Abstract
Absence of the “Don’t Eat Me” signal results in aberrant T cell responses to Leishmania major 2260958
The Journal of immunology (1950), Vol.215(Supplement_1), vkag1411008
08/01/2026
DOI: 10.1093/jimmun/vkag141.1008
Abstract
Introduction
CD47 is a ubiquitously expressed cell surface protein that regulates immune homeostasis by engaging signal regulatory protein alpha (SIRPa) on phagocytes to inhibit their activation. While the CD47-SIRPa axis is known to regulate both innate immunity and T cell responses in cancer & sterile inflammation, its role in infectious disease is poorly defined. Leishmania major (L. major) is an intracellular protozoan parasite that infects phagocytes. Macrophages and CD4+ T cells are both critical for immunity to L. major infection, so we interrogated the role that “don’t eat me” signals play in immunity to L. major.
Methods
We infected Cd47-/- & Sirpa-/- mice on a C57BL/6 background subcutaneously in each footpad and harvested draining lymph nodes & spleens at several critical time points for flow cytometry. T cell responses were assessed further by ICS & transcription factor staining.
Results
Cd47-/- & Sirpa-/- disease is severe. They present increased lesions, swelling, & parasite burden compared to controls. Decrease in T cells & increase in antigen experienced T cells is seen. IFNg & TNFa producers are reduced, likely liable for the severity. Conversely, T cell activation is increased in KO mice during acute disease (15dpi) when severity is similar.
Conclusion
Further studies are in progress to characterize why Cd47-/- & Sirpa-/- mice fail to control L. major infection despite strong early Th1 responses. This is a novel finding showing CD47-SIRPa is required for protective T cell responses to infection.
Details
- Title: Subtitle
- Absence of the “Don’t Eat Me” signal results in aberrant T cell responses to Leishmania major 2260958
- Creators
- Hanna Paton - University of IowaPrajwal Gurung - University of IowaAustin Paden - University of IowaSaurabh` Saini - University of Iowa
- Resource Type
- Abstract
- Publication Details
- The Journal of immunology (1950), Vol.215(Supplement_1), vkag1411008
- DOI
- 10.1093/jimmun/vkag141.1008
- ISSN
- 0022-1767
- eISSN
- 1550-6606
- Publisher
- OXFORD UNIV PRESS
- Grant note
- University of Iowa Mechanisms in Parasitism Predoctoral T32 Fellowship: T32 AI007511 NIH: R01AI155425, VAI0BX006091
University of Iowa Mechanisms in Parasitism Predoctoral T32 Fellowship, T32 AI007511 NIH R01AI155425, VAI0BX006091
- Language
- English
- Date published
- 08/01/2026
- Academic Unit
- Infectious Diseases; Stead Family Department of Pediatrics; Internal Medicine
- Record Identifier
- 9985214918802771
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