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B Pernis

Publications and source records attributed to B Pernis.

At least 73 records · Page 4Linked to original sources

Cellular localization of rheumatoid factor idiotypes.

the stimulation of lymphocytes from rheumatoid arthritis patients with pokeweed mitogen produces a large number of plasma cells that express the dominant cross-reactive idiotype previously found on monoclonal IgM anti-gamma-globulins from patients with mixed cryoglobulinemia. Similar experiments with the cells of normal individuals show a much lower percentage of these cells with a lower intensity of staining with the fluorescent reagents utilized. Efforts to demonstrate rheumatoid factor in the same cells by fluorescent staining with aggregated gammaglobulin were entirely unsuccessful. This also proved to be the case for pokeweed mitogen-stimulated cells from the mixed cryoglobulinemic patients with large amounts of rheumatoid factor in the serum, despite high percentages of cells expressing the cross-reactive idiotype and also the individual idiotype. On the other hand, native plasma cells from synovial tissue of rheumatoid arthritis patients showed some cells with both the cross-reactive idiotype and aggregate staining. The exact reason for the failure to demonstrate rheumatoid factor by aggregate staining in pokeweed mitogen-stimulated cultures remains to be determined despite considerable effort to resolve the problem. The most likely possibility is that these plasma cells are relatively immature and have not accumulated polymeric IgM in their cytoplasm to the degree seen in synovial tissue plasma cells. The monomeric forms are readily recognized by the antiidiotypic antibodies and these reagents appear to be of particular value for cellular studies of this type.

Adult↗

Spontaneous in vitro differentiation of antigen-specific lymphocytes from a patient with immunoglobulin M gammopathy.

Recently we have identified two monoclonal immunoglobulin M (IgM) proteins that bind Klebsiella polysaccharides. The lymphocytes of one of these patients (M.A.Y.) were available for study. A substantial proportion of the B lymphocytes isolated from this patient's peripheral blood also bound Klebsiella polysaccharides with a pattern of specificity identical to that of the monoclonal IgM, and reacted with an anti-idiotypic antiserum directed against this IgM. Stripping the surface immunoglobulin from these lymphocytes eliminated this reactivity. Although no plasma cells were detected in the freshly isolated peripheral blood lymphocytes of this patient, plasma cells binding Klebsiella polysaccharide appeared after 7 d of in vitro culture. This occurred regardless of whether the cultures were supplemented with autologous plasma, normal human plasma, or fetal calf serum. Pokeweed mitogen neither stimulated nor inhibited the in vitro differentiation of the monoclonal B lymphocytes into plasma cells. This differentiation was, however, abrogated by F(ab')2 fragments of anti-human IgM and by anti-idiotypic antibodies, as well as by the Klebsiella polysaccharide with which the monoclonal IgM reacted.

Aged↗

A phorbol ester tumor promoter induces changes in the expression of immunoglobulins and DR antigens in human lymphoblastoid cells.

The present study indicates that 12-O-tetradecanoyl phorbol 13-acetate (TPA) can induce either increases or decreases in the relative expression of membrane-associated IgM and IgD as well as the expression of other markers of lymphocyte differentiation on human B lymphoblasts, depending on the clone studied. The changes in membrane Ig expression are apparent within 24 hr and are maximal at about 48 hr after the addition of the compound. In clone BL, TPA decreases the membrane IgM/IgD ratio as determined by the percentage of cells bearing these isotypes and by their densities on single cells. In clone MW-E, TPA has the opposite effect. Although these changes are followed by an increase in Ig secretion by MW-E cells, measured by immunofluorescence and the protein A plaque assay, there is no induction of Ig secretion in BL cells. In addition, TPA increases the expression in BL of an additional B lymphocyte marker, the D region-related (DR) antigens, while having the opposite effect in MW-E. In two sublines of Daudi, a membrane IgM-positive, IgD-negative, nonsecreting cell line, TPA treatment resulted in the expression of membrane IgD without the induction of Ig secretion. Thus, the TPA-induced changes in the IgM/IgD ratio and DR antigen expression are inversely related and are not due to differential proliferation of subpopulations. Taken together, it appears that, depending on the particular clone of B lymphoblasts studied, TPA can induce or inhibit a coherent program of B lymphocyte maturation.

Antibody-Producing Cells↗

Physiology of IgD. I. Compensatory phenomena in B lymphocyte activation in mice treated with anti-IgD antibodies.

The role of delta-positive cells in the immune response was studied by comparing the effects of treatment with allotype-specific IgD hybridoma antibody on homozygous BALB/c or SJL/J and heterozygous (BALB x SJL)F1 mice. Homozygous mice, injected from birth with the relevant anti-delta antibody, made primary or secondary immune responses to intravenously injected trinitrophenyl (TNP)-Brucella abortus, TNP-Ficoll, and TNP-keyhole limpet hemocyanin, which did not differ significantly from those of control mice, despite the fact that IgD+ cells were depleted and Ig+ cells were markedly reduced in the spleens of treated mice. Responses in nodes draining a local injection of TNP-Brucella abortus were, however, significantly suppressed. Heterozygous mice, injected from birth with either anti-Ig-5a or anti-Ig-5b, showed a marked reduction in the number cells producing IgG antibody of linked allotype specificity in the secondary response to intravenously injected sheep erythrocytes. A corresponding decrease in the amount of serum IgG2a of that allotype specificity was also noted. However, in agreement with the results obtained in homozygotes, heterozygotes injected simultaneously with anti-IgD directed against each of the allotypes made normal, if not enhanced, plaque-forming cell responses of both allotype specificities. Similarly, serum IgG2a levels were normal in all but one mouse treated in this fashion. These results indicate that IgD+ cells are not essential for an immune response in vivo. Although the delta-positive cell is used preferentially under normal conditions, it appears that an alternative mechanism exists by which, in the absence of these cells, the animal is able to make a normal immune response.

Animals↗

Exclusion of VHa and VHy loci expression on individual B cells from normal and VH allotype-suppressed rabbits.

The distribution of two heavy chain subgroups, VHa and VHy, on rabbit peripheral blood lymphocytes was examined by double membrane immunofluorescence. Fluroescent anti-a1 and anti-y33 were found to react with separate B cell populations; no doubly stained cells were observed. Further evidence for the independent expression of genes controlling the VHa and VHy subgroups were obtained by neonatal suppression of a 2 or y33 in a2y33/a3y- heterozygous rabbits. Suppression of VHa did not affect the expression of VHy, nor did the suppression of VHy affect the expression of VHa. The expression of a single VH gene per B cell is in marked contrast to the simultaneous expression of multiple CH genes.

Aging↗

Antigen recognition by T cells activated in the mixed lymphocyte reaction: specific binding of allogeneic cell material after removal of surface-bound antigen by trypsin.

T cell blasts activated in the mixed lymphocyte reaction (MLR) carry on their surface stimulator alloantigens which can be removed by treatment of the blasts with trypsin. After overnight incubation in trypsin-free medium, the treated cells exhibit specific alloantigen binding ability: they bind much more effectively cellular material, either obtained from the corresponding MLR supernatant or released by nitrogen cavitation from fresh cells from the stimulating strain, than that from an unrelated H-2 different strain. Trypsin-treated cells which have been incubated in the presence of low concentrations of puromycin are unable to bind stimulator cell fragments.

Animals↗

Induction of an antibody response in cultures of human peripheral blood lymphocytes.

A culture system is descirbed which provides adequate conditions for in vitro immunization of humand peripheral blood lymphocytes to heterologous erythrocytes. Making use of this method we could obtain, with a number of different donors, an antibody response which peaked at about day 8 of culture with 30-300 plaque-forming cells (PFC) per 10(6) input lymphocytes. However, in a number of experiments poor or negative results were obtained, even with donors that had previously given good response. This variability in the results was shown not to be due to a too low number of precursor cells present in the blood and could be overcome by treating the cells, before initiation of the culture, with a factor produced by mouse T cells educated to sheep erythrocytes (SRBC). Under these conditions a PFC responce was obtained which peaked at about day 8 and which in some experiments could be as high as 20,000 PFC per 10(6) input lymphocytes. Paralleling the increase in PFC was an increase in cell number. The cells recovered from the treated cultures were at all times more numerous than in the nontreated cultures. The height of both the proliferative and antibody-producing responses varied from experiment to experiment, a higher proliferative response, accompanying a higher PFC response. Although the mechanisms that are at the basis of the antibody response in vitro described in this paper still need to be clarified, this system may become a useful tool in studying the immune response in man.

Animals↗

Specific binding of alloantigens to T cells activated in the mixed lymphocyte reaction.

Immunoglobulin (Ig) is present on a large fraction of T cells from unfractionated lymphocytes activated by in vitro stimulation with H-2-incompatible cells (mixed lymphocyte reaction [MLR]). Removal of bursa equivalent-derived (B) cells from the responder cell population before mixed culture, by filtration through nylon wool columns, reduces the percentage of Ig-bearing responder T blasts to background levels. Thus, Ig on the T blast is probably of B cell origin. A large fraction of T blasts activated against the stimulator cells. This staining occurs with "early" and hyperimmune alloantisera, including the 7S fraction of the latter. B-depleted responder cells were activated against a mixture of two different stimulator cells and the resulting T blasts stained with different concentrations of sera directed either against one or both stimulator cells. We obtained results which strongly suggest that most or all responder T blasts stain with only one antistimulator serum. When antisera directed against different segments of the H-2 complex of the stimulator cells were used, it seemed that most responder T cells only bound antibody directed against a single segment. We propose that T cells activated in MLR carry stimulator alloantigens on their surface, and that this is due to specific antigen binding, not requiring the presence of B-cell-derived antibody. These histocompatibility antigen-binding T blasts can be detected by appropriate antistimulator alloantibodies.

Animals↗

Human T cell receptor for IgM: specificity for the pentameric Fc fragment.

The specificity of the IgM receptor expressed by human T cells cultured in IgM-free media has been investigated. IgM receptors have been detected using a rosette system with ox erythrocytes coated with rabbit antibody (EA(IgM)), and the inhibitory capacity of different IgM fragments in the rosette system has been tested. It was found that F(c)5mu but not F(ab')2mu, nor monomeric IgM (8 S IgM) inhibited EA (IgM) rosette-forming cells. This indicates that the receptor present on the surface of T cells has affinity for a structure located in the Fc portion of the pentameric IgM.

Binding Sites↗

A study of immunoglobulin classes present on the membrane and in the cytoplasm of human tonsil plasma cells.

The problem of whether immunoglobulin (Ig)-containing plasma cells expressed membrane Ig has been investigated using cells from human tonsils. In tonsils, IgG-containing cells are predominant, but a certain number of IgM, IgA and IgD-containing cells are also present. By using a double staining immunofluorescent technique for the simultaneous detection of membrane and intracytoplasmic Ig, it has been possible to ascertain that the large majority of IgA, IgM and IgD-containing cells had membrane immunoglobulin (mIg) of a class coincident with that of intracytoplasmic Ig. In addition a noticeable proportion of IgM-containing cells expressed membrane IgD, thus indicating that a certain number of these cells bore both membrane IgM and IgD. About 60% of IgG-containing cells had membrane IgG, while the remaining cells did not express mIg. Furthermore the surface staining of these cells was generally fainter than that of the cells containing other Ig classes. Experiments on the surface light chain type expressed by the single Ig-containing cells (IgCC) as compared to that found in the cytoplasm have shown that in the large majority of IgCC the light chain type of mIg coincided with that of intracytoplasmic Ig. Discordant light chain types of membrane and cytoplasmic Ig were found on about 12% of IgCC only. These values can be taken as a measure of how many IgCC had passively acquired mIg.

Cytoplasm↗

The effect of anti-immunoglobulin antibodies of Fc rosettes.

This study demonstrated that Fc rosettes detected by antibody-labeled bovine erythrocytes can be inhibited by immune complexes of rabbit IgG (b4 allotype) and anti-b4 IgG, thus showing that these complexes effectively compete for the receptor for erythrocyte-antibody rosettes. Incubation of mouse lymphocytes with goat F(ab')2 anti-mouse IgG did not inhibit Fc rosettes. When immunoglobulin on murine and human B lymphocytes was redistributed in a polar cap on the membrane by interaction with anti-immunoglobulin antibodies, the number of Fc rosettes after 'capping' was unchanged; most of the indicator erythrocytes, however, were distributed in a cap as well. This erythrocyte cap was superimposed on the immunoglobulin cap.

Animals↗

Ia antigens and Fc receptors.

The function of Fc receptors (FcR) on mouse spleen cells as detected by a sensitive rosetting system using antibody-labeled bovine erythrocytes as indicator cells was shown to be inhibited by anti-Ia antiserum. Furthermore, the Ia specificities of each I-region sublocus (I-1A, I-1B, I-C) seem to be associated with FrR, since FcR function was also inhibited when the blocking anti-Ia antiserum recognized only restricted Ia specificities. Antiserum directed against antigens coded for by the K-end of the major histocompatibility complex did not inhibit FcR function. The function of C3 receptors and Fc receptors on macrophages and Fc-receptor-positive cells in the fetal liver was not inhibited by anti-Ia antiserum. These findings are discussed in view of a possible arrangement of Fc receptors and Ia antigens on the cell membrane.

Animals↗

IgD receptors of lymphoid cells.

While present in normal human serum in very low amounts and undetectable in sera of non-human primates as well as of mice, IgD is found on the surface of the majority of B lymphocytes in all the above mentioned species. Lymphocytes which carry IgD on their membrane also have IgM. The two molecules are present in relative amounts that can be very different in different cells. Both IgM and IgD of a single cell are the actual product of the cell itself. They have the same light chain and, more importantly, the same combining site and idiotype. IgD/IgM bearing lymphocytes are the majority of all B lymphocytes in spleen, lymph nodes and Peyer's patches, whereas in bone marrow they account for half of the immunoglobulin positive cells. Although the percentage of double IgD/IgM cells is very similar in different tissues, the total amount of IgD, as well as the relative amounts of IgD and IgM as detected by biochemical methods varies. In fact, lymph nodes, and even more Peyer's patches are much richer than spleen in cells having levels of IgD higher than those of IgM; conversely, in the bone marrow, all the positive cells have very low levels of IgD. In ontogeny, as in evolution, IgD appears after IgM: in human foetuses IgD bearing cells are not detectable before 13 weeks of gestation, and in the mouse they appear only after birth. IgD receptors seem to disappear from B cells which undergo maturation to secretion, as indicated by the fact that only a proportion of IgM secreting plasma cells show membrane IgD. IgD is never found on the membrane of IgG-containing cells, and also lymphocytes bearing simultaneously IgD and IgG are very rare, and it might well be that for these cells, the double expression for short periods of time does not actually correspond to simultaneous synthesis.

Antibodies, Anti-Idiotypic↗