The human body’s immune-based response to the presence of
deleterious microbes engages a very intricate and complex system that has
evolved over many millions of years. In
this regard, we share many aspects in common with the entire vertebrate world. Immunity can be regarded as consisting of
two categories of responses – innate and adaptive. In the present discussion, we will focus our
attention on the innate immune system.
The innate immune system has the extraordinary capability of
recognizing a wide range of microbes and inducing the production of many
proteins that become engaged in an elaborate defense against the invading
organism and ultimately involve the adaptive response. Over many years of concerted research
efforts, it has been shown that the molecular basis of this recognition system
involves a host of genetically determined pattern recognition receptors – an
example being the so-called “Toll-like receptors” (TLRs). It is the binding to these receptors that
triggers a cascade of immune responses.
It has recently been discovered that long non-coding RNAs
(lncRNAs) play a significant role in this process. As a class of biologically active compounds,
literally thousands of these lncRNAs have been discovered in mammalian genomes
and they have been shown to regulate gene expression in a number of biological
processes. It is, therefore, of some
interest to determine whether lncRNAs play a role in the innate immune system
as well.
The work of Dr. Susan Carpenter and her colleagues at the
Division of Infectious Diseases and Immunology in the Department of Medicine at
the University of Massachusetts Medical School has helped answer this
question. The efficacy of the
antimicrobial innate defense is wholly dependent upon the induction of inflammatory
gene expression. Implicated in this
complex response is the activation of transcription factors, transcription
co-regulators and other factors.