PubMed Health⌕ Search

Biomedical subjects

D L Kastner

Publications and source records attributed to D L Kastner.

65 records · Page 4Linked to original sources

Primary in vitro cytotoxic response of NZB spleen cells to Qa-1b-associated antigenic determinants.

We have shown that cytotoxic lymphocytes generated in primary cultures of NZB spleen cells with H-2-identical BALB/c or B10.D2 stimulator cells exhibit specificity for Qa-1b-associated antigenic determinants. This unidirectional cytotoxicity constitutes the initial demonstration of a primary in vitro response to antigens of the Qa-Tla system. Such responses do not require H-2 homology between effector and target cells in the assay system. In fact, when H-2Dd homologous target cells were employed there was little, if any, evidence for development of primary H-2-restricted responses to minor locus histocompatibility antigens or viral antigens. In view of the recently defined role of Qa-1+, Ly-1,2,3+ cells as regulators of antibody responses, and of the deficiency of such cells in NZB mice, the observation of hyperreactivity for determinants of this system may be relevant to the development of autoimmunity in these animals.

Animals↗

Regulation of alloantigen-induced cytotoxic responses by concanavalin A-activated lymphoid cells: suppression by antigen elimination.

Spleen cells activated by concanavalin A (Con A) and subsequently irradiated with 1500 R were able to suppress the primary in vitro cytotoxic lymphocyte (CL) response of syngeneic splenocytes to H-2 disparate targets. Similarly activated and irradiated BALB/c (H-2d) splenocytes which were cultured with C57BL/6 (H-2b) stimulators for 24 hr developed cytotoxicity for H-2b, but not H-2d, tumor cell targets. This suggested that Con A-activated cells allogeneic to the stimulator might suppress the development of cytotoxic lymphocytes by eliminating antigen early in mixed leukocytes culture. This hypothesis was supported by the observation that suppression of primary cytotoxic responses was overridden by the use of greater numbers of stimulator cells. Moreover, Con A-activated (A X B)F1 lymphocytes suppressed the response of parent A to the H-2 disparate strain C to a much greater extent than they suppressed A-anti-B responses generated in such cultures. Addition of greater numbers of F1 suppressor cells did reveal a suppressive effect not readily explicable on a cytotoxic mechanism, in that modest but significant suppression of the A-anti-B response was observed. Thus, antigen elimination is a major, but not exclusive, mechanism in the suppression of CL responses by Con A-activated cells.

Animals↗

Regulatory mechanisms in cell-mediated immune responses. V. H-2 homology requirements for the production of a minor locus-induced suppressor factor.

A mixed leukocyte reaction suppressor factor is produced by spleen cells sensitized in vivo and restimulated in vitro across non-H-2 antigenic barriers. Cells capable of producing this factor appear in the spleens of minor locus-immunized animals later than in animals sensitized to major histocompatibility complex-encoded antigens. However, both H-2 and non H-2-induced factors suppress proliferative responses to any alloantigen. Splenocytes from animals immunized with H-2-identical, minor locus-disparate cells produce suppressor factor in vitro only when restimulated with cells sharing both H-2 and non-H-2 antigens with the in vivo stimulators.

Animals↗

Analysis of CARD15/NOD2 haplotypes fails to identify common variants associated with rheumatoid arthritis susceptibility.

OBJECTIVES: The CARD15/NOD2 gene product plays an important role in host response to bacterial lipopolysaccharides and bacterial muramyl dipeptide via activation of NF-kappaB in monocytes. Mutations in CARD15 are associated with Crohn's disease (CD), a chronic inflammatory bowel disease. In this study we sought to determine whether CD-associated mutations or any common variants of this gene might contribute to susceptibility to another chronic inflammatory disease, rheumatoid arthritis (RA). METHODS: We genotyped 376 Caucasian RA cases and 376 ethnically matched healthy controls for three CD-associated CARD15 mutations. We also genotyped these 752 individuals for 12 common CARD15 single nucleotide polymorphisms (SNPs), determined the linkage disequilibrium structure of the gene, and compared the frequencies of the common CARD15 haplotypes in the RA cases and controls. RESULTS: None of the CD-associated mutations or the CARD15 SNPs was associated with susceptibility to RA. We also found no significant difference in the frequencies of any of the common haplotypes of the CARD15 gene in RA patients and controls. Our haplotype analysis was consistent with earlier observations that all three CD-associated variants independently arose on the same ancestral haplotype. CONCLUSIONS: These data suggest that CARD15 variants are not associated with RA susceptibility.

Adolescent↗

Genealogy construction in a historically isolated population: application to genetic studies of rheumatoid arthritis in the Pima Indian.

PURPOSE: Due to the characteristics of complex traits, many traits may not be amenable to traditional epidemiologic methods. We illustrate an approach that defines an isolated population as the "unit" for carrying out studies of complex disease. We provide an example using the Pima Indians, a relatively isolated population, in which the incidence and prevalence of Type 2 diabetes, gallbladder disease, and rheumatoid arthritis (RA) are significantly increased compared with the general U.S. population. A previous study of RA in the Pima utilizing traditional methods failed to detect a genetic effect on the occurrence of the disease. METHODS: Our approach involved constructing a genealogy for this population and using a genealogic index to investigate familial aggregation. We developed an algorithm to identify biological relationships among 88 RA cases versus 4,000 subsamples of age-matched individuals from the same population. Kinship coefficients were calculated for all possible pairs of RA cases, and similarly for the subsamples. RESULTS: The sum of the kinship coefficient among all combination of RA pairs, 5.92, was significantly higher than the average of the 4,000 subsamples, 1.99 (p < 0.001), and was elevated over that of the subsamples to the level of second cousin, supporting a genetic effect in the familial aggregation. The mean inbreeding coefficient for the Pima was 0.00009, similar to that reported for other populations; none of the RA cases were inbred. CONCLUSIONS: The Pima genealogy can be anticipated to provide valuable information for the genetic study of diseases other than RA. Defining an isolated population as the "unit" in which to assess familial aggregation may be advantageous, especially if there are a limited number of cases in the study population.

Arizona↗

Mapping of the familial Mediterranean fever gene to chromosome 16.

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent attacks of fever, synovitis, peritonitis, or pleurisy. Some patients eventually develop systemic amyloidosis. The biochemical cause of the disease is unknown. We have conducted a genome-wide search for the FMF locus using 125 different DNA markers and mapped the FMF gene to the short arm of chromosome 16. The study was performed on 35 Israeli families primarily of North African and Iraqi origin. For the five markers D16S82 (p41-1 Sacl), D16S80 (24-1 Taq1), D16S84 (pCMM65 Taq1), D16S83 (pEKMDA2-1 Rsal), and HBA (5'HVR Rsal) we obtained maximum lod scores of 2.72 (theta = 0.08), 10.34 (theta = 0.04), 9.66 (theta = 0.050, 9.35 (theta = 0.03), and 14.31 (theta = 0.08), respectively. Multipoint analysis with HBA and D16S84 defined as a fixed loci gave a maximum lod score of 19.86 centromeric to D16S84. Crossovers defined by these markers place the FMF gene in an area of approximately 5 cM between D16S80 and D16S84. Other genes mapped to this area (16p13.3) include phosphodiesterase IB (PDE1B), hydroxyacyl-glutathione hydrolase (HAGH), phosphoglycolate phosphatase (PGP), and the gene that causes adult polycystic kidney disease (PKD1). None of these genes bear an obvious pathophysiological relationship to FMF. Using additional markers from this region we hope to localize more precisely the FMF gene and to offer the possibility of prenatal diagnosis in selected cases. Our ultimate goal is to isolate and characterize the FMF gene.

Africa, Northern↗