Project Title

Endothelial Specific HSPA12B Plays a Critical Role in Maintaining Hepatic Kupffer Cell Bacterial Clearance

Authors' Affiliations

Samuel Alejandro Garcia Olmos, Departments of Surgery, Center for Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN. Fei Tu, Departments of Surgery, Center for Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN Joseph Adams, Departments of Surgery, Center for Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN. Xiaohui Wang, Departments of Surgery, Center for Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN.

Location

Culp Room 217

Start Date

4-6-2022 1:45 PM

End Date

4-6-2022 2:00 PM

Faculty Sponsor’s Department

Surgery

Name of Project's Faculty Sponsor

Xiaohui Wang

Classification of First Author

Undergraduate Student

Competition Type

Non-Competitive

Type

Boland Symposium

Project's Category

Infectious Diseases

Abstract or Artist's Statement

Sepsis is defined as a life-threatening disease that is characterized by multiple organ dysfunction caused by an uncontrolled host response to an infection. Hepatic dysfunction contributes to sepsis-induced mortality and morbidity. Hepatic Kupffer cells are a first-line defense in the clearance of bacteria or bacterial products, thus limiting the spread of the infection. We have previously shown that endothelial cell-specific HSPA12B prevents sepsis-induced multiple organ injury and mortality. However, there is no data available on the role of endothelial cell HSPA12B in hepatic (i.e. Kupffer cell) clearance of bacteria from the blood. To address this important question, we administered 5x107 E.coli-GFP to endothelial-specific HSAP12B deficient (Hspa12B ECKO) and wild type (WT) mice by i.v injection. Twenty minutes after injection, we collected blood specimens and harvested liver tissues for analysis of bacterial load in peripheral blood by flow cytometry and in the livers by immunofluorescence staining. Flow cytometric analysis showed that there was a significantly greater bacterial burden in the peripheral blood from Hspa12B ECKO mice than in WT mice. Immunofluorescence staining of liver tissues shows that there were fewer bacteria uptaken by hepatic Kupffer cells in Hspa12B ECKO mice, compared with WT mice. To investigate whether endothelial cell HSPA12B influenced Kupffer cell survival in the liver tissue, we induced polymicrobial sepsis in Hspa12B ECKO and WT mice and examined Kupffer cell numbers by F4/80 immunostaining. We observed that endothelial cell HSPA12B deficiency exacerbates sepsis-induced loss of Kupffer cells. These data suggest that endothelial cell HSPA12B is required for maintaining Kupffer cell numbers and regulating Kupffer cell bacterial uptake and clearance. βglucan can induce the trained immune phenotype. We examined whether β-glucan could improve Kupffer cell function and attenuate sepsis-induced mortality in Hspa12B ECKO mice. We treated Hspa12B ECKO mice with β-glucan (1mg/Kg) seven days before the induction of sepsis. We found that β-glucan treatment significantly attenuates sepsis-induced Kupffer cell loss and mortality. We conclude that endothelial-specific HSPA12B influences Kupffer cell survival in the liver and regulates Kupffer cell bacterial uptake. We also found that innate immune training can enhance Kupffer cell function in Hspa12B ECKO.

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Apr 6th, 1:45 PM Apr 6th, 2:00 PM

Endothelial Specific HSPA12B Plays a Critical Role in Maintaining Hepatic Kupffer Cell Bacterial Clearance

Culp Room 217

Sepsis is defined as a life-threatening disease that is characterized by multiple organ dysfunction caused by an uncontrolled host response to an infection. Hepatic dysfunction contributes to sepsis-induced mortality and morbidity. Hepatic Kupffer cells are a first-line defense in the clearance of bacteria or bacterial products, thus limiting the spread of the infection. We have previously shown that endothelial cell-specific HSPA12B prevents sepsis-induced multiple organ injury and mortality. However, there is no data available on the role of endothelial cell HSPA12B in hepatic (i.e. Kupffer cell) clearance of bacteria from the blood. To address this important question, we administered 5x107 E.coli-GFP to endothelial-specific HSAP12B deficient (Hspa12B ECKO) and wild type (WT) mice by i.v injection. Twenty minutes after injection, we collected blood specimens and harvested liver tissues for analysis of bacterial load in peripheral blood by flow cytometry and in the livers by immunofluorescence staining. Flow cytometric analysis showed that there was a significantly greater bacterial burden in the peripheral blood from Hspa12B ECKO mice than in WT mice. Immunofluorescence staining of liver tissues shows that there were fewer bacteria uptaken by hepatic Kupffer cells in Hspa12B ECKO mice, compared with WT mice. To investigate whether endothelial cell HSPA12B influenced Kupffer cell survival in the liver tissue, we induced polymicrobial sepsis in Hspa12B ECKO and WT mice and examined Kupffer cell numbers by F4/80 immunostaining. We observed that endothelial cell HSPA12B deficiency exacerbates sepsis-induced loss of Kupffer cells. These data suggest that endothelial cell HSPA12B is required for maintaining Kupffer cell numbers and regulating Kupffer cell bacterial uptake and clearance. βglucan can induce the trained immune phenotype. We examined whether β-glucan could improve Kupffer cell function and attenuate sepsis-induced mortality in Hspa12B ECKO mice. We treated Hspa12B ECKO mice with β-glucan (1mg/Kg) seven days before the induction of sepsis. We found that β-glucan treatment significantly attenuates sepsis-induced Kupffer cell loss and mortality. We conclude that endothelial-specific HSPA12B influences Kupffer cell survival in the liver and regulates Kupffer cell bacterial uptake. We also found that innate immune training can enhance Kupffer cell function in Hspa12B ECKO.