Martijn H. Breuning

Two genetic markers closely linked to adult polycystic kidney disease on chromosome 16.

The genetic locus for autosomal dominant adult polycystic kidney disease was recently assigned to chromosome 16 by the finding of genetic linkage to the alpha globin gene cluster. Further study showed that the phosphoglycolate phosphatase locus is also closely linked to both the locus for adult polycystic kidney disease and the alpha globin gene cluster. These findings have important implications for the prenatal and presymptomatic diagnosis of adult polycystic kidney disease and for a better understanding of its pathogenesis.

In vitro-isolated human cytotoxic T-lymphocyte clones detect variations in serologically defined HLA antigens

T cells of two donors, JR (HLA-A23, 29; B7,7; G; DRw5) and HG (HLA-A2, 23; B40, w44; Cw4), were stimulated with cells from an HLA homozygous lymphoblastoid cell line JY (HLA-A2, 2; B7,7, C-, DRw4, 6) and cloned by limiting dilution after the third stimulation. Two cytotoxic T-cell (CTL) clones, JR-2-16 (from donor JR) and HG-31 (from donor HG), were used for detailed studies. The results of a panel study using lymphocytes from HLA-typed individuals and a study with two HLA recombinant families indicate that the antigens recognized by the CTL clones JR-2-16 and HG-31 were highly associated with HLA-A2 and HLA-B7, respectively. Blocking studies with a monoclonal antibody recognizing a framework determinant on HLA-A, -B and-C antigens and a monoclonal antibody reacting with HLA-A2 support the notion that JR-2-16 and HG-31 interact with the HLA-A2 and the HLA-B7 antigens per se. However, these clones did not recognize the HLA-A2 and HLA-B7 of all donors typed for these antigens, suggesting that the HLA-A2 and HLA-B7 antigens of these particular donors are variants of the serologically defined HLA antigens. These results indicate that in vitro-derived human CTL clones detect variations in the serologically defined allospecificities and can be used as reagents to elucidate the polymorphism of HLA antigens further.

Localization of HLA on the Short Arm of Chromosome 6

SummaryA detailed marker gene study in a large Dutch kindred segregating for a reciprocal translocation between the chromosomes 6 and 20, t(6;20) (p21;p13), revealed a close linkage between the HLA genes and the breakpoint on the short arm of 6. During this study an apparent peak lod score of 2.9 was obtained at a recombination value of 0.05 for a linkage between HLA and the breakpoint, indicating that the chromosomal region, carrying the HLA genes, is situated near the breakpoint in band 6p21 close to the transition to 6p22.

Anti-H-2 antibodies induced by syngeneic immunization

Alloreactive cytotoxic antibodies were induced in BALB/c mice by syngeneic immunization with normal lymphoid cells. Sixteen out of 41 mice produced antibodies with distinct anti-H-2 specificity. Anti-Kk antibodies were present in all positive sera, but the individual sera produced different reactivity patterns when tested on a panel ofH-2 haplotypes. Absorption and immunoprecipitation experiments confirmed the H-2 specificity of the syngeneic sera.We hypothesize that virus-modified H-2d structures have triggered alloreactive B-cell clones to produce anti-H-2 antibodies.

Partial trisomy 6p due to familial translocation t(6;20)(p21;p13)

SummaryCytogenetic findings in a case of partial trisomy 6p due to a translocation t(6;20)(p21;p13) and eleven balanced translocation heterozygotes are described.The clinical data of the proposita are compared with those of five other published cases. A partial trisomy 6p syndrome is postulated, characterized by: low birth weight, psychomotor retardation, craniofacial abnormalities (such as high prominent forehead, large fontanel, wide sagittal suture, blepharoptosis, low-set and/or malformed ears), congenital heart malformation, small kidneys, and proteinuria. Linkage studies have shown that the breakpoint in chromosome 6 involved in this translocation is close to the HLA gene cluster.

Natural H-2-specific antibodies in sera of aged mice.

Alloantigens are regularly demonstrable by antibodies from alloimmunized individuals, whereas naturally occurring alloantibodies, which could be detected only against a small proportion of alloantigens, occur irregularly and their origin is enigmatic (Perrault 1973, van Loghem 1978). Human Aand B-blood group-specific antibodies are directed towards antigens of a polysaccharide nature which are commonly present in the microbial, animal, and plant worlds. Naturally occurring erythrocyte antibodies to chicken MHC antigens have been found in xenogeneic and allogeneic sera (Longenecker and Mosmann 1980). However, naturally occurring HLA antibodies have been found only in the sera of some patients with myeloma (Smith et al. 1974, Falk et al. 1973), carcinoma (Vos et al. 1975) and chronic immunological disorders (Terasaki et al. 1970, Waters et al. 1971, Collins et al. 1973) and in one case of a nontransfused healthy male (Lepage et al. 1976). We report in this paper on the presence of naturally occurring lymphocytotoxic H-2-specific antibodies in sera from about 25 percent of aged C57BL mice. Some of these antibodies had a high titer and sera from individual mice contained antibodies of different specificities for public H-2 antigens. Thus, age-dependent changes in the regulation of the immunological apparatus and/or modified cell-membrane antigens are implicated in the generation of naturally occurring H-2-specific antibodies. The search for H-2-specific antibodies in aged mice was initiated by experiments in which it was found that individual mice of one highly inbred strain produced alloantibodies with different H-2 specificities (Ivanyi et al. 1978, 1979). During an anti-H-2L d (BALB/c-H-2 am2 ant i -BALB/c-H-2 e) immunization, some mice did not produce antibodies reactive with donor cells, although they produced strong cytotoxic antibodies against third-party (H-2 k and H-2 r) cells. We have hypothesized, that these heteroclitic antibodies were not induced by the antigenic

A cloned cytotoxic T-lymphocyte (CTL) line recognizing a subtype of HLA B27

The lymphoblastoid cell-line JY (HLA-A2,2;B7,7;C-; DR4,w6) was used to stimulate T cells from donor HG (HLA-A2,w23; B40,w44; Cw4; DRw6,7). Cloned CTL line were obtained by limiting dilution after tertiary stimulation. Strong cytotoxic activity on stimulator cells was found with all CTL clones obtained. One of the clones (HG-31 recognized a subtype of the HLA-B7 antigen. In this paper, we describe another long-term cloned CTL line (HG-61). This line, when tested on a panel of 107 target cells from unrelated individuals, recognized a subtype of HLA-B27 (B27 K). There was no significant association with any other HLA antigen. The cloned CTLs were T8+ and their cytotoxic activity could be blocked by the monoclonal antibody W6/32 which recognizes a framework determinant on HLA-A, -B, and -C molecules. In families, reactivity with cells of the CTL line (HG-61) segregated with HLA. It is concluded that the CTL line interacts with an antigenic determinant shared between the HLA-B7 antigen and JY and the subtype of HLA-B27 (B27 K), or detects products of a gene closely linked to HLA-B, not revealed by present-day serology.

UNEXPECTED LYMPHO‐CYTOTOXIC REACTIONS OF ANTI‐H‐2 SERA ON NORMAL LYMPH‐NODE CELLS: ARE THEY DUE TO ALTERED H‐2 STRUCTURES OR ANTI‐VIRAL ANTIBODIES?

When testing the serum of an individual anti‐H‐2 immunized mouse (B10 x A.SW)F1 anti‐B10.M by the routine micro‐lymphocytotoxicity test on lymph‐node cells, unexpected antibodies were found. The most striking finding was that after absorption of anti‐H‐2.8 antibodies with B10.A(2R) (Kk) cells, antibodies remained which reacted with AKR, B10.AKM and B10.A V + mice while B10.A V‐, B10.BR and C3H mice were negative. While all these strains share the Kk allele, only the positively reacting strains express high titres of infectious RNA turnover viruses. Unexpected reactions were observed also with H‐2d, H‐2j and H‐2r cells and absorption experiments indicated two or three antibody populations.