(Note: Johan Grooten's lab is part of the UGent Department of Biomedical Molecular Biology but not a VIB unit)
Due to their phagocytic activity, macrophages (MΦ) are an important component of the innate immune defense. Toll-like receptors and other pattern recognition receptors allow the cells to discriminate non-self from modified-self, resulting in engulfment and clearance of infectious agents. Signal transduction driving gene expression confers to the activated MΦ additional inflammatory effector functions. Responsiveness to T lymphocyte-derived cytokines and other adaptive immune effectors, such as antibody-antigen complexes, further diversifies the resultant MΦ activation. When appropriately activated, presentation of engulfed antigens to Th-lymphocytes may raise tolerogenic responses or modify the nature of the immune inflammatory response.
In view of this multiplicity of MΦ functions and responsiveness, our research group explores the bi-directional relationship between Mf activation by local inflammatory conditions, and steering by the activated MΦ of the inflammatory response and underlying immune reactivity. Gene expression profiling of MΦ isolated from inflamed airways (models of asthma, pneumonia, COPD) with MΦ focus arrays made in-house is combined with functional analysis by macrophage transfer experiments and local application of MΦ-targeted triggers. Special emphasis is placed on the regulatory role of MΦ at the innate-adaptive immune interphase, thus interfering with the upstream causal immune reactivity as well as with the downstream inflammatory process.
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