. 2023 Oct 5;14:1233085. doi: 10.3389/fimmu.2023.1233085

Table 3.

Phenotypes and functions of important TIL-B cells.

TIL-B cells	Phenotype	Functions
GC B cell	CD19⁺CD20⁺CD27⁺CD38⁺CD10⁺IgD^-; BCL6, AID, SEMA4A, and Ki67 expression	Dark zone GC B cells undergo clonal expansion and somatic hypermutation before migrating into the light zone and interacting further with T_FH cells and follicular DCs for affinity maturation. The delivery of transcription factors by mature follicular DCs and T_FH cells determines whether GC B cells become memory B cells or terminal differentiated plasma cells.
Memory B cell	CD19⁺CD20⁺CD24⁺CD27⁺CD38^low (atypical CD27^- phenotype)	Sustain long-term immune response.
antigen-presenting phenotype	MHC-mediated; CD40/CD80/CD86 expression	Present antigens to T cells, and stimulate the activation and effector functions of cytotoxic CD8⁺ T cell.
direct tumor killing phenotype	IFN-γ, IL-12p40, GrB and TRAIL expression	Direct tumor cell killing effect.
Plasma cell	CD19^lowCD20^lowCD24^-CD27^hiCD38^hi, IgG or IgA expression	Produce antibodies which recognize the tumor-associated antigens, cause antibody-dependent cellular cytotoxic and phagocytosis, activate the complement system, and augment antigen presentation by DCs.
Regulatory B cell	Multiple phenotypes	Produce immunosuppressive cytokines, such as IL-10, IL-35, and TGF-β; induce effector T and B cell malfunction; promote the proliferation of Treg cells and MDSCs; promote tumor progression and metastasis.

TIL-B cells, tumor-infiltrating B cells; GC B cell, germinal center B cell; DC, dendritic cell, T_FH cell, follicular helper T cell; MHC, major histocompatibility complex; AID, activation-induced deaminase; GrB, granzyme B; Treg cell, regulatory T cell; MDSC, myeloid-derived suppressor cell; hi, high; dim, medium.