B cells

Note: Frequencies of distinct subsets vary depending on mouse strain, age, and several other factors. Therefore, an average number cannot be provided (PMID: 18544662).

There are three principal classes of B lymphocytes: B-1 B cells, and B-2–derived marginal zone (MZ) or follicular (FO) B cells (PMID: 21151033).  A small percentage of these B cells produce IL-10 and are referred to as regulatory B (B reg) cells. Mouse B cells are additionally classified into transitional/immature, naive B cells, memory B cells, and plasma cells. Further subsets of memory B cells and plasma cells are identified based on their Ig isotype expression (IgM, IgD, IgG, IgA).

B-1 B cells develop from the fetal liver and disseminate into the periphery. They are principally found in the pleural and peritoneal cavities. Based on the surface expression of CD138, CD43, and CD5, two distinct subsets can be identified: B-1a and B-1b. B-1a B cells are the most abundant and express CD5, whereas B-1b B cells lack CD5 expression. B-1 cells are involved in innate-like immune responses and are the main producers of natural antibodies. Interestingly, they express specific TLRs and thus, can mount a response in the absence of (BCR) triggering.

B-2 B cells develop from bone marrow, migrate to the periphery as immature B cells, and mature once they reach the spleen or other secondary lymphoid organs. They can give rise to both marginal zone (MZ) or follicular B cells (FO). The latter are considered the conventional B cell subset and are progenitors for the developmental B lymphocyte subsets, i.e., naive, activated, germinal center, memory, and plasma cells (PMID: 22224772).

B cells in lymphoid organs reside in structures called follicles. In response to antigen encounter within the follicle, naive B cells initiate the formation of germinal centers. These transient structures are critical for the development of the adaptive humoral response, and are the location where B cells differentiate and proliferate to generate long-lasting immunological memory. Within germinal centers, B cells undergo IgV somatic hypermutation, affinity maturation, and Ig class switching, leading to the development of switched memory B cells and plasma cells. Elucidating the dynamics and mechanics of the germinal center reaction is a major research subject in adaptive immunity, immunodeficiency, and B cell diseases, and of critical importance for the development of improved vaccination strategies.

Miltenyi Biotec has created dedicated application protocols for working with mouse B cells.

• Multicolor flow cytometric analysis of B cell subsets from mouse spleen

Lymphoid tissues must be dissociated into a single-cell suspension for many downstream applications, including isolation of cell subpopulations, cell culture, or flow cytometry analysis. Dissociation can be accomplished fully automatically using a gentleMACS™ Dissociator and specific Tissue Dissociation Kits (e.g. Spleen Dissociation Kit, mouse). A special protocol for the preparation of single-cell suspensions from mouse spleen without enzymatic treatment can be downloaded from the Related resources panel to the right. Alternatively, tissues can be dissociated using a manual procedure.

For details about sample preparation of lymphoid tissues and bone marrow, see the corresponding chapters. 

Miltenyi Biotec has developed numerous products for the magnetic separation of the various B cell types and subsets that can be found in mouse lymphoid tissue. For details on MACS® Cell Separation Technology, see the MACS Handbook chapter Magnetic cell separation .

Miltenyi Biotec offers a broad portfolio of products for the routine cell surface and intracellular staining of B cell–specific markers to examine B cell populations and subsets by flow cytometry. The vast portfolio of recombinant REAfinity™ Antibodies enables comprehensive B cell analysis.

Miltenyi Biotec offers a broad portfolio of over 150 cytokines and growth factors as well as related proteins to culture or stimulate B cells, and to investigate their function. For example, Miltenyi Biotec's high-quality cytokines and CpG oligodeoxynucleotides are perfectly suited for the activation and expansion of mouse B cells for further studies.

Mononuclear cells are typically isolated from bone marrow before subsequent separation of B cells.

For details about sample preparation of lymphoid tissues and bone marrow, see the corresponding MACS Handbook chapters.

Miltenyi Biotec has developed numerous products for the magnetic separation of the various B cell types and subsets. For details on MACS® Cell Separation Technology, see the MACS Handbook chapter Magnetic cell separation.