Immunoglobulins In Response Research Articles

Functional and Phenotypic Characterization of Human B Lymphocyte Subsets Isolated by Unit Gravity Sedimentation

We report the use of unit gravity sedimentation with a CelSep apparatus to generate two volumetrically similar but functionally and phenotypically distinct subsets of human peripheral blood B cells. One subset, comprised of small B lymphocytes, underwent a significant size change in response to anti-mu, proliferated synergistically to low concentrations of anti-mu plus B cell growth factor (BCGF) or phorbol myristate acetate plus BCGF, and could be induced to produce immunoglobulin in response to pokeweed-mitogen-derived T-lymphocyte-replacing factors. These cells were primarily sIg+, B1+, B2+, and were virtually free of monocytes (less than 0.01%). Unlike these resting B lymphocytes, the large cells proliferated directly to BCGF, without displaying synergy with anti-mu. These cells displayed very little B2 (less than 7%), did not increase in volume in the presence of anti-mu, and made more immunoglobulin in response to TRF than the small resting B lymphocytes. However, neither population synthesized immunoglobulin spontaneously. This technique, which is highly reproducible, not equipment intensive, and produces high cell recovery (greater than 90%), allows for a precise analysis of the steps involved in the maturation of a resting B lymphocyte to an immunoglobulin-secreting cell.

Multiple Fusobacterium Nucleatum Liver Abscesses

A previously healthy 29-year-old man developed multiple hepatic abscesses secondary to Fusobacterium nucleatum. No underlying local disease was found. The leading portal of entry for the bacterium may have been the oral cavity; 4 days before the onset of his illness he had had extensive dental work. Immunological evaluation during the illness and in late convalescence (16 weeks after onset) revealed a persistent B cell abnormality characterized by markedly depressed in vitro secretion of immunoglobulins in response to pokeweed mitogen; however, serum immunoglobulins and IgG subclasses were normal. Abnormal numbers of suppressor T cells (OKT8+) and increased suppressor function were also present. Anaerobic pyogenic liver abscesses may occur in the absence of obvious underlying disease, but this case suggests that there may be an association with in vitro abnormalities of the immune system.

Proliferative and Differentiative Responses of B Cells From Human Marrow Graft Recipients to T Cell-Derived Factors

Upon activation, B cells express growth and differentiation receptors that permit them to proliferate and differentiate. The aim of this study is to define the nature of the intrinsic B cell defects found in marrow recipients using assays for B cell activation, proliferation, and differentiation. B cells from five short-term (less than three months postgrafting) and 15 long-term (greater than one year postgrafting) marrow recipients (ten with and five without chronic graft-v -host disease [GVHD]) were studied. T cell supernatants (T-sup) were prepared by stimulating normal T cells with 12-0-tetradecanoyl-phorbol-13-acetate (TPA) and phytohemagglutinin. Highly purified B cells were used to assess B cell proliferation responses to T-sup after Staphylococcus aureus Cowan I (SAC) activation and for B cell immunoglobulin production responses to T-sup stimulation after SAC activation. B cells from all five short-term patients and one long-term patient with chronic GVHD did not respond to any stimulation. B cells from two patients with chronic GVHD responded to SAC but had decreased proliferative and differentiative responses to T-sup. B cells from three of seven patients with chronic GVHD and two of five long-term healthy patients could proliferate but could not secrete immunoglobulin in response to SAC plus T-sup stimulation. Furthermore, there was a significant correlation between serum IgG and/or IgM in marrow recipients and the differentiative responses of their B cells to T-sup (P = 0.0075, Fisher's Exact). B cell defects occur at various stages of maturation postgrafting. These defects include the failure to respond to the SAC activation signal, the failure to proliferate in response to T-sup, and the failure to differentiate in response to T-sup. These findings are probably due to the inability of B cells from certain marrow recipients to undergo a second round of ontogeny.

Proliferative and differentiative responses of B cells from human marrow graft recipients to T cell-derived factors

Upon activation, B cells express growth and differentiation receptors that permit them to proliferate and differentiate. The aim of this study is to define the nature of the intrinsic B cell defects found in marrow recipients using assays for B cell activation, proliferation, and differentiation. B cells from five short-term (less than three months postgrafting) and 15 long-term (greater than one year postgrafting) marrow recipients (ten with and five without chronic graft-v -host disease [GVHD]) were studied. T cell supernatants (T-sup) were prepared by stimulating normal T cells with 12–0-tetradecanoyl- phorbol-13-acetate (TPA) and phytohemagglutinin. Highly purified B cells were used to assess B cell proliferation responses to T-sup after Staphylococcus aureus Cowan I (SAC) activation and for B cell immunoglobulin production responses to T-sup stimulation after SAC activation. B cells from all five short-term patients and one long-term patient with chronic GVHD did not respond to any stimulation. B cells from two patients with chronic GVHD responded to SAC but had decreased proliferative and differentiative responses to T-sup. B cells from three of seven patients with chronic GVHD and two of five long-term healthy patients could proliferate but could not secrete immunoglobulin in response to SAC plus T-sup stimulation. Furthermore, there was a significant correlation between serum IgG and/or IgM in marrow recipients and the differentiative responses of their B cells to T-sup (P = 0.0075, Fisher's Exact). B cell defects occur at various stages of maturation postgrafting. These defects include the failure to respond to the SAC activation signal, the failure to proliferate in response to T-sup, and the failure to differentiate in response to T-sup. These findings are probably due to the inability of B cells from certain marrow recipients to undergo a second round of ontogeny.

Suppression of B-Lymphocyte Function by T-Lymphocytes in Patients With Advanced Lung Cancer<xref ref-type="fn" rid="FN2">2</xref><xref ref-type="fn" rid="FN3">3</xref>

The ability of B-lymphocytes to produce immunoglobulins in response to pokeweek mitogen stimulation was studied in 21 untreated stage III lung cancer patients by culture of their mononuclear cells in vitro. The number of immunoglobulin-producing cells was significantly lower in 20 of the 21 patients when compared to responses shown by normal control subjects. In contrast, the proliferative responses of many of the patients were within the normal range. When the T-lymphocytes of these patients were irradiated with 1,250 rad to eliminate the suppressor T-cell activity and then cultured with autologous B-cells, the number of immunoglobulin-producing cells was enhanced to the normal range in 7 of the 18 patients. These results indicate that B-cell function is impaired in most patients with advanced lung cancer. They also suggest that, in addition to suppression by radiosensitive suppressor T-cells, other mechanisms are involved in the observed B-cell functional abnormality.

Reevaluation of suppressor cell function in systemic lupus erythematosus

This study was undertaken to reevaluate suppressor cell function in patients with systemic lupus erythematosus (SLE). First, we found that preculture of normal peripheral blood mononuclear cells (PBM) with or without Con A developed suppressor cells that inhibited the capacity of fresh normal PBM to secrete immunoglobulins in response to PWM. The degree of suppression produced by Con A-activated PBM was much greater than that produced by precultured PBM. Then, using this suppressor cell assay, we demonstrated that both precultured and Con A-activated SLE PBM secreted a significant amount of immunoglobulins without any stimulation and, also inhibited the ability of fresh normal PBM to synthesize immunoglobulins in vitro. The suppressive activity of precultured or Con A-activated SLE PBM did not differ from that of normal PBM. Thus, this study demonstrated for the first time that there was no defect in suppressor cell function in SLE in vitro.

Human splenic and peripheral blood lymphocyte response to lipopolysaccharide

In this study we investigated the mitogenic effect of lipopolysaccharide (LPS) on human splenic and peripheral blood lymphocytes. Human splenic lymphocytes were found to proliferate and synthesize IgG, IgA, and IgM in response to LPS. The sensitivity of our assay for IgA and IgG classes of immunoglobulin may account for our observation of their synthesis. Fresh human peripheral blood lymphocytes did not proliferate or synthesize immunoglobulin in response to LPS. Increasing the doses of LPS and altering the length of incubation did not affect this result. If the lymphocytes were incubated for 20 hr prior to exposure to LPS, however, both proliferation and immunoglobulin synthesis, similar in magnitude to LPS-stimulated splenic lymphocytes, were observed. These results suggest the presence of a suppressor cell which is eliminated by preincubation or the maturation of an LPS-responding population during preincubation. The former explanation appears more likely when the results of other investigations are taken into consideration.

B cell differentiation and immunoregulatory T cell function in human cord blood lymphocytes.

The functional maturity of T and B lymphocyte populations from human newborns was evaluated using a reverse hemolytic plaque assay to detect immunoglobulin-secreting cells generated in in vitro cultures stimulated with pokeweed mitogen (PWM), a T cell-dependent polyclonal activator, and the Epstein-Barr virus (EBV), a T cell-independent B cell activator. Cord blood lymphocytes failed to produce immunoglobulin in response to PWM, but did respond with immunoglobulin synthesis to stimulation with EBV. Co-culture experiments demonstrated that cord blood T cells would inhibit immunoglobulin production by adult cells stimulated with PWM, but not with EBV. Cord blood T cells did suppress immunoglobulin production by cord blood B cells when stimulated with a mixture of EBV and PWM, indicating that cord blood, in contrast to adult blood, contains a population of suppressor T cell precursors that are easily activated by PWM. Irradiation of the cord blood T cells with 2,000 rad eliminated the suppressor activity and revealed normal helper function for immunoglobulin (Ig) G, A, and M when these T cells were co-cultured with adult B cells. Cord blood B cells co-cultured with adult T cells or irradiated cord blood T cells did produce immunoglobulin in response to PWM, but the response was significantly lower than that of adult B cells, and only IgM was produced in these cultures. These studies demonstrate that both the T and B cells of the human newborn have significant functional differences compared with the functions of T and B lymphocyte populations in adults.

Studies on the pathogenesis of an immune defect in multiple myeloma.

The reduced capacity of patients with multiple myeloma to respond to antigen challenge is well recognized. Response to antigen involves antigen recognition, cell proliferation, and synthesis and secretion of antibody. This study examines this sequence of events in peripheral blood lymphocytes from untreated and treated patients with myeloma, from individuals with benign monoclonal gammopathy, and from normal healthy donors. Antigen-binding capacity was assessed by testing the ability of lymphocytes to bind radio-labeled pneumococcal polysaccharide, tetanus toxoid, or diptheria toxin. The in vitro proliferative response to these antigens as well as to pokeweed mitogen and streptokinase-streptodornase was evaluated. The secretion of immunoglobulin in response to pneumococcal polysaccharide, tetanus toxoid, and pokeweed mitogen by 2-4 x 10(6) lymphocytes in 7-day cultures was determined. The effects of coculture of myeloma peripheral blood lymphocytes and normal peripheral blood lymphocytes on immunoglobulin production and mixed leukocyte reactions were explored. All myeloma patients had normal numbers (3-8/5,000 cells) of antigen-binding cells. However, most showed a diminished antigen-induced blast transformation as measured by uptake of [(125)I]5-iodo-2'-deoxyuridine in culture. Immunoglobulin production in response to specific antigen in myeloma lymphocytes was 30-80% less than in normal lymphocytes. Immunoglobulin synthesis and mixed leukocyte responses by normal peripheral blood lymphocytes could be suppressed by myeloma lymphocytes. Multiple suppressor populations were present. Thus, the immune defect in myeloma is beyond the antigen recognition step and involves both the proliferation of antigen-sensitive cells and immunoglobulin production. Further suppressive effects are imposed on normal cells, implying defects in immunoregulation in this disease.

Immunoglobulins of the Chicken Antibody to Newcastle Disease Virus (Mukteswar and F Strain)

The qualitative and quantitative development of chicken immunoglobulins in response to R2B (Mukteswar) and F strain of Newcastle disease virus was studied. One primary (R2B) and two secondary (R2B – R2B, F – R2B) vaccination trials were conducted. Sera was collected at weekly intervals and analyzed. There was an increase in total serum protein content in parallel to an increase in serum neutralizing (SN), hemagglutination inhibition (HI), and precipitating antibodies. The SN, HI and precipitating activities were detected both in IgM and IgG immunoglobulins when sera were treated with mercapto-ethanol. However, Sephadex G-200 fractionated sera showed only SN activity in the IgM fraction, whereas the IgG fraction showed both HI and SN activity. Serum IgM antibodies appeared during the first week following vaccination, then diminished, then rose again following secondary vaccination. Apparently, immunoglobulin induction and serological activities were not significantly influenced by the age of the chickens.

Immunoglobulins and Antibody-Production in Amphibians

SYNOPSIS. Recent evidence suggests Ihat amphibians represent a key transition stage in the evolution of immunological competence. In particular, anuran amphibians exhibit a significant advance relative to more primitive vertebrates in their capacity to synthesize two distinct classes of immunoglobulins in response to antigenic stimulation.These two classes of antibody molecule resemble the γM and γG antibodies of man in size and polypeptide chain structure. Furthermore, cellular aspects of antibodyproduction in anura resemble those of mammals in the method of retention of antigen and the range of antibody-forming cells (lymphocytes to plasma cells). In addition to these parameters of antibody-formation, a state of specific nonresponsiveness (high zone tolerance) can be induced in adult anura by pretreatment with large doses of protein antigen. Studies of larval anurans establish that these forms become immunologically competent early in development, but possess only γM immunoglobulins. These larval stages provide feasible model systems for the study of the activation of genes which specify immunoglobulins. Antibody-formation in urodeles is discussed in relation to the emergence of immunological competence in amphibians.