Listeria in the Spleen (image) Helmholtz Centre for Infection Research Caption When infected with Listeria monocytogenes (green) it is important to have the right immune cells present at the right time. Too many natural killer cells for example can block the recruitment of neutrophilic granulocytes (red) which are vital for the immune response. Credit © HZI / Jablonska Usage Restrictions Please name "HZI / Jablonska" as the source of this image Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.