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Decreased percentage of polymorphonuclear neutrophils in mouse peripheral blood after inoculation with material from
Abstract:
Mice inoculated with brain homogenates from multiple sclerosis (MS) cases showed marked changes in their leukocyte differential counts, with a decrease in per cent polymorphonuclear neutrophils (PMN) and an increase in the per cent lymphocytes. These changes were based upon an absolute decrease in the number of circulating PMN. The decrease in PMN percentages was apparent at 16 hr after infection and persisted for at least 11 months. The factor responsible for the decrease in PMN was (a) recoverable from 12 hr to 8(1/2) months after inoculation, (b) present in human brain homogenate at a concentration of 3 x 10(12), and (c) between 25 and 50 nm in diameter. Inoculation of 100 units of factor into mice and subsequent titration showed that the factor had undergone a net increase in the mouse of at least 10(9)-fold. The factor causing the PMN decrease was found in all MS material thus far tested: three brains, one spleen, three sera, and two cerebrospinal fluid (CSF) from nine cases of MS. The factor was not found in normal human material that included two brains, one spleen, two sera, and two CSF.
Insights
Researchers discovered a factor in multiple sclerosis (MS) brain homogenates that significantly decreases polymorphonuclear neutrophils (PMN) in mice. This factor, present in MS tissues, shows a substantial increase after inoculation, suggesting a potential role in MS pathogenesis.
Area of Science:
- Neuroimmunology
- Pathogen Discovery
Background:
- Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system.
- Leukocyte differential counts are crucial in diagnosing and monitoring inflammatory conditions.
Purpose of the Study:
- To investigate the effects of MS brain homogenates on leukocyte counts in mice.
- To identify and characterize a factor in MS tissue responsible for observed hematological changes.
Main Methods:
- Mice were inoculated with brain homogenates from MS cases and healthy controls.
- Leukocyte differential counts were analyzed over time.
- A specific factor was isolated, quantified, and its physical properties determined.
Main Results:
- MS homogenates caused a decrease in polymorphonuclear neutrophils (PMN) and an increase in lymphocytes in mice.
- This PMN-depleting factor was recoverable from 12 hours to 8.5 months post-inoculation.
- The factor, sized 25-50 nm, was present in MS brain, spleen, serum, and CSF but not in normal human tissues.
Conclusions:
- A specific, MS-associated factor induces significant changes in leukocyte counts, particularly a reduction in PMN.
- This factor demonstrates a substantial in vivo amplification in mice.
- The findings suggest a potential etiological or pathogenetic role for this factor in multiple sclerosis.