Heterogeneity of acid phosphatase activity in human polymorphonuclear leukocytes

Neutrophil function and oral disease

The pathological sequela of reduced neutrophil function in the oral cavity and the mechanisms behind dysfunction have added to our understanding of infectious diseases. Numerous examples have been given, and the overriding conclusion must be that any impairment of neutrophil function will lead to some degree of increased susceptibility to infection. Perhaps the tissue most sensitive to pathological changes in the oral cavity is the periodontium. In cases of severe neutrophil dysfunction, there is severe periodontal breakdown, but also in cases of "mild" neutrophil dysfunction, where there is no other infection, such as in individuals with LJP, there is severe periodontal breakdown. The molecular basis of neutrophil dysfunction is beginning to be understood in individuals with LJP, LAD, CGD, and AIDS. It is our hope that further research in this area will help to delineate the pathogenesis of these and other oral diseases.

On the acid phosphatase isoenzymes existing in American Leishmania promastigotes

1. Two partially purified acid phosphatase activities present in American Leishmania promastigote homogenates were characterized by biochemical methods. 2. One isoenzyme acts preferentially on p-nitrophenyl phosphate, is strongly inhibited by 30 mM alloxan, citrate, maleate, malonate and succinate, and strongly stimulated by 3 mM spermine. Its pI is 4.8. 3. The other isoenzyme acts preferentially on beta-glycerophosphate and is resistant to 30 mM alloxan, citrate, maleate, malonate and succinate and also to 3 mM spermine. Its pI is 5.7. 4. Both acid phosphatase isoenzymes have an optimum pH of 5.2, are tartrate-sensitive and strongly membrane-bound, as shown by differential centrifugation and density gradient equilibration. 5. Both isoenzymes were separated by using homogenates prepared in 2% Triton X-100, differential centrifugation, Sepharose 4B/CL-4B gel filtration, ion exchange chromatography and electrofocusing. After this procedure, they were still contaminated with several different proteins. 6. Purification was around 150-fold, with a 32% yield. 7. When these acid phosphatase activities were measured in total homogenates from 12 different Leishmania isolates, p-nitrophenyl phosphatase specific activity values were quite close; beta-glycerophosphatase-specific activity had around a 2-fold variation. 8. This variation was independent from taxonomic classification or infectivity of susceptible hosts.

Neutrophil function and oral disease

The pathologic sequela of reduced neutrophil function have been reviewed. In each case, the mechanism for the reduction in function has been elaborated when known. Special emphasis has been placed upon the pathologic changes in the oral cavity as a result of neutrophil dysfunction. Numerous examples have been given, and the overriding conclusion must be that any impairment of neutrophil function will lead to some degree of increased susceptibility to infection. Perhaps the tissue most sensitive to pathologic changes in the oral cavity is the periodontium. In cases of severe neutrophil dysfunction there is severe periodontal breakdown. But also in cases of "mild" neutrophil dysfunction, where there is no other infection, such as in individuals with LJP, there is severe periodontal breakdown. The molecular basis of neutrophil dysfunction is beginning to be understood in individuals with LJP. It is our hope that further research in this area will help to delineate the pathogenesis of periodontal diseases.

Acid phosphatase activity in the cytosol fraction of the breast cancer tissue

Acid phosphatase activity was studied in the cytosol fraction of breast cancer tissue. Serum, plasma, and extracts of leukocyte and platelet were used for reference. The breast cancer tissue fraction had an electrophoretic mobility intermediate to leukocyte-derived bands 2 and 4 and corresponding to the platelet-derived band 3. The enzymes derived from platelet and breast cancer tissue were both inhibited by L-tartrate and showed a similar pattern for preferred substrates. By contrast, the breast cancer tissue-derived enzyme was different from the enzyme fraction responsible for the elevated serum enzyme activity in some patients with disseminated breast cancer. The two fractions could be distinguished by electrophoretic mobility and tartrate sensitivity. These findings substantiate our previous report, which suggested that the fraction responsible for elevated serum enzyme activity in the course of breast cancer is not derived from cancer tissue. It is proposed that the osteolysis, resulting from bone metastases, may be responsible for elevated serum enzyme activity in this disease.

Two new, direct, and specific methods of acid phosphatase determination. National field trial

A national study of the new specific assays for prostatic acid phosphatase was conducted by the National Prostatic Cancer Project. The results of the study have confirmed that the counterimmunoelectrophoretic method is easily reproducible, highly specific, and sufficiently sensitive. Based on tests as performed by different institutions, the counterimmunoelectrophoretic (CIEP) method was also shown to have high reproducibility and was found to be of much greater sensitivity than the conventional biochemical methods for the detection of earlier stages of prostatic cancer. The national study of the radioimmunoassay (RIA) has shown that although being a highly sensitive method, it could not be readily distributed at this time from one specialized center. It requires highly specific, expensive technical assistance and is not yet available nationwide. CIEP is recommended at this time to be used as the preferred method in the evaluation and diagnosis of prostatic cancer. The value of counterimmunoelectrophoresis in detecting early prostatic cancer as a screening method is promising, but still under study.

Biochemical and morphological characterization of azurophil and specific granules of human neutrophilic polymorphonuclear leukocytes

Postnuclear supernates from homogenates of purified neutrophil polymorphonuclear leukocytes (PMNs) from human blood were fractionated by zonal sedimentation and isopycnic equilibration in sucrose gradients. The fractions were characterized biochemically by measuring protein content and the activities of eight enzymes. Selected fractions were further analyzed by electron microscopy. In both centrifugation systems, azurophil and specific granules could be resolved almost completely. Azurophil granules sediment three to four times faster than the specifics and have an average density of 1.23. They contain all the peroxidase of the cells, large portions of four lysosomal hydrolases, and about half of the total lysozyme, and therefore appear to be, in biochemical terms, very similar to the azurophil granules of rabbit PMNs. The specific granules, which have an average density of 1.19, contain the remaining half of the lysozyme but appear to be free of the other components of the azurophil granules, and of alkaline phosphatase. Isopycnic equilibration disclosed a minor lysosomal population, which strongly overlaps the specific granules, and made possible the identification of a membrane-fraction which is characterized by the presence of the thiol-sensitive acid 4-nitrophenyl phosphatase and of alkaline phosphatase.