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The interaction in vitro between polymorphonuclear leukocytes and mycoplasma
Abstract:
The interaction, between mycoplasma (PPLO) and human or rabbit leukocytes was examined in vitro. Upon incubation of M. hominis or M. arthritidis for 2 hr with rabbit peritoneal exudate granulocytes or leukocytes from human peripheral blood, no killing of mycoplasma was observed either in the presence or absence of type-specific antiserum. However, (14)CO(2) production from glucose-1-(14)C was stimulated up to 10-fold in the presence of live or heat-killed PPLO. The extent of stimulation depended upon the number of organisms and the presence of type-specific antiserum. The stimulation of (14)CO(2) production seems not because of tight adherence of PPLO to the leukocytes, since PPLO were quantitatively recovered in the medium after sedimenting the granulocytes. The enhanced conversion of medium lysolecithin to cellular lecithin that accompanies phagocytosis of polystyrene particles was significantly reduced when PPLO were also present. Mycoplasma alone elicited no stimulation of lecithin formation. Killing of E. coli, a microorganism readily engulfed and killed by leukocytes in vitro, was diminished when the leukocytes were preincubated with mycoplasma. These findings indicate that M. hominis and M. arthritidis are not ingested by granulocytes to any detectable extent, but that these organisms affect the leukocytes' metabolism and also impair phagocytosis of E. coli.
Insights
Mycoplasma (PPLO) does not kill leukocytes, but stimulates their metabolism and impairs their ability to engulf and kill E. coli. These findings reveal mycoplasma
Area of Science:
- Immunology
- Microbiology
- Cell Biology
Background:
- Leukocytes are critical immune cells involved in pathogen defense.
- Mycoplasma species are common human and animal pathogens.
- Understanding host-pathogen interactions at the cellular level is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the in vitro interaction between Mycoplasma (PPLO) and leukocytes.
- To determine if mycoplasma is ingested or killed by leukocytes.
- To assess the impact of mycoplasma on leukocyte metabolism and phagocytic function.
Main Methods:
- Incubation of human or rabbit leukocytes with Mycoplasma hominis or M. arthritidis.
- Measurement of (14)CO(2) production from glucose-1-(14)C to assess metabolic activity.
- Quantification of mycoplasma recovery after leukocyte sedimentation.
- Assessment of lysolecithin to lecithin conversion during phagocytosis.
- Evaluation of leukocyte-mediated killing of E. coli.
Main Results:
- No killing of mycoplasma by leukocytes was observed, with or without antiserum.
- Mycoplasma significantly stimulated leukocyte (14)CO(2) production, dependent on organism number and antiserum.
- Mycoplasma did not adhere tightly to leukocytes.
- Mycoplasma impaired the enhanced lecithin formation associated with phagocytosis.
- Preincubation with mycoplasma diminished leukocyte-mediated killing of E. coli.
Conclusions:
- Mycoplasma species are not significantly ingested or killed by granulocytes.
- Mycoplasma affects leukocyte metabolism, indicated by increased glucose metabolism.
- Mycoplasma impairs the phagocytic capacity of leukocytes, hindering their ability to kill other bacteria like E. coli.