IgG-bearing Cells Research Articles

New insight into the origin of IgG-bearing cells in the bursa of Fabricius.

The bursa of Fabricius is a primary lymphoid organ for B-cell development and gut-associated lymphoid tissue. After hatching, IgG-containing cells with reticular branches are found in the medulla of bursal follicles on frozen sections stained with anti-Cγ antibody, and IgM(+)IgG(+) B cells are detected in single-cell suspension of the bursa. IgG-containing cells in the medulla do not biosynthesize IgG and are composed of aggregated maternal IgG and environmental antigens. Then, those cells in the medulla are acknowledged as follicular dendritic cells retaining immune complexes. Also, it is presumed that IgM(+)IgG(+) B cells are generated by the attachment of immune complexes to IgM(+) bursal B cells because IgM(+)IgG(+) B cells are induced by antigen-dependent attachment of maternal IgG. Therefore, it is reasonable to suppose that immune complexes exert further B-cell differentiation in the medulla.

IgG4‐related inflammatory aneurysm of the aortic arch

IgG4-related sclerosing disease can occur in the cardiovascular system and some inflammatory abdominal aortic aneurysms have been shown to belong to IgG4-related sclerosing disease. Herein is reported a case of IgG4-related inflammatory aortic aneurysm of the aortic arch. A 71-year-old Japanese man was found to have an aneurysm of the aortic arch with maximum dimension of 5.5 cm. The surgically resected aneurysm wall had conspicuous fibrosclerotic changes, dense lymphoplasmacytic infiltration and occasional obliterative phlebitis in the adventitia; the thickness of the adventitia was 6.5 mm. Immunohistochemistry indicated numerous IgG4-positive plasma cell infiltrates; 84% of the IgG-bearing cells were IgG4 positive. The diagnosis of IgG4-related inflammatory aortic aneurysm of the aortic arch was made. Although previously reported IgG4-related inflammatory aortic aneurysms were confined to the abdominal aorta, the present case report demonstrates that IgG4-related inflammatory aortic aneurysm can occur in the aortic arch, thereby extending the spectrum of IgG4-related periaortitis. Further studies are needed to clarify the spectrum of IgG4-related sclerosing disease in the cardiovascular system.

Characterization of mast cell numbers and subtypes in biopsies from the gastrointestinal tract of dogs with lymphocytic-plasmacytic or eosinophilic gastroenterocolitis

It has been suggested but not proven that hypersensitivity type I reactions are involved in the pathogenesis of canine inflammatory bowel disease (IBD). The main effector cells in type I hypersensitivity reactions are mast cells (MCs). Canine MCs, as human MCs, can be subdivided into three subtypes according to their content of mast cell-specific proteases: tryptase (MC T), chymase (MC C), or tryptase and chymase bearing MCs (MC TC). In this study, numbers and subsets of mast cells were investigated in biopsies from the gastrointestinal tract of dogs with histopathologically confirmed lymphocytic-plasmacytic enteritis (LPE) ( n = 4), lymphocytic-plasmacytic colitis (LPC) ( n = 1) and eosinophilic gastroenterocolitis (EGE) ( n = 11). Paraffin sections of formalin-fixed samples from the stomach, small intestine (duodenum, jejunum, ileum) and colon were stained by using a metachromatic staining method (kresylecht-violet; KEV) and a combined enzyme histochemical and immunohistochemical technique for chymase and tryptase. Additionally, immunohistochemistry with antibodies against T cells (CD3), macrophages (myeloid/histiocyte antigen) and IgA, IgG and IgM bearing cells was conducted. Quantitative evaluation of mast cells and semiquantitative scoring of immunohistochemically stained cells were performed. Between the two histopathologically defined groups clear differences concerning mast cell numbers were detected. In most affected intestinal tissue locations of dogs with LPE/LPC a decrease in metachromatically (kresylecht-violet) stained granule-containing MCs and immunohistochemically stained MC T,C,TC was found. This reduction could be due to mast cell degranulation, a T helper cell 1 dominated reaction pattern or a “thinning out” due to increasing T cells, IgA and IgG bearing cells. Dogs with EGE displayed higher variability in mast cell numbers but most of the affected large and small intestinal locations had increased numbers of MCs. In these cases, T cells, IgA bearing cells and macrophages also increased. Increased numbers of MCs and eosinophils seen in the intestinal mucosa of dogs with EGE could indicate the presence of a type I hypersensitivity reaction (T helper cell 2 pattern) in response to dietary antigens. Changes in cell numbers occurred also in unaffected locations of dogs with LPE/LPC and EGE which showed reduced MC T,C,TC, increased KEV positive cells and partially increased leucocytes and macrophages.

Significant IgG-immunoreactivity of the spermatogonia of the germ cell-depleted testis after busulfan treatment

Busulfan kills spermatogonia with the exception of a few that are attached to the basal membrane of the seminiferous epithelium. In mice, these remaining spermatogonia reacted strongly to a goat anti-mouse IgG antibody. Spermatogonia in untreated testes rarely showed the same reactivity. Testicular IgG levels are normally minimal but increase markedly, 4 weeks after busulfan treatment before peaking at week 6. Laser scanning cytometry analysis of control and busulfan-treated testicular cells showed busulfan treatment increased the frequency of cells that were positive for not only IgG (from 0.67 ± 0.29 to 16.5 ± 3.8%) but also for α6-integrin, β1-integrin, GFR(-1 and/or Ret. Thus, an enrichment in putative male stem cells correlates with appearance of IgG expression. Confocal microscopy revealed busulfan-treated cells contained both IgG and GFRα-1, and that the initial surface IgG became intracellular in the weeks following busulfan treatment. The basement membranes of the seminiferous tubules were compromised by busulfan treatment as the mRNA expression profiles of various adhesion molecules in the basement membranes were altered and electron microscopy revealed severe damage. Serum IgG levels increased in a manner corresponding with the increase in testicular IgG levels. Thus, it appears that in the busulfan-treated testis, small breaches of the blood-testis barrier leak IgG that is then taken up by a significant number of spermatogonia. When the busulfan-resistant germ cells were transferred into recipient germ cell-depleted testes, they settled and repopulated the recipient testes. Thus, the IgG-bearing cells observed after busulfan treatment may be putative spermatogonial stem cells.

Presence of immunoglobulins and antigens in serum, lung and small intestine in Ascaris suum infected and immunised pigs

The immunodetection of local Ascaris suum antigens and local and systemic antibodies were analysed in pigs reinfected with eggs or immunized with the 14, 42 and 97 kilodalton (kDa) fractions from A. suum. Twenty-one Iberian pigs were divided in 7 groups of 3 pigs. Groups 1 and 2 were uninfected and challenge control groups, respectively. Groups 3 and 4 were infected weekly with increasing doses of A. suum eggs and Group 4 was additionally treated with pyrantel pamoate. Groups 5, 6 and 7 were immunised with the 14, 42 or 97 kDa fractions from adult worms, respectively. Groups 2–7 were challenged with 10,000 infective eggs. Animals of Groups 3 and 4 showed a pulmonary granulomatous reaction with moderate number of eosinophils and leukocytes, while Groups 5–7 presented higher number of cells, especially in animals immunized with the 42 kDa fraction. These immunized groups presented abundant deposition of Ascaris body fluid (BF) and body wall (BW) antigens as well as the 14 and 42 kDa fractions in the pulmonary and intestinal tissues, while lower deposition of antigens was observed in animals of Groups 3 and 4. The immunized pigs of Groups 5 and 6 showed the highest systemic IgG titres in serum and these antibodies were negatively correlated with the number of larvae recovered in the lungs, suggesting that the IgG response may have a protective function against the ascariosis. The highest concentrations of IgA-bearing cells were observed in animals of Groups 3 and 4 compared to the immunised pigs (Groups 5–7), suggesting that local IgA production may be involved in the protection against migrating larvae. The main localisations of IgA-bearing cells were the bronchial and peribronchial areas of lungs and the lamina propia of duodenum. Low numbers of local IgG-bearing cells were observed in all animals and no IgM-bearing cells were detected in the local tissues.

Immunoanalysis of IgG and IgM molecules on the surface of BLV infected cattle lymphocytes

The BLV-infected animals were divided into lymphocytotic (9 animals: BLV+PL+) and non lymphocytotic (11 animals: BLV+PL -). BLV-free animals formed a control group (7 animals: BLV-PL-). Flow cytometry immunofluorescence (FACS) and scanning electron microscopy (SEM) were used to evaluate the expression of IgG and IgM molecules on the surface of the lymphocytes of cattle infected with the bovine leukaemia virus (BLV). The percentage of IgM-bearing cells was significantly higher in the BLV+PL+ (75% and 74%) than in BLV+PL (43% and 50%) and BLV-PL (39% and 44%) groups by FACS and SEM respectively. The percentage of IgG-bearing cells was higher in BLV+PL+ (6%) and BLV+PL (8%) compared to BLV-PL (0.7%) determined by FACS and significantly higher in BLV+PL+ (62%) in relation to BLV+PL (17%) and BLV-PL (8%) groups ascertained by SEM. A significantly higher intensity of IgM expression was observed in the BLV+PL+ group by SEM and FACS; a higher intensity of IgG expression in BLV+PL+ group was detected only by SEM. The results suggest that FACS and SEM are complementary. The finding of significant differences in the expression of IgG molecules in BLV+ groups compared with BLV - animals confirms the sensitivity of the SEM method.

Lymphocyte Dynamic Patterns in Cattle during a Primary Infection with Cryptosporidium parvum

Changes in intraepithelial (IEL), lamina propria (LPL), and draining lymph node (LNL) lymphocytes were assessed in 9-day-old calves during primary infection with Cryptosporidium parvum and in similarly aged noninfected calves. A very low percentage of both CD4+ and CD8+ T cells were found in IEL and LPL of noninfected calves. In infected compared to controls, percentages of CD2+, CD3+, CD4+, and CD8+ T cells in IEL exhibited a significant increase (P < 0.05), whereas the percentage of IL2R+ increased and the percentage of IgG+ cells decreased, but neither of these changes were statistically significant. In LPL, percentages of CD2+, CD3+, CD8+, and IL2R+ T cells were increased in infected compared to noninfected calves, whereas the percentage of IgG-bearing cells decreased; but only the increase in CD3+, CD8+, and IL2R+ cells was significant (P < or = 0.05). In LNL only minimal changes were seen. In fact, the percentage of CD2+ T cells increased whereas the percentage of CD8+ T cells decreased, but neither of these differences was statistically significant. These findings indicate that T cells subsets in the ileal mucosa of naive neonatal calves are different than those of adult cattle, and that the immune response to C. parvum infection differs in ileal mucosa when compared to the regional lymph nodes.

Expression and quantification of IgG and IgM molecules on the surface of lymphocytes of cattle infected with bovine leukaemia virus

Immunogold-labelled antibodies were used with scanning electron microscopy ( SEM) and fluorescent-labelled antibodies were used with flow cytometry ( FACS) to evaluate the expression and quantity of IgG and IgM molecules on the surface of the lymphocytes of cattle infected with bovine leukaemia virus ( BLV). The BLV-infected animals were divided serologically and haematologically into groups with ( BLV +PL + ) and without ( BLV +PL − ) persistent lymphocytosis ( PL). The percentage of IgM-bearing cells was significantly higher in the BLV +PL + group than in the BLV −PL − and BLV +PL − groups by FACS. There was a significantly higher percentage of IgG-bearing cells in the BLV +PL + group than in the BLV −PL − and BLV +PL − groups by SEM, but no differences were found by FACS. A significantly higher intensity of IgM expression was observed in the BLV +PL + group by SEM. A higher intensity of IgG expression in some animals was detected only by SEM. An increase in the number of larger IgM cells was observed in the BLV +PL − and BLV +PL + groups by SEM. The SEM analysis was more sensitive than FACS in this experiment.

Primary biliary cirrhosis is associated with specific changes in liver IgG-bearing cell subpopulations

Background/Aims: The density of total IgG-bearing cells and the distribution of their subclasses were studied in the liver of patients with primary biliary cirrhosis. Methods: Immunohistochemistry and computerized image analysis were used to compare liver specimens from 18 patients with primary biliary cirrhosis and 28 with chronic hepatitis of different etiology. Results: The density of total IgG-bearing cells was similar in the two groups. However, in patients with primary biliary cirrhosis the proportion of IgG3-positive cells was significantly higher than in patients with chronic hepatitis (53±7% vs. 7.5±2.4%) ( p<10 −8). Conversely, IgG1-positive cells were significantly less prevalent in patients with primary biliary cirrhosis than in chronic hepatitis patients (27±6.9% vs. 68±7.2%, p<10 −8). Stratification of patients with primary biliary cirrhosis according to histology did not show any difference in the distribution of IgG subclasses associated with the progression of disease. Conclusion: These data suggest a pathogenetic role of local IgG3-bearing cells in primary biliary cirrhosis.

Moraxella (Branhamella) catarrhalis-induced experimental otitis media in the chinchilla.

Otitis media was introduced in chinchillas by direct transbullar inoculation with either viable or formalin-inactivated Moraxella (Branhamella) catarrhalis. Both groups of animals developed middle ear fluids (MEF) and severe inflammatory changes in the tubotympanum. Pure cultures of M. catarrhalis were recovered for up to 5 days after inoculation from those animals inoculated with viable bacteria. Significantly elevated anti-M. catarrhalis antibody titers were detected in post-inoculation sera and in MEF or bullar lavages, and an increased number of IgG-bearing cells was also observed in the tubotympanum of these animals. Control chinchillas inoculated with pyrogen-free sterile saline failed to show any signs of otitis media. Our data indicate that viable M. catarrhalis induce acute otitis media in the chinchilla but that the bacteria are rapidly eliminated from the middle ear, precluding its usefulness as a model to study acute otitis media. Moreover, the same concentration of nonviable organisms also induces severe inflammatory changes in the middle ear. These data indicate that the chinchilla may be a useful model for studying the role of nonviable M. catarrhalis or its cell wall components on the induction and persistence of inflammation in the middle ear.

Systemic-oral immunization with 56 kDa molecule of Giardia lamblia affords protection in experimental mice

Prior systemic-oral immunization of inbred mice with Giardia lamblia surface-associated antigen of molecular mass 56 kDa not only significantly blocked colonization but also resulted in elimination of G. lamblia trophozoites by 9–11 days following challenge. The colonization and multiplication of the trophozoites in unprotected animals were accompanied by a pronounced influx of suppressor T cells in intraepithelial or lamina propria of the small intestine and a significant decline in IgA-bearing plasma cells in the lamina propria. An induction of helper/inducer T cells in the intraepithelial and lamina propria and significant enhancement of IgA and IgG-bearing cells in the lamina propria of the small gut resulted in a decline, and eventual elimination, of the trophozoites from the gut. The completion of the immunization of animals with 56 kDa G. lamblia antigen resulted in: significant enhancement of helper/inducer T lymphocytes with no effect on suppressor T cells in the intraepithelial and lamina propria of the small gut; significant enhancement of IgA- and IgG-bearing plasma cells in lamina propria; and significant elevation of antibodies to 56 kDa G. lamblia antigen in the systemic circulation. The stimulation of such effector mechanisms in 56 kDa-immunized animals appears to result in failure of the trophozoites to get established, prevention of multiplication and earlier elimination from the gut. The data suggest that the 56 kDa molecule of G. lamblia immunoregulates the giardial infection.

Long-term effects of hysterectomy and bilateral oophorectomy on lymphoid tissue in female Lewis rats

The effects of ovariectomy, ovariohysterectomy and hysterectomy on morphologically demonstrable characteristics of lymphoid organs, peripheral white blood cells counts and antibody production against sheep red blood cells (SRBC) were studied in female Lewis rats. Removal of ovaries induced enlarged thymus weight and cellularity. No differences were observed between the groups in spleen weight, while hysterectomy together with ovariectomy influenced relative uterus draining lymph node (UDLN) weight. The percent numbers of pan T, helper T lymphocytes, cytotoxic/suppressor T cells and IgG bearing cells (B lymphocytes) of all investigated organs showed only moderate changes caused by the surgical procedures. In contrast, removal of ovaries generated elevated total leukocyte and lymphocyte counts in peripheral blood. The changes in absolute blood lymphocyte counts were accompanied by similar variations in absolute T and B lymphocyte numbers. Ovariohysterectomy had slightly greater effects on these parameters than ovariectomy alone. In addition, ovaries and uterus had only moderate influences on systemic immune responses toward SRBC. In conclusion, the present results indicate that the removal of ovaries and uterus can modify morphological characteristics of lymphoid organs and peripheral blood but antibody production showed only moderate changes caused by the surgical procedures.

内リンパ嚢局所免疫反応による実験的内リンパ水腫の機序 免疫組織学的検討

Secondary endolymphatic sac (ES) immune response against keyhole limpet hemocyanin (KLH) were immunohistochemically investigated in guinea pigs by analysing the distribution of IgG and C3 complement in the inner ear over a 4-week period. After systemic sensitization with KLH and Freund's adjuvant, KLH was inoculated into the right ES by trans-cranial approach. KLH was found in the ES immediately after KLH challenge and then disappeared on the 7th day. On the 2nd and 3rd day moderate endolymphatic hydrops and a massive cell infiltrations within the ES were observed, and they gradually decreased their severity with time. Diffuse stainings with IgG and C3 were found in the ES, the epithelial and subepithelial regions of the vestibule. Similar findings were obtained in the spiral ligament and the hair cells after antigen challenge. IgG bearing cells were detected within the endolymphatic sac alone. Our results suggested that endolymphatic hydrops may be produced by the imbalance of in-out flow of the endolymph and the immunologically mediated inflammation through IgG-complement system.

Evaluation of IgG-bearing cells in the liver by means of immunoperoxidase method and computerized image analysis

Evaluation of IgG-bearing cells in the liver by means of immunoperoxidase method and computerized image analysis

Immunological state of adult germfree miniature Minnesota pigs.

Fundamental hematological and immunological data were obtained on sexually mature germfree miniature pigs fed, after the milk diet period, with cereal-type diet sterilized by gamma-radiation, and were compared with data of control conventional animals. Germfree adult pigs had a lower count of peripheral blood leukocytes with a lower percentage of neutrophil granulocytes and without any younger forms, a lower total serum protein level with a negligible amount of gamma and alpha 2 globulin fractions and a higher serum albumin and beta globulin level. In the mesenteric lymph nodes and in spleen, surface IgA-bearing cells predominated over surface IgG-bearing cells. Also a large amount of IgA-containing cells was found in the intestinal lamina propria, where the IgG cells were present in a negligible amount. IgM cells were the most frequent surface isotype in peripheral blood. The count of blood T lymphocytes was more than doubled.

Serial immunologic and histopathologic studies in the treatment of necrotizing fasciitis with combined immunodeficiency by a bovine thymic extract (Thymostimulin)

A 25-day-old Chinese female baby developed necrotizing fasciitis (NF) with indurated erythematous patches with superficial necrosis over two thirds of the back. Skin cultures of the lesions yielded Streptococcus pyogenes, enterococcus, Pseudomonas aeruginosa, and Candida species. The patient had lymphopenia with low T cells and T cell subsets. The lymphoproliferative response to mitogen and macrophage migration (MIF) production were also poor. Her lymphocytes were unable to produce IgG in vitro. Also, IgG bearing cells were not demonstrable. The initial lymph node biopsy demonstrated an absence of follicular formation and depletion of lymphocytes in both thymic-dependent and thymic-independent areas. Five weeks after bovine thymic extract (Thymostimulin) treatment, a second lymph node biopsy demonstrated germinal centers containing IgG bearing cells. Three weeks later, a third lymph node biopsy showed germinal centers with cuffs of lymphocytes. Differentiation of the cortex and medulla of the node was demonstrated. IgG was also detectable in an in vitro Ig synthesis study. The total T cells, T cell subsets, lymphoproliferative response MIF production also increased gradually after Thymostimulin treatment. This investigation demonstrated the therapeutic effectiveness of Thymostimulin in NF with underlying combined immuno-deficiency, both serious and frequently fetal diseases, by the histologic and immunologic reconstitution of T and B cell function.

Dietary Fatty Acid Modulation of Murine B-Cell Responsiveness

These studies were designed to determine how dietary fat concentration and degree of saturation influence antibody response to a T-dependent antigen. In vivo fatty acid manipulation did not affect the total number of nucleated spleen cells or IgM or IgG-bearing cells. After primary immunization with sheep red blood cells (SRBC), the number of splenic IgM and IgG antigen specific plaque-forming cells (PFC) was lower in mice fed a diet containing a high level of polyunsaturated fat (PUF, safflower oil) than in mice fed a diet containing minimal essential fatty acids (EFA, 0.5% corn oil). Mice fed a high level of saturated fat (SF, coconut oil) exhibited greater IgM PFC responses than the control. After secondary immunization, the number of IgG-producing cells followed a similar response pattern. These differences were also reflected in the serum anti-SRBC IgM and IgG levels as determined by solid-phase radioimmunoassay. Although the level of linoleic acid in whole lymphocytes has been previously reported to change in direct relation to the serum fatty acid level, no differences in the fatty acid composition of isolated lymphocyte plasmalemma were observed. Thus, changes in the number of antibody-forming cells appear to be inversely related to the levels of linoleic acid in other cell compartments. Fluorescence polarization measurements of the lipopholic probe, 1, 6-diphenyl-1,3,5-hexatriene (DPH), in the purified lymphocyte plasmalemma from mice fed a diet high in PUF indicated an increase in mobility. Polarization values for lymphocyte plasmalemmas from mice receiving diets high in SF were not significantly different from the controls. We conclude that dietary fat modulation of splenic B-cell responses was manifested through changes in the number of cells producing antibody and level of antibody produced, not through total splenic B-cell numbers. This B-cell response can be modified, depending upon the fatty acids available to the cell, and may be related to differential effects upon plasma membrane structure.

Surface IgG-bearing cells retain the capacity to secrete IgM.

Our previous studies indicated that a large proportion of surface IgG+-primed B cells give rise to clones secreting IgM antibodies. Due to the implications of this result relative to molecular mechanisms of class switching, it was important to document that the surface IgG had been endogenously synthesized by the surface IgG+ cells and was not present as a result of cytophilic IgG. Therefore, spleen cells from immunized mice were treated sequentially with anti-immunoglobulin and protease which removed greater than 99% of surface immunoglobulin. After overnight incubation to allow resynthesis of surface immunoglobulin, the treated cells were sorted for surface IgG-bearing cells and were transferred to carrier-primed, irradiated adoptive recipients for analysis in the splenic focus assay. It was found that the majority of antibody-secreting clones derived from these surface IgG+ B cells still synthesized IgM. These data are discussed relative to current concepts of molecular mechanisms of immunoglobulin class switching.

Immunohistological Study with Peroxidase‐Antiperoxidase Staining in a Case of Generalized Prepubertal Periodontitis

A case of prepubertal periodontitis was observed and examined immunohistologically with peroxidase-antiperoxidase staining. The patient was an 11-year and 7-month-old Japanese girl, well-developed and well-nourished. Her parents were first cousins. Her chief complaint was the loosening and loss of the permanent teeth. There was a similar history of primary dentition. Her remaining permanent teeth were loosened with severe alveolar bone loss, but calculus deposit was minimal. Significantly, there was no palmar-plantar hyperkeratosis. General examination showed normal data except for the increase of the immunoglobulin concentrations. In neutrophil function tests chemotaxis was depressed, although phagocytosis, random migration and superoxide production were within normal limits. Histologically, neutrophils were seen in the gingival tissue and other findings were also similar to those of adult periodontitis. In immunohistological examination, IgG-bearing cells which mostly consisted of plasma cells predominated in the lesion. Considering the past history, the immunodeficiency and the absence of palmar-plantar hyperkeratosis, the case was diagnosed as prepubertal periodontitis.

Changes in conjunctival lymphocyte populations induced by oral immunization with Chlamydia trachomatis.

The populations of lymphocyte subsets in the conjunctiva were assessed in monkeys enterically immunized with different preparations of Chlamydia trachomatis prior to ocular challenge. Subsets were identified in immunohistochemical studies employing cross-reactive anti-human monoclonal and polyclonal reagents. Ocular challenge of orally immunized animals resulted in more equal numbers of T-helper and T suppressor/cytotoxic cells, compared to the higher proportion of TS seen in naive monkeys. TH:TS/CTL ratios of 1.0-2.0 and 0.1-0.5 respectively were observed. Orally immunized monkeys also showed proportionately more IgA- and IgG-bearing cells and less IgM-bearing cells. B cells of each class were commonly seen immediately under the epithelial basement membrane. Although oral immunization induced a number of changes in the proportions and distribution of lymphocyte subsets which subsequently appeared in the conjunctiva, these changes were not correlated with disease outcome, except for the appearance of increased proportions of follicular IgA-bearing cells in partially protected monkeys.