Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores
Abstract The spore-forming capacity of Bacillus spp. enables environmental persistence and stable product formulations, yet the interactions of environmental Bacillus spores and vegetative cells with the human immune system are not fully understood. We investigated the immunostimulatory potential of...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-08-01
|
| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-025-12833-7 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849226283137892352 |
|---|---|
| author | Max Dekeukeleire Dieter Vandenheuvel Tippapron Khondee Lize Delanghe Tim Van Rillaer Sofie Thys Jean-Pierre Timmermans Sarah Lebeer Irina Spacova |
| author_facet | Max Dekeukeleire Dieter Vandenheuvel Tippapron Khondee Lize Delanghe Tim Van Rillaer Sofie Thys Jean-Pierre Timmermans Sarah Lebeer Irina Spacova |
| author_sort | Max Dekeukeleire |
| collection | DOAJ |
| description | Abstract The spore-forming capacity of Bacillus spp. enables environmental persistence and stable product formulations, yet the interactions of environmental Bacillus spores and vegetative cells with the human immune system are not fully understood. We investigated the immunostimulatory potential of seven environmental Bacillus isolates (B. subtilis, B. velezensis, B. licheniformis, B. pumilus) and optimized their inactivation methods to preserve surface integrity and immunostimulatory activity. Inactivation was evaluated using heat/UV-C and 10–100% formalin, followed by scanning electron microscopy and human reporter cell assays (THP1-Dual monocytes, HEK-Blue hTLR2/6 and hTLR4). Heat/UV-C treatment retained Bacillus morphology and enhanced immune activation compared to 10–100% formalin treatment. Spores and vegetative cells activated key immune transcription factors (nuclear factor kappa B and interferon regulatory factors) in human monocytes, with spores inducing 1.5- to 8-fold lower responses compared to vegetative cells, and strain- and species-dependent effects observed. All tested Bacillus isolates significantly activated Toll-like receptor TLR2/6, but not TLR4. Genome analysis identified Bacillus spore envelope components (SpsAEIK, CotBCGQ) that may influence differences in immune responses. Our findings improve understanding of Bacillus-human immune interactions, revealing strain- and species-specific immunostimulatory activity. These results support further exploration of Bacillus isolates for immune-related and environmental applications. |
| format | Article |
| id | doaj-art-7b4368a1a42e453397a7ee6237bb6608 |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-7b4368a1a42e453397a7ee6237bb66082025-08-24T11:28:33ZengNature PortfolioScientific Reports2045-23222025-08-0115111610.1038/s41598-025-12833-7Immunostimulatory activity of inactivated environmental Bacillus isolates and their endosporesMax Dekeukeleire0Dieter Vandenheuvel1Tippapron Khondee2Lize Delanghe3Tim Van Rillaer4Sofie Thys5Jean-Pierre Timmermans6Sarah Lebeer7Irina Spacova8Laboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Cell Biology and Histology (CHB), Department of Pharmaceutical, Biomedical and Veterinary Sciences, University of AntwerpLaboratory of Cell Biology and Histology (CHB), Department of Pharmaceutical, Biomedical and Veterinary Sciences, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpLaboratory of Applied Microbiology and Biotechnology (LAMB), Department of Bioscience Engineering, University of AntwerpAbstract The spore-forming capacity of Bacillus spp. enables environmental persistence and stable product formulations, yet the interactions of environmental Bacillus spores and vegetative cells with the human immune system are not fully understood. We investigated the immunostimulatory potential of seven environmental Bacillus isolates (B. subtilis, B. velezensis, B. licheniformis, B. pumilus) and optimized their inactivation methods to preserve surface integrity and immunostimulatory activity. Inactivation was evaluated using heat/UV-C and 10–100% formalin, followed by scanning electron microscopy and human reporter cell assays (THP1-Dual monocytes, HEK-Blue hTLR2/6 and hTLR4). Heat/UV-C treatment retained Bacillus morphology and enhanced immune activation compared to 10–100% formalin treatment. Spores and vegetative cells activated key immune transcription factors (nuclear factor kappa B and interferon regulatory factors) in human monocytes, with spores inducing 1.5- to 8-fold lower responses compared to vegetative cells, and strain- and species-dependent effects observed. All tested Bacillus isolates significantly activated Toll-like receptor TLR2/6, but not TLR4. Genome analysis identified Bacillus spore envelope components (SpsAEIK, CotBCGQ) that may influence differences in immune responses. Our findings improve understanding of Bacillus-human immune interactions, revealing strain- and species-specific immunostimulatory activity. These results support further exploration of Bacillus isolates for immune-related and environmental applications.https://doi.org/10.1038/s41598-025-12833-7 |
| spellingShingle | Max Dekeukeleire Dieter Vandenheuvel Tippapron Khondee Lize Delanghe Tim Van Rillaer Sofie Thys Jean-Pierre Timmermans Sarah Lebeer Irina Spacova Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores Scientific Reports |
| title | Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores |
| title_full | Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores |
| title_fullStr | Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores |
| title_full_unstemmed | Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores |
| title_short | Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores |
| title_sort | immunostimulatory activity of inactivated environmental bacillus isolates and their endospores |
| url | https://doi.org/10.1038/s41598-025-12833-7 |
| work_keys_str_mv | AT maxdekeukeleire immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT dietervandenheuvel immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT tippapronkhondee immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT lizedelanghe immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT timvanrillaer immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT sofiethys immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT jeanpierretimmermans immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT sarahlebeer immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores AT irinaspacova immunostimulatoryactivityofinactivatedenvironmentalbacillusisolatesandtheirendospores |