CD301b lectin expression in the breast tumor microenvironment augments tumor growth

Ahmet Ozdilek1, Amy V Paschall1, Zahra Nawaz1

  • 1Department of Biochemistry, Emory Vaccine Center, Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322.

Insights

Aberrant tumor glycosylation impacts immune recognition. This study identifies CD301b+ myeloid cells as key drivers of breast tumor growth, suggesting CD301b as a therapeutic target.

Area of Science:

  • Immunology
  • Cancer Biology
  • Glycobiology

Background:

  • Aberrant tumor glycosylation influences immune recognition, but its role in tumor progression via glycan-lectin interactions is unclear.
  • The tumor microenvironment (TME) plays a critical role in cancer progression and immune evasion.
  • Understanding specific glycan-lectin interactions is crucial for developing novel cancer therapies.

Purpose of the Study:

  • To investigate the role of C-type lectin receptor CD301b in breast tumor progression.
  • To elucidate the function of CD301b+ immune cells within the tumor microenvironment.
  • To identify potential therapeutic targets for reprogramming the breast cancer TME.

Main Methods:

  • Utilized a murine triple-negative breast cancer model.
  • Employed CD301b depletion and genetic knockout strategies.
  • Conducted phenotypic analyses, single-cell RNA sequencing, and transcriptomic profiling.

Main Results:

  • Tumors expressing the Tn glycoantigen exhibited accelerated growth, facilitated by CD301b+ immune cells.
  • Loss or depletion of CD301b significantly suppressed tumor growth, indicating CD301b promotes tumor progression.
  • CD301b+ cells were identified as type 2 conventional dendritic cells (cDC2s), and their human ortholog CLEC10A is expressed in human breast cancers.
  • Mice lacking Mgl2 (encoding CD301b) showed a shift towards an immune-activated state with enhanced antitumor immunity.

Conclusions:

  • CD301b signaling in myeloid cells, particularly cDC2s, promotes breast tumor progression.
  • Aberrant tumor glycosylation and CD301b-mediated myeloid cell interactions are critical regulators of the TME.
  • CD301b represents a promising therapeutic target for enhancing antitumor immunity in breast cancer.