Antibacterial immunity in respiratory tract: what role for the myeloid diffentiation primary response protein 88 (MyD88) adaptor?

As an essential interface between the external environment and the organism, the respiratory tract is particularly exposed to the potential injuries due to microorganisms, such as bacteria. Against these aggressions, the immune system has a key role, involving detection of germs followed by the establishment of innate and adaptive immune processes. During these responses, the adaptor protein MyD88 has a central place in the development of immune response: i) it contributes to innate immune response through the production of cytokines and chemokines, allowing recruitment and activation of effector cells; ii) it is involved secondarily in the development and orientation of antibacterial adaptive response, iii) and participates in sustaining immune homeostasis. Its importance is reflected in human pathology (MyD88 hereditary deficiency) by increasing susceptibility to few pathogenic bacteria responsible for respiratory infections which mainly occur in the upper respiratory tract. Since it has a key role, MyD88 is an essential factor for antibacterial immunity and more broadly for anti-infectious immunity. This protein might be therefore a possible therapeutic target.