Table 4.

The Role of Exosomes from MDSC, B Cells, Mast Cells and Neutrophils in the Tumor Microenvironment

Source of Exosomes	Cargo Loaded	Targeted cells	Effect on Tumor (+ for Promotion, - for Inhibition)	Outcome	Reference
MDSC	Immunosuppressive function related proteins and RNA	Tumor cells	+	Tumor immunosuppression	[119]
MDSC	S100A9	Colorectal cancer cells (Induced CAC model in BALB/c mice)	+	The percentage of total T cells and their subsets in peripheral blood and the number of CD3+CD8+T cells in colorectal tissues of G-MDSCs-Exo treated CAC mice decreased, thereby weakening tumor immunity	[120]
MDSC	miR-143-3p	Lung cancer cell (Including the subcutaneous model of C57B6 mice)	+	Promote the proliferation of tumor	[121]
MDSC	ILs, TNF-α, etc	CD8+T cells (MDSC derived exosomes treated C57B6 and Balb/c mice models)	+	Promote apoptosis of CD8+ T cells	[122]
B cells	MHCII, FasL	CD4+T cells		Immunosuppression	[125]
B cells	CD19	Tumor cells (C57BL/6J, NSG mice, Adora2aflox/flox, Rab27afl/fl, Hif1afl/fl, Cd19-cre mice)	+	The production of adenosine inhibits the proliferation and killing ability of CD8+ T cells	[126]
B cells	miR-330-3p	Non mesenchymal ovarian cancer cells (Models of subcutaneous tumorigenesis and peritoneal metastasis)	+	To promote its mesenchymal transformation	[127]
Mast cells	MHC II, CD86, LFA-1 and ICAM-1	B and T cells		Induced its proliferation and cytokine production	[130]
Mast cells	Exogenous Ags and endogenous heat shock proteins	DC cells		Promote its mature to play the role of antigen presentation	[131]
Mast cells	OX40L	CD4+T cells		Promote proliferation and differentiation	[132]
Mast cells	KIT	Lung adenocarcinoma cell	+	Promote the proliferation of tumor cells	[133]
Neutrophils	miR-4466	Brain tumor cells (athymic nude mice, BALB/c mice)	+	Promote tumor cell stem and metastasis	[136]