This book chapter compiles a general idea of steroids and their overall
biological significance in immunity and immune-associated diseases. Steroids
chemically comprise a group of cyclical organic compounds constituted by seventeen
carbon atoms that consist of four fused rings called sterane, and
cyclopentanoperhydrophenanthrene. The four-ringed structures are mainly synthesized
by mitochondria and smooth endoplasmic reticulum through the cyclization of thirty-carbon chain squalene into lanosterol or cycloartenol. Steroid hormones differ only in
number of oxygen and carbon atoms, but all are derived from cholesterol. The
biological significance of steroids and their derivatives range from energy metabolism,
and body growth to the control of reproductive activities. However, deficiency or
malfunctioning of steroids can lead to direct effects on body salt/sugar levels, sexual
differentiation and immunity. As far as immune responses are concerned, a lot of
research works have emerged which show the importance of steroids in immune
regulation, and in extreme cases, they are also known to result in immune-related
diseases. Most of these effects are mediated by the influence of steroids on gene
expression in cells and this could in turn prove to be novel drug targets as well. We
have made an attempt in this chapter to update and highlight the role of steroids in
immune regulation and immune-related diseases, which we hope would open up
therapeutic options for diseases.
Keywords: Steroids, Immune System, Macrophages, Cytokines, inflammation
