IgG subclasses in human periodontal disease. II. Cytophilic and membrane IgG subclass immunoglobulins

Serum antibody responses in human periodontitis to cellular components of Capnocytophaga

Serum levels of IgM, IgG and IgG-antibody subclasses directed against cell envelopes, lipopolysaccharides and cytoplasmic fractions from Capnocytophaga sputigena, C. gingivalis and C. ochracea were examined in age-, race- and sex-matched periodontally healthy (n = 25) subjects and subjects with adult periodontitis (n = 25). The envelopes and cytoplasmic fractions were obtained by ballistic disintegration of the cells and ultracentrifugation. Cell envelopes were treated with DNase, RNase and lysozyme. Lipopolysaccharides were obtained by hot phenol-water extraction and treated with DNase and RNase. The relative levels of the antibodies in response to the cell fractions were measured by the streptavidinbiotin micro enzyme-linked immunosorbent assay. Both groups showed IgM and IgG antibodies to each fraction of the three Capnocytophaga species, but the frequency of positive IgG subclass responses varied. The IgG4 responses were lower than the other subclasses. There were no significant differences between the IgM antibody levels of the two groups. However, the adult periodontitis group had significantly lower IgG antibody titres to the cell envelopes and cytoplasmic fractions of C. gingivalis and C. ochracea, and lipopolysaccharide of C. gingivalis. These results were reflected in the depressed levels of IgG1 and/or IgG2 to these cellular fractions from the same bacterial species. The adult periodontitis group also showed a lower level of IgG1 to the cytoplasmic fractions of C. sputigena without any depression in the total IgG antibody level. There were no significant differences between the groups in IgG3 and IgG4 antibody levels to any of the cellular fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemotaxis of germinal center B cells in response to C5a

An infiltrate of B cells and plasma cells is characteristic of certain chronic inflammatory lesions. However, mechanisms involved in the local accumulation of these cells have not been established. Efforts to demonstrate that B cells from normal animals can migrate in response to inflammation-induced chemoattractants have been inconclusive. The objective of this study was to determine if murine germinal center (GC) B cells could respond chemotactically to a C5a gradient. On successive days after secondary immunization, draining lymph nodes were harvested and the activated GC B cells isolated. These GC B cells were placed in modified Boyden chambers, incubated for 3 h and the distance the leading front of cells migrated through the filters was determined. The results show that GC B cells migrated to factors in zymosan- and lipopolysaccharide-activated serum. The migratory response demonstrated distinct kinetics. Cells isolated between 2 to 4 days after secondary immunization migrated, whereas cells isolated at day 0 and beyond day 6 did not. Checkerboard analysis revealed that the migratory response was attributable to both chemokinesis and chemotaxis. Anti-C5 inhibited the migration of day-3 GC B cells implicating C5 in the migration mechanism. Studies using recombinant C5a established that this C5 fragment was chemotactically active. In conclusion, GC B cells generally were not chemotactically active. However, at a particular stage of maturation B cells in the GC become responsive to C5a as a chemotactic agent. Thus, B cells from normal animals may respond chemotactically, and C5a may play a role in recruitment of recently activated B cells into inflammatory sites.

The role of histopathology in the diagnosis and prognosis of periodontal diseases

The histological evaluation of surgical biopsies from affected tissues is a standard way of assessing pathological change and determining treatment in many diseases. In most forms of periodontal disease, however, this approach finds limited application. Here, we review what uses the histopathological approach has in the study and evaluation of the periodontal diseases. Current understanding of the changes in epithelial anatomy during pocket formation, the cellular composition and dynamics of the inflammatory infiltrate and the mechanisms of bone resorption and repair are reviewed from the perspective of the information available from microscopical investigation, including the uses and potential application of modern immunocytochemical methods to these questions. The usefulness of histological study of biopsy material is reassessed in the light of advances made in immunohistochemical techniques and their application to gingival inflammatory infiltrates and epithelia. Such techniques offer immediately valuable research opportunities with potential for diagnostic applications, noteably the recognition of phases of destructive activity and their differentiation from periods of effective host defence.

IgG subclasses in gingival crevicular fluid from active versus stable periodontal sites

Since IgG subclasses are common immunoglobulins associated with the periodontium and have different biological characteristics, these subclasses were measured in gingival crevicular fluid (GCF) from periodontally active (greater than or equal to 2 mm clinical attachment loss within three months of sample) versus clinically similar but stable or healthy sites. A sandwich enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies was performed to quantitate IgG subclass and albumin concentrations in serum and interproximal GCF samples from at least one each of the three disease categories from each of 20 periodontal maintenance patients. Although much variability existed among sites, mean IgG1 (p less than 0.05) and IgG4 (p less than 0.01) concentrations were higher in GCF from active periodontitis areas than stable sites, even though both had similar clinical characteristics. When IgG subclass concentrations were adjusted per mg albumin, both IgG1 and IgG4 levels in GCF from active sites were still significantly elevated over stable areas (p less than 0.05). Mean adjusted concentrations in GCF were generally greater than in serum, especially for IgG4 (active site GCF:serum = 24.2:1). GCF IgG4 concentrations may be useful as an indicator of the immunopathological changes which occur in active periodontitis.

Gingivitis

Gingivitis is caused by substances derived from microbial plaque accumulating at or near the gingival sulcus; all other suspected local and systemic etiologic factors either enhance plaque accumulation or retention, or enhance the susceptibility of the gingival tissue to microbial attack. Microbial species specifically associated with gingival health include Streptococcus sanguis 1, S. D-7, and Fusobacterium naviforme. Bacteria involved in the etiology of gingivitis include specific species of Streptococcus, Fusobacterium, Actinomyces, Veillonella, and Treponema and possibly Bacteroides, Capnocytophaga, and Eikenella. Microbial colonization and participation is sequential, with the complexity of the associated flora increasing with time. The pathogenesis has been separated into the initial, early, and established stages, each with characteristic features. The initial lesion is an acute inflammation which can be induced experimentally by application of extracts of plaque bacteria to normal gingiva. The early lesion is characterized by a lymphoid cell infiltrate predominated by T lymphocytes, characteristic of lesions seen at sites of cell-mediated hypersensitivity reactions. The early lesion can be induced by application of purified contact antigens to the gingival tissues of previously sensitized animals. As the clinical condition worsens, the established lesion appears, predominated by B lymphocytes and plasma cells. Established lesions may remain stable for indefinite periods of time, they may revert, or they may progress. Periodontal destruction does not result from the conversion of a predominantly T cell to a predominantly B cell lesion as has been suggested, but rather from episodes of acute inflammation. Clinical manifestations of gingivitis are episodic phenomena characterized by discontinuous bursts of acute inflammation. Most lesions are transient or persistent but not progressive. Attachment loss may precede alveolar bone loss and may occur without the manifestations of a concurrent or a precursor gingivitis. On the other hand, the evidence indicates that a portion of gingivitis lesions can and does progress to periodontitis. Gingivitis and the periodontal microflora differ in children and adults. Clinical signs of gingivitis either do not appear as plaque accumulates, or they are greatly delayed in children, and the inflammatory infiltrate consists mostly of T lymphocytes. The conversion to a B cell lesion does not appear to occur. The evidence supports the conclusion that gingivitis is a disease, and that control and prevention is a worthwhile goal and a health benefit.(ABSTRACT TRUNCATED AT 400 WORDS)

The nature of the inflammatory infiltrates in childhood gingivitis, juvenile periodontitis and adult periodontitis: immunocytochemical studies using a monoclonal antibody to HLADr

Routinely fixed and processed gingival biopsies from childhood gingivitis, juvenile periodontitis and chronic adult periodontitis patients have been stained immunocytochemically with a monoclonal anti HLADr antibody to aid in the identification and quantification of cell types in the inflammatory infiltrates. Using immunoperoxidase staining and morphological criteria, 9 cell types were quantified in 30 patients. Lesions in the 3 groups were found to differ widely both in size and composition. In the small childhood gingivitis lesions, most cells were small lymphocytes, over half of which were HLADr positive, whereas in juvenile periodontitis biopsies, well over half the infiltrate was plasma cells. The chronic adult periodontitis samples showed greater variability in composition between these 2 extremes, perhaps reflecting differences in disease activity. These results suggest that, when disease is quiescent, the volume of inflamed gingival connective tissue is small and is dominated by B-small lymphocytes, whilst on activation, the lesion increases in size and much of the B-lymphocyte population is transformed to plasma cells. This view corroborates the results of other workers with regard to juvenile periodontitis, but suggests a different interpretation of the quiescent lesion of childhood gingivitis from that current in the literature.

Dextran-induced inflammation and its effect on keratinized gingival epithelium in monkeys

The cell population present during dextran-induced inflammation and its effect upon induced keratinization of the sulcular epithelium was investigated in two young adult male Rhesus monkeys. Keratinization of the sulcus epithelium was induced by a combined regimen of scaling, an intravenous injection of achromycin and daily rubber cup prophylaxes. After keratinization was confirmed by means of biopsies, inflammation was induced either by injecting 200 microliters of a 5% dextran saline solution or by applying the solution topically on the marginal gingiva for 2 weeks. Clinical grade dextran, molecular weight 70,000, was used. Physiologic saline solution, either injected or topical, was also used. At the same time, the daily prophylaxes were continued. After the 2 weeks, gingival biopsies were taken from each tooth treated with the different regimens. One-half of each biopsy was routinely processed and stained with hematoxylin and eosin or Rhodamine B, while the other half was processed for and stained with alcoholic and aqueous PAS to detect dextran in tissues. Histologic evaluation was carried out in three areas: a crestal zone, a cervical zone and an oral gingival zone. An Inflammatory Index (II) was determined and the width and length of keratin were measured. Dextran, either topical or injected, produced mainly a chronic inflammatory response characterized by lymphocytes (30-35%), monocytes-macrophages (5-10%), plasma cells (10%), polymorphonuclear leukocytes (PMNs) (15%) and unidentified cells (35%). Conversely, the physiologic saline-induced inflammation showed PMNs (75%), lymphocytes (5%) and unidentified cells (20%). The II for injected areas was significantly higher than for those topically treated or for nontreated controls. However, the increased II did not affect the degree of keratinization achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibroblast cytotoxicity associated with plasma cells and lymphocytes in chronic periodontitis lesions in rats

INTERDENTAL PERIODONTITIS LESIONS in rats 20 to 27 months of age were found to contain large aggregations of plasma cells and lymphocytes. Fibroblasts in areas of dense immunocyte infiltration appeared damaged. The close juxtaposition of both plasma cells and lymphocytes to the altered fibroblasts suggests that a cytotoxic effect of immunocyte origin might be a significant element in connective tissue alteration in advanced periodontitis lesions in older rats. At the ultrastructural level, the damaged fibroblasts exhibited alteration of the nucleus, loss of cytoplasmic content including microfilaments and microtubules, swelling and degeneration of mitochondria and Golgi vesicles and cisternae. Dilation of the rough endoplasmic reticulum, including the perinuclear cisterna, along with vesiculation of the cytoplasmic membranes, suggests osmotic dysfunction in various cellular organelles.

Identification and distribution of immunocompetent cells in inflamed gingiva of human chronic periodontitis

Advanced human periodontitis is considered to be a B-cell lesion, but the cellular infiltrate contains several cell types, the distribution of which has not been determined. This experiment was designed to characterize and identify the immunocompetent cells on histological sections and in eluates from diseased human gingiva. Immunoglobulin-bearing cells were detected on histological sections by direct immunofluorescence with F(ab')2 antisera monospecific for human immunoglobulin G (IgG), IgA, or IgM. Plasma cells predominated in the central portion of the lamina propria, with the proportions positive for IgG, IgA, and IgM accounting for 65.2 +/- 9.5, 11.2 +/- 1.1, and 1.3 +/- 1.1% of the total infiltrating cells, respectively. T lymphocytes, identified by indirect immunofluorescence with monoclonal antibody (Leu-1) against human T cells, accounted for 29.3 +/- 10.0% of the total infiltrated cells. Most of the T cells were located subjacent to the pocket epithelium, but there were a few in the central lamina propria. Similarly, Fc receptor-bearing cells detected by EA rosetting and macrophages and monocytes detected by nonspecific esterase staining with alpha-naphthylbutyrate esterase were also localized to the region immediately subjacent to the pocket epithelium. Infiltrated cells were harvested from minced gingival tissue after digestion with collagenase, hyaluronidase, and DNase. The eluates contained 35.3 +/- 6.0% T lymphocytes, 30.0 +/- 14.9% Fc receptor-bearing cells, and 12.9 +/- 4.4% monocytes and macrophages. Whereas T gamma cells comprised 13.3 +/- 1.4% of peripheral blood T cells, they accounted for only 6.0 +/- 2.0% of the eluate T cells. In contrast, T mu cells accounted for 44.7 +/- 4.9% of the T cells in the eluates and 51.6 +/- 4.4% in the peripheral blood. The decreased proportion of T gamma cells in the gingiva may indicate a form of abnormal immune regulation concerned with T suppression of B-cell proliferation.

Evidence for local immunoglobulin synthesis in periodontitis

Periodontitis lesions are characterized by an increased plasma cell infiltrate. These cells have been shown to increase in number with the severity of the disease and in vitro synthesis of immunoglobulins by gingival plasma cells has been shown in tissue culture. This study correlated gingival and serum immunoglobulin levels to reflect the in vivo production of immunoglobulin. An electroimmunoassay technique was employed to determine serum and gingival IgG concentrations simultaneously relative to reference albumin levels in 16 patients with periodontitis. Results indicated that local immunoglobulin synthesis and accumulation occurs at the gingival site. Data obtained demonstrated that an average of 74.56% of the IgG found in gingiva from periodontitis patients was of local origin.

Quantitative distribution of inflammatory cells in recurrent aphthous stomatitis

Histologic quantitation of leukocytes in biopsies of recurrent aphthous ulcers revealed at least two morphologically-distinct inflammatory infiltrates. Lymphocytes were found consistently in pre-ulcerative lesions and in the expanding margins of the developing ulcer. In contrast, polymorphonuclear leukocytes predominated only in areas of frank ulceration.

Identification of collagenase in cultured blood mononuclear cells

Mononuclear cells isolated from peripheral whole blood were fractionated by erythrocyte-rosetting into T cells and non-T cell subpopulations which were tested for collagenase-producing capacity. Mononuclear cells and purified T lymphocytes, as well as non-T (B) lymphocytes, produced collagenase during serum-free culture. Removal of the macrophages from the non-T cells did not affect collagenase production by lymphocytes.

Human gingival lymphocytes. I. Methodology for the isolation of human gingival lymphocytes

Various methodologies were examined for the isolation of inflammatory cells from diseased human gingiva. The best recovery of viable gingival lymphocytes (gMNC) was achieved by a method which combined initial collagenase digestion followed by gentle teasing with an 18-gauge needle.

IgG subclasses in human periodontal disease: III. Serum concentrations of IgG subclass immunoglobulins and circulating immune complexes

No quantitative changes in serum IgG subclass concentrations could be correlated clinically with periodontal disease, despite evidence of restrictive IgG sublcass antibody responses in inflamed gingiva. Serum from periodontal patients also lacked circulating immune complexes.