Recombinant Cytokines for Immune Cell Culture

Cytokines provide many of the necessary signals for T cell activation, proliferation, differentiation, and survival in vitro. Human recombinant cytokines such as these can be used to reproducibly induce cell proliferation and differentiation to support development of CAR T cell therapies.

T cells can be broadly classified as CD4+ or CD8+ T cells (also known as cytotoxic T cells), each with several subtypes. Activation and differentiation of these T cells is driven by the cytokines listed below.

Cytokines play important roles in NK cell culture by providing signals for activation, proliferation, differentiation, and effector functions. For example, IL-15 promotes the differentiation of NK cells toward maturity generating memory-like NK cells, which exhibit enhanced effector functions and long-term persistence.

Applying the appropriate recombinant cytokines at the right time and optimizing their concentrations in vitro are important aspects to productive NK cell cultures.

Cytokines are involved in multiple other aspects of successful B cell culture including growth, survival, and differentiation. One key feature of mature B cells is antibody production and class switching. In B cell culture, recombinant cytokines help drive these functions. For instance, IL-5 enhances the production of IgA antibodies, while IL-10 can stimulate the production of various antibody isotypes, including IgG and IgE.

Cultivation of B cells in a laboratory setting often requires supplementation of media with recombinant cytokines. 

Monocytes are leukocytes that play key roles in homeostasis and pathogen response. Monocytes circulate through the body and are recruited to certain sites by chemokines. In immune cell culture, various cytokines are needed to maintain monocytes, activate them to differentiate, and expand macrophages and their subtypes.

Application of recombinant cytokines in culture can drive macrophages to different phenotypes. For example, IFN-gamma combined with lipopolysaccharide (LPS) induces the polarization of monocytes/macrophages into an M1 phenotype, which is involved in pro-inflammatory responses and pathogen clearance. Alternatively, monocytes can be driven to one of several M2 phenotypes based on the cytokines to which they are exposed.

Dendritic cells (DCs) can be differentiated from monocytes or induced pluripotent stem cells or isolated from bone marrow. Regardless of source, recombinant cytokines are used to influence DC activation, maturation, and function in vitro. For example, both interferon-alpha (IFN-α) and IFN-γ enhance the antigen-presenting capacity of DCs in culture via signaling pathways that upregulate MHC class I and II molecules.

Optimizing the recombinant cytokine mixture in DC cultures is essential for developing robust cell-based assays, immunotherapies and effectively studying the complex interactions between DCs and other components of the immune system.