntary activity were significantly improved. Histologically, treated mice showed a reversal of alveolar enlargement (a hallmark of emphysema) and complete restoration of elastic fibers. Donepezil treatment also dramatically increased bronchus-associated lymphoid tissue (iBALT) formation. iBALT is the repository of tissue-resident memory lymphocytes, including memory cholinergic lymphocytes that produce acetylcholine to suppress inflammation during secondary infections. The age-related loss of iBALT contributes to the increased risks associated with respiratory infection in the elderly. This indicates that age-related lung function and respiratory immune deficits can be modulated by improving acetylcholine signaling. Repurposing an approved medication provides a direct pathway to clinical application for improving respiratory health and infection resistance during aging.