The mycoplasma lipoproteins play a key role in infection, although some of them do not cause clinical symptoms in humans. They are important factors in the inflammation process and are probably also involved in leukocyte recruitment to the infected tissue. Their ability to undergo size or phase variation at a high frequency appears to be a means of adapting to different conditions, including the host’s immune response. The conjugation, diacylated or triacylated lipopeptides, and the size of the C-terminal sequence have the effect on the immunity through TLRs. Some studies have revealed the basic structure, signaling pathway, and cooperation functions of TLRs in innate immune reactions. Over-expression studies are often used to know about the function of signal transduction molecules, but sometimes their results can be mislieading. Canparent to it, using knockout mice or RNA interference might get better results. Also, the sample components should be highly purified and synthetic compounds be used whenever possible, so that the interaction between mycoplasma lipoproteins and TLRs in vitro will be better examined (Akira et al., 2001). As for structural biology research, more X-ray crystallography and NMR spectroscopy studies are necessary to evaluate the interaction.
The current understanding of the cellular mechanisms involved in the TLR-mediated anti-mycoplasmas activity is minimal, and the signaling pathway of TLRs is still elusive. However, as long as researchers continue to explore and understand the biological structure and components of mycoplasma lipoproteins and TLR proteins, it will be possible to develop strategies to obtain antibodies or vaccines for defense.