Human neutrophils kill Acinetobacter

4 de July de 2017

Using different advanced microscopy techniques, a group of researchers from the REIPI network demonstrated that human neutrophils easily phagocytose and kill Acinetobacter baumannii and A. pittii. After bacteria-cell contact, neutrophils rapidly and continuously engulf and kill bacteria during at least 4 hours of infection in vitro. Also, neutrophils release neutrophil extracellular traps (NETs) against Acinetobacter. This neutrophil response to these pathogens could partially prevent their dissemination during the infection. An unexpected finding of the study was the presence of very large filopodia emerging from the neutrophil body to sense the environment and even to catch bacteria. New knowledge through a deeper study on the modulation and regulation of these filopodia may prove helpful in understanding the pathogenesis of these and other bacteria. Furthermore, co-cultivation of neutrophils with human differentiated macrophages before infections shows that human neutrophils, but not macrophages, are key immune cells to control Acinetobacter. As neutrophils are also responsible for tissue damage and inflammation during certain circumstances, an overactivation of these cells could be detrimental to the host. Therefore, future detailed studies at the molecular level will help these researchers to decipher the mechanisms involved in the regulation of neutrophils, both alone or in combination with other immune cells.

This work “Human neutrophils phagocytose and kill Acinetobacter baumannii and A. pittii” was published on-line on July 4, in Scientific Reports.

María Lázaro-Díez1,2,8, Itziar Chapartegui-González1,2, Santiago Redondo-Salvo1, Chike Leigh3, David Merino1,4, David San Segundo1,4, Jesús Navas1,5, José Manuel Icardo6, Félix Acosta7, Alain Ocampo-Sosa1,2,8 , Luis Martínez-Martínez8,9,10 and José Ramos-Vivas1,2,8*

1Instituto de Investigación Valdecilla IDIVAL, Santander, 39011, Spain.

2Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, 39008, Spain.

3New York University School of Medicine, New York, 10003, U.S.A.

4Servicio de Inmunología, Hospital Universitario Marqués de Valdecilla, Santander, 39008, Spain.

5Departamento de Biología Molecular, Universidad de Cantabria, Santander, 39011, Spain.

6Departamento de Anatomía y Biología Celular, Universidad de Cantabria, Santander, 39011, Spain.

7Grupo de Investigación en Acuicultura, Universidad de Las Palmas de Gran Canaria, Gran Canaria, 35214, Spain.

8Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, 28029, Spain.

9Unidad de Gestión Clínica de Microbiología, Hospital Universitario Reina Sofía, Córdoba, 14004, Spain.

10Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, 14004, Spain.