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Bisimwa PN, Ongus JR, Tonui R, Bisimwa EB, Steinaa L. Resistance to African swine fever virus among African domestic pigs appears to be associated with a distinct polymorphic signature in the RelA gene and upregulation of RelA transcription. Virol J 2024; 21:93. [PMID: 38658979 PMCID: PMC11041040 DOI: 10.1186/s12985-024-02351-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/24/2024] [Indexed: 04/26/2024] Open
Abstract
African swine fever virus (ASFV) is a highly contagious and fatal hemorrhagic disease of domestic pigs, which poses a major threat to the swine industry worldwide. Studies have shown that indigenous African pigs tolerate ASFV infection better than European pigs. The porcine v-rel avian reticuloendotheliosis viral oncogene homolog A (RelA) encoding a p65 kD protein, a major subunit of the NF-kB transcription factor, plays important roles in controlling both innate and adaptive immunity during infection with ASFV. In the present study, RelA genes from ASFV-surviving and symptomatic pigs were sequenced and found to contain polymorphisms revealing two discrete RelA amino acid sequences. One was found in the surviving pigs, and the other in symptomatic pigs. In total, 16 nonsynonymous SNPs (nsSNPs) resulting in codon changes were identified using bioinformatics software (SIFT and Polyphen v2) and web-based tools (MutPre and PredictSNP). Seven nsSNPs (P374-S, T448-S, P462-R, V464-P, Q478-H, L495-E, and P499-Q) were predicted to alter RelA protein function and stability, while 5 of these (P374-S, T448-S, P462-R, L495-E, and Q499-P) were predicted as disease-related SNPs.Additionally, the inflammatory cytokine levels of IFN-α, IL-10, and TNF-α at both the protein and the mRNA transcript levels were measured using ELISA and Real-Time PCR, respectively. The resulting data was used in correlation analysis to assess the association between cytokine levels and the RelA gene expression. Higher levels of IFN-α and detectable levels of IL-10 protein and RelA mRNA were observed in surviving pigs compared to healthy (non-infected). A positive correlation of IFN-α cytokine levels with RelA mRNA expression was also obtained. In conclusion, 7 polymorphic events in the coding region of the RelA gene may contribute to the tolerance of ASFV in pigs.
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Affiliation(s)
- Patrick N Bisimwa
- Molecular Biology Laboratory, Department of Animal Sciences and Production, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo.
- Institut Supérieur de Dévelopement Rural de Kaziba, Kaziba, Democratic Republic of Congo.
| | - Juliette R Ongus
- Department of Medical Laboratory Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- Biotechnology Laboratory, Departement of Molecular Biology and Biotechnology, Pan African University Institute of Basic Sciences, Technology and Innovation, Nairobi, Kenya
| | - Ronald Tonui
- Department of Medical Laboratory Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Espoir B Bisimwa
- Molecular Biology Laboratory, Department of Animal Sciences and Production, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo
| | - Lucilla Steinaa
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
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2
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Zhou Y, Zhang J, Sun H, Tao D, Xu B, Han X, Ren R, Ruan J, Steinaa L, Hemmink JD, Han J, Li X, Xu J, Zhao S, Xie S, Zhao C. Sensitive and Specific Exonuclease III-Assisted Recombinase-Aided Amplification Colorimetric Assay for Rapid Detection of Nucleic Acids. ACS Synth Biol 2023; 12:2877-2886. [PMID: 37729559 DOI: 10.1021/acssynbio.3c00137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The development of a contamination-free and on-site nucleic acid detection platform with high sensitivity and specificity but low-cost for the detection of pathogenic nucleic acids is critical for infectious disease diagnosis and surveillance. In this study, we combined the recombinase-aided amplification (RAA) with the exonuclease III (Exo III)-assisted signal amplification into a platform for sensitive and specific detection of nucleic acids of African swine fever virus (ASFV). We found that this platform enabled a naked eye visual detection of ASFV at a detection limit as low as 2 copies/μL in 30 min. As expected, no cross-reactivity was observed with other porcine viruses. In addition, to avoid aerosol contamination, a one-tube RAA-Exo III colorimetric assay was also established for the accurate detection of ASFV in clinical samples. Taken together, we developed a rapid, instrument-free, and low-cost Exo III-assisted RAA colorimetric-assay-based nucleic acid detection platform.
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Affiliation(s)
- Yuan Zhou
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Jinfu Zhang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Haowen Sun
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Dagang Tao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Bingrong Xu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Xiaosong Han
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Ruimin Ren
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Jinxue Ruan
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Lucilla Steinaa
- Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Johanneke D Hemmink
- Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Jianlin Han
- CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources, Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, P. R. China
- Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Xinyun Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, P. R. China
- Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, P. R. China
| | - Jing Xu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, P. R. China
- Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, P. R. China
| | - Shengsong Xie
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, P. R. China
- Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, P. R. China
| | - Changzhi Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, P. R. China
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Hemmink JD, Khazalwa EM, Abkallo HM, Oduor B, Khayumbi J, Svitek N, Henson SP, Blome S, Keil G, Bishop RP, Steinaa L. Deletion of the CD2v Gene from the Genome of ASFV-Kenya-IX-1033 Partially Reduces Virulence and Induces Protection in Pigs. Viruses 2022; 14:v14091917. [PMID: 36146726 PMCID: PMC9503863 DOI: 10.3390/v14091917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/12/2022] [Accepted: 08/21/2022] [Indexed: 11/20/2022] Open
Abstract
Infection of pigs with the African swine fever virus (ASFV) leads to a devastating hemorrhagic disease with a high mortality of up to 100%. In this study, a CD2v gene deletion was introduced to a genotype IX virus from East Africa, ASFV-Kenya-IX-1033 (ASFV-Kenya-IX-1033-∆CD2v), to investigate whether this deletion led to reduced virulence in domestic pigs and to see if inoculation with this LA-ASFV could induce protective immunity against parental virus challenge. All pigs inoculated with ASFV-Kenya-IX-1033-ΔCD2v survived inoculation but presented with fever, reduced appetite and lethargy. ASFV genomic copies were detected in only one animal at one time point. Seven out of eight animals survived subsequent challenge with the pathogenic parental strain (87.5%) but had mild to moderate clinical symptoms and had a gross pathology compatible with chronic ASFV infection. All mock-immunised animals developed acute ASF upon challenge with ASFV-Kenya-IX-1033 and were euthanised upon meeting the humane endpoint criteria. ASFV genome copy numbers after challenge were similar in the two groups. ASFV-Kenya-IX-1033-∆CD2v is therefore a useful tool to investigate the development of immunity to ASFV genotype IX, but safety concerns preclude its use as a candidate vaccine without further attenuation.
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Affiliation(s)
- Johanneke D. Hemmink
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
- Correspondence: (J.D.H.); (L.S.)
| | - Emmanuel M. Khazalwa
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Hussein M. Abkallo
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Bernard Oduor
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Jeremiah Khayumbi
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Nicholas Svitek
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Sonal P. Henson
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
- Deep Seq, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK
| | - Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, Insel Riems, 17493 Greifswald, Germany
| | - Günther Keil
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, Insel Riems, 17493 Greifswald, Germany
| | | | - Lucilla Steinaa
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
- Correspondence: (J.D.H.); (L.S.)
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4
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Svitek N, Saya R, Zhang H, Nene V, Steinaa L. Systematic Determination of TCR–Antigen and Peptide–MHC Binding Kinetics among Field Variants of a Theileria parva Polymorphic CTL Epitope. J I 2022; 208:549-561. [PMID: 35031580 PMCID: PMC8802549 DOI: 10.4049/jimmunol.2100400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/23/2021] [Indexed: 11/24/2022]
Abstract
Positions 1–3 in the Tp9 CTL epitope are required for binding to BoLA-1*023:01. Positions 5–8 in the Tp9 epitope are required for TCR recognition in diverse CTLs. Tp9-specific CTLs from Muguga-immunized animals can cross-react with variants 4 and 7.
CTLs are known to contribute to immunity toward Theileria parva, the causative agent of East Coast fever. The Tp967–75 CTL epitope from the Muguga strain of T. parva is polymorphic in other parasite strains. Identifying the amino acids important for MHC class I binding, as well as TCR recognition of epitopes, can allow the strategic selection of Ags to induce cellular immunity toward T. parva. In this study, we characterized the amino acids important for MHC class I binding and TCR recognition in the Tp967–75 epitope using alanine scanning and a series of variant peptide sequences to probe these interactions. In a peptide–MHC class I binding assay, we found that the amino acids at positions 1, 2, and 3 were critical for binding to its restricting MHC class I molecule BoLA-1*023:01. With IFN-γ ELISPOT and peptide–MHC class I Tet staining assays on two parasite-specific bovine CTL lines, we showed that amino acids at positions 5–8 in the epitope were required for TCR recognition. Only two of eight naturally occurring polymorphic Tp9 epitopes were recognized by both CTLs. Finally, using a TCR avidity assay, we found that a higher TCR avidity was associated with a stronger functional response toward one of two variants recognized by the CTL. These data add to the growing knowledge on the cross-reactivity of epitope-specific CTLs and specificities that may be required in the selection of Ags in the design of a wide-spectrum vaccine for East Coast fever.
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Affiliation(s)
- Nicholas Svitek
- International Livestock Research Institute, Animal and Human Health Program, Nairobi, Kenya; and
| | - Rosemary Saya
- International Livestock Research Institute, Animal and Human Health Program, Nairobi, Kenya; and
| | - Houshuang Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Minhang District, Shanghai, China
| | - Vishvanath Nene
- International Livestock Research Institute, Animal and Human Health Program, Nairobi, Kenya; and
| | - Lucilla Steinaa
- International Livestock Research Institute, Animal and Human Health Program, Nairobi, Kenya; and
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5
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Xie S, Tao D, Fu Y, Xu B, Tang Y, Steinaa L, Hemmink JD, Pan W, Huang X, Nie X, Zhao C, Ruan J, Zhang Y, Han J, Fu L, Ma Y, Li X, Liu X, Zhao S. Rapid Visual CRISPR Assay: A Naked-Eye Colorimetric Detection Method for Nucleic Acids Based on CRISPR/Cas12a and a Convolutional Neural Network. ACS Synth Biol 2022; 11:383-396. [PMID: 34937346 PMCID: PMC8713390 DOI: 10.1021/acssynbio.1c00474] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Indexed: 12/26/2022]
Abstract
Rapid diagnosis based on naked-eye colorimetric detection remains challenging, but it could build new capacities for molecular point-of-care testing (POCT). In this study, we evaluated the performance of 16 types of single-stranded DNA-fluorophore-quencher (ssDNA-FQ) reporters for use with clusters of regularly spaced short palindrome repeats (CRISPR)/Cas12a-based visual colorimetric assays. Among them, nine ssDNA-FQ reporters were found to be suitable for direct visual colorimetric detection, with especially very strong performance using ROX-labeled reporters. We optimized the reaction concentrations of these ssDNA-FQ reporters for a naked-eye read-out of assay results (no transducing component required for visualization). In particular, we developed a convolutional neural network algorithm to standardize and automate the analytical colorimetric assessment of images and integrated this into the MagicEye mobile phone software. A field-deployable assay platform named RApid VIsual CRISPR (RAVI-CRISPR) based on a ROX-labeled reporter with isothermal amplification and CRISPR/Cas12a targeting was established. We deployed RAVI-CRISPR in a single tube toward an instrument-less colorimetric POCT format that required only a portable rechargeable hand warmer for incubation. The RAVI-CRISPR was successfully used for the high-sensitivity detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and African swine fever virus (ASFV). Our study demonstrates this RAVI-CRISPR/MagicEye system to be suitable for distinguishing different pathogenic nucleic acid targets with high specificity and sensitivity as the simplest-to-date platform for rapid pen- or bed-side testing.
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Affiliation(s)
- Shengsong Xie
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
- Animal and Human Health Program, Biosciences,
International Livestock Research Institute (ILRI), P.O. Box
30709, Nairobi 00100, Kenya
- The Cooperative Innovation Center for Sustainable Pig
Production, Huazhong Agricultural University, Wuhan 430070,
P. R. China
| | - Dagang Tao
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Yuhua Fu
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Bingrong Xu
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - You Tang
- Electrical and Information Engineering College,
Jilin Agricultural Science and Technology University, Jilin
132101, P. R. China
| | - Lucilla Steinaa
- Animal and Human Health Program, Biosciences,
International Livestock Research Institute (ILRI), P.O. Box
30709, Nairobi 00100, Kenya
| | - Johanneke D. Hemmink
- Animal and Human Health Program, Biosciences,
International Livestock Research Institute (ILRI), P.O. Box
30709, Nairobi 00100, Kenya
| | - Wenya Pan
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Xin Huang
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Xiongwei Nie
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Changzhi Zhao
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Jinxue Ruan
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Yi Zhang
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Jianlin Han
- CAAS-ILRI Joint Laboratory on Livestock and Forage
Genetic Resources, Institute of Animal Science, Chinese Academy of
Agricultural Sciences (CAAS), Beijing 100193, P. R.
China
- LiveGene Program, Biosciences,
International Livestock Research Institute (ILRI), P.O. Box
30709, Nairobi 00100, Kenya
| | - Liangliang Fu
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Yunlong Ma
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
| | - Xinyun Li
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig
Production, Huazhong Agricultural University, Wuhan 430070,
P. R. China
- Hubei Hongshan Laboratory, Frontiers
Science Center for Animal Breeding and Sustainable Production, Wuhan
430070, P. R. China
| | - Xiaolei Liu
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig
Production, Huazhong Agricultural University, Wuhan 430070,
P. R. China
- Hubei Hongshan Laboratory, Frontiers
Science Center for Animal Breeding and Sustainable Production, Wuhan
430070, P. R. China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics,
Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and
Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural
University, Wuhan 430070, P. R. China
- The Cooperative Innovation Center for Sustainable Pig
Production, Huazhong Agricultural University, Wuhan 430070,
P. R. China
- Hubei Hongshan Laboratory, Frontiers
Science Center for Animal Breeding and Sustainable Production, Wuhan
430070, P. R. China
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6
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Svitek N, Taracha ELN, Saya R, Awino E, Nene V, Steinaa L. Analysis of the Cellular Immune Responses to Vaccines. Methods Mol Biol 2022; 2465:283-301. [PMID: 35118627 DOI: 10.1007/978-1-0716-2168-4_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Flow cytometry, enzyme-linked immunospot (ELISpot), and cellular cytotoxicity assays are powerful tools for studying the cellular immune response toward intracellular pathogens and vaccines in livestock species. Lymphocytes from immunized animals can be purified using Ficoll-Paque density gradient centrifugation and evaluated for their antigen specificity or reactivity toward a vaccine. Here, we describe staining of bovine lymphocytes with peptide (p)-MHC class I tetramers and antibodies specific toward cellular activation markers for evaluation by multiparametric flow cytometry, as well as interferon (IFN)-γ ELISpot and cytotoxicity using chromium (51Cr) release assays. A small component on the use of immunoinformatics for fine-tuning the identification of a minimal CTL epitope is included, and a newly developed and simple assay to measure TCR avidity.
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Affiliation(s)
- Nicholas Svitek
- Animal and Human Health, International Livestock Research Institute, Nairobi, Kenya
| | | | - Rosemary Saya
- Animal and Human Health, International Livestock Research Institute, Nairobi, Kenya
| | - Elias Awino
- Animal and Human Health, International Livestock Research Institute, Nairobi, Kenya
| | - Vish Nene
- Animal and Human Health, International Livestock Research Institute, Nairobi, Kenya
| | - Lucilla Steinaa
- Animal and Human Health, International Livestock Research Institute, Nairobi, Kenya.
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7
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Abkallo HM, Svitek N, Oduor B, Awino E, Henson SP, Oyola SO, Mwalimu S, Assad-Garcia N, Fuchs W, Vashee S, Steinaa L. Rapid CRISPR/Cas9 Editing of Genotype IX African Swine Fever Virus Circulating in Eastern and Central Africa. Front Genet 2021; 12:733674. [PMID: 34527025 PMCID: PMC8435729 DOI: 10.3389/fgene.2021.733674] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/10/2021] [Indexed: 11/17/2022] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of a contagious and fatal disease of domestic pigs that has significant economic consequences for the global swine industry. Due to the lack of effective treatment and vaccines against African swine fever, there is an urgent need to leverage cutting-edge technologies and cost-effective approaches for generating and purifying recombinant virus to fast-track the development of live-attenuated ASFV vaccines. Here, we describe the use of the CRISPR/Cas9 gene editing and a cost-effective cloning system to produce recombinant ASFVs. Combining these approaches, we developed a recombinant virus lacking the non-essential gene A238L (5EL) in the highly virulent genotype IX ASFV (ASFV-Kenya-IX-1033) genome in less than 2 months as opposed to the standard homologous recombination with conventional purification techniques which takes up to 6 months on average. Our approach could therefore be a method of choice for less resourced laboratories in developing nations.
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Affiliation(s)
- Hussein M Abkallo
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Nicholas Svitek
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Bernard Oduor
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Elias Awino
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Sonal P Henson
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Samuel O Oyola
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Stephen Mwalimu
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Nacrya Assad-Garcia
- Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, Rockville, MD, United States
| | - Walter Fuchs
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Sanjay Vashee
- Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, Rockville, MD, United States
| | - Lucilla Steinaa
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
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Bisimwa PN, Dione M, Basengere B, Mushagalusa CA, Steinaa L, Ongus J. Risk factors of African swine fever virus in suspected infected pigs in smallholder farming systems in South-Kivu province, Democratic Republic of Congo. J Vet Sci 2021; 22:e35. [PMID: 34056876 PMCID: PMC8170224 DOI: 10.4142/jvs.2021.22.e35] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/09/2021] [Accepted: 02/26/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND African swine fever (ASF) is an infectious viral disease of domestic pigs that presents as a hemorrhagic fever, and for which no effective vaccine is available. The disease has a serious negative social and economic impact on pig keepers. There is limited information on the potential risk factors responsible for the spread of ASF in South Kivu. OBJECTIVE The aim of this study was to determine the potential risk factors associated with ASF infection in suspected ASF virus (ASFV)-infected pigs. METHODS We sampled whole blood from 391 pigs. Additionally, 300 pig farmers were interviewed using a structured questionnaire. Viral DNA was detected by using the real-time polymerase chain reaction technique. RESULTS The majority of pigs sampled, 78% (95% confidence interval [CI], 74.4-82.6), were of local breeds. Over half, 60.4% (95% CI, 55.5-65.2), were female, and most of them, 90.5% (95% CI, 87.6-93.4), were adult pigs (> 1 year old). Viral DNA was detected in 72 of the 391 sampled pigs, indicating an overall infection rate of 18.4% (95% CI, 14.5-22.4). Multivariable logistic regression analysis revealed several risk factors positively associated with ASFV infection: feeding with swill in pen (odds ratio [OR], 3.8; 95% CI, 2.12-6.77); mixed ages of pigs in the same pen (OR, 3.3; 95% CI, 1.99-5.57); introduction of new animals to the farm (OR, 5.4; 95% CI, 1.91-15.28). The risk factors that were negatively (protective) correlated with ASFV positivity were the presence of male animals and the use of an in-pen breeding system. CONCLUSION Local pig farmers should be encouraged to adopt proper husbandry and feeding practices in order to increase the number of ASF-free farms.
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Affiliation(s)
- Patrick N Bisimwa
- Department of Animal Sciences and Production, Université Evangélique en Afrique, Bukavu 3323, Democratic Republic of Congo.,Department of Molecular Biology and Biotechnology, Pan African University Institute of Basic Sciences, Technology and Innovation, Nairobi 62000-00200, Kenya.
| | - Michel Dione
- International Livestock Research Institute, Dakar 24265, Senegal.,Department of Animal and Human Health, International Livestock Research Institute, Nairobi 30709, Kenya
| | - Bisimwa Basengere
- Department of Animal Sciences and Production, Université Evangélique en Afrique, Bukavu 3323, Democratic Republic of Congo
| | - Ciza Arsène Mushagalusa
- Department of Animal Sciences and Production, Université Evangélique en Afrique, Bukavu 3323, Democratic Republic of Congo
| | - Lucilla Steinaa
- International Livestock Research Institute, Dakar 24265, Senegal.,Department of Animal and Human Health, International Livestock Research Institute, Nairobi 30709, Kenya
| | - Juliette Ongus
- Department of Molecular Biology and Biotechnology, Pan African University Institute of Basic Sciences, Technology and Innovation, Nairobi 62000-00200, Kenya.,Department of Medical Laboratory Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi 62000-00200, Kenya
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Zhang J, Khazalwa EM, Abkallo HM, Zhou Y, Nie X, Ruan J, Zhao C, Wang J, Xu J, Li X, Zhao S, Zuo E, Steinaa L, Xie S. The advancements, challenges, and future implications of the CRISPR/Cas9 system in swine research. J Genet Genomics 2021; 48:347-360. [PMID: 34144928 DOI: 10.1016/j.jgg.2021.03.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/10/2021] [Accepted: 03/13/2021] [Indexed: 12/11/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) genome editing technology has dramatically influenced swine research by enabling the production of high-quality disease-resistant pig breeds, thus improving yields. In addition, CRISPR/Cas9 has been used extensively in pigs as one of the tools in biomedical research. In this review, we present the advancements of the CRISPR/Cas9 system in swine research, such as animal breeding, vaccine development, xenotransplantation, and disease modeling. We also highlight the current challenges and some potential applications of the CRISPR/Cas9 technologies.
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Affiliation(s)
- Jinfu Zhang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Emmanuel M Khazalwa
- Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Hussein M Abkallo
- Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Yuan Zhou
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Xiongwei Nie
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Jinxue Ruan
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Changzhi Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Jieru Wang
- Key Laboratory of Pig Molecular Quantitative Genetics of Anhui Academy of Agricultural Sciences, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, PR China
| | - Jing Xu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Xinyun Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Erwei Zuo
- Lingnan Guangdong Laboratory of Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, PR China.
| | - Lucilla Steinaa
- Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya.
| | - Shengsong Xie
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China; Animal and Human Health Program, Biosciences, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, PR China.
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10
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Bisimwa PN, Ongus JR, Steinaa L, Bisimwa EB, Bochere E, Machuka EM, Entfellner JBD, Okoth E, Pelle R. The first complete genome sequence of the African swine fever virus genotype X and serogroup 7 isolated in domestic pigs from the Democratic Republic of Congo. Virol J 2021; 18:23. [PMID: 33478547 PMCID: PMC7819171 DOI: 10.1186/s12985-021-01497-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/12/2021] [Indexed: 11/25/2022] Open
Abstract
Background African swine fever (ASF), a highly contagious hemorrhagic disease, affects domestic pigs in the Democratic Republic of Congo (DRC) where regular outbreaks are reported leading to high mortality rates approaching 100% in the affected regions. No study on the characteristics of the complete genome of strains responsible for ASF outbreaks in the South Kivu province of DRC is available, limited a better understanding of molecular evolution and spread of this virus within the country. The present study aimed at determining the complete genome sequence of ASFV strains genotype X involved in 2018–2019 ASF disease outbreaks in South Kivu province of DRC. Materials and methods Genomic DNA of a spleen sample from an ASFV genotype X-positive domestic pig in Uvira, during the 2018–2019 outbreaks in South Kivu, was sequenced using the Illumina HiSeq X platform. Obtained trimmed reads using Geneious Prime 2020.0.4 were blasted against a pig reference genome then contigs were generated from the unmapped reads enriched in ASFV DNA using Spades implemented in Geneious 2020.0.4. The assembly of the complete genome sequence of ASFV was achieved from the longest overlapping contigs. The new genome was annotated with the genome annotation transfer utility (GATU) software and the CLC Genomics Workbench 8 software was further used to search for any ORFs that failed to be identified by GATU. Subsequent analyses of the newly determined Uvira ASFV genotype X genome were done using BLAST for databases search, CLUSTAL W for multiple sequences alignments and MEGA X for phylogeny. Results 42 Gbp paired-end reads of 150 bp long were obtained containing about 0.1% of ASFV DNA. The assembled Uvira ASFV genome, termed Uvira B53, was 180,916 bp long that could be assembled in 2 contigs. The Uvira B53genome had a GC content of 38.5%, encoded 168 open reading frames (ORFs) and had 98.8% nucleotide identity with the reference ASFV genotype X Kenya 1950. The phylogenetic relationship with selected representative genomes clustered the Uvira B53 strain together with ASFV genotype X reported to date (Kenya 1950 and Ken05/Tk1). Multiple genome sequences comparison with the two reference ASFV genotype X strains showed that 130 of the 168 ORFs were fully conserved in the Uvira B53. The other 38 ORFs were divergent mainly due to SNPs and indels (deletions and insertions). Most of 46 multigene family (MGF) genes identified were affected by various genetic variations. However, 8 MGF ORFs present in Kenya 1950 and Ken05/Tk1 were absent from the Uvira B53 genome including three members of MGF 360, four of MGF 110 and one of MGF 100 while one MGF ORF (MGF 360-1L) at the left end of the genome was truncated in Uvira B53. Moreover, ORFs DP96R and p285L were also absent in the Uvira B53 genome. In contrast, the ORF MGF 110-5L present in Uvira B53 and Ken05/Tk1 was missing in Kenya 1950. The analysis of the intergenic region between the I73R and I329L genes also revealed sequence variations between the three genotype X strains mainly characterized by a deletion of 69 bp in Uvira B53 and 36 bp in Kenya 1950, compared to Ken05/Tk1. Assessment of the CD2v (EP402R) antigen unveiled the presence of SNPs and indels particularly in the PPPKPY tandem repeat region between selected variants representing the eight serogroups reported to date. Uvira B53 had identical CD2v variable region to the Uganda (KM609361) strain, the only other ASFV serogroup 7 reported to date. Conclusion We report the first complete genome sequence of an African swine fever virus (ASFV) p72 genotype X and CD2v serogroup 7, termed Uvira B53. This study provides additional insights on genetic characteristics and evolution of ASFV useful for tracing the geographical spread of ASF and essential for improved design of control and management strategies against ASF.
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Affiliation(s)
- Patrick N Bisimwa
- Institute of Basic Sciences, Technology and Innovation, Department of Molecular Biology and Biotechnology, Pan African University, Nairobi, Kenya. .,Department of Animal Science and Production, Université Evangélique en Afrique, P.O. Box 3323, Bukavu, Democratic Republic of Congo.
| | - Juliette R Ongus
- Institute of Basic Sciences, Technology and Innovation, Department of Molecular Biology and Biotechnology, Pan African University, Nairobi, Kenya.,Department of Medical Laboratory Sciences, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Lucilla Steinaa
- International Livestock Research Institute, Animal and Human Health, Nairobi, Kenya
| | - Espoir B Bisimwa
- Department of Animal Science and Production, Université Evangélique en Afrique, P.O. Box 3323, Bukavu, Democratic Republic of Congo
| | - Edwina Bochere
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Eunice M Machuka
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Jean-Baka Domelevo Entfellner
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Edward Okoth
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Roger Pelle
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100, Kenya.
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11
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Lacasta A, Mody KT, De Goeyse I, Yu C, Zhang J, Nyagwange J, Mwalimu S, Awino E, Saya R, Njoroge T, Muriuki R, Ndiwa N, Poole EJ, Zhang B, Cavallaro A, Mahony TJ, Steinaa L, Mitter N, Nene V. Synergistic Effect of Two Nanotechnologies Enhances the Protective Capacity of the Theileria parva Sporozoite p67C Antigen in Cattle. J Immunol 2021; 206:686-699. [PMID: 33419770 PMCID: PMC7851744 DOI: 10.4049/jimmunol.2000442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 12/03/2020] [Indexed: 11/19/2022]
Abstract
East Coast fever (ECF), caused by Theileria parva, is the most important tick-borne disease of cattle in sub-Saharan Africa. Practical disadvantages associated with the currently used live-parasite vaccine could be overcome by subunit vaccines. An 80-aa polypeptide derived from the C-terminal portion of p67, a sporozoite surface Ag and target of neutralizing Abs, was the focus of the efforts on subunit vaccines against ECF and subjected to several vaccine trials with very promising results. However, the vaccination regimen was far from optimized, involving three inoculations of 450 μg of soluble p67C (s-p67C) Ag formulated in the Seppic adjuvant Montanide ISA 206 VG. Hence, an improved formulation of this polypeptide Ag is needed. In this study, we report on two nanotechnologies that enhance the bovine immune responses to p67C. Individually, HBcAg-p67C (chimeric hepatitis B core Ag virus-like particles displaying p67C) and silica vesicle (SV)-p67C (s-p67C adsorbed to SV-140-C18, octadecyl-modified SVs) adjuvanted with ISA 206 VG primed strong Ab and T cell responses to p67C in cattle, respectively. Coimmunization of cattle (Bos taurus) with HBcAg-p67C and SV-p67C resulted in stimulation of both high Ab titers and CD4 T cell response to p67C, leading to the highest subunit vaccine efficacy we have achieved to date with the p67C immunogen. These results offer the much-needed research depth on the innovative platforms for developing effective novel protein-based bovine vaccines to further the advancement.
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Affiliation(s)
- Anna Lacasta
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya;
| | - Karishma T Mody
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ine De Goeyse
- Enzootic, Vector-borne and Bee Diseases, Sciensano, 1180 Brussels, Belgium.,Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium
| | - Chengzhong Yu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jun Zhang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - James Nyagwange
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Stephen Mwalimu
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Elias Awino
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Rosemary Saya
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Thomas Njoroge
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Robert Muriuki
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Nicholas Ndiwa
- Research Methods Group, International Livestock Research Institute, Nairobi 00100, Kenya; and
| | - Elisabeth Jane Poole
- Research Methods Group, International Livestock Research Institute, Nairobi 00100, Kenya; and
| | - Bing Zhang
- Department of Agriculture and Fisheries, Brisbane, Queensland 4102, Australia
| | - Antonino Cavallaro
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Timothy J Mahony
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Lucilla Steinaa
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
| | - Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Vishvanath Nene
- Animal and Human Health Program, International Livestock Research Institute, Nairobi 00100, Kenya
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12
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Bisimwa PN, Ongus JR, Tiambo CK, Machuka EM, Bisimwa EB, Steinaa L, Pelle R. First detection of African swine fever (ASF) virus genotype X and serogroup 7 in symptomatic pigs in the Democratic Republic of Congo. Virol J 2020; 17:135. [PMID: 32883295 PMCID: PMC7468181 DOI: 10.1186/s12985-020-01398-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/14/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND African swine fever (ASF) is a highly contagious and severe hemorrhagic viral disease of domestic pigs. The analysis of variable regions of African swine fever virus (ASFV) genome led to more genotypic and serotypic information about circulating strains. The present study aimed at investigating the genetic diversity of ASFV strains in symptomatic pigs in South Kivu province of the Democratic Republic of Congo (DRC). MATERIALS AND METHODS Blood samples collected from 391 ASF symptomatic domestic pigs in 6 of 8 districts in South Kivu were screened for the presence of ASFV, using a VP73 gene-specific polymerase chain reaction (PCR) with the universal primer set PPA1-PPA2. To genotype the strains, we sequenced and compared the nucleotide sequences of PPA-positive samples at three loci: the C-terminus of B646L gene encoding the p72 protein, the E183L gene encoding the p54 protein, and the central hypervariable region (CVR) of the B602L gene encoding the J9L protein. In addition, to serotype and discriminate between closely related strains, the EP402L (CD2v) gene and the intergenic region between the I73R and I329L genes were analyzed. RESULTS ASFV was confirmed in 26 of 391 pigs tested. However, only 19 and 15 PPA-positive samples, respectively, were successfully sequenced and phylogenetically analyzed for p72 (B646L) and p54 (E183L). All the ASFV studied were of genotype X. The CVR tetrameric repeat clustered the ASFV strains in two subgroups: the Uvira subgroup (10 TRS repeats, AAAABNAABA) and another subgroup from all other strains (8 TRS repeats, AABNAABA). The phylogenetic analysis of the EP402L gene clustered all the strains into CD2v serogroup 7. Analyzing the intergenic region between I73R and I329L genes revealed that the strains were identical but contained a deletion of a 33-nucleotide internal repeat sequence compared to ASFV strain Kenya 1950. CONCLUSION ASFV genotype X and serogroup 7 was identified in the ASF disease outbreaks in South Kivu province of DRC in 2018-2019. This represents the first report of ASFV genotype X in DRC. CVR tetrameric repeat sequences clustered the ASFV strains studied in two subgroups. Our finding emphasizes the need for improved coordination of the control of ASF.
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Affiliation(s)
- Patrick N. Bisimwa
- Department of Molecular Biology and Biotechnology, Pan African University, Institute of Basic Sciences, Technology and Innovation, Nairobi, Kenya
- Department of Animal Science and Production, Université Evangélique en Afrique, Bukavu, Democratic Republic of the Congo
| | - Juliette R. Ongus
- Department of Molecular Biology and Biotechnology, Pan African University, Institute of Basic Sciences, Technology and Innovation, Nairobi, Kenya
- Department of Medical Laboratory Sciences, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Christian K. Tiambo
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100 Kenya
- Centre for Tropical Livestock Genetics and Health (CTLGH), International Livestock Research Institute, Nairobi, Kenya
| | - Eunice M. Machuka
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Espoir B. Bisimwa
- Department of Animal Science and Production, Université Evangélique en Afrique, Bukavu, Democratic Republic of the Congo
| | - Lucilla Steinaa
- International Livestock Research Institute, Animal and Human Health, Nairobi, Kenya
| | - Roger Pelle
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Naivasha Road, P.O. Box 30709, Nairobi, 00100 Kenya
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Lacasta A, Mwalimu S, Kibwana E, Saya R, Awino E, Njoroge T, Poole J, Ndiwa N, Pelle R, Nene V, Steinaa L. Immune parameters to p67C antigen adjuvanted with ISA206VG correlate with protection against East Coast fever. Vaccine 2018; 36:1389-1397. [PMID: 29429808 PMCID: PMC5835154 DOI: 10.1016/j.vaccine.2018.01.087] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/18/2018] [Accepted: 01/28/2018] [Indexed: 11/25/2022]
Abstract
Three doses of p67C antigen generated stronger immune responses than two doses. Antibody titers and CD4+ T-cell proliferation correlated with protection against ECF. The number of doses could not be reduced from three to two without compromising the protection.
East Coast fever (ECF) is a lymphoproliferative disease caused by the tick-transmitted protozoan parasite Theileria parva. ECF is one of the most serious cattle tick-borne diseases in Sub-Saharan Africa. We have previously demonstrated that three doses of the C-terminal part of the sporozoite protein p67 (p67C) adjuvanted with ISA206VG confers partial protection against ECF at a herd level. We have tested the efficacy of two doses of this experimental vaccine, as reducing the vaccination regimen would facilitate its deployment in the field. We reconfirm that three antigen doses gave a significant level of protection to severe disease (46%, ECF score < 6) when compared with the control group, while two doses did not (23%). Animals receiving three doses of p67C developed higher antibody titers and CD4+ T-cell proliferation indices, than those which received two doses. A new panel of immune parameters were tested in order to identify factors correlating with protection: CD4+ proliferation index, total IgG, IgG1, IgG2 and IgM half maximal titers and neutralization capacity of the sera with and without complement. We show that some of the cellular and humoral immune responses provide preliminary correlates of protection.
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Affiliation(s)
- Anna Lacasta
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Stephen Mwalimu
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Elisabeth Kibwana
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Rosemary Saya
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Elias Awino
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Thomas Njoroge
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Jane Poole
- Research Methods Group, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi, Kenya.
| | - Nicholas Ndiwa
- Research Methods Group, International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi, Kenya.
| | - Roger Pelle
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi, Kenya.
| | - Vishvanath Nene
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
| | - Lucilla Steinaa
- Animal and Human Health (AHH), International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya.
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14
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Svitek N, Saya R, Awino E, Munyao S, Muriuki R, Njoroge T, Pellé R, Ndiwa N, Poole J, Gilbert S, Nene V, Steinaa L. An Ad/MVA vectored Theileria parva antigen induces schizont-specific CD8 + central memory T cells and confers partial protection against a lethal challenge. NPJ Vaccines 2018; 3:35. [PMID: 30245859 PMCID: PMC6134044 DOI: 10.1038/s41541-018-0073-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/22/2018] [Accepted: 07/02/2018] [Indexed: 01/03/2023] Open
Abstract
The parasite Theileria parva is the causative agent of East Coast fever (ECF), one of the most serious cattle diseases in sub-Saharan Africa, and directly impacts smallholder farmers’ livelihoods. There is an efficient live-parasite vaccine, but issues with transmission of vaccine strains, need of a cold chain, and antibiotics limit its utilization. This has fostered research towards subunit vaccination. Cytotoxic T lymphocytes (CTL) are crucial in combating the infection by lysing T. parva-infected cells. Tp1 is an immunodominant CTL antigen, which induces Tp1-specific responses in 70–80% of cattle of the A18 or A18v haplotype during vaccination with the live vaccine. In this study, human adenovirus serotype 5 (HAd5) and modified vaccinia Ankara (MVA) were assessed for their ability to induce Tp1-specific immunity. Both viral vectors expressing the Tp1 antigen were inoculated in cattle by a heterologous prime-boost vaccination regimen. All 15 animals responded to Tp1 as determined by ELISpot. Of these, 14 reacted to the known Tp1 epitope, assayed by ELISpot and tetramer analyses, with CTL peaking 1-week post-MVA boost. Eleven animals developed CTL with specific cytotoxic activity towards peripheral blood mononuclear cells (PBMC) pulsed with the Tp1 epitope. Moreover, 36% of the animals with a Tp1 epitope-specific response survived a lethal challenge with T. parva 5 weeks post-MVA boost. Reduction of the parasitemia correlated with increased percentages of central memory lymphocytes in the Tp1 epitope-specific CD8+ populations. These results indicate that Tp1 is a promising antigen to include in a subunit vaccine and central memory cells are crucial for clearing the parasite. A vaccine expressing parasitic proteins offers more convenient East Coast fever prophylaxis. Current vaccination for the cattle disease, caused by the parasite Theileria parva and a detriment to sub-Saharan African farmers, involves inconvenient injection with live parasites before antibiotic treatment (ITM). A collaboration led by Nicholas Svitek, of the Kenyan International Livestock Research Institute, designed a candidate to provoke cellular immune responses against the parasitic antigen Tp1—an ITM vaccine candidate. In tests on cattle, 93% created Tp1-targeting T cells, and 33% survived a lethal dose of T. parva. The East Coast fever reduction seen in animals in this research outperformed a recent study and was able to generate the same immune memory cells that ITM inspires to provide long-lasting protection. Future research might integrate more antigens with this Tp1 vaccine to provide more comprehensive protection.
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Affiliation(s)
- Nicholas Svitek
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Rosemary Saya
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Elias Awino
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Stephen Munyao
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Robert Muriuki
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Thomas Njoroge
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Roger Pellé
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Nicholas Ndiwa
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Jane Poole
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Sarah Gilbert
- 2The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive Oxford, OX3 7DQ UK
| | - Vishvanath Nene
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
| | - Lucilla Steinaa
- 1International Livestock Research Institute (ILRI), P.O. Box 30709, 00100 Nairobi, Kenya
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Steinaa L, Svitek N, Awino E, Njoroge T, Saya R, Morrison I, Toye P. Immunization with one Theileria parva strain results in similar level of CTL strain-specificity and protection compared to immunization with the three-component Muguga cocktail in MHC-matched animals. BMC Vet Res 2018; 14:145. [PMID: 29716583 PMCID: PMC5930519 DOI: 10.1186/s12917-018-1460-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 04/16/2018] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND The tick-borne protozoan parasite Theileria parva causes a usually fatal cattle disease known as East Coast fever in sub-Saharan Africa, with devastating consequences for poor small-holder farmers. Immunity to T. parva, believed to be mediated by a cytotoxic T lymphocyte (CTL) response, is induced following natural infection and after vaccination with a live vaccine, known as the Infection and Treatment Method (ITM). The most commonly used version of ITM is a combination of parasites derived from three isolates (Muguga, Kiambu 5 and Serengeti-transformed), known as the "Muguga cocktail". The use of a vaccine comprising several strains is believed to be required to induce a broad immune response effective against field challenge. In this study we investigated whether immunization with the Muguga cocktail induces a broader CTL response than immunization with a single strain (Muguga). RESULTS Four MHC haplotype-matched pairs of cattle were immunized with either the trivalent Muguga cocktail or the single Muguga strain. CTL specificity was assessed on a panel of five different strains, and clonal responses to these strains were also assessed in one of the MHC-matched pairs. We did not find evidence for a broader CTL response in animals immunized with the Muguga cocktail compared to those immunized with the Muguga strain alone, in either the bulk or clonal CTL analyses. This was supported by an in vivo trial in which all vaccinated animals survived challenge with a lethal dose of the Muguga cocktail vaccine stabilate. CONCLUSION We did not observe any substantial differences in the immunity generated from animals immunized with either Muguga alone or the Muguga cocktail in the animals tested here, corroborating earlier results showing limited antigenic diversity in the Muguga cocktail. These results may warrant further field studies using single T. parva strains as future vaccine candidates.
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Affiliation(s)
- Lucilla Steinaa
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Nicholas Svitek
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Elias Awino
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Thomas Njoroge
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Rosemary Saya
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
| | - Ivan Morrison
- The Roslin Institute, The University of Edinburgh, Midlothian, EH25 9RG UK
| | - Philip Toye
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya
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Nyagwange J, Nene V, Mwalimu S, Henson S, Steinaa L, Nzau B, Tijhaar E, Pelle R. Antibodies to in silico selected GPI-anchored Theileria parva proteins neutralize sporozoite infection in vitro. Vet Immunol Immunopathol 2018; 199:8-14. [PMID: 29678234 PMCID: PMC5956992 DOI: 10.1016/j.vetimm.2018.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/06/2018] [Accepted: 03/10/2018] [Indexed: 11/18/2022]
Abstract
East Coast fever (ECF) caused by Theileria parva kills cattle in East, Central and Southern Africa leading to significant economic losses. Vaccination is used as a control strategy against ECF and is presently dependent on deliberate infection with live sporozoites and simultaneous treatment with a long-acting oxytetracycline. Although effective, this method has serious limitations; the immunity is parasite strain specific and immunized cattle can become life-long asymptomatic carriers of the parasite, posing risk for the spread of the disease. In efforts to develop a subunit vaccine, the role of antibodies in the neutralization of T. parva sporozoites infection of host cells has been investigated and a circumsporozoite protein, p67, is able to induce such neutralizing antibodies. However, the p67 protein only protects a proportion of immunized cattle against T. parva challenge and such protection might be improved by inclusion of additional parasite antigens that neutralize sporozoite infection. In an attempt to identify such antigens, we searched the re-annotated T. parva genome for genes predicted to contain GPI anchor signals, since they are likely to be located on the cell surface, and expressed fragments of six of the selected genes in E. coli. The recombinant proteins were used to raise antisera in mice. Antisera to two proteins, TpMuguga_01g00876 and TpMuguga_01g00939, neutralized sporozoite infectivity to a high degree, while antisera to two additional proteins, TpMuguga_01g00095 and TpMuguga_04g00437, exhibited moderate neutralizing capacity. We conclude that these four antigens are potential vaccine candidates, which should be evaluated further in cattle.
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Affiliation(s)
- James Nyagwange
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya; Cell Biology and Immunology Group, Wageningen University, The Netherlands
| | - Vishvanath Nene
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya
| | - Stephen Mwalimu
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya
| | - Sonal Henson
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya
| | - Lucilla Steinaa
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya
| | - Benjamin Nzau
- International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya
| | - Edwin Tijhaar
- Cell Biology and Immunology Group, Wageningen University, The Netherlands
| | - Roger Pelle
- Biosciences Eastern and Central Africa - International Livestock Research Institute (BecA-ILRI) Hub, P. O. Box 30709, Nairobi, Kenya.
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Steinaa L, Svitek N, Awino E, Saya R, Toye P. Cytotoxic T lymphocytes from cattle sharing the same MHC class I haplotype and immunized with live Theileria parva sporozoites differ in antigenic specificity. BMC Res Notes 2018; 11:44. [PMID: 29343295 PMCID: PMC5773172 DOI: 10.1186/s13104-018-3145-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 01/09/2018] [Indexed: 12/04/2022] Open
Abstract
Objectives The objective of this study was to assess whether cytotoxic T cells (CTL) generated by the live vaccine, known as “ITM Muguga cocktail”, which is used for the cattle disease East Cost fever (ECF) in Sub-Saharan Africa, showed a broad reactivity against many different strains of the causative parasite Theileria parva. We also assessed whether immune responses were similar in cattle expressing the same MHC class I haplotypes. Results The antigenic specificity of CTL from MHC class I-matched cattle vaccinated with the Muguga cocktail were different. Three cattle of MHC class I haplotype A18, one A18/A19 and two haploidentical (A18v/A12) animals, showed differential recognition of autologous cells infected with a panel of T. parva isolates. This could have implications in the field where certain strains could break through the vaccine. Furthermore, neither of the haploidentical cattle recognized the CTL epitope (Tp1214–224), presented by the A18 haplotype, in contrast to the third animal, showing differences in immunodominance in animals of the same haplotype A18. This suggests that the CTL specificities following immunization with the Muguga cocktail can vary even between haploidentical individuals and that some parasite strains may break through immunity generated by the Muguga cocktail. Electronic supplementary material The online version of this article (10.1186/s13104-018-3145-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lucilla Steinaa
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100, Kenya.
| | - Nicholas Svitek
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Elias Awino
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Rosemary Saya
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100, Kenya
| | - Philip Toye
- International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100, Kenya
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Abstract
Flow cytometry, enzyme-linked immunospot (ELISpot) and cellular cytotoxicity assays are powerful tools for studying the cellular immune response towards intracellular pathogens and vaccines in livestock species. Lymphocytes from immunized animals can be purified using Ficoll-Paque density gradient centrifugation and evaluated for their antigen specificity or reactivity towards a vaccine. Here, we describe staining of bovine lymphocytes with peptide (p)-MHC class I tetramers and antibodies specific towards cellular activation markers for evaluation by multiparametric flow cytometry, as well as interferon (IFN)-γ ELISpot and cytotoxicity using chromium ((51)Cr) release assays. A small component on the use of immunoinformatics for fine-tuning the identification of a minimal CTL epitope is included.
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Affiliation(s)
- Nicholas Svitek
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya
| | - Evans L N Taracha
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya
| | - Rosemary Saya
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya
| | - Elias Awino
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya
| | - Vishvanath Nene
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya
| | - Lucilla Steinaa
- Vaccine Biosciences, International Livestock Research Institute, Att: Lucilla Steinaa, Vaccine Biosciences, 30709, 00100, Nairobi, Kenya.
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Mutua MP, Steinaa L, Shadrack MM, Muita GM. Activation of peroxisome proliferator-activated receptor gamma induces anti-inflammatory properties in the chicken free avian respiratory macrophages. J Anim Sci Technol 2015; 57:40. [PMID: 26594385 PMCID: PMC4653948 DOI: 10.1186/s40781-015-0073-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/15/2015] [Indexed: 11/10/2022]
Abstract
Background Activation of peroxisome proliferator activated receptor gamma (PPAR γ) in the alveolar macrophages (AM) by selective synthetic PPAR γ ligands, improves the ability of the cells to resolve inflammation. In birds, respiratory macrophages are known as free avian respiratory macrophages (FARM) and show distinct functional differences from AM. The effects of treating FARM with PPAR γ ligands are unclear. Methods FARM were harvested by lavage of chicken respiratory tract and their morphology assessed at microscopic level. The effects of PPAR γ agonists on the FARM in vitro viability, phagocytic capacity and proinflammatory cytokine (TNF-α) production were assessed. Results FARM had eccentric nucleus and plasma membrane ruffled with filopodial extensions. Ultrastructurally, numerous vesicular bodies presumed to be lysosomes were present. FARM treated with troglitazone, a selective PPAR γ agonist, had similar in vitro viability with untreated FARM. However, treated FARM co-cultured with polystyrene particles, internalized more particles with a mean volume density of 41 % compared to that of untreated FARM of 21 %. Further, treated FARM significantly decreased LPS-induced TNF-α production in a dose dependent manner. Conclusion Results from this study show that PPAR γ synthetic ligands enhance phagocytic ability of FARM. Further the ligands attenuate production of proinflammatory cytokines in the FARM, suggesting potential therapeutic application of PPAR γ ligands in the management of respiratory inflammatory disorders in the poultry industry.
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Affiliation(s)
- Mbuvi P Mutua
- Department of Zoological Sciences, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya
| | - Lucilla Steinaa
- International Livestock Research Institute, P.O Box 30709-00100, Nairobi, Kenya
| | - Muya M Shadrack
- Department of Zoology, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-0200, Nairobi, Kenya
| | - Gicheru M Muita
- Department of Zoological Sciences, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya
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Svitek N, Awino E, Nene V, Steinaa L. BoLA-6*01301 and BoLA-6*01302, two allelic variants of the A18 haplotype, present the same epitope from the Tp1 antigen of Theileria parva. Vet Immunol Immunopathol 2015; 167:80-5. [PMID: 26139380 DOI: 10.1016/j.vetimm.2015.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/28/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
Abstract
We have recently shown that the BoLA-A18 variant haplotype (BoLA-6*01302) is more prevalent than the BoLA-A18 haplotype (BoLA-6*01301) in a sample of Holstein/Friesian cattle in Kenya. These MHC class I allelic variants differ by a single amino acid polymorphism (Glu97 to Leu97) in the peptide-binding groove. We have previously mapped an 11-mer peptide epitope from the Theileria parva antigen Tp1 (Tp1214-224) that is presented by BoLA-6*01301. Crystal structure data indicates that Glu97 in the MHC molecule plays a role in epitope binding through electro-static interaction with a lysine residue in position 5 of the epitope, which also functions as an additional anchor residue. In contrast to expectations, we demonstrate that the amino acid substitution in BoLA-6*01302 does not divert the CTL response away from Tp1214-224. The two MHC molecules exhibit similar affinity for the Tp1 epitope and can present the epitope to parasite-specific CTLs derived from either BoLA allelic variants. These data confirm that this BoLA polymorphism does not alter Tp1 epitope specificity and that both allelic variants can be used for Tp1 vaccine studies.
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Affiliation(s)
- N Svitek
- Vaccine Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya.
| | - E Awino
- Vaccine Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya.
| | - V Nene
- Vaccine Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya.
| | - L Steinaa
- Vaccine Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya.
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Svitek N, Nzau B, Steinaa L, Nene V. A method to discriminate between closely related bovine major histocompatibility complex class I alleles by combining established PCR-SSP assays with RFLPs. ACTA ACUST UNITED AC 2015; 85:278-82. [PMID: 25789713 DOI: 10.1111/tan.12524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 11/22/2014] [Accepted: 01/19/2015] [Indexed: 12/23/2022]
Abstract
We have developed a polymerase chain reaction-sequence-specific primers-restriction fragment length polymorphism (PCR-SSP-RFLP) method to rapidly differentiate between the A18 and A18 variant (v) BoLA haplotypes and between A14 and A15/A15v BoLA haplotypes in Holstein/Friesian cattle. We used published SSP to PCR amplify BoLA alleles expressed in animals of known haplotype and exposed the amplicons to the restriction enzyme PvuII that was predicted to cut at a unique site in the middle of BoLA-6*01302 (A18v) and BoLA-1*00901 (A15) but not in BoLA-6*01301 (A18) or BoLA-1*02301 (A14) alleles. Whereas the method does not discriminate between the A15 and A15v haplotypes, as the BoLA-1*00902 allele associated with A15v also contains a PvuII site, we are interested in cattle of A18 and A14 haplotype for vaccine related studies. Our results also indicated that the BoLA-6*01302 (A18v) allele is much more abundant than BoLA-6*01301 (A18) in the cattle that we sampled.
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Affiliation(s)
- N Svitek
- International Livestock Research Institute (ILRI), Vaccine Biosciences, Nairobi 00100, Kenya
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Svitek N, Hansen AM, Steinaa L, Saya R, Awino E, Nielsen M, Buus S, Nene V. Use of "one-pot, mix-and-read" peptide-MHC class I tetramers and predictive algorithms to improve detection of cytotoxic T lymphocyte responses in cattle. Vet Res 2014; 45:50. [PMID: 24775445 PMCID: PMC4018993 DOI: 10.1186/1297-9716-45-50] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 04/07/2014] [Indexed: 11/10/2022] Open
Abstract
Peptide-major histocompatibility complex (p-MHC) class I tetramer complexes have facilitated the early detection and functional characterisation of epitope specific CD8+ cytotoxic T lymphocytes (CTL). Here, we report on the generation of seven recombinant bovine leukocyte antigens (BoLA) and recombinant bovine β2-microglobulin from which p-MHC class I tetramers can be derived in ~48 h. We validated a set of p-MHC class I tetramers against a panel of CTL lines specific to seven epitopes on five different antigens of Theileria parva, a protozoan pathogen causing the lethal bovine disease East Coast fever. One of the p-MHC class I tetramers was tested in ex vivo assays and we detected T. parva specific CTL in peripheral blood of cattle at day 15-17 post-immunization with a live parasite vaccine. The algorithm NetMHCpan predicted alternative epitope sequences for some of the T. parva CTL epitopes. Using an ELISA assay to measure peptide-BoLA monomer formation and p-MHC class I tetramers of new specificity, we demonstrate that a predicted alternative epitope Tp229-37 rather than the previously reported Tp227-37 epitope is the correct Tp2 epitope presented by BoLA-6*04101. We also verified the prediction by NetMHCpan that the Tp587-95 epitope reported as BoLA-T5 restricted can also be presented by BoLA-1*02301, a molecule similar in sequence to BoLA-T5. In addition, Tp587-95 specific bovine CTL were simultaneously stained by Tp5-BoLA-1*02301 and Tp5-BoLA-T5 tetramers suggesting that one T cell receptor can bind to two different BoLA MHC class I molecules presenting the Tp587-95 epitope and that these BoLA molecules fall into a single functional supertype.
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Affiliation(s)
- Nicholas Svitek
- International Livestock Research Institute (ILRI), P,O, Box 30709, Nairobi 00100, Kenya.
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Wendoh J, Waihenya R, Saya R, Awino E, Nene V, Steinaa L. Perforin Expression in <i>Theileria parva</i> Specific Cytotoxic T Cells Correlates with Cytotoxicity. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/oji.2014.43014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Koefoed K, Steinaa L, Søderberg JN, Kjær I, Jacobsen HJ, Meijer PJ, Haurum JS, Jensen A, Kragh M, Andersen PS, Pedersen MW. Rational identification of an optimal antibody mixture for targeting the epidermal growth factor receptor. MAbs 2011; 3:584-95. [PMID: 22123060 DOI: 10.4161/mabs.3.6.17955] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is frequently dysregulated in human malignancies and a validated target for cancer therapy. Two monoclonal anti-EGFR antibodies (cetuximab and panitumumab) are approved for clinical use. However, the percentage of patients responding to treatment is low and many patients experiencing an initial response eventually relapse. Thus, the need for more efficacious treatments remains. Previous studies have reported that mixtures of antibodies targeting multiple distinct epitopes are more effective than single mAbs at inhibiting growth of human cancer cells in vitro and in vivo. The current work describes the rational approach that led to discovery and selection of a novel anti-EGFR antibody mixture Sym004, which is currently in Phase 2 clinical testing. Twenty-four selected anti-EGFR antibodies were systematically tested in dual and triple mixtures for their ability to inhibit cancer cells in vitro and tumor growth in vivo. The results show that targeting EGFR dependent cancer cells with mixtures of antibodies is superior at inhibiting their growth both in vitro and in vivo. In particular, antibody mixtures targeting non-overlapping epitopes on domain III are efficient and indeed Sym004 is composed of two monoclonal antibodies targeting this domain. The superior growth inhibitory activity of mixtures correlated with their ability to induce efficient EGFR degradation.
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Steinaa L, Rasmussen PB, Gautam A, Mouritsen S. Breaking B-cell Tolerance and CTL Tolerance in three OVA-transgenic Mouse Strains Expressing Different Levels of OVA. Scand J Immunol 2008; 67:113-20. [DOI: 10.1111/j.1365-3083.2007.02045.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The aim of this study was to evaluate the effect of including a foreign T helper cell epitope in vaccines designed for generation of CTL against self-antigens and for inhibition of tumour growth. Two different vaccine designs were composed, a minimal epitope vaccine and a modified full length self-antigen, both based on OVA containing either a colinearily synthesized or an inserted Th-epitope, respectively. These vaccines were used for immunization of tolerant OVA transgenic mice (RIP-OVA(low)) and non-tolerant C57BL/6 mice. First, it was shown that transgenic mice were tolerant to OVA in the CD4 compartment. Secondly, only the vaccines containing the foreign Th-epitope and not the wild-type constructs were able to induce self-reactive CTL in the transgenic mice. Thirdly, these self-reactive CTL induced by the Th-epitope modified constructs also inhibited tumour growth in the OVA transgenic mice. Overall, these results demonstrate that inclusion of a foreign Th-epitope circumvents the tolerance in this OVA transgenic strain. In addition, these results show the importance of including strong T-cell help in cancer vaccines.
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Meijer PJ, Andersen PS, Haahr Hansen M, Steinaa L, Jensen A, Lantto J, Oleksiewicz MB, Tengbjerg K, Poulsen TR, Coljee VW, Bregenholt S, Haurum JS, Nielsen LS. Isolation of Human Antibody Repertoires with Preservation of the Natural Heavy and Light Chain Pairing. J Mol Biol 2006; 358:764-72. [PMID: 16563430 DOI: 10.1016/j.jmb.2006.02.040] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 02/13/2006] [Accepted: 02/14/2006] [Indexed: 10/25/2022]
Abstract
The humoral immune system in higher vertebrates is unique in its ability to generate highly diverse antibody responses against most pathogens as well as against certain malignancies. Several technologies have been developed to exploit this vast source of potentially therapeutic antibodies, including hybridoma technology, phage display and yeast display. Here, we present a novel, high-throughput technology (the Symplex Technology) for rapid direct cloning and identification of human antigen-specific high-affinity antibodies from single antibody-producing cells of immune individuals. The utility of the technology was demonstrated by isolation of diverse sets of unique high-affinity antibodies against tetanus toxoid and influenza virus from immunized volunteers. Hence, the Symplex Technology is a new method for the rapid isolation of high-affinity antibodies directly from humans.
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Affiliation(s)
- Per-Johan Meijer
- Symphogen A/S, Elektrovej, Building 375, DK-2800 Lyngby, Denmark
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Steinaa L, Rasmussen PB, Wegener AM, Sonderbye L, Leach DR, Rygaard J, Mouritsen S, Gautam AM. Linked Foreign T-Cell Help Activates Self-Reactive CTL and Inhibits Tumor Growth. J Immunol 2005; 175:329-34. [PMID: 15972665 DOI: 10.4049/jimmunol.175.1.329] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Transgenic mice expressing membrane-bound OVA under the rat insulin promoter, RIP-mOVA, has previously been suggested to display deletional tolerance toward the dominant CTL epitope, SIINFEKL, and provide an elegant model system to test the hypothesis that the lack of T cell help contributes to the tolerance. To understand how the CD8 tolerance is maintained in these mice, a set of neo-self-Ags, OVA, modified to contain a foreign Th peptide, were constructed and tested for their ability to induce CTL responses in RIP-mOVA mice. Immunization with these Th peptide-modified OVA molecules and not with the wild-type OVA induced self-reactive CTLs recognizing dominant CTL peptide, SIINFEKL. Importantly, immunization with the modified OVA constructs also prevented the growth of OVA-expressing tumors in transgenic mice. Since endogenous OVA Th peptides did not contribute toward breaking self CTL tolerance, these results also highlighted a very robust CD4 T cell tolerance toward OVA in RIP-mOVA mice that has not been previously described. These results therefore provide direct evidence that it is the tolerance in the CD4 Th cell compartment that helps maintain the CTL tolerance against self-Ag in these mice. Since the CTL tolerance can be broken or bypassed by foreign Th peptides inserted into a self Ag, potential of using this approach in generating effective therapeutic cancer vaccines is discussed.
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Dalum I, Butler DM, Jensen MR, Hindersson P, Steinaa L, Waterston AM, Grell SN, Feldmann M, Elsner HI, Mouritsen S. Therapeutic antibodies elicited by immunization against TNF-alpha. Nat Biotechnol 1999; 17:666-9. [PMID: 10404159 DOI: 10.1038/10878] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Tumor necrosis factor-alpha (TNF-alpha) is critically involved in the pathogenesis of several chronic inflammatory diseases. Monoclonal antibodies against TNF-alpha are currently used for the treatment of rheumatoid arthritis and Crohn's disease. This report describes a simple and effective method for active immunization against self TNF-alpha. This vaccination approach leads to a T-cell-dependent polyclonal and sustainable anti-TNF-alpha autoantibody response that declines upon discontinuation of booster injections. The autoantibodies are elicited by injecting modified recombinant TNF-alpha molecules containing foreign immunodominant T-helper epitopes. In mice immunized with such molecules, the symptoms of experimental cachexia and type II collagen-induced arthritis are ameliorated. These results suggest that vaccination against TNF-alpha may be a useful approach for the treatment of rheumatoid arthritis and other chronic inflammatory diseases.
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Affiliation(s)
- I Dalum
- M&E Biotech A/S, Hørsholm, Denmark
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30
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Spetzler JC, Meldal M, Meinjohanns E, Steinaa L, Mouritsen S, Bock K. Synthetic hFSH peptide constructs in the evaluation of previous studies on the hFSH receptor interaction. J Pept Sci 1997. [DOI: 10.1002/(sici)1099-1387(199711)3:6<397::aid-psc113>3.0.co;2-k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Spetzler JC, Meldal M, Meinjohanns E, Steinaa L, Mouritsen S, Bock K. Synthetic hFSH peptide constructs in the evaluation of previous studies on the hFSH receptor interaction. J Pept Sci 1997; 3:397-414. [PMID: 9467969 DOI: 10.1002/(sici)1099-1387(199711)3:6%3c397::aid-psc113%3e3.0.co;2-k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The human follicle-stimulating hormone (hFSH) belongs to a family of glycoprotein hormones which contains two non-identical subunits. This paper describes the design and synthesis of a series of synthetic hFSH constructs as putative ligands for the receptor. The design of these constructs is based on the crystal structure of hCG and molecular modelling using the program package Insight II/Discover. The designed constructs contain peptides ranging from 7 to 48 amino acid residues, disulphide bridges and glycan residues. All the synthetic peptides were synthesized by the stepwise solid-phase method using Fmoc chemistry. Two of the synthetic peptides contain the glycosylated amino acid. Asn(GlcNAc-GlcNAc) and both were prepared using fully protected glycosylated building blocks in the solid-phase peptide synthesis. The disulphide bridges were formed from acetamidomethyl-protected glycopeptides and peptides by a direct deprotection/oxidation method using thallium(III) trifluoroacetate. Mass spectroscopy and amino acid analysis were used for characterization of the synthetic hFSH glycopeptides and peptides. The synthetic hFSH constructs were tested for binding activity on FSH receptor assays but none showed improved binding properties compared with the naturally occurring hormone. It was finally demonstrated that non-related peptides showed non-specific binding at the same level as reported for specific peptides.
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Affiliation(s)
- J C Spetzler
- Department of Chemistry, The Carlsberg Laboratory, Valby, Denmark
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32
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Abstract
Monoclonal antibodies against a synthetic peptide (aa 138-152) from HIV-1 Nef protein were produced and characterized. Three hybridoma lines producing monoclonal antibodies (MAbs) against the synthetic peptide were generated by fusion between P3-X63 Ag8.653 myeloma cells and BALB/c splenocytes from mice immunized with the synthetic peptide coupled to keyhole limpet hemocyanin (KLH). The hybridomas were screened and selected by ELISA with the peptide coupled to bovine serum albumin (BSA) immobilized to the polystyrene surface and specificity for the peptide was confirmed by competitive ELISA with the peptide free in solution. The reactions of the MAbs with a 5-aa motif (WCYKL) included in the sequence were examined with synthetic peptides and two of the MAbs reacted with the motif. The recognitions of recombinant full-length Nef protein were also tested. One MAb reacted with the protein in both ELISA and dot blot, and one only in dot blot, whereas the last MAb did not recognize the recombinant full-length Nef protein.
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Affiliation(s)
- L Steinaa
- Department of Infectious Diseases, Hvidovre Hospital, Denmark
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Abstract
The HIV-1 transactivator protein Tat is essential for viral replication. Tat is released from infected cells and can be taken up and transactivate HIV-LTR in LTR-CAT transfected cell lines. The present study shows that the addition of monoclonal antibody to Tat in IIIB and MN-infected cultures reduces the HIV antigen production in a concentration dependent manner. These data suggest that external Tat might be important in the replication of HIV, exerting the effect in a paracrine fashion. Using 1 microgram/ml of anti-Tat antibody resulted in a decline of HIV antigen production to 33% and 45% of controls in IIIB and MN infected H9 cells, respectively. A time course experiment showed progressively increased inhibition of replication during 7 days of exposure to anti-Tat antibody, which could be due to increasing Tat concentration. The inhibitory effect of anti-Tat antibodies on the replication of HIV could play an important regulatory role during infection in vivo.
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Affiliation(s)
- L Steinaa
- Department of Infectious Disease, Hvidovre Hospital, University of Copenhagen, Denmark
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Werner T, Ferroni S, Saermark T, Brack-Werner R, Banati RB, Mager R, Steinaa L, Kreutzberg GW, Erfle V. HIV-1 Nef protein exhibits structural and functional similarity to scorpion peptides interacting with K+ channels. AIDS 1991; 5:1301-8. [PMID: 1768378 DOI: 10.1097/00002030-199111000-00003] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The persistent infection of human glial cells with HIV-1 is characterized by prominent expression of the Nef protein. In order to evaluate the possible role of Nef in the development of HIV-1-associated neurological disorders, we compared Nef with known neuroactive proteins. We found that HIV Nef shares sequence and structural features with scorpion peptides known to interact with K+ channels. Sequence similarity encompasses two distinct regions of scorpion peptides. Based on crystallography data, both regions in scorpion peptides cooperate in forming a common domain stabilized by ion pairs between charged amino-acid residues. Recombinant Nef protein, as well as a synthetic part of a scorpion channel active peptide (M10), reversibly increased the total K+ current of chick dorsal root ganglions in patch-clamp experiments without killing the cells. These results indicate that a region conserved in HIV Nef and scorpion peptides concurs in both structure and electrophysiological activity and suggest that Nef, like scorpion peptides, may affect neuronal cell function.
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Affiliation(s)
- T Werner
- GSF Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Germany
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