Human skin tissue acts as the first line of defense against outside stimuli attempting to enter the body. It also provides an important role in maintaining an ongoing level of internal homeostasis. Separated into the Epidermis, Dermis, and Hypodermis, each layer performs a specific function essential to the maintenance of ongoing bodily function.
Keratinocytes are the main cell type within the epidermal layer, constituting 95% of the tissue’s composition. Their resilient structure and tight junctions create a robust boundary to external factors that pose a threat to the body. Additionally, they perform several important immune functions, such as producing pro-inflammatory mediators that attract leukocytes to the site of pathogen invasion. Keratinocytes are an important resource in the ongoing assessment of potentially harmful components found within newly developed dermal treatments (Choi and Lee, 2015). Because of their dominating presence with the epidermal layer, they act as a primary identifier of positive and negative reactions to potential treatments and applications.
Melanocytes are another important cell type found within the lower layer of the epidermis, compromising 5-10% of all cells found there. They create a majority of the skin’s melanin through a process called melanogenesis. This melanin is responsible for the skin’s pigment and functions as a way of protecting the lower layers of tissue from UV-B radiation.
Fibroblasts are mainly found within the hypodermis. They secrete precursors that help in the formation of materials needed to create the extracellular matrix. This matrix helps to maintain the structural integrity of tissues throughout the body. Similar to keratinocytes, fibroblasts also perform an important immunological role and help to support wound healing. Not only do they stimulate an inflammatory response, but they create the collagen that helps to close wounds and rebuild damaged tissue.
Vitiligo is a relatively common skin disease that affects up to 2% of the general population (Latheef et al., 2017). The condition is generally characterized by demarcated patches of white skin that develop due to the disappearance of melanocytes within the tissue (Latheef et al., 2017). Numerous factors can lead to the development of vitiligo. Therefore it is somewhat difficult to generate a universal treatment for the disease. However, research is currently underway to see if vitiligo can be remedied by the transplantation of autologous melanocyte-keratinocyte cultures, acting to replenish cells within target regions in which they had previously disappeared (Latheef et al., 2017).
100 patients with focal stable vitiligo (defined as no increased lesion size within a minimum of one year) were treated by first isolating a suspension of melanocyte and keratinocyte cells from healthy epidermal tissue collected from a non-lesioned portion of the body (Latheef et al., 2017). Recipient treatment areas (the vitiligo lesion) were then abraded with a high-speed dermabrader and treated with the autologous melanocyte-keratinocyte culture (Latheef et al., 2017). Treatment areas were regularly monitored over a period of 5 years, with serial photographs being taken at every patient visit (Latheef et al., 2017).
At the end of 5 years, 44% of patients experienced an “excellent” response to treatment, with pigmentation in the lesioned areas returning to levels of 90-100% of those seen within normal/healthy tissues (Latheef et al., 2017). And of the 100 patients treated, 90% experienced a marked increase in pigmentation within those areas that received the melanocyte-keratinocyte transplant (Latheef et al., 2017). Although further ongoing studies are needed that would include a larger pool of treatment recipients; these initial results do point towards a strong potential for autologous cell transplantation being used as a viable treatment method for vitiligo.
Another important area of research into autologous skin cells is with the use of donor-derived fibroblasts for the treatment of aging skin and dermal defects (Tang et al., 2015). Many cosmetic therapies for facial defects aim to correct issues through treatments that provide immediate and noticeable results (dermal filler, Botox injections, etc.). However, results from these methods are often only temporary and ongoing treatment sessions are normally required to maintain results.
The injection of autologous cultured fibroblasts for the treatment of cosmetic deficiencies has been effectively used since 1995 (Boss et al., 2000). Although results from this method often are not immediately noticeable, and a few serial treatments are usually required, the introduction of living cells into problem areas helps to restore much of the skin’s inherent structural functionality and can maintain a greater persistence than what is seen with more-traditional treatments. These treatments also have further applications in correcting other skin deformities such as scars, acne irregularities, wounds, and atrophy (Tang et al., 2015). Because the fibroblasts used for treatment are often donor-derived, there is a significantly lower likelihood of adverse reactions in comparison to other options like dermal fillers and Botox (Tang et al., 2015).
The expansion of research into skin-derived primary cells creates many implications for future developments and treatments that aim to correct various dermatological conditions. By further expanding the availability and uses for these cell lines within the industry, scientists will be better equipped to treat patients efficiently and with a lower likelihood of an adverse reaction.
To learn more about BioreclamationIVT’s skin tissue and primary cell products used in the study of dermatological conditions, click here.
Boss Jr, W.K., Usal, H., Fodor, P.B., Chernoff, G. (2000). Autologous cultured fibroblasts: A protein repair system. Annals of Plastic Surgery, 44, 536-542.
Choi, M. and Lee, C. (2015). Immortalization of primary keratinocytes and its application to skin research. Biomolecules & Therapeutics, 23(5), 391-399.
Latheef, E.N.A., Muhammed, K., Riyaz, N. and Binitha, M.P. (2017). A retrospective study of 100 cases of focal vitiligo treated by autologous, noncultured melanocyte-keratinocyte cell transplantation. International Journal of Research in Dermatology, 3(1), 33-36.
Tang, MY., Jin, R., Zhang, Y., Shy, YM., Sun, BS., Zhang, L., and Zhang, YG. (2015). Plastic and Aesthetic Research, 3, 83-85.