Skin immune status - live imaging of the skin in 3D

Published on May 4, 2014   33 min
0:00
I want to welcome you to this presentation. My name is Kenji Kabashima. I'm an associate professor of the Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan. In this lecture, I'd like to discuss the skin immune status in the perspective of live imaging of the skin in three dimensions.
0:25
In this lecture, I would like to talk on four topics: immune response in the skin, live imaging of the skin in three dimensions, immune response to haptens, and immune response to protein antigens. First of all, I will talk on the overview of immune response in the skin.
0:47
This is an immunohistochemical staining of the skin, with S100 protein, which illustrates epidermal Langerhans cells. There are about 1,000 Langerhans cells per square millimeter in the epidermis. Since Langerhans cells function as antigen presenting cells in the skin, this histological finding implies that the skin is an immune organ.
1:16
The skin is exposed to a variety of external stimuli, including physical stress, dryness, ultraviolet light exposure, bacteria, fungus, virus, parasite infection, haptens, metals, chemicals, and protein antigens.
1:37
As a result of immune responses to external stimuli, the skin exhibits a variety of skin diseases, including urticaria to egg and fish taken orally, contact to dermatitis to metal, urushiol, atopic dermatitis to mite, dust, pollen, and psoriasis vulgaris to possible self antigens or self DNA.
2:06
A variety of immune responses are mediated by CD4 positive helper T-cell subsets, at least in part. For example, contact dermatitis is mediated by interferon- γ-producing TH1 cells, which are induced from naive CD4 T cells by IL-12. Atopic dermatitis and urticaria are mediated by IL-4, IL-5, IL-13- producing Th2 cells. Psoriasis is induced by IL-17 and IL-22 -producing Th17 cells. In contrast to the effector function of effector T-cells, another T-cell subset, regulatory T-cells, we call Tregs have been identified. Tregs oppress immune responses, or are involved in inducing tolerance. Therefore, skin immune responses are as a result of the balance between effector T-cells and regulatory T-cells.
3:13
As I mentioned earlier, the skin can elicit a variety of immune responses. Therefore, the next question is how are the variety of immune responses induced in the skin?
3:28
Conventionally, we have addressed this issue using two-dimensional histological analysis and cell culture assay. In fact, these approaches have made a great advance in this field.
3:45
But one important thing we should keep in mind is that skin is the three-dimensional organ.
3:55
Therefore, we sought to visualize the skin three-dimensionally.
4:01
Two photon laser is characterized by long wavelengths, which reaches deep areas up to 500 micrometers. Therefore, this labor enables pinpoint excitation, which allows high resolution analysis with low phototoxicity. Therefore, this microscope is suitable for visualizing 3D live imaging of the skin.
4:33
This image is two-dimensional of epidermal Langerhans cells.
4:41
But when we visualize Langerhans cells three-dimensionally we can get another information that Langerhans cells extend their dendrites upwards to the surface of the skin, which suggests that Langerhans cells are efficient cells to capture foreign antigens invading from the skin surface.
Hide

Skin immune status - live imaging of the skin in 3D

Embed in course/own notes