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Enumeration of T cells, B cells and monocytes in the peripheral blood of normal and lymphocytotic cattle.

The rosette-forming capacity of bovine peripheral blood lymphocytes (PBL) was determined with dextran and 2-aminoethylisothiouronium bromide (AET)-treated sheep erythrocytes (SRBC). Both dextran and AET-enhanced rosette formation; however, AET-treated SRBC detected a larger percentage of rosette-forming cells and thus was used in this study. The specificity of rosette formation by bovine thymus-derived (T) lymphocytes was shown by (1) demonstration of rosettes and surface-membrane immunoglobulins sIg) on different cells in PBL and nylon-wool fractionated lymphocyte populations and (2) rosette formation by a large percentage (83--90%) of thymocytes from three bovine foetuses and two 14-month-old heifers. A procedure was also developed to identify bovine monocytes by latex phagocytosis and 10--30% latex-ingesting cells were detected in PBL preparations isolated by Ficoll-Hypaque flotation. The frequency of sIg-bearing latex-ingesting, and sIg-bearing latex non-ingesting cells in bovine peripheral blood was also determined. These procedures were utilized to determine the distribution of T and bone-marrow derived (B) lymphocytes in peripheral blood of normal and lymphocytotic cattle. PBL from twenty normal cattle contained approximately 63% T and 11% B (sIg+ latex non-ingesting) lymphocytes. In peripheral blood of three cattle with persistent lymphocytosis, a prodromal stage of bovine leukaemia, the percentage of B cells was elevated approximately to 59% whereas T lymphocytes decreased to 35%, thus providing additional evidence that persistent lymphocytosis is a B-cell disease.

Animals

Complement-dependent and -independent pathways of T cell-B cell cooperation.

BDF1 mice treated with CoV had markedly reduced levels (less than 20%) of native serum C3 32 hr later, whereas the frequency of splenic CR+ cells was normal. CoV treatment before immunization reduced the IgM PFC response to a T-dependent antigen (TNP-SRBC) by more than 60%. Inclusion of highly specific anti-C3 antibody had no effect on the T-dependent IgM response of CR- B cells. The residual PFC responses in cultures of unfractionated spleen cells treated with anti-C3 could be largely or completely accounted for by CR- B cells in the cultures. The effect of anti-C3 antibody was not due to cytotoxicity. These data collectively indicate that the effect of CoV on T-dependent antibody responses is due to decreased C3 in serum rather than to interaction of C receptors directly with CoV or with C3 cleavage products. They suggest the existence of at least two distinct pathways of T-B cooperation, one in which C3 is an obligatory participant and another in which it may be uninvolved.

Animals

T cells, B cells and intermediate forms in the newborn studied by scanning electron microscopy and phosphatase marker.

Scanning electron microscopic studies of peripheral blood lymphocytes showed that percentage of T cells was lower in four cases of premature infants born between 30th and 34th week of gestation when compared with that in four cases of term infants (18.6% and 39.9% counted from 956 and 1,379 lymphocytes, respectively). The occurence of lymphocytes with intermediate patterns of surface morphology (I cells) was noted in both groups studied. Percentages of B and I cells were higher in the premature than in the term infant (26.3% and 55.1% and 20.0% and 39.1%, respectively). Analogous tendency in the T cell occurence in the premature and the term infant was demonstrated with acid phosphatase as T cell marker.

Acid Phosphatase

Ontogeny of T cells, B cells and monocytes in the bovine foetus.

The ontogeny of lymphocyte subpopulations and monocytes was studied in developing bovine foetuses. Fifty-four bovine foetuses ranging in age from 3 to 9 months of gestation were collected and examined for the presence of thymus-derived (T lymphocytes), bone marrow-derived (B lymphocytes) and phagocytic (macrophage) cells from thymus, spleen and peripheral blood. Detection of the cells expressing T lymphocyte surface markers was done using a modified sheep red blood cell rosette assay. Lymphocytes bearing surface immunoglobulin (sIg) were detected by staining with a fluoresceinated rabbit antibody prepared against bovine IgG. The procedure used for detecting monocytes was a latex bead phagocytic assay. In the thymus, the percentage of T lymphocytes was relatively constant throughout gestation at approximately 60-70%, with B lymphocytes remaining at about 1%, whereas the phagocytic cells showed an increase from 1% at 3 months to approximately 8% at term. The spleen showed an increasing percentage of T lymphocytes, from 11% at 3 months to over 40% at term, whereas the percentage of B lymphocytes remained consistent at about 2-3% from 3 months until term. The percentage of monocytes increases from 1% at 3 months to over 20% at 9 months. Peripheral blood T lymphocytes increased steadily from approximately 1% at 3 months to 45% at term. B lymphocyte levels remained low, about 1%, throughout gestation, whereas monocytes increased from 1% at 3 months to 5% at 9 months.

Animals

New groups and segregant series among B-cell alloantigens of the Merrit system. A study of leukemia cells, peripheral B cells, and lymphoblastoid cell lines.

On the basis of reactions with a chronic lymphatic leukemia cell panel, evidence for 6 new specificities of the Merrit B-cell alloantigenic system in man is presented, bringing the number of provisionally defined specificities to 19. These can be roughly divided into two segregant series. The system is well represented on both homozygous and heterozygous B-type lymphoblastoid cell lines. In the cell lines some specificities show a suggestive but inexact correlation with HLA-D locus factors. This correlation is represented also on peripheral blood B cells, on the non-T variety of acute lymphatic leukemia cells, and on acute myeloid leukemia cells. Although great similarities exist, each of the cell populations may manifest differences other than or in addition to mere differences in B-cell antigen frequencies.

B-Lymphocytes

Defining three dimensional chromatin structures of pediatric and adolescent B cells using primary B cell and EBV-immortalized B cell reference genomes.

BACKGROUND/PURPOSE: Knowledge of the 3D genome is essential to elucidate genetic mechanisms driving autoimmune diseases. The 3D genome is distinct for each cell type, and it is uncertain whether cell lines faithfully recapitulate the 3D architecture of primary human cells or whether developmental aspects of the pediatric immune system require use of pediatric samples. We undertook a systematic analysis of B cells and B cell lines to compare 3D genomic features encompassing risk loci for juvenile idiopathic arthritis (JIA), systemic lupus (SLE), and type 1 diabetes (T1D). METHODS: We isolated B cells from four healthy individuals, ages 9-17. HiChIP was performed using a CTCF antibody, and CTCF peaks were called within each sample separately. Peaks observed in all four samples were identified. CTCF loops were called within the pediatric samples using three CTCF peak datasets: 1) self-called CTCF consensus peaks called within the pediatric samples, 2) ENCODE's publicly available GM12878 CTCF ChIP-seq peaks, and 3) ENCODE's primary B cell CTCF ChIP-seq peaks from two adult females. Differential looping was assessed within the pediatric samples and each of the three peak datasets. RESULTS: The number of consensus peaks called in the pediatric samples was similar to that identified in ENCODE's GM12878 and primary B cell datasets. We observed&#x2009;<&#x2009;1% of loops that demonstrated significantly differential looping between peaks called within the pediatric samples themselves and when called using ENCODE GM12878 peaks. Significant looping differences were even fewer when comparing loops of the pediatric called peaks to those of the ENCODE primary B cell peaks. When querying loops found in juvenile idiopathic arthritis, type 1 diabetes, or systemic lupus erythematosus risk haplotypes, we observed significant differences in only 2.2%, 1.0%, and 1.3% loops, respectively, when comparing peaks called within the pediatric samples and ENCODE GM12878 dataset. The differences were even less apparent when comparing loops called with the pediatric vs ENCODE adult primary B cell peak datasets. CONCLUSION: The 3D chromatin architecture in B cells is similar across pediatric, adult, and EBV-transformed cell lines. This conservation of 3D structure includes regions encompassing autoimmune risk haplotypes. Thus, even for pediatric autoimmune diseases, publicly available adult B cell and cell line datasets may be sufficient for assessing effects exerted in the 3D genomic space.

Humans

Immunity to Plasmodium Berghei yoelii in mice. I. The course of infection in T cell and B cell deficient mice.

The course of infection with 17X nonlethal Plasmodium berghei yoelii was examined in BALB/c mice which were deficient in either T cells or B cells. Markedly increased parasitemia and mortality were observed in athymic (nude) mice which had been backcrossed on a BALB/c background (T cell deficient) compared to similar mice which had been grafted with neonatal BALB/c thymus, and were also observed in BALB/c mice suppressed from birth with goat antiserum to mouse mu-chain (B cell deficient) compared to age- and sex-matched BALB/c controls. These results establish the requirement for the presence of both T cells and B cells for effective resistance to an intercurrent infection with 17XNL P.b. yoelii in adult BALB/c mice. Mechanisms by which the requirement for both T cells and B cells could be explained were discussed. The model of mu suppression was shown to be a valuable tool for an evaluation of the cellular basis of immunity to an infectious disease.

Animals

Reduced responsiveness of immature B cells to the B cell mitogen, lipoprotein.

When pre-B cells are isolated from bone marrow and incubated in vitro for several days, they spontaneously differentiate into LPS-reactive B cells. These newly produced B cells do not respond to another B cell mitogen, lipoprotein (Lp). The lack of Lp reactivity of newly produced B cells represents a qualitative difference between these cells and B cells in peripheral tissues that respond equally well to both LPS and Lp. Thus, responsiveness to different mitogens provides unique markers to identify B cells at early stages of development.

Animals

The histocompatibility restrictions on macrophage T-helper cell interaction determine the histocompatibility restrictions on T-helper cell B-cell interaction.

To study the histocompatibility restriction between macrophages and helper T cells, carrier primed guinea pig T cells were positively selected in vitro with antigenpulsed macrophages for 7 days and the selected T cells were then mixed with hapten-primed B cells and stimulated with antigen in a modified Mishell-Dutton system. Helper T cells could only be selected with syngeneic, but not allogeneic, antigen-pulsed macrophages and would then collaborate only with syngeneic, but not allogeneic, hapten-primed spleen cells. When F1 T cells were selected with antigen-pulsed parental macrophages they would only collaborate with B cells of the same parental strain as the macrophages used in the selection culture. These results are strongly in support of the view that the primed T cell is activated by carrier determinants of the nominal antigen in association with Ia antigens on macrophages and the helper T cell, in turn, activates B cells which bear the same Ia antigens and determinants of the nominal antigen bound to immunoglobulin receptors on their surface. In addition, in experiments with antigens the response to which is controlled by I-linked genes, we demonstrated that primed (responder X nonresponder)F1 T cells would only collaborate with B cells of the responder parent. The defect appeared to be at the level of the B cell in that the addition to the cultures of antigen-presenting cells of the responder type did not restore the ability of F1 T cells to collaborate with non-responder B cells.

Animals

Isolation of T-cells, B-cells and macrophages by a two-stage adherence procedure.

This communication describes a method to obtain enriched populations of T-cells, B-cells and macrophages. Spleen cells were initially fractionated on nylon wool columns. The nylon wool adherent fraction was removed by mechanical agitation and further separated on the basis of adherence to a coated-plastic surface in the presence of autologous serum. The tissue flask adherent population was removed with the aid of a rubber policeman. The nylon wool non-adherent and the tissue flask non-adherent and adherent fractions were characterized for the presence of cell surface markers, size, and functional activity and were identified as T-cells, B-cells and macrophages, respectively. The two-stage adherence procedure is simple to perform and does not require sophisticated equipment or expensive reagents.

Animals

Heterogeneity of B cells reacting with T-cell factors. Evidence for matching T-cell and B-cell subsets.

Spleen T cells have been stimulated with Concanavalin A (Con A) under conditions which lead to the production of non-specific factor (NSF), a substance which replaces T cells for B-cell responses to certain antigens. We have examined the ability of multiple aliquots of B cells to react to the NSF derived from single T cells, and have found great heterogeneity of response. We postulate that there exist subsets of T cells which vary in either the quantity or the quality of the non-specific factor(s) they can produce on stimulation, and that in turn there must also be matching subsets of B cells which may vary in their susceptibility to such factors.

Animals

Differences in purine metabolizing enzyme activities in human leukemia T-cell, B-cell and null cell lines.

Clear metabolic differences between T- and B-cells were demonstrated. Both adenosine deaminase (ADA) and nucleoside phosphorylase (NP) activities increased during logarithmic growth and then decreased in T-cells, but remained essentially constant during the growth cycle of B-cells. When these enzyme activities were examined in a number of T-cell, B-cell, and null cell lines, ADA activity was clearly higher in T-cells as compared to all others. With NP, the opposite appeared to be true, although the differences were much smaller and not statistically significant in all instances. No clear differences were found in the isoenzyme distributions of both enzymes in the various cell types.

Adenosine Deaminase