Douglas G. Gilmour

Nomenclature for chicken major histocompatibility (B) complex.

1 Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois 60115 z Houghton Poultry Research Station, Huntingdon, Cambs PE17 2DA, United Kingdom 3 The Wistar Institute, Thirty-Sixth Street at Spruce, Philadelphia, Pennsylvania 19104 4 Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, New York 10016 5 College de France, Laboratoire de M6dicine Exp6rimentale, 11, Place Marcelin-Berthelot, 75231 Paris, Cedex 05, France 6 Institute for General and Experimental Pathology, University of Innsbruck, Fritz-Pregl-Strasse 3, A-6020 Innsbruck, Austria 7 Institute for Experimental Immunology, University of Copenhagen, N0rre Alle 71, DK-2100 Copenhagen 0, Denmark s Department of Immunology and MRC Group of Immunoregulation, University of Alberta, Edmonton, Alberta, Canada 9 Department of Animal Science, Iowa State University, Ames, Iowa 50011 10 Basel Institute for Immunology, Grenzacherstrasse 487, CH-4005 Basel, Switzerland ~1 Department of Avian Medicine, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30605 a Department of Medical Microbiology, Turku University, Turku, Finland 20520

Bu-1 andTh-1, two loci determining surface antigens of B or T lymphocytes in the chicken

Alloantisera were prepared by reciprocal immunizations with bursal or thymic lymphoid cells between chickens of two inbred lines identical at theB major histocompatibility locus. In cytotoxic assays, antibursa sera were specific for donor-line bursa cells without absorption; antithymus sera were similarly specific for donor-line thymus cells. Both types of sera cytolyzed some peripheral lymphoid cells from spleen, bone marrow, and blood. Absorption of either type of serum with peripheral blood leukocytes removed all cytotoxic reactivity for central lymphoid cells. The inheritance of the alloantigens detected by these specific antisera was studied in F1, F2, and backcross progeny from the two lines. Phenotypes were determined by a method in which antisera preabsorbed with progeny leukocytes were reacted against51Cr-labeled bursal or thymic cells from chickens of both lines. The results established two independent autosomal loci-Bu-1 andTh-1-determining antigens expressed, respectively, on bursal cells and peripheral B lymphocytes or on thymic cells and peripheral T lymphocytes. Cytotoxic testing of bursal or thymic cells from chickens of other inbred lines and F1 populations led to the tentative conclusion that the number of alleles atBu-1 is restricted, whileTh-1 exhibits considerable multiple allelism.

A T-cell antigen system of chickens: Ly-4 and Marek's disease

A search was made for lymphocyte antigens associated with resistance or susceptibility to the T-cell lymphoma induced by the herpes virus of Mareks disease (MD), the experimental model for Burkitts lymphoma of humans. Antisera were produced by reciprocal immunization with whole blood between an MD-resistant and susceptible line of chickens compatible at the major histocompatibility complex (MHC), and were tested against lymphocytes of both lines. The lymphocytes were not agglutinated, immobilized, or lysed, but their ability to evoke graft-versus-host (GVH) splenomegaly was reduced. This inhibitory activity was line-specific, and these sera had a maximum limiting effect on GVH splenomegaly at a dilution of 1/50 and a minimum at 1/800 dilution. A test based on the differential limitation of GVH splenomegaly by a pair of alloantisera was used to identify the antigens in F1 and F2 generations. The segregation results established a locus,Ly-4, with two codominant alleles,Ly- 4a andLy-4b.Ly-4 is distinct from theA, B, orC blood group loci and from theBu-1 locus determining B-cell antigens, but may be linked to theTh-1 locus determining T-cell antigens (recombination frequency of 32 percent). Tentative evidence was obtained from comparisons of homozygous F2 and F3 progeny for association of theLy-4 allele characteristic of the susceptible line with increased incidence of MD.

Diabetes Mellitus and the Gene for Fanconi's Anemia

An increased prevalence of diabetes mellitus has been found in relatives of eight probands homozygous for the rare recessive syndrome Fanconis anemia. Since many of these relatives are expected to be heterozygous for the gene for Fanconis anemia, this gene may predispose to diabetes in single dose.

H-Y Antigen in the Chicken

To determine whether asymmetrical development of the chicken ovary could be related to differential expression or function of H-Y antigen, the putative ZW ovary inducer, we compared the ability of cells from the left and right gonad to absorb H-Y antibodies in 17-day chick embryos and in one-day-old hatchlings. In addition, we studied uptake of soluble H-Y antigen by gonadal cells in 17-day embryos, one-day-old hatchlings, and young adults. Indications are that H-Y is present in the left gonad of the female, and to a lesser extent in the right, and not in the testes of the male. Our preliminary results indicate moreover that the right ZW gonad may lack receptor sites for soluble H-Y at around the time of hatching. It may be inferred that expression of H-Y antigen is a prerequisite of ovarian development in birds, although it remains to be determined unambiguously whether H-Y is the primary inducer of the ZW gonad or an accessory molecule involved in some intermediate aspect of gonadal development.

Genetics of Ia-like alloantigens in chickens and linkage with B major histocompatibility complex.

Two sets of backcross matings were performed to test for linkage between genes coding for the Ia-like antigens (“Ia”) and the B erythrocyte antigens (Ea-B) of the chicken. Evidence is presented which indicates that the “la” antigens are determined by a single codominant locus and that theEa-B and “Ia” loci are on the same chromosome. Failure to detect a single recombinant between theEa-B and “Ia” loci out of 208 progeny suggests close linkage of the two genes with a map distance of up to about 2 centimorgans. The “Ia” genes are thus included in theB major histocompatibility complex of the chicken.

Effects of a nonapeptide FTS on lymphocyte differentiations in vitro

BACH et al.1,2 have reported the amino acid sequence of a putative thymic hormone isolated from pig serum3, a nonapeptide called FTS (facteur thymique serique). Natural and synthetic FTS showed high activity in the rosette test used as a bioassay1,2. Bioassays for thymic hormones4, however, can be spuriously triggered by many substances of non-thymic origin5, a finding probably related to mediation by a cyclic AMP second signal6. Early steps in B-cell differentiation are also mediated by cyclic AMP (refs 6–9) and comparison of induction of T cells and B cells from committed precursor cells in vitro (the dual induction assay) enables a distinction to be made between selective and non-selective inducing agents7,8. This is exemplified by induction studies in the mouse with thymopoietin10,11 and ubiquitin7,12,13. Bovine thymopoietin selectively induces T-cell differentiation and actually inhibits B-cell differentiation9. By contrast, ubiquitin is non-selective, inducing both T- and B-cell differentiation7. Ubiquitin at high concentrations does not induce differentiation whereas these high concentrations do not impair induction by thymopoietin or other agents8,14. Another feature of induction by ubiquitin is its inhibition by the β-adrenoceptor-blocking drug propranolol, which is without effect on induction by thymopoietin7. We have evaluated synthetic FTS in the dual induction system in the chicken to determine whether it showed inductive selectivity appropriate to a thymic hormone, and have found that it induced non-selective differentiation of both T cells and B cells and closely resembled ubiquitin in its activity.

Influence of Non-MHC T Lymphocyte Alloantigens on Regression of Rous sarcomas in the Chicken

Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 63 regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line 72, although these lines are identical for the major histocompatibility complex (MHC, B complex). They differ, however, at two independent autosomal loci, Ly-4 and Th-1, which determine surface alloantigens of partly overlapping subsets of T lymphocytes. Association of genotypes at these loci with quantitative variation in ability to regress Rous sarcomas was tested in segregating progeny derived from crosses of lines 63 and 72. In the F4 generation chickens of the Ly-4a/Ly-4a, Th-1a/Th-1agenotype (symbolized aa/aa) had significantly higher regressor ability than any of the other three double homozygous genotypes. In F5, all nine genotypes formed by combinations of homozygotes and heterozygotes were tested, and higher regressor ability was shown by the aa/aa, ab/aa, and aa/ab genotypes. These results indicate that higher regression is associated with: (1) interaction between the line 63Ly-4aand Th-1aalleles in homozygous form; and (2) dominance x dominance interaction, in that the a allele at each locus is dominant for higher regression only within the homozygous aa genotype at the other locus.

Immune response differences between two inbred chicken lines identical at the major histocompatibility complex

We compared two of the East Lansing Regional Poultry Research Laboratory inbred chicken lines for immune responses to four antigens injected in Freunds complete adjuvant, and to the chemical oxazolone as a contact sensitizer. Line EL6 chickens gave higher delayed hypersensitivity responses than did EL7 birds to BSA, dodecanoic acid-conjugated BSA, and ferritin, as well as to oxazolone. Line EL6 gave the higher primary antibody responses to the first three of these antigens, but EL7 gave the higher responses to the hapten DNP. Since these lines are identical for theB major histocompatibility complex by serological and functional tests, these results imply the existence of differences in levels of immune responsiveness which are apparently non-MHC-associated.

Genetic interaction between Non-MHC T- and B-cell alloantigens in response to rous sarcomas in chickens

Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 63 regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line RPRL 100, although these lines are identical for the major histocompatibility B complex. They differ, however, at three independent autosomal loci: Ly-4 and Th-1 determine the surface alloantigens of partly overlapping subsets of T lymphocytes, and Bu-1 determines a surface alloantigen of B lymphocytes. The association of genotypes at these loci with quantitative variation in their ability to regress Rous sarcomas was tested in segregating F4 generation progeny derived from crosses of lines 100 and 63. The Ly-4 and Bu-1 genotypes showed association with Rous sarcoma regression, but the Th-1 genotype did not. Chickens of the Ly-4a/Ly-4a, Bu-1b/Bu-1b and Ly-4b/Ly-4b, Bu-1a/Bu-1a genotypes had a significantly higher regressor ability than the other two double homozygous genotypes. These results indicate that higher regression is associated with (1) interaction between the Ly-4 and Bu-1 loci, and (2) complementation between either the line 6 Ly-4a allele and the line 100 Bu-1b allele, or the line 100 Ly-4b allele and the line 6 Bu-1a allele.