Macrophages, large phagocytic cells of the innate immune system, respond to many different stimuli, such as messenger substances or pathogens.

They are activated via altered transcription: the entire transcription program is adjusted to the new requirements. During the macrophages’ maturation they activate certain genes of their DNA, which are converted into transcripts. This can be examined by RNA analyses.

So far it was assumed that they matured only to either inflammatory or anti-inflammatory immune cell types. However, the scientists at LIMES headed by Prof. Joachim Schultze have discovered that there are at least nine different forms. The researchers suggest that this is how the body is able to optimally control bacterial invaders.

For their studies the researchers harvested macrophage progenitor cells from blood donors, smokers and COPD Patients. The immune cells were isolated by magnetic cell isolation and cleaned. They were then exposed to specific chemical messengers so as to mimic inflammation. The researchers compared the differences in the ribonucleic acids of the cell types by RNA analysis.

The scientists detected that macrophages from the lungs of smokers and COPD patients did not produce special inflammatory signals. In addition, the researchers compared the human transcriptome with those of mice and found out that there are activation independent core areas both in human and in the murine macrophages.

With their findings the researchers hope to find entirely new therapeutic approaches for many common diseases such as atherosclerosis, diabetes or asthma.

Source: http://www.innovations-report.de/

Origionalpaper:
Jia Xue, Susanne V. Schmidt, Jil Sander, Astrid Draffehn, Wolfgang Krebs, Inga Quester, Dominic De Nardo, Trupti D. Gohel, Martina Emde, Lisa Schmid leithner, Hariharasudan Ganesan, Andrea Nino-Castro, Michael R. Mallmann, Larisa Labzin, Heidi Theis, Michael Kraut, Marc Beyer, Eicke Latz, Tom C. Freeman, Thomas & Joachim L. Schultze Ulas (2014): Transcriptome-Based Network Analysis Reveals a Spectrum Model of Human Macrophage
Activation. Immunity 40: 274-288. http://dx.doi.org/10.1016/j.immuni.2014.01.006