Differentiation of Bone Marrow Macrophages in Space (BONEMAC) - 05.30.18

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
This experiment investigates how long term exposure to microgravity, such as would be experienced on missions to the Moon and Mars, effects production of cells critical to the human immune system.
Science Results for Everyone
Studies have shown that spending a long time in space has a negative impact on the immune system of crew members. Medical scientists are particularly concerned about disruption of the development of white blood cells  which are our first line of defense against illness. The BONEMAC investigation analyze some defense cells from mouse bone marrow, and find that their numbers increase a lot faster during space flight than on the ground.  Space flight also has an impact on coagulation, or blood clotting. These changes could affect production of white blood cells, which would affect the body’s ability to defend itself against pathogens on long-term spaceflights.

The following content was provided by Bradley J. Behnke, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
Bradley J. Behnke, Ph.D., University of Florida, Dept. of Applied Physiology and Kinesiology, Gainesville, FL, United States

Information Pending

NASA Ames Research Center, Moffett Field, CA, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)

Research Benefits
Information Pending

ISS Expedition Duration
October 2008 - April 2009

Expeditions Assigned

Previous Missions
This experiment has flown on STS-57, STS-60, STS-62, and STS-63. Previous experiments explored macrophage differentiation using space test tubes and by examining changes to rat bone marrow cells. The use of the ADSEP hardware and CellCult cassettes will provide a better level of environmental and experimental control during cell culturing and fixation, leading to higher quality and more reproducible results.

^ back to top

Experiment Description

Research Overview

  • Exposure to microgravity interferes with several important immune system and blood cell production processes. Disruption of the development of white blood cells (cells which are the first line of defense against new pathogens) is of particular concern for future space flights to the Moon and Mars.

  • The BONEMAC experiment investigates the effects of microgravity on macrophage production and development using rodent bone marrow.

  • The study will also examine how bone loss during space flight may adversely impact blood cell production.

Space flight has been shown to hinder the development of mature macrophages (white blood cells); however, the mechanism for disrupting this critical immune process is poorly understood. An understanding of which cellular and molecular immune processes are affected by microgravity and how their disrupted functions affects macrophage development from bone marrow stem cells will provide key data for assessing immune function during space flight and crew risks associated with long duration missions to the Moon and Mars. Macrophage cell cultures will be developed using Advanced Separation (ADSEP) hardware and three removable CellCult cassettes. Cultures will be fixed on orbit and returned for analysis.

Mature macrophage cells and their activities are critical for immune function because they are immediately available for combating pathogens to which the body has never been exposed. Also, macrophages play a key role in signaling the activation of other immune cells and responses. The objectives of the BONEMAC experiment are:

  • to investigate the effects of the space flight environment on blood production, the bone marrow, macrophage differentiation and gene expression, using primary rodent (mouse) bone marrow cultures

  • determine the macrophage differentiation molecular mechanisms disrupted by space flight

  • to obtain valuable information about which mechanisms involved in blood production are susceptible to disruption by loss of bone mass.
The expected results include increased understanding of how macrophage development is compromised by space flight conditions, and how this results in decreased immune response. This information is of critical importance for determining the potential effects of long duration space flight on human health.

^ back to top


Space Applications
Astronauts traveling to the Moon or Mars will experience degradation of their immune system function due to disruption of blood cell production mechanisms. The results of this experiment will help develop drugs to counteract these disruptions to blood cell production, and help minimize potential crew sickness from exposure to altered or novel bacteria and viruses.

Earth Applications
Investigation of the effects of bone loss on blood cell production may help improve the efficacy of treatments for similar conditions suffered by patients on Earth.

^ back to top


Operational Requirements and Protocols
A total of three rodent (mouse) bone marrow cultures will be used for BONEMAC. Three ADSEP CellCult bioreactor cassettes will be utilized in order to culture 30,000,000 cells. Each cassette consists of three fluid flow paths (feed cell path, sample collection path, and fixative path), which circulate the medium and fixative throughout the system. The ADSEP hardware will perform the various pump and valve operations automatically. 15,000,000 macrophage cells per bioreactor will be fixed on orbit and returned for analysis. Flow cytometry and other molecular techniques will be used to pinpoint the precise molecular path of disrupted stem cell differentiation in retrieved cassettes after landing.
Following launch, a Shuttle Mission Specialist will activate the three mouse bone marrow cultures, each contained in separate cassettes. All three cassettes will be housed within the ADSEP hardware for the duration of the mission. Each day the ADSEP hardware will be examined for 15 minutes to determine proper operational status. On flight day 7, the CellCult cassette mechanisms will be deactivated and the cell cultures fixed. Cassettes will be retrieved for analysis following Shuttle landing.

^ back to top

Decadal Survey Recommendations

Information Pending

^ back to top

Results/More Information

Experiments were carried out in vitro (outside the living animal), over the course of a two week space shuttle mission, on macrophages, originating from mouse bone marrow stem cells, to test the hypothesis that changes in the receptor for macrophage colony stimulating factor (M-CSF) may have been responsible for the effects of space flight on bone marrow macrophage enhanced growth.

Bone marrow cells were analyzed in this study as a complete bone marrow population and as cell subpopulations distinguished by size and internal complexity. Results showed that the number of bone marrow-derived macrophages increased faster during space flight compared to ground controls confirming previous findings. Macrophage cell counts in both living and preserved cell cultures increased an average of 5.7 fold in flight and an average of 3.9 fold on the ground after 14 and 17-day periods. However, no changes in receptor expression for M-CSF and no consistent pattern of advanced or retarded macrophage differentiation (the process of cells becoming more specialized) during space flight were found. There also was a surprising pattern of space flight influence on genes involved in coagulation. Observed changes in gene duplication suggest impacts on the cells from space flight were of a global nature not just on specific molecular signaling pathways. There were no significant differences in gross bone morphology between treatment groups or changes in the bone marrow cell numbers between flight and ground-control mice. Therefore, space flight did not radically disrupt the distribution of bone marrow cell subpopulations. These data confirm that space flight can have an impact on the in vitro development of macrophages from mouse bone marrow cells (Ortega 2009, 2012).

^ back to top

Results Publications

    Ortega MT, Lu N, Behnke BJ.  Evaluation of in vitro Macrophage Differentiation During Space Flight. Advances in Space Research. 2012 May; 49(10): 1441-1455. DOI: 10.1016/j.asr.2012.02.021.

    Ortega MT, Delp MD, Zawieja DC, Stodieck LS, Ferguson VL, Behnke BJ.  Shifts in Bone Marrow Cell Phenotypes Caused by Space Flight. Journal of Applied Physiology. 2009 Feb; 106(2): 548-555. DOI: 10.1152/japplphysiol.91138.2008. PMID: 19056998.

^ back to top

Ground Based Results Publications

^ back to top

ISS Patents

^ back to top

Related Publications

^ back to top

Related Websites

^ back to top


image NASA Image: STS095-325-013 - Astronaut, John Glenn, changing out a cassette in the ADSEP processing hardware on STS-95.
+ View Larger Image

image BONEMAC experiment inside a CellCult cassette.
+ View Larger Image

image This image shows the Group Activation Packs (GAPs) that housed the specimens for NLP-Cells-1 for their on-orbit operations. Image courtesy of BioServe Space Technologies, University of Colorado, Boulder, CO.
+ View Larger Image

image In this image shows the Group Activation Packs (GAPs) placed into the Commercial Generic Bioprocessing Apparatus (CGBA) which provides environmental controls from cold stowage to incubation temperatures. Image courtesy of BioServe Space Technologies, University of Colorado, Boulder, CO.
+ View Larger Image