Line CB Research Articles

Comparative Analysis of Different Inbred Chicken Lines Highlights How a Hereditary Inflammatory State Affects Susceptibility to Avian Influenza Virus.

Evidence suggests that susceptibility to avian influenza A virus in chickens is influenced by host genetics, but the mechanisms are poorly understood. A previous study demonstrated that inbred line 0 chickens are more resistant to low-pathogenicity avian influenza (LPAI) infection than line CB.12 birds based on viral shedding, but the resistance was not associated with higher AIV-specific IFNγ responses or antibody titres. In this study, we investigated the proportions and cytotoxic capacity of T-cell subpopulations in the spleen and the early immune responses in the respiratory tract, analysing the innate immune transcriptome of lung-derived macrophages following in vitro stimulation with LPAI H7N1 or the TLR7 agonist R848. The more susceptible C.B12 line had a higher proportion of CD8αβ+ γδ and CD4+CD8αα+ αVβ1 T cells, and a significantly higher proportion of the CD8αβ+ γδ and CD8αβ+ αVβ1 T cells expressed CD107a, a surrogate marker of degranulation. Lung macrophages isolated from line C.B12 birds expressed higher levels of the negative regulator genes TRIM29 and IL17REL, whereas macrophages from line 0 birds expressed higher levels of antiviral genes including IRF10 and IRG1. After stimulation with R848, the macrophages from line 0 birds mounted a higher response compared to line C.B12 cells. Together, the higher proportion of unconventional T cells, the higher level of cytotoxic cell degranulation ex vivo and post-stimulation and the lower levels of antiviral gene expression suggest a potential role of immunopathology in mediating susceptibility in C.B12 birds.

EVALUATION OF THE PROMISING COTTON LINE (CB 58 × Giza 90) IN SOUTH EGYPT

The promising cotton line CB 58 x Giza 90 was grown compared with Giza 90 and Giza 95 cultivars and a new promising line at four locations during 2016 and 2017 seasons (eight environments) in South Egypt. The randomized complete block design with four replications was used at each location. The characters studied were seed cotton yield, lint yield, boll weight, lint percentage, seed index, lint index, fiber length, length uniformity ratio, micronaire reading and fiber strength. Significant differences were detected among genotypes for all traits except boll weight. In addition, significant differences were found among environments for all characters. Genotype by environment interaction was significant for all studied characters except boll weight, seed index and lint index. The promising line CB 58 x Giza 90 surpassed the commercial cultivars for yield traits but, it did not differ significantly with the promising line [((G.83 x G.80) x G.89) × Australian] for lint percentage. The promising cotton line CB 58 x Giza 90 was equal to the commercial cultivars for length uniformity ratio. The commercial cultivars recorded the highest values for seed and lint index. Giza 95 cultivar recorded the best values for fiber characters. The promising line CB 58 x Giza 90 produced the highest values for most characters at sohag location where it surpassed the commercial cultivars for yield characters and with no significant difference for fiber length. Therefore, it seems necessary to continue evaluating the new cotton genotypes at several locations over an adequate number of years before recommending a given variety for a certain location. Giza 90 cultivar was considered stable across a wide range of environments. Giza 95 cultivar was less sensitive to environmental changes. So it could be more adapted to poor- yielding environments. The genotypes, Giza 90 and the two lines had more general adaptability to all environments.

Discussion of “Experimental Validation of Suction Stress Characteristic Curve from Nonfailure Triaxial K0 Consolidation Tests” by Seboong Oh, Ning Lu, Tae-Kyung Kim, and Young Huy Lee

The authors’method to obtain the suction stress characteristic curve from nonfailure triaxial K0 consolidation tests is fully granted. The discusser’s point of view is that the suction stress can be calculated from the nonfailure triaxialK0 consolidation test results directly, and the suction stress is not a unique function of the matric suction. In Fig. 1, line OA is theK0 consolidation line of the saturated soil in which matric suction is equal to 0. Line CB is the K0 line of the unsaturated soil with a matric suction ua. From the authors’Eq. (16), the suction stress for both the saturated soil (line OA) and the unsaturated soil (line CB) in theK0 consolidated tests can be calculated as

V- src oncogene-specific carboxy-terminal peptide is immunoprotective against Rous sarcoma growth in chickens with MHC class I allele B-F12

B 12 haplotype of the inbred chicken line CB ( B 12/ B 12) contains, like the bulk of chicken MHC( B) haplotypes, only a single dominantly expressed class I molecule (B-F). The peptide binding motifs for this major B-F12 molecule in chickens of Rous sarcoma regressor line CB ( B 12/ B 12) have been determined. Using stringent and relaxed motifs, several peptides were found in the v- src molecule of the PR-RSV-C, but most of these peptides are identical with that of endogenous c- src. Only the v- src C-tail peptide 517–524 (LPACVLEV) contains critical anchor amino acids (valine at positions 5 and 8) and shows a sequence different from the corresponding c- src peptide. This v- src C-tail peptide up-regulates expression of the B-F12 class I molecule on PBL, as assessed by FACS analysis, and stimulates T cell proliferation in a [ 3 H ]thymidine uptake assay. A protective effect of the immune response to LPACVLEV against RSV challenge was demonstrated in CB ( B 12/ B 12) chickens immunised with peptides encapsulated in liposomes.

Эндогенные ALV-родственные ретровирусы в ДНК кур линии СВ

Эндогенные ALV-родственные ретровирусы в ДНК кур линии СВ

Analysis of genetic regulation of chicken spontaneous autoimmune thyroiditis, an animal model of human Hashimoto's thyroiditis.

We analyzed the genetic regulation of spontaneous autoimmune thyroiditis (SAT) by means of crosses between Obese strain (OS) chickens with the disease, and healthy inbred chicken of line CB. Mononuclear cell infiltration of the thyroid was used as a criterion for the disease. We confirmed the existence of one recessive gene, regulating the susceptibility of the thyroid gland to autoimmune attack. From the frequency of progeny with the thyroid infiltration in backcross and F2 generations, we presume the existence of one or two additional dominant genes coding for abnormal reactivity of the immune system. The total number of genes regulating SAT is therefore a maximum of three. We attempted to identify disease-specific transcripts responsible for the initiation of the disease using suppression subtractive hybridization of RNA prepared from OS and CB thyroid lobes, obtained from 3-day-old chicks. From forward and reverse subtractions, we recovered a fragment mixture in the range of 300 bp to 1.5 kb. In total, 768 clones were screened and 9 were sequenced. Four of them represent unknown sequences. Two, specific for OS thyroid, correspond to envelope genes of avian endogenous viruses (ev)-1, -3 and -6. The expressed product of an env gene could be iodinated in the thyroid gland and become involved in thyroglobulin metabolism. This may be another possible mechanism driving SAT, as iodine modulates SAT in the chicken. Further experiments will be required to prove this hypothesis. Two thyroid-specific clones had significant alignment to human thyroglobulin, and one clone to human coatomer protein. We analyzed, by RFLP and RNA dot blots, cosegregation between clones for the env gene of endogenous viruses as the most promising candidate for involvement in driving SAT; we did not find differences at the DNA and RNA levels. We can possibly therefore rule out a simple involvement of env genes with the initiation of disease.

Immune Response to NIP-BSA and Brucella abortus in Two Pairs of B Congenic Chicken Lines.

Humoral immune responses to NIP-BSA and Brucella abortus (BA) in two pairs of B congenic chicken lines were examined. Inbred line CB (B12B12) and line HA (B11B11), selected for graft-vs-host reaction (GVHR) high, served as the genetic background of the experiment. Chickens from these lines were crossed to produce F1 progeny and then backcrossed to CB and HA lines, respectively, upto nine generations for the production of CBH (B11B12) and HCB (B11B12) lines. At 14 wk of age, 40 birds from the respective lines were injected intravenously with equally mixed one ml of the above antigens. Blood samples were taken from the chickens at 7 and 14d of post primary immunization (PPI) and post econdary immunization (PSI). Total antibody titer to NIP was significantly higher in the CB line than other lines at 7 d of PPI and 7 and 14d of PSI. Anti-BA total antibody titer was also significantly higher in the CB line than other lines at 7d of PPI, and than HA and HCB lines, at 14d of PSI. The CB line also showed significantly higher mercaptoethanol (ME) resistant antibody titer to BA than HA line as well as HCB line at 14d of PPI, and than other lines 7 and 14d of PSI, except, HA line at 14d of PSI. Total antibody titer to bovine serum albumin (BSA) was significantly higher in the HA line, compared to other lines, at 7d of PPI and PSI, and than CBH line at 14d of PPI and PSI. A significant difference between the CBH and HCB lines, having the same B11B12 genotype, was observed for total antibody titers to NIP at 7 and 14d of PPI and PSI, and to BSA at 14d of PSI. These results further indicate that genes of the non MHC as well as the MHC gene play a vital role in the regulation of immune responses in chickens.

Immunocompetences in Two Pairs of B Congenic Chicken Lines.

Influences of chicken major histocompatibility complex (B) on immunoglobulin M (IgM) and G (IgG) production, cell mediated immune response, and immunity against different disease agents were examined in two pairs of B congenic chicken lines. Inbred line CB (B12 B12) and line HA (B11 B11), selected for graft-vs-host reaction (GVHR) high, were served as the genetic background for the experiment. Heterozygous genotype birds from these lines (B11 B12) were backcrossed to the CB and HA ones, respectively, upto eight generations for the production of CBH (B11 B12) and HCB (B11 B12) lines. At 10 wk of age, IgM and IgG levels were measured. A significant difference was found between the pairs of congenic lines for the production of serum IgM and IgG, and the heterozygous genotype was involved for higher IgM and IgG production than the homozygous genotypes. Cell mediated immune response, measured by splenomegaly index at 12 wk of age, was significantly higher in the CBH line than the CB line. The HA line showed significantly lower immunity against Mycoplasma gallisepticum, Mycoplasma synoviae, and Coryza type C than the HCB line. On the other hand, the HCB line was associated with lower immunity to Coryza type A. These results demonstrated that genes of the MHC had a significant effect on serum IgM and IgG production. Splenomegaly index and immunity to disease agents were also influenced by the genes of the MHC. A heterozygotic advantage of B haplotypes on IgM and IgG production, splenomegaly index, and immunity to MG, MS, and CC were observed.

Src-specific immunity in inbred chickens bearing v-src DNA- and RSV-induced tumors.

The growth pattern (progression/regression) of v-src DNA- and Rous sarcoma virus (RSV)-induced tumors was analogous on a panel of inbred chicken lines. The decisive role of the major histocompatibility complex [Mhc(B)] alleles in resistance to the progression of these tumors was formally proved in segregating backcross populations. The immune mechanism of tumor regression was demonstrated by both in vivo and in vitro assays. A protective effect of v-src-specific immunity against RSV challenge was shown in Rous sarcoma regressor, line CB (B12/B12). Immune cells from regressors of v-src DNA-induced tumors can protect syngeneic hosts from the development of tumor after challenge with both v-src DNA and RSV. Suppression of RSV-induced tumor cell growth in vitro was also achieved by the use of cocultivation with spleen cells from chickens in which v-src DNA-induced tumors had regressed. This in vitro sarcoma-specific response was Mhc(B)-restricted. Chickens of the congenic Rous sarcoma progressor line CC (B4/B4) are sometimes able to regress v-src DNA-induced tumors, but immune cells can only slow the growth of v-src DNA-induced tumors in syngeneic hosts. This suggests that the primary reason for the susceptibility of CC chickens is a weak v-src-specific immune response. Furthermore, some of the v-src DNA-induced tumors were transplantable across the Mhc(B) barrier. The growth of tumor allografts was able to be facilitated when immunological tolerance to the B-F/L region antigens (class I and class II) had been established. This demonstrated that a high tumorigenicity of the transplantable tumor was not due to the lack of Mhc(B) antigens on tumor cells.

Non-specific Morphological Changes in the Organs of Chickens Infected Experimentally with Marek's Disease Virus

Halouzka, R., V. Jurajda: Non,Specijic Morphological Changes in the Organs of Chickens Injected Experimentally with Marek's Disease Viruses. Acta vet. Brno, 61, 1992: 123-131. Description is given of hitherto unnoticed pathological changes in the organs of Hybro, White Hisex, Fl inbred line CB x IA and Brown Leghorn chickens after experimental infection with oncogenic strains (GA, field isolates VUB-83 and RB -IB) and non-oncogenic strains (field isolates M and K) of Marek's disease virus (MDV). The chickens were infected on the 2nd post-hatching day and sacrificed at weekly intervals up to the 5th week p. i. Pathomorphological examination re­ vealed, in addition to MD-specific and cytolytic morphological changes in the organs, the presence of syncytial formations, granulomas, corpuscle-like structures, dystrophic changes in follicular epithelium-associated (FAE) cells and changes in the corticomedullary membrane of the bursa of Fabricius follicles, hypertrophy and hyperplasia of Hassall's corpuscles, hyperplasia of myoid elements in the thymus, spheroids in peripheral nerves and glomerulopathy. The changes observed in the lymphoid organs are regarded as a morphological manifestation of local cellular defence, and the changes in the nerves and kidney as an autoimmune process and, consequently, as non-specific of MD. Their de­ scription contributes to a better understanding of the complex pathogenesis of Marek's disease of poultry.

Chicken major histocompatibility complex congenic lines differ in the percentages of lymphocytes bearing CD4 and CD8 antigens

In the experiments to be described two congenic inbred lines CB and CC and two recombinant lines CB.R1 and CC.R1 were used. All four lines differ only in regard to the major histocompatibility complex (MHC). To determine the percentage distributions of the two cell subsets in peripheral blood lymphocytes (PBL) in these lines, monoclonal antibodies to these two antigens were used. By FACScan there were more CD4+PBL in CB and CB.R1 lines (share B-F/B-L region, controlling class I/class II antigens with line CB) than CC and CC.R1, while the reverse was true with CD8+ subsets. There were more CD8+ PBL in the CC and CC.R1 lines and less in CB and CB.R1 lines. The ratio of CD4+ to CD8+ in CB chickens was 3.4 +/- 0.2 and in CC chickens 1.6 +/- 0.1.