Related Experiment Video
Updated: Aug 19, 2026
Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells
Published on: August 5, 2016
Immunogenicity of major cell surface protein(s) of Brucella melitensis Rev 1
N K Mahajan1, R C Kulshreshtha, G Malik
1Department of Veterinary Epidemiology and Preventive Medicine, CCS Haryana Agricultural University, Hisar-125 004, India. mahajannk@hau.nic.in
Abstract:
Brucella melitensis Rev 1 organisms were salt-extracted and the cell surface proteins (BCSPs) were found to be mainly 39-42 kDa (group 2 porin proteins) in addition to 31.6, 32.5, 58.5 and 14.7 kDa proteins. DEAE-Sephadex anion-exchange column chromatography of BCSPs yielded fraction 1, which contained one major protein (39.8-42.0 kDa) and a minor protein (31.6 kDa). All these proteins were found to be immunogenic by Western blotting. Fraction 1 along with monophosphoryl lipid A and trehalose dicorynomycolate adjuvants as well as BCSPs alone induced significant (p < or = 0.05) protection in BALB/c mice. Both these immunizing agents produced almost equivalent protection to live B. melitensis Rev 1 vaccine at 15 and 30 days post challenge. Lymphocyte stimulation test as well as delayed-type hypersensitivity reaction revealed that both these preparations induced cell-mediated immune response. These preparations also induced humoral immune response as indicated by indirect ELISA. Neither of the immune responses was significantly less (p < or = 0.05) than that with live B. melitensis Rev 1 vaccine, except that their duration was short.
Insights
Brucella melitensis Rev 1 cell surface proteins (BCSPs) and a purified fraction induced significant protection in mice, comparable to the live vaccine. These BCSPs generated both cell-mediated and humoral immune responses.
Area of Science:
- Immunology
- Microbiology
- Vaccine Development
Background:
- Brucella melitensis Rev 1 is a live vaccine for brucellosis.
- Identifying protective antigens is crucial for developing subunit vaccines.
Purpose of the Study:
- To isolate and characterize immunogenic cell surface proteins (BCSPs) from Brucella melitensis Rev 1.
- To evaluate the protective efficacy of these proteins, alone and with adjuvants, against Brucella infection in mice.
Main Methods:
- Salt extraction and DEAE-Sephadex chromatography to isolate BCSPs.
- Western blotting to assess protein immunogenicity.
- Challenge studies in BALB/c mice to evaluate protection.
- Lymphocyte stimulation tests, delayed-type hypersensitivity reactions, and indirect ELISA to assess immune responses.
Main Results:
- BCSPs were identified, with a major fraction (39.8-42.0 kDa) and a minor protein (31.6 kDa) found to be immunogenic.
- BCSPs and Fraction 1, with or without adjuvants, induced significant protection in mice, comparable to the live B. melitensis Rev 1 vaccine.
- Both cell-mediated and humoral immune responses were induced by the preparations.
Conclusions:
- Purified Brucella melitensis Rev 1 cell surface proteins are promising candidates for subunit vaccine development.
- These protein-based immunogens elicit protective immunity and stimulate both cellular and humoral immune responses.
