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Lymphocyte Antigen (lymphocyte + antigen)

Distribution by Scientific Domains

Medical Sciences	88%

Selected Abstracts

Lymphocyte antigens in sheep: linkage to the MHC class II DRB1 gene

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4 2001
B. M. Jugo
Summary In this work a typing battery of sera was developed to test lymphocyte antigens in sheep. Eight antigens were detected in a Latxa sheep sample. The serological determination of these antigens is described. As some of the detected antigens segregated in close linkage with class II DRB1 SSCP patterns in two half-sib families, we can conclude that they are coded by genes located in the MHC. Gene frequencies were very similar in Latxa Mutur Gorria and Latxa Mutur Beltza, the two varieties of the Latxa breed. Although few animals were typed in the comparison with other typing sera, it seems that two of our sera clusters detect the same antigens as those detected by other research groups working in other breeds with their own typing batteries. [source]

Fucosyltransferase VII-positive, skin-homing T cells in the blood and skin lesions of atopic dermatitis patients

EXPERIMENTAL DERMATOLOGY, Issue 3 2008
Yoshiko Mizukawa
Abstract: Patients with atopic dermatitis (AD) have an abnormally increased frequency of cutaneous lymphocyte antigen (CLA)+ Th2 cells responsible for local inflammation; however, this is paradoxical, given the well-recognized defective capacity of Th2 cells to migrate to the skin sites of inflammation. These discrepant observations would stem from the ambiguity of CLA+ T cells, because CLA does not represent the epitope required for binding to E-selectin but the epitope generated by fucosyltransferase VII (Fuc-TVII) and because skin-homing T cells are composed of three distinct subpopulations; Fuc-TVII+ E-selectin ligand (ESL)+ CLA,, Fuc-TVII+ ESL+ CLA+ and Fuc-TVII, ESL, CLA+ cells. We therefore asked which subpopulations of skin-homing Th2 cells could be increased in the blood and skin lesions of AD. We analysed the frequencies of the three subpopulations in purified CD4+ peripheral blood T cells from AD patients and healthy controls by immunohistochemistry and flow cytometry. The Fuc-TVII+ CLA+ or CLA+ ESL+ CCR4+ cells were dramatically increased in frequency not only in the blood but also in the skin lesions of AD patients and this increase was related to the severity of the clinical symptoms. Our data indicate the clinical importance of identifying skin-homing T cells with the potent capacity to migrate into the skin by analysing their Fuc-TVII expression and E-selectin binding ability in patients with AD. [source]

Single nucleotide polymorphisms and haplotype of MD-1 gene associated with high serum IgE phenotype with mite-sensitive allergy in Taiwanese children

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 6 2007
J. Y. Wang
Summary MD-1 (myeloid differentiation 1; also known as Ly86, lymphocyte antigen 86), interacting with RP105, plays an important role in Toll-like receptor 4 (TLR4) signalling pathway. It has been suggested to be involved in the pathological mechanism of inflammation and atopic diseases. The purpose of this study was to investigate the genetic association between single nucleotide polymorphisms (SNPs) of MD-1 promoter and coding region and mite-sensitive allergy in Taiwanese children. We conducted a case-control study on 237 controls and 281 allergic patients sensitive to Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) by genotyping 35 SNPs in MD-1 gene region. In the promoter region we identified three SNPs, rs1334710, rs4959389, and rs977785 that are associated with mite-sensitive allergy in Taiwanese children. The P -values ranged from 0.0150 to 0.009. The haplotypes including promoter region were also associated with mite-sensitive allergy. Our results suggested that MD-1 could be a susceptible gene for mite-sensitive allergy in Taiwanese children. [source]

Proliferative alloresponse of T-cytotoxic cells identifies rejection-prone children with steroid-free liver transplantation

LIVER TRANSPLANTATION, Issue 8 2009
Chethan Ashokkumar
Donor-induced and third-party,induced proliferation of T-helper and T-cytotoxic (Tc) cells and their naïve and memory subsets was evaluated simultaneously in single blood samples from 77 children who received steroid-free liver transplantation (LTx) after induction with rabbit anti-human thymocyte globulin. Proliferation was measured by dilution of the intravital dye carboxyfluorescein succinimidyl ester (CFSE) in a 3- to 4-day mixed lymphocyte response coculture. The ratio of donor/third-party,induced proliferated (CFSElow) T-cells was reported as the immunoreactivity index (IR) for each subset. Rejectors were defined as those who experienced biopsy-proven acute cellular rejection within 60 days of the assay. IR > 1 signified increased risk of rejection, and IR < 1 implied decreased risk. Demographics for 32 rejectors and 45 nonrejectors were similar. Proliferated CFSElow T-cells and subsets were significantly higher among rejectors compared with nonrejectors. In 33 of 77 randomly selected children, logistic regression, leave-one-out cross-validation, and receiver operating characteristic analyses showed that the IR of Tc cells was best associated with biopsy-proven rejection (sensitivity > 75%, specificity > 88%). Sensitivity and specificity were replicated in the remaining 44 children who composed the validation cohort. IR of CFSElow Tc cells correlated significantly with IR of proinflammatory, allospecific CD154+ Tc cells (r = 0.664, P = 0.0005) and inversely with IR of allospecific, anti-inflammatory, cytotoxic T lymphocyte antigen 4,positive Tc cells (r = ,0.630, P = 0.007). In conclusion, proliferative alloresponses of Tc cells can identify rejection-prone children receiving LTx. Liver Transpl 15:978,985, 2009. © 2009 AASLD. [source]

Genetic variation in BoLA microsatellite loci in Portuguese cattle breeds

ANIMAL GENETICS, Issue 1 2009
C. Bastos-Silveira
Summary Major histocompatibility complex (MHC) typing based on microsatellites can be a valuable approach to understanding the selective processes occurring at linked or physically close MHC genes and can provide important information on variability and relationships of populations. Using microsatellites within or in close proximity with bovine lymphocyte antigen (BoLA) genes, we investigated the polymorphisms in the bovine MHC, known as the BoLA, in eight Portuguese cattle breeds. Additional data from non-BoLA microsatellite loci were also used to compare the variability between these regions. Diversity was higher in BoLA than in non-BoLA microsatellites, as could be observed by the number of alleles, allelic richness and observed heterozygosity. Brava de Lide, a breed selected for aggressiveness and nobility, presented the lowest values of observed heterozygosity and allelic richness in both markers. Results from neutrality tests showed few statistically significant differences between the observed Hardy,Weinberg homozygosity (F) and the expected homozygosity (FE), indicating the apparent neutrality of the BoLA microsatellites within the analysed breeds. Nevertheless, we detected a trend of lower values of observed homozygosity compared with the expected one. We also detected some differences in the levels of allelic variability among the four BoLA microsatellites. Our data showed a higher number of alleles at the BoLA-DRB3 locus than at the BoLA-DRBP1 locus. These differences could be related to their physical position in the chromosome and may reflect functional requirements for diversity. [source]

CTLA4 exon 1 and promoter polymorphisms in patients with multiple sclerosis

ACTA NEUROLOGICA SCANDINAVICA, Issue 6 2009
G. Yousefipour
Objective ,, The polymorphisms of exon 1 (+49 A/G) and promoter regions (,1722 T/C, ,1661 A/G and ,318 C/T)of cytotoxic T lymphocyte antigen 4 (CTLA4) and also haplotypes constructed from mentioned loci were investigated amongst 153 Iranian patients with definite multiple sclerosis (MS) and 190 healthy controls. Methods ,, The polymorphisms were genotyped by PCR-restriction fragment length polymorphisms and PCR-amplification refractory mutation system. The 4-locus haplotypes were estimated by Arlequin software (University of Berne, Berne, Switzerland). Results ,, Preliminary results showed significant increase of +49 G allele and ,1661 AG genotype, as well as TGCA haplotype among patients than controls (P < 0.036, P = 0.009 and P < 0.010, respectively). The distribution of ,1722 T/C, ,1661 A/G, ,318 C/T and +49 A/G (TACA) haplotype, from the contrary, was observed to be significantly increased among controls (P < 0.001). Conclusions ,, After Bonferroni correction, the results provide preliminary evidence that CTLA4 genetic variation at ,1661 locus may render Iranian individuals to be more susceptible to MS, whereas harboring TACA haplotype might be protective. [source]

Cytotoxic T lymphocyte antigen 4 polymorphisms and allergic asthma

CLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2004
A. J. M. Van oosterhout
First page of article [source]

Lymphocyte antigens in sheep: linkage to the MHC class II DRB1 gene

New frontiers of assisted reproductive technology (Chien Tien Hsu Memorial Lecture 2007)

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2009
P. C. Ho
Abstract Many significant advances have been made in assisted reproductive technology since the birth of the first baby conceived with in vitro fertilization and embryo transfer. The development of recombinant gonadotropins and gonadotropin releasing hormone antagonists helps to simplify the ovarian stimulation. Excessive ovarian stimulation should be avoided because of the risks of ovarian hyperstimulation syndrome and reduction in endometrial receptivity. Maturation of oocytes in vitro has been developed in some centers. It is still uncertain whether techniques such as assisted hatching, blastocyst transfer and pre-implantation aneuploidy screening can improve the live birth rates in assisted reproduction. The introduction of pre-implantation genetic diagnosis for selection of human lymphocyte antigens (HLA) compatible embryos for treatment of siblings has raised ethical concerns. There is a higher risk of obstetric complications and congenital abnormalities even in singleton pregnancies achieved with assisted reproduction. Because of the risks of multiple pregnancies, elective single embryo transfer is increasingly used in good-prognosis patients. With a good freezing program, the cumulative pregnancy rate (including the pregnancies from subsequent replacement of frozen-thawed embryos) is not adversely affected. Improvement in cryopreservation techniques has made it possible to cryopreserve slices of ovarian tissue or oocytes, thus helping women who have to receive sterilizing forms of anti-cancer treatment to preserve their fertility. It is important that the development of the new techniques should be based on good scientific evidence. Ethical, legal and social implications should also be considered before the introduction of new techniques. [source]