Anti-Rous sarcoma response of major histocompatibility (B) complex haplotypes B23, B24 and B30

Responses to Rous sarcoma virus (RSV) induced tumours were studied in UNH 105, a non-inbred line of New Hampshire chickens. Six single male matings encompassing a total of 50 dams produced 345 progeny which segregated for B complex genotypes B23/B23, B23/B24, B23/B30, B24/B24, B24/B30 and B30/B30. Six-week-old chicks were wingweb inoculated with a pseudotype of Bryan high titre Rous sarcoma virus, BH RSV (RAV-1). Tumours were scored for size six times over a 10-week period post-inoculation. Each chick was assigned a tumour profile index (TPI) as an indicator of immunological response. The number of days to death (DTD) was recorded for 148 chicks with terminal tumours. Genotypes B23/B23, B23/B24 and B23/B30, with TPIs of 1.8, 1.7 and 2.0 respectively, did not differ significantly from each other, suggesting dominance of response of B23 over B24 and B30 haplotypes. B24/B30 chicks with the highest TPI (3.4) and shortest DTD (34.6) were significantly different from B30/B30 (2.8; 41.6) but not from B24/B24 (3.1; 34.9) suggesting dominance of response of the B24 haplotype over B30 in the absence of B23.     

Increased growth of RSV-induced tumors in chickens partially tolerant to MHC alloantigens

Chickens with B2B2 MHC genotypes were made partically tolerant to B5 MHC cell-surface antigens and the fate of their Rous-sarcoma-virus (RSV)-induced tumors was determined. B2B2 chickens partially tolerant to viable or lysed white blood cells (WBC) or viable red blood cells (RBC) from B5B5 chickens had a significantly higher incidence of tumor progression than untreated, PBS-treated, or B2B2 chickens inoculated with WBC from other B2B2 chickens. The criteria for tolerance were absence of antibody titer to the cell type inoculated and acceptance of allografts from B5B5 donors by B2B2 chickens. Graft-vs-host reactions occurred only in B2B2 chickens inoculated with viable WBC from B5B5 chickens. It appears that B2B2 chickens partially tolerant to B5 antigens failed to mount a successful immune response to RSV-induced tumors partly because of a B5 MHC antigen(s) cross-reacted with a tumor associated antigen(s) thereby severely limiting B2B2 host recognition of the tumor as foreign. Since WBC and RBC cell-surface antigens appear to contribute similarly to the effect, the B-F- region of the MHC may be involved.     

Isolation, Identification and Evaluation of Bacterial Antagonists against Botrytis elliptica on Lily

Of the 700 micro-organisms isolated from lily plants and screened by dual and concomitant cultures, 10 isolates (B99, B111, B128, B131, B171, B190, B196, B203, B501 and BS) had antagonistic effects against Botrytis elliptica on three lily cultivars in greenhouse trials. Using the Biolog system, isolates B99 and B111 were identified as Burkholderia gladioli , and B128 and B190 as Bacillus amyloliquefaciens. In the field, B. gladioli B111, B. amyloliquefaciens B128, B190 or 100 p.p.m. flusilazole effectively controlled the occurrence of lily grey mould (significance, P= 0.05).     

Relationships of wild Brassica species with chromosome number 2n = 18, based on RFLP studies.

An array of 10 wild Brassica species with chromosome number 2n = 18 represented by 34 populations was analyzed for genome similarity using genomic and cDNA clones. Species studied included B. bourgeaui (Webb) O. Kuntze, B. cretica Lam., B. hilarionis G.E. Post, B. incana Ten., B. insularis Moris, B. macrocarpa (Guss.) Caruel, B. montana Pourret, B. oleracea L., B. rupestris Rafin., and B. villosa Biv. The RFLP data were used to calculate similarities between populations that were subsequently treated in a cluster analysis. Most populations of a species were grouped together and were separate from populations of other species. The previously identified B. incana - B. rupestris - B. villosa complex was verified, and genetic similarity between the species B. montana and B. oleracea was evident. An interesting association between B. insularis and B. macrocarpa was observed. The UPGMA analysis showed that the species tended to cluster according to geographic region: B. cretica and B. hilarionis comprise a cluster that could be called Eastern Mediterranean; B. oleracea, B. bourgeaui, and B. montana define an Atlantic - Western Mediterranean cluster; B. incana, B. rupestris, and B. villosa form an Italian group; and a B. insularis - B. macrocarpa association may be called Central Mediterranean.     

B4, a human B lymphocyte-associated antigen expressed on normal, mitogen-activated, and malignant B lymphocytes

The characterization of a new B cell-specific antigen (B4) is described in this report. With the use of a monoclonal antibody to B4, it was shown that B4 is present on B cells isolated from peripheral blood and lymphoid organs, on cell lines derived from normal and malignant B cells, and on tumor cells isolated from patients with B cell-derived neoplasms. B4, in contrast, was not detected on normal, activated, or malignant cells of T or myeloid origin. The B4 antigen is distinct from known B cell antigens, including sIg, Ia, B1, B2, Fc, and C3. Examination of mitogen-stimulated B lymphocytes suggests that the B4 antigen initially increases with B cell activation and then is lost at the terminal stage of B cell differentiation. Moreover, the observation that B4 is expressed on almost all early B cell tumors suggests that it may precede B1, CALLA, cytoplasmic mu, and B2 in early B cell ontogeny.     

Phosphorylation of the B1 (CD20) molecule by normal and malignant human B lymphocytes

The B1 molecule (CD20) is a phosphoprotein found only on B lymphocytes. Multiple isoforms of the B1 molecule are expressed with Mr of 33,000, B1(33) and Mr of 34,500-36,000, B1(35). In this study it was found that nonproliferating B cells did not incorporate 32PO4 into B1 although phosphorylated class I histocompatibility molecules were easily detected. In contrast B1 isolated from proliferating or malignant B cells or B cell lines was heavily phosphorylated. Cross-linking B1 on the cell surface by antibody resulted in enhanced phosphorylation of B1 as did exposure to phorbol esters, and the membrane permeable diacylglycerol analog 1,2,-dioctanoylglyceron. B1(33) and B1(35) produced identical peptide maps following limited proteinase digestion. However, B1(35) contained both phosphoserine and phosphothreonine, while B1(33) only contained phosphoserine. In addition alkaline phosphatase was able to remove the phosphate residue(s) that resulted in generation of the B1(35) form of B1 but was unable to remove the phosphorylation of B1(33). These results suggest that phosphorylation of B1 molecules is associated with proliferation and that the different Mr forms of B1 result from the phosphorylation of B1 at different sites. Also, the finding that antibody binding to B1 generated a transmembrane signal may explain why antibody binding to B1 alters B cell function.     

Notes on the Chinese Brachytheciaceae (II)

From 1896 to 1898, Carolo Mueller published thirteen Chinese species in the genus Brachythecium based on Jos. Giraldi’s collections from Shaanxi Province made during 1890～1896. They are B . campylothallum , B . amnicolum , B . homocladum , B . pinnirameum , B . permolle , B . glauco-viride, B . garovaglioides, B . viridefactum, B . glauculum, B . perminusculum, B . dicranoides , B . micrangium and B . thraustum . In this paper, holotypes of nine species, isotypes of three species, and one specimen which was examined by Mueller himself and referred to as B . thraustum by him, were studied. As a result, B . permolle and B . glauco-viride are reduced to B . rivulare as synonyms, B . wichurae is reduced to B . garovaglioides, B . micrangium is transferred to the genus Okamuraea as an independent species, i. e. O. micrangia (C. Muell. ) Wanget Hu, and the remaining 9 species are still recognized as species in the genus Brachythecium.     

A systematic review of the species of the genus Bryconamericus (Teleostei: Characidae) from Central America

A systematic revision of the fish genus Bryconamericus from Central America was done based in museum collections (UCR, STRI, BMNH, USNM, UMMZ) and samples collected by the author in Panama. Five valid species are recognized: B. bayano, B. emperador, B. gonzalezoi sp. nov. B. scleroparius and B. terrabensis: B. ricae is synonyms of B. scleroparius. Moreover, B. scleroparius and B. terrabensis were redescribed with fresh material and the lectotype of B. scleroparius was designated. Bryconamericus baudoensis, B. ortholepis, B. scopiferus (from western of Colombia), B. cascajalensis and B. zeteki (from Central America) are synonyms of B. emperador.     

Dual fluorochrome analysis of human B lymphocytes: phenotypic examination of resting, anti-immunoglobulin stimulated, and in vivo activated B cells

B cell-enriched preparations were prepared from human peripheral blood and lymphoid tissues by the depletion of T cells and monocytes. Only B cells by virtue of their staining with anti-B1 conjugated to fluorescein were additionally examined. Dual fluorescence staining and flow cytometric analysis demonstrated that the majority of "resting" human peripheral blood and splenic B cells co-express the B cell-restricted B1 and B2 antigens and lack B5, a B cell-restricted activation antigen, and interleukin 2 receptor (IL 2R). In contrast, nearly 2/3 and 1/3 of B1+ cells isolated from lymph node expressed IL 2R and B5 antigens, respectively. When B1+ B cells from peripheral blood and spleen were "activated" by anti-Ig, they lost the B2 antigen and acquired the B5 and/or IL 2R antigens. 2/3 of B1+ cells strongly expressed IL 2R, and up to 1/2 of B1+ cells co-expressed B5. Delineation of increased numbers of B1+ cells that co-express B5 and/or IL 2R within lymphoid tissues obtained from patients with diseases characterized by "activated" B cells provides in vivo confirmation that these phenotypic changes correlate with B cell activation. We believe that the identification and isolation of these and similar subsets of cells defined by differing cell surface phenotypes should further our understanding both of normal B cell activation and the pathophysiology of B cell disease states.     

Identification of two distinct factors, B151-TRF1 and B151-TRF2, inducing differentiation of activated B cells and small resting B cells into antibody-producing cells

We demonstrated previously that cellfree supernatant of the B151K12 T cell hybridoma (B151-CFS) contained T cell-replacing factor (here in after referred to as B151-TRF1) capable of inducing growth and differentiation of antigen-activated B cells into antigen-specific plaque-forming cells (PFC). In the present study, we have identified in B151-CFS another unique lymphokine activity (referred to as B151-TRF2), which induces polyclonal differentiation of unstimulated B cells into IgM-secreting cells without concomitant stimulation of antigen, mitogen, or anti-Ig antibody. The B151-TRF2 activity induced polyclonal IgM PFC responses via the action on surface Ig-positive small resting B cells from normal unprimed mice. This activation was effective across an H-2 barrier, and apparently independent of the presence of T cells and accessory cells. Interestingly, the B151-TRF2 activity notably stimulated B cells of neonatal and mutant DBA/2Ha mice, which are nonresponders to B151-TRF1, whereas it failed to activate the xid B cells from CBA/N mice. To substantiate that B151-TRF1 and B151-TRF2 activities are mediated by mutually distinguishable molecules, an absorption experiment of B151-CFS was performed by utilizing DBA/2Ha B cells which are lacking in B151-TRF1 receptor. It was found that DBA/2Ha B cells could absorb B151-TRF2 activity but not B151-TRF1 activity. In contrast, murine chronic B cell leukemia BCL1 cells, which were shown to differentiate into IgM-secreting cells by stimulation with B151-CFS, selectively removed B151-TRF1 activity but not B151-TRF2 activity. Furthermore, biochemical analysis revealed that the B151-TRF2 was a heat (56 degrees C for 30 min)-sensitive protein with an apparent m.w. of 30,000 by gel filtration, whereas B151-TRF1 was a heat-resistant glycoprotein with m.w. of 50,000. In addition, it was shown that prostaglandin E2 selectively inhibited B151-TRF2-mediated B cell responses. These results demonstrate clearly that B151-TRF1 and B151-TRF2 are distinct B cell differentiation factors involved in the different activation pathways of distinct B cell subpopulations. The immunologic implication of B151-TRF2 activity in B cell differentiation is discussed in comparison with other lymphokines so far reported to activate small resting B cells.     

Absence of histone H2B in nucleosomes containing histone TH2B and interaction of immunoglobulin with nucleosomes

Nucleosomes containing histone TH2B were isolated from chromatin subunits of rat testis nuclei (MNT) by incubating with anti-TH2B immunoglobulin (IgTH2B) which was covalently attached to agarose gels. Electrophoretic separation of histones of these isolated nucleosomes revealed that histone H2B was completely absent, suggesting that histone TH2B, the variant of H2B, existed in nucleosomes only as TH2B X TH2B and that TH2B X H2B was not likely to exist in chromatin. Sucrose gradient ultracentrifugation of mixtures of MNT and IgTH2B revealed that when excess amounts of immunologically active IgTH2B were present, complexes of higher sedimentation coefficients than MNT X IgTH2B were formed, but with limited amounts of active IgTH2B, only MNT X IgTH2B was formed. When purified IgTH2B was coated on polystyrene tubes and incubated with MNT, those MNT immobilized by the tube-coated IgTH2B adsorbed IgTH2B from diluted antiserum during subsequent incubation. Those results suggested the absence of steric hindrance in the binding of IgTH2B to MNT X IgTH2B. When MNT was coated on polystyrene tubes and incubated with DNase and then with dilute anti-TH2B antiserum, it was found that DNase digestion increased the binding of immunoglobulin to the tubes approximately 76%. Interaction of chromatin subunits of rat liver nuclei (MNL) with anti-TH2B antiserum was negligible, but DNase digestion of MNL coated on tubes was followed by considerable interaction with anti-TH2B antiserum. Those results indicated DNase unmasked at least part of the determinants encased by DNA. Anti-H2B immunoglobulin (IgH2B) interacted with histone H2B and TH2B to the same extent, and interacted significantly to a lesser extent with either MNT or MNL. DNase digestion of MNT and MNL increased binding of IgH2B approximately 170 and 117%, respectively.     

Isolation and functional analysis of human B cell populations. I. Characterization of the B1+B2+ and B1+B2- subsets

Distinct populations of human B lymphocytes can be identified by their expression and/or co-expression of the B cell-restricted antigens B1 and B2. Dual fluorochrome staining and flow cytometric cell sorting permitted the isolation of the B1+B2+ and B1+B2- cells to homogeneity. In contrast, very few B1-B2+ cells were obtainable from normal lymphoid organs. Virtually all B1+B2+ cells expressed IgM and IgD, but lacked IgG and the plasma cell antigens PCA-1 and PC-1, whereas the B1+B2- cells more frequently expressed IgG, PCA-1 and PC-1. Both populations were noncycling and were composed of similar percentages of small and large cells. The B1+B2+ cells proliferate to anti-mu or to anti-mu + PHA-LCM, but not to PHA-LCM alone. They require both T cells and PWM to produce Ig. In contrast, B1+B2-cells do not significantly proliferate to anti-mu, PHA-LCM, or anti-mu and PHA-LCM. They produce Ig in response to T cells alone without PWM. These phenotypic and functional observations provide preliminary evidence that these populations are distinct and that the B1+B2+ cell may be a "resting" B cell, whereas the B1+B2- cell appears to be more "differentiated." The present studies further suggest that they will also be helpful in characterizing B cells in some human disease states. We believe that the identification and isolation of these and similar subsets of B cells defined by differing cell surface phenotype should aid our understanding both of normal B cell differentiation and of B cell disease states.     

Phylogenetic diversity in the genus Bacillus as seen by 16S rRNA sequencing studies

Comparative sequence analysis of 16S ribosomal (r)RNAs or DNAs of Bacillus alvei, B. laterosporus, B. macerans, B. macquariensis, B. polymyxa and B. stearothermophilus revealed the phylogenetic diversity of the genus Bacillus. Based on the presently available data set of 16S rRNA sequences from bacilli and relatives at least four major "Bacillus clusters" can be defined: a "Bacillus subtilis cluster" including B. stearothermophilus, a "B. brevis cluster" including B. laterosporus, a "B. alvei cluster" including B. macerans, B. maquariensis and B. polymyxa and a "B. cycloheptanicus branch".     

Occurrence of cold-labile NAD-specific glutamate dehydrogenase in Bacillus species

A nicotinamide adenine dinucleotide-specific glutamate dehydrogenase (NAD-GluDH; EC 1.4.1.3) inactivated by incubation at low temperatures was detected in several species of the genus Bacillus, including strains of B. cereus, B. laterosporus, B. lentus, B. panthotenicus, B. pasteurii, B. sphaericus, B. stearothermophilus, B. subtilis and B. thuringiensis. Incubation of cell-free extracts of these strains at 0 degrees C resulted in an 80-100% inactivation of NAD-GluDH activity within 120 min. The addition of 20% glycerol protected the enzyme from this inactivation in the cold. Strains of B. fastidiosus, B. licheniformis, B. macerans, B. megaterium and B. pumilus were found to lack NAD-GluDH activity.     

Histamine-sensitizing Factor, Mouse-protective Antigens, and Other Antigens of Some Members of the Genus Bordetella

The three species of the genus Bordetella-B. pertussis, B. parapertussis, and B. bronchiseptica-have many antigens in common. Studies on representative strains of these species have shown that there are only a few specific antigens in each species. Whole-cell vaccines and extracts from B. pertussis contained specific mouse-protective antigen and a histamine-sensitizing factor. In addition, whole-cell vaccines and some saline extracts protected mice against intracranial challenge with B. bronchiseptica. Cells and a saline extract of B. parapertussis also protected against B. bronchiseptica but not against B. pertussis. Whole cells of B. bronchiseptica protected against B. bronchiseptica, but only one of three saline extracts protected against this challenge. Neither whole cells nor saline extracts from B. bronchiseptica protected against B. pertussis. The antigen in B. pertussis responsible for cross-protection against B. bronchiseptica was less resistant to heat than the protective antigen in B. bronchiseptica. Since histamine-sensitizing factor was not detected in B. bronchiseptica or B. parapertussis cells or extracts, this factor is not required to protect mice against B. bronchiseptica challenge. Whether B. pertussis vaccines protected against B. bronchiseptica by a nonspecific mechanism was not established, but it is clear that the specific antigen responsible for protection against B. pertussis was found only in B. pertussis and not in B. bronchiseptica or B. parapertussis.     

B48 is preferentially translated over B100 in cells with increased endogenous apo B mRNA

We recently demonstrated that expression of BHMT in McArdle RH-7777 (McA-BHMT) cells increases apo B mRNA abundance, leading to parallel increases in apo B secretion. The ratio of unedited to edited apo B mRNA was unchanged by BHMT expression. Based on the observation that secretion of B48 is increased relative to B100 in McA-BHMT cells, current studies now include comparison of B48 and B100 synthesis and intracellular degradation. Minor differences in co- and posttranslational degradation were unable to account for relative increase in B48 secretion, and the disappearance kinetics of B48 were similar in McA-BHMT and control cells. Consistent with the increase in endogenous apo B mRNA in McA-BHMT cells, B48 synthesis is increased significantly. In contrast, synthesis of B100 was not significantly increased. We conclude that B48 is preferentially translated compared to B100 when endogenous apo B mRNA is increased.     

The effect of B chromosomes on fitness components inAegilops speltoides Tausch

The effect of B chromosomes (Bs) on various components of vigour and fertility inAegilops speltoides was studied. We designed three types of synthetic populations. In the first type we compared plants from the localities Haifa (which has Bs in nature) and Ashkelon (which has not). Non significant differences were found between the plants from both populations, and between B carriers and non carriers among Haifa individuals. In the second synthetic population we compared 0B, 1B, 2B, 3B and 5B plants from Haifa. We found that vigour variables were not affected by the presence of Bs, while fertility variables were significantly correlated with B number, in such a way that 1B plants produce more grains per plant than any other constitution, while 5Bs produce a remarkable deleterious effect. In the third type of synthetic populations we compared plants with 0B and 1B, 0B and 2B, 0B and 3B, and 0B and 5B. In this case we also found that 1B plants were the most fertile, but the variation of reproductive fitness was higher from plot to plot within the same B class than among B classes. We conclude that the effect of B chromosomes on the fitness variables that we have estimated is close to neutrality in this species. We discuss the relation between the strength of the mechanism of accumulation and the deleterious effects of B chromosomes.