1
|
Feng M, Swevers L, Sun J. Hemocyte Clusters Defined by scRNA-Seq in Bombyx mori: In Silico Analysis of Predicted Marker Genes and Implications for Potential Functional Roles. Front Immunol 2022; 13:852702. [PMID: 35281044 PMCID: PMC8914287 DOI: 10.3389/fimmu.2022.852702] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/07/2022] [Indexed: 12/16/2022] Open
Abstract
Within the hemolymph, insect hemocytes constitute a heterogeneous population of macrophage-like cells that play important roles in innate immunity, homeostasis and development. Classification of hemocytes in different subtypes by size, morphology and biochemical or immunological markers has been difficult and only in Drosophila extensive genetic analysis allowed the construction of a coherent picture of hemocyte differentiation from pro-hemocytes to granulocytes, crystal cells and plasmatocytes. However, the advent of high-throughput single cell technologies, such as single cell RNA sequencing (scRNA-seq), is bound to have a high impact on the study of hemocytes subtypes and their phenotypes in other insects for which a sophisticated genetic toolbox is not available. Instead of averaging gene expression across all cells as occurs in bulk-RNA-seq, scRNA-seq allows high-throughput and specific visualization of the differentiation status of individual cells. With scRNA-seq, interesting cell types can be identified in heterogeneous populations and direct analysis of rare cell types is possible. Next to its ability to profile the transcriptomes of individual cells in tissue samples, scRNA-seq can be used to propose marker genes that are characteristic of different hemocyte subtypes and predict their functions. In this perspective, the identities of the different marker genes that were identified by scRNA-seq analysis to define 13 distinct cell clusters of hemocytes in larvae of the silkworm, Bombyx mori, are discussed in detail. The analysis confirms the broad division of hemocytes in granulocytes, plasmatocytes, oenocytoids and perhaps spherulocytes but also reveals considerable complexity at the molecular level and highly specialized functions. In addition, predicted hemocyte marker genes in Bombyx generally show only limited convergence with the genes that are considered characteristic for hemocyte subtypes in Drosophila.
Collapse
Affiliation(s)
- Min Feng
- Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Aghia Paraskevi, Athens, Greece
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
2
|
Pan Q, Shikano I, Felton GW, Liu TX, Hoover K. Host permissiveness to baculovirus influences time-dependent immune responses and fitness costs. INSECT SCIENCE 2021; 28:103-114. [PMID: 31953986 DOI: 10.1111/1744-7917.12755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/16/2019] [Accepted: 01/03/2020] [Indexed: 05/25/2023]
Abstract
Insects possess specific immune responses to protect themselves from different types of pathogens. Activation of immune cascades can inflict significant developmental costs on the surviving host. To characterize infection kinetics in a surviving host that experiences baculovirus inoculation, it is crucial to determine the timing of immune responses. Here, we investigated time-dependent immune responses and developmental costs elicited by inoculations from each of two wild-type baculoviruses, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and Helicoverpa zea single nucleopolyhedrovirus (HzSNPV), in their common host H. zea. As H. zea is a semi-permissive host of AcMNPV and fully permissive to HzSNPV, we hypothesized there are differential immune responses and fitness costs associated with resisting infection by each virus species. Newly molted 4th-instar larvae that were inoculated with a low dose (LD15 ) of either virus showed significantly higher hemolymph FAD-glucose dehydrogenase (GLD) activities compared to the corresponding control larvae. Hemolymph phenoloxidase (PO) activity, protein concentration and total hemocyte numbers were not increased, but instead were lower than in control larvae at some time points post-inoculation. Larvae that survived either virus inoculation exhibited reduced pupal weight; survivors inoculated with AcMNPV grew slower than the control larvae, while survivors of HzSNPV pupated earlier than control larvae. Our results highlight the complexity of immune responses and fitness costs associated with combating different baculoviruses.
Collapse
Affiliation(s)
- Qinjian Pan
- State Key Laboratory of Crop Stress Biology for Arid Areas, and Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- Department of Entomology and Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA
| | - Ikkei Shikano
- Department of Entomology and Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Gary W Felton
- Department of Entomology and Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA
| | - Tong-Xian Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, and Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
| | - Kelli Hoover
- Department of Entomology and Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
3
|
Matsuda–Imai N, Katsuma S. Characterization of Bombyx mori nucleopolyhedrovirus infection in fat body-derived Bombyx mori cultured cells. J Invertebr Pathol 2020; 177:107476. [DOI: 10.1016/j.jip.2020.107476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/19/2020] [Accepted: 09/21/2020] [Indexed: 01/28/2023]
|
4
|
Hemocyte Changes During Immune Melanization in Bombyx Mori Infected with Escherichia coli. INSECTS 2019; 10:insects10090301. [PMID: 31527493 PMCID: PMC6780253 DOI: 10.3390/insects10090301] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 01/21/2023]
Abstract
Hemolymph melanization is a conserved immune response in insects and other arthropods. However, the physiological process of the hemolymph system in the melanization response is hardly studied. Here, alterations of hemocytes in immune melanization were observed by Escherichia coli infection in Bombyx mori. Results first showed that there were cells aggregating into clusters. However, it vanished, and only part of clustered hemocytes were melanized during the period of intense immunity. The hemocyte numbers immediately decreased following an immune challenge, slowly increased to a peak, then reduced and finally returned to normalization. Granulocytes participated in cells aggregation at the early and later immune stage, while plasmatocytes were responsible for hemocytes agglomerate and melanization for the longest time, and more oenocytoids appeared at the peak stage of melanization. Moreover, hemocytes played a crucial role in resisting invasion of pathogens by agglomerate and melanization, and the circulatory system maintained higher hemocyte numbers and stronger antibacterial activity in fifth than fourth instar larvae after infection. In vitro immune melanization was most likely preferentially implemented in an independent process. These were the main characteristics reflecting the physiological process of hemolymph immune melanization, which provided an important foundation for further study of the complete mechanisms in the immunity of silkworm.
Collapse
|
5
|
Hikida H, Kokusho R, Kobayashi J, Shimada T, Katsuma S. Inhibitory role of the Bm8 protein in the propagation of Bombyx mori nucleopolyhedrovirus. Virus Res 2018; 249:124-131. [PMID: 29574100 DOI: 10.1016/j.virusres.2018.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/15/2018] [Accepted: 03/19/2018] [Indexed: 11/27/2022]
Abstract
Lepidopteran nucleopolyhedroviruses have distinct viral tissue tropisms in host larvae. We previously identified the Bm8 gene of Bombyx mori nucleopolyhedrovirus (BmNPV), the product of which inhibits viral propagation in the middle silk gland (MSG). However, it is unknown whether this inhibitory function of the Bm8 protein is specific to MSGs. Here we generated a Bm8-disrupted recombinant BmNPV expressing green fluorescent protein (GFP) and examined viral propagation in B. mori cultured cells and larvae. We found that Bm8-disrupted BmNPV produced fewer budded viruses and more occlusion bodies (OBs) than the wild-type virus in both cultured cells and larvae. Microscopic observation of OB production and GFP expression revealed that Bm8 disruption accelerated the progression of viral infection in various larval tissues. Furthermore, quantitative reverse transcription-polymerase chain reaction experiments showed that the loss of Bm8 enhanced viral gene expression in BmNPV-infected larval tissues. These results indicate that the Bm8 protein suppresses viral propagation to varying degrees in each larval tissue, which may establish BmNPV tissue tropisms in B. mori larvae.
Collapse
Affiliation(s)
- Hiroyuki Hikida
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryuhei Kokusho
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Jun Kobayashi
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| |
Collapse
|
6
|
Shikano I, Hua KN, Cory JS. Baculovirus-challenge and poor nutrition inflict within-generation fitness costs without triggering transgenerational immune priming. J Invertebr Pathol 2016; 136:35-42. [DOI: 10.1016/j.jip.2016.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/22/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
|
7
|
Kokusho R, Kawamoto M, Koyano Y, Sugano S, Suzuki Y, Shimada T, Katsuma S. Bombyx mori nucleopolyhedrovirus actin rearrangement-inducing factor 1 enhances systemic infection in B. mori larvae. J Gen Virol 2015; 96:1938-46. [PMID: 25809914 DOI: 10.1099/vir.0.000130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The actin rearrangement-inducing factor 1 (arif-1) gene is a baculoviral early gene conserved in most alphabaculoviruses. Previous studies reported that Autographa californica nucleopolyhedrovirus ARIF-1 protein induces filamentous actin concentration on the plasma membrane during the early stage of infection in Trichoplusia ni TN-368 cells, but its role in larval infection remains unknown. In this study, we performed behavioural screening using Bombyx mori larvae infected with Bombyx mori nucleopolyhedrovirus (BmNPV) mutants and found that larvae infected with arif-1-mutated BmNPVs did not show locomotor hyperactivity that was normally observed in BmNPV-infected larvae. arif-1-deficient BmNPVs also showed reduced pathogenicity and total viral propagation in B. mori larvae, whereas viral propagation of arif-1-deficient viruses was comparable with that of control viruses in B. mori cultured cells. An arif-1-defective BmNPV expressing the GFP gene (gfp) was used to monitor the progression of infection in B. mori larvae. GFP expression and quantitative reverse transcription-PCR analyses revealed that infection by the arif-1-disrupted virus was significantly delayed in trachea, fat body, suboesophageal ganglion and brain. These results indicated that BmNPV ARIF-1 enhanced systemic infection in B. mori larvae.
Collapse
Affiliation(s)
- Ryuhei Kokusho
- 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Munetaka Kawamoto
- 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasue Koyano
- 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Sumio Sugano
- 2Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Yutaka Suzuki
- 3Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan
| | - Toru Shimada
- 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| |
Collapse
|
8
|
Zhang J, Chen XM, Zhang CD, He Q, Dong ZQ, Cao MY, Dong XL, Pan CX, Lu C, Pan MH. Differential susceptibilities to BmNPV infection of two cell lines derived from the same silkworm ovarian tissues. PLoS One 2014; 9:e105986. [PMID: 25221982 PMCID: PMC4164443 DOI: 10.1371/journal.pone.0105986] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 07/30/2014] [Indexed: 11/18/2022] Open
Abstract
We previously established and characterized two insect cell lines (BmN-SWU1 and BmN-SWU2) from Bombyx mori ovaries. Here, we examined their differential susceptibilities to Bombyx mori nucleopolyhedrovirus (BmNPV) despite having originated from the same tissue source. BmN-SWU1 cells were susceptible and supported high titers of BmNPV replication, while BmN-SWU2 cells were resistant to BmNPV infection. Subcellular localization analysis demonstrated that very few BmNPV particles could be imported into BmN-SWU2 cells. However, initiation of BmNPV DNA replication but not amplification was detected in BmN-SWU2 cells after transfection with vA4prm-VP39-EGFP bacmid DNA. BmNPV transcription assays showed that late and very late but not early viral genes apparently were blocked in BmNSWU2 cells by unknown mechanisms. Further syncytium formation assays demonstrated that the BmNPV envelope fusion protein GP64 could not mediate BmN-SWU2 host cell-cell membrane fusion. Taken together, these results indicate that these two cell lines represent optimal tools for investigating host-virus interactions and insect antiviral mechanisms.
Collapse
Affiliation(s)
- Jun Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China; Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Xue-Mei Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Chun-Dong Zhang
- Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing, China
| | - Qian He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Zhan-Qi Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ming-Ya Cao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Xiao-Long Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cai-Xia Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Min-Hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| |
Collapse
|