Search

Genes encoding killer cell immunoglobulin-like receptors (KIRs) are variable among individuals. Sequence-specific primer-directed polymerase chain reaction (PCR) amplification (PCR-SSP) and sequence-specific oligonucleotide hybridization of the PCR-amplified products (PCR-SSO) are the methods currently used to characterize the diversity of KIR gene content. Both these methods include time-consuming post-PCR analyses. Here, we developed a real-time PCR method that identifies the presence or absence of 16 KIR genes during PCR and avoids post-PCR analyses. This method is specific, sensitive, shortens the turnaround time compared with the conventional PCR-SSP and PCR-SSO methods, and it can be easily adapted for automation. [ABSTRACT FROM AUTHOR]

Background and Objective: Substance P may play a role in the pathogenesis of periodontal disease; however, its mechanisms of modulation are not clear. This study evaluated the effect of two concentrations of Substance P on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human gingival fibroblasts. Material and Methods: Fibroblasts were stimulated for 48 h with 10−4 or 10−9 m Substance P; untreated fibroblasts served as controls. The expression of MMP-1, -2, -3, -7 and -11 and of TIMP-1 and -2 was evaluated using real-time polymerase chain reaction and western blotting. Results: There was a significant, concentration-dependent stimulatory effect of Substance P on MMP-1, -2, -3 and -7 and TIMP-2 gene expression ( p < 0.05), and a probable effect on MMP-11 ( p = 0.06). At the higher concentration (10−4 m Substance P), MMP-1, -2, -3, -7 and -11 and TIMP-2 showed the greatest up-regulation; at the lower concentration (10−9 m Substance P), MMP-1, -3 and -7 and TIMP-2 exhibited diminished up-regulation, with MMP-2 and -11 showing down-regulation ( p < 0.05). Expression of TIMP-1 was not affected by Substance P ( p > 0.05). Western blotting confirmed that Substance P up-regulated MMP-1, -2, -3 and -11 and TIMP-2. MMP-1, -3 and -11 and TIMP-2 showed greater up-regulation at the higher Substance P concentration and diminished up-regulation at the lower concentration. MMP-2 was up-regulated to a similar degree at both Substance P concentrations. Conclusion: In gingival fibroblast cells, Substance P at the higher concentration (10−4 m) induced greater up-regulation of MMP-1, -3 and -11 and TIMP-2 expression, but at the lower concentration (10−9 m) induced diminished up-regulation, which may represent a mechanism for modulating periodontal breakdown. [ABSTRACT FROM AUTHOR]

Abstract: The killer-cell immunoglobulin-like receptors (KIR) expressed by human natural killer (NK) cells are encoded by a family of genes on chromo-some 19. The number of KIR genes varies with haplotype and the individ-ual genes exhibit polymorphism. To investigate KIR diversity we studied KIR cDNA and genes of four human donors: two Caucasians, one Black American and one Asian Indian. From analysis of these donors seventeen novel KIR variants were identified and characterized. Fifteen of the new variants appear to have a simple allelic relationship with a known KIR, whereas two of them combine the sequences of two different KIR genes. Fourteen of the seventeen KIR variants were isolated from the two non-Caucasoid blood donors. These data show that much human KIR diversity remains to be characterized, particularly in non-Caucasoid populations. [ABSTRACT FROM AUTHOR]