New insights into the mechanism of alcohol-mediated organ damage via its impact on immunity, metabolism, and repair pathways: A summary of the 2021 Alcohol and Immunology Research Interest Group (AIRIG) meeting.

On November 19th, 2021, the annual Alcohol and Immunology Research Interest Group (AIRIG) meeting was held at Loyola University Chicago Health Sciences Campus in Maywood, Illinois. The 2021 meeting focused on how alcohol misuse is linked to immune system derangements, leading to tissue and organ damage, and how this research can be translated into improving treatment of alcohol-related disease. This meeting was divided into three plenary sessions: the first session focused on how alcohol misuse affects different parts of the immune system, the second session presented research on mechanisms of organ damage from alcohol misuse, and the final session highlighted research on potential therapeutic targets for treating alcohol-mediated tissue damage. Diverse areas of alcohol research were covered during the meeting, from alcohol's effect on pulmonary systems and neuroinflammation to epigenetic changes, senescence markers, and microvesicle particles. These presentations yielded a thoughtful discussion on how the findings can lead to therapeutic treatments for people suffering from alcohol-related diseases.

High-Fat High-Sucrose Diet Increases ACE2 Receptor Expression in Lung and Pancreatic Islets in SIV-Infected Rhesus Macaques: Implications for Increased Risk for SARS-CoV-2 Infection

People with pre-existing conditions including obesity, diabetes, and kidney disease are at greater risk for complications of COVID-19, the disease caused by SARS-CoV-2 infection. Predisposing risk factors could include poor dietary quality and at-risk alcohol use. Increased survival and aging of people living with HIV (PLWH) on antiretroviral therapy (ART) is complicated by comorbidities including at-risk alcohol use, metabolic dysregulation, diabetes, and chronic renal disease, with obesity and metabolic syndrome highest in southern states. We hypothesize that poor dietary quality in combination with at-risk alcohol use may increase risk factors for SARS-CoV-2 infection in PLWH. To test this hypothesis, biospecimen obtained from a longitudinal study in female rhesus macaques (macaca mulatta) were used to determine whether high-fat high-sucrose diet (HFD;protein/fat/carbohydrates 16/42/42% of total kcal and 27% sucrose by weight) and chronic binge alcohol administration (CBA) increased expression of the machinery required for SARS-CoV-2 cell entry. Female macaques (n=10) were assigned to HFD or standard chow diet (SD;protein/fat/carbohydrates 29/14/57% of total kcal) and CBA (50-60 mM peak blood alcohol, 5 days/week) or isovolumetric water (VEH) beginning 3 months before SIVmac251 infection. ART was initiated at 2.5 months of SIV infection. Tissue samples including lung, pancreas, and kidney were collected at study endpoint (~12 months post-SIV infection). Immunohistochemistry was performed on formalin-fixed, paraffin embedded samples to determine protein expression of angiotensin converting enzyme 2 (ACE2) receptor and transmembrane serine protease 2 (TMPRSS2). Images were obtained at 20x magnification and fluorescence intensity was used for quantification. RNA was extracted from frozen samples and mRNA expression of ACE2 and TMPRSS2 was measured by qPCR and quantified relative to ribosomal protein S13. Normality of data was verified and outliers identified using Grubbs test. Data were then analyzed using a 2 (alcohol) ? 2 (diet) ANOVA. Protein expression of ACE2 in the lung (p<0.01, ?2=0.59), whole pancreas (p<0.05, ?2=0.64), and pancreatic islets (p<0.05, ?2=0.44) was greater in HFD- than SD-fed macaques and was not significantly altered by CBA. No alcohol- or diet-mediated differences in ACE2 protein expression were observed for whole kidney or proximal tubules. No alcohol- or diet-mediated differences in protein expression of TMPRSS2 or relative mRNA expression of ACE2 or TMPRSS2 were observed. Results indicate that a high-fat, high-sucrose diet increases expression of the ACE2 receptor in SIV-infected female macaques. Because the ACE2 receptor is required for SARS-CoV-2 cell entry, this diet-mediated increase in expression may increase risk for greater vulnerability to COVID-19 disease and associated complications. These data provide direct evidence for a link between dietary quality and risk for SARS-CoV-2 infection in the context of SIV/HIV infection, urging diet counseling and increased access to higher-quality foods in this population.