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Interactions of Mycoplasma hyopneumoniae membranes with porcine lymphocytes
Abstract:
Nonspecific mitogenicity of Mycoplasma hyopneumoniae membranes for blood lymphocytes (BL) and bronchial lymph node lymphocytes (LNL) from swine was investigated. Additionally, the influence of respiratory tract exposure to the same membrane preparation on responsiveness of these cells was evaluated. Membranes utilized in lymphocyte transformation tests and for inoculation of swine were prepared by osmotic lysis of mycoplasma cells. Conventionally reared and cesarean-derived, colostrum-deprived swine were given membranes intratracheally and responses of BL and LNL to membranes were assessed from postinoculation day 0 to 14. Utilizing a stimulation index of 3 as the cutoff, heated (56 C) M hyopneumoniae membranes exerted moderate nonspecific stimulation of BL 11 of 12 times when BL were collected from normal (control or preinoculation) swine. Similarly, LNL from conventionally reared and control groups of swine were stimulated nonspecifically 4 of 6 times by the same membrane preparations. Exposure of the respiratory tract to membranes appeared to have no influence on stimulation responses of BL at postinoculation days 6 or 13, whereas moderate to marked increases in responsiveness of LNL were detected when collected at necropsy on postinoculation days 7 or 14. These findings indicated that compartmentalization of lymphocyte sensitization in the bronchial lymph nodes resulted from respiratory tract exposure to mycoplasmal membranes. Results obtained confirm that M hyopneumoniae has a moderate nonspecific stimulatory effect on porcine lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Mycoplasma hyopneumoniae membranes nonspecifically stimulate swine lymphocytes. Respiratory tract exposure enhanced lymphocyte sensitization in bronchial lymph nodes, but not blood lymphocytes.
Area of Science:
- Veterinary immunology
- Microbiology
- Swine respiratory disease
Background:
- Mycoplasma hyopneumoniae is a significant swine respiratory pathogen.
- Understanding its immunomodulatory effects is crucial for disease control.
Purpose of the Study:
- To investigate the nonspecific mitogenicity of M. hyopneumoniae membranes on swine lymphocytes.
- To evaluate the impact of respiratory tract exposure to these membranes on lymphocyte responsiveness.
Main Methods:
- Preparation of M. hyopneumoniae membranes via osmotic lysis.
- Lymphocyte transformation tests using blood lymphocytes (BL) and bronchial lymph node lymphocytes (LNL).
- Intratracheal inoculation of swine with membranes and assessment of lymphocyte responses.
Main Results:
- Heated M. hyopneumoniae membranes showed moderate nonspecific stimulation of BL and LNL in control swine.
- Respiratory exposure enhanced LNL responsiveness significantly by days 7-14 post-inoculation.
- No significant influence on BL responsiveness was observed after respiratory exposure.
Conclusions:
- M. hyopneumoniae membranes possess moderate nonspecific mitogenic activity for porcine lymphocytes.
- Respiratory tract exposure leads to compartmentalized lymphocyte sensitization in bronchial lymph nodes.