Genome-Wide Transcriptome Analysis of Human Papillomavirus 16-Infected Primary Keratinocytes Reveals Subtle Perturbations Mostly due to E7 Protein Expression.

It is established that the host cell transcriptomes of natural lesions, organotypic rafts, and human papillomavirus (HPV)-immortalized keratinocytes are altered in the presence of HPV genomes. However, the establishment of HPV-harboring cell lines requires selection and immortalization, which makes it impossible to distinguish between alterations directly induced by HPV or indirectly by the need for immortalization or selection. To address direct effects of HPV infection on the host cell transcriptome, we have used our recently established infection model that allows efficient infection of primary keratinocytes with HPV16 virions. We observed only a small set of genes to be deregulated at the transcriptional level at 7 days postinfection (dpi), most of which fall into the category regulated by pocket proteins pRb, p107, and p130. Furthermore, cell cycle genes were not deregulated in cells infected with a virus lacking E7 despite the presence of episomal genome and viral transcripts. These findings imply that the majority of transcriptional changes are due to the E7 protein impairing pocket protein function. Additional pathways, such as the Fanconi anemia-BRCA pathway, became perturbed only after long-term culturing of infected cells. When grown as organotypic raft cultures, keratinocytes infected with wild-type but not E7 mutant virus had perturbed transcriptional regulation of pathways previously identified in natural lesions and in rafts derived from immortalized keratinocytes. We conclude that the HPV infection model provides a valuable tool to distinguish immediate transcriptional alterations from those induced by persistent infection and the need for selection and immortalization.IMPORTANCE To establish infection and complete the viral life cycle, human papillomavirus (HPV) needs to alter the transcriptional program of host cells. Until recently, studies were restricted to keratinocyte-derived cell lines immortalized by HPV due to the lack of experimental systems to efficiently infect primary keratinocytes. Need for selection and immortalization made it impossible to distinguish between alterations induced by HPV and secondary adaptation due to selection and immortalization. With our recent establishment of an extracellular matrix (ECM)-to-cell transfer system allowing efficient infection of primary keratinocytes, we were able to identify transcriptional changes attributable to HPV16 infection. Most perturbed genes fall into the class of S-phase genes, which are regulated by pocket proteins. Indeed, infection with viruses lacking E7 abrogated most transcriptional changes. It is important to note that many transcriptional alterations thought to be important for the HPV life cycle are actually late events that may reflect immortalization and, possibly, disease progression.

A new cell culture model to genetically dissect the complete human papillomavirus life cycle.

Herein, we describe a novel infection model that achieves highly efficient infection of primary keratinocytes with human papillomavirus type 16 (HPV16). This cell culture model does not depend on immortalization and is amenable to extensive genetic analyses. In monolayer cell culture, the early but not late promoter was active and yielded a spliced viral transcript pattern similar to HPV16-immortalized keratinocytes. However, relative levels of the E8^E2 transcript increased over time post infection suggesting the expression of this viral repressor is regulated independently of other early proteins and that it may be important for the shift from the establishment to the maintenance phase of the viral life cycle. Both the early and the late promoter were strongly activated when infected cells were subjected to differentiation by growth in methylcellulose. When grown as organotypic raft cultures, HPV16-infected cells expressed late E1^E4 and L1 proteins and replication foci were detected, suggesting that they supported the completion of the viral life cycle. As a proof of principle that the infection system may be used for genetic dissection of viral factors, we analyzed E1, E6 and E7 translation termination linker mutant virus for establishment of infection and genome maintenance. E1 but not E6 and E7 was essential to establish infection. Furthermore, E6 but not E7 was required for episomal genome maintenance. Primary keratinocytes infected with wild type HPV16 immortalized, whereas keratinocytes infected with E6 and E7 knockout virus began to senesce 25 to 35 days post infection. The novel infection model provides a powerful genetic tool to study the role of viral proteins throughout the viral life cycle but especially for immediate early events and enables us to compare low- and high-risk HPV types in the context of infection.

The association of ERAP1 and ERAP2 single nucleotide polymorphisms and their haplotypes with psoriasis vulgaris is dependent on the presence or absence of the HLA-C*06:02 allele and age at disease onset.

The aim of this case-control study was to elucidate the role of some single nucleotide polymorphisms (SNPs) in the ERAP1 (rs27524, rs27044, rs30187, rs2287987 and rs26653) and ERAP2 (rs2248374) genes in predicting the risk for psoriasis vulgaris in the Polish population. ERAP1, ERAP2 and HLA-C*06:02 typing was done using the TaqMan SNP genotyping assays. We confirmed a strong association of the HLA-C*06:02 allele with early-onset psoriasis. In ERAP1, rs30187T increased the risk of psoriasis in HLA-C*06:02-positive patients, most strongly in late onset psoriasis, whereas it was protective when the HLA-C*06:02 allele was absent. We also found a protective effect of the ERAP2 rs2248374A allele and rs2248374AA genotype only in HLA-C*06:02 carriers, especially in the subgroup of patients with juvenile psoriasis. Analysis of combined haplotypes for ERAP1 and ERAP2 also revealed differences when the patients and controls were stratified by HLA-C*06:02. An ERAP1 haplotype known to possess high enzymatic activity was associated with psoriasis if HLA-C*06:02 was present and a functional ERAP2 allele was absent. In the absence of HLA-C*06:02, an ERAP1 haplotype of low activity was conducive to psoriasis if a functional ERAP2 allele was present, but the same ERAP1 haplotype was protective if the ERAP2 allele was defective.

Incoming human papillomavirus 16 genome is lost in PML protein-deficient HaCaT keratinocytes.

Human papillomaviruses (HPVs) target promyelocytic leukemia (PML) nuclear bodies (NBs) during infectious entry and PML protein is important for efficient transcription of incoming viral genome. However, the transcriptional down regulation was shown to be promoter-independent in that heterologous promoters delivered by papillomavirus particles were also affected. To further investigate the role of PML protein in HPV entry, we used small hairpin RNA to knockdown PML protein in HaCaT keratinocytes. Confirming previous findings, PML knockdown in HaCaT cells reduced HPV16 transcript levels significantly following infectious entry without impairing binding and trafficking. However, when we quantified steady-state levels of pseudogenomes in interphase cells, we found strongly reduced genome levels compared with parental HaCaT cells. Because nuclear delivery was comparable in both cell lines, we conclude that viral pseudogenome must be removed after successful nuclear delivery. Transcriptome analysis by gene array revealed that PML knockdown in clonal HaCaT cells was associated with a constitutive interferon response. Abrogation of JAK1/2 signaling prevented genome loss, however, did not restore viral transcription. In contrast, knockdown of PML protein in HeLa cells did not affect HPV genome delivery and transcription. HeLa cells are transformed by HPV18 oncogenes E6 and E7, which have been shown to interfere with the JAK/Stat signaling pathway. Our data imply that PML NBs protect incoming HPV genomes. Furthermore, they provide evidence that PML NBs are key regulators of the innate immune response in keratinocytes. IMPORTANCE: Promyelocytic leukemia nuclear bodies (PML NBs) are important for antiviral defense. Many DNA viruses target these subnuclear structures and reorganize them. Reorganization of PML NBs by viral proteins is important for establishment of infection. In contrast, HPVs require the presence of PML protein for efficient transcription of incoming viral genome. Our finding that PML protein prevents the loss of HPV genome following infection implies that the host cell may be able to recognize chromatinized HPV genome or the associated capsid proteins. A constitutively active interferon response in absence of PML protein suggests that PML NBs are key regulators of the innate immune response in keratinocytes.

Incoming human papillomavirus type 16 genome resides in a vesicular compartment throughout mitosis.

During the entry process, the human papillomavirus (HPV) capsid is trafficked to the trans-Golgi network (TGN), whereupon it enters the nucleus during mitosis. We previously demonstrated that the minor capsid protein L2 assumes a transmembranous conformation in the TGN. Here we provide evidence that the incoming viral genome dissociates from the TGN and associates with microtubules after the onset of mitosis. Deposition onto mitotic chromosomes is L2-mediated. Using differential staining of an incoming viral genome by small molecular dyes in selectively permeabilized cells, nuclease protection, and flotation assays, we found that HPV resides in a membrane-bound vesicle until mitosis is completed and the nuclear envelope has reformed. As a result, expression of the incoming viral genome is delayed. Taken together, these data provide evidence that HPV has evolved a unique strategy for delivering the viral genome to the nucleus of dividing cells. Furthermore, it is unlikely that nuclear vesicles are unique to HPV, and thus we may have uncovered a hitherto unrecognized cellular pathway that may be of interest for future cell biological studies.

Topography of the Human Papillomavirus Minor Capsid Protein L2 during Vesicular Trafficking of Infectious Entry.

UNLABELLED: The human papillomavirus (HPV) capsid is composed of the major capsid protein L1 and the minor capsid protein L2. During entry, the HPV capsid undergoes numerous conformational changes that result in endosomal uptake and subsequent trafficking of the L2 protein in complex with the viral DNA to the trans-Golgi network. To facilitate this transport, the L2 protein harbors a number of putative motifs that, if capable of direct interaction, would interact with cytosolic host cell factors. These data imply that a portion of L2 becomes cytosolic during infection. Using a low concentration of digitonin to selectively permeabilize the plasma membrane of infected cells, we mapped the topography of the L2 protein during infection. We observed that epitopes within amino acid residues 64 to 81 and 163 to 170 and a C-terminal tag of HPV16 L2 are exposed on the cytosolic side of intracellular membranes, whereas an epitope within residues 20 to 38, which are upstream of a putative transmembrane region, is luminal. Corroborating these findings, we also found that L2 protein is sensitive to trypsin digestion during infection. These data demonstrate that the majority of the L2 protein becomes accessible on the cytosolic side of intracellular membranes in order to interact with cytosolic factors to facilitate vesicular trafficking. IMPORTANCE: In order to complete infectious entry, nonenveloped viruses have to pass cellular membranes. This is often achieved through the viral capsid protein associating with or integrating into intracellular membrane. Here, we determine the topography of HPV L2 protein in the endocytic vesicular compartment, suggesting that L2 becomes a transmembrane protein with a short luminal portion and with the majority facing the cytosolic side for interaction with host cell transport factors.

A single nucleotide polymorphism -35 kb T>C (rs9264942) is strongly associated with psoriasis vulgaris depending on HLA-Cw(∗)06.

HLA class I molecules play a role both in viral infection control and in autoimmune diseases development. rs9264942T>C polymorphism in HLA-C gene was found to impact on HLA-C surface expression level and to be associated with HIV-1 control. It was found that these HLA alleles which protect against AIDS are associated with autoimmune disease e.g. psoriasis vulgaris (PsV). Whether rs9264942 SNP is associated with PsV was investigated here. rs9264942T>C was genotyped in 292 PsV patients, and 254 controls using TaqMan Genotyping Assay. PsV patients differed from controls in frequencies of rs9264942T>C alleles (p=3.62 × 10(-16)) and genotypes (5.67 × 10(-15)). However, rs9264942C allele was predisposing to PsV 3-fold weaker than HLA-Cw(∗)06 (OR=5.04 vs. OR=15.61, respectively). In addition, this SNP was described earlier to be in strong linkage disequilibrium (LD) with another SNP, rs67384697 ins/del, which by affecting a microRNA binding is responsible for regulating HLA-C expression. However, typing for is cheaper and simpler than that for rs67384697, therefore we think it may substitute for it to some extent.

Killer immunoglobulin-like receptor (KIR) and HLA genotypes affect the outcome of allogeneic kidney transplantation.

BACKGROUND: Recipient NK cells may detect the lack of recipient's (i.e., self) HLA antigens on donor renal tissue by means of their killer cell immunoglobulin-like receptors (KIRs). KIR genes are differently distributed in individuals, possibly contributing to differences in response to allogeneic graft. METHODOLOGY/PRINCIPAL FINDINGS: We compared frequencies of 10 KIR genes by PCR-SSP in 93 kidney graft recipients rejecting allogeneic renal transplants with those in 190 recipients accepting grafts and 690 healthy control individuals. HLA matching results were drawn from medical records. We observed associations of both a full-length KIR2DS4 gene and its variant with 22-bp deletion with kidney graft rejection. This effect was modulated by the HLA-B,-DR matching, particularly in recipients who did not have glomerulonephritis but had both forms of KIR2DS4 gene. In contrast, in recipients with glomerulonephritis, HLA compatibility seemed to be much less important for graft rejection than the presence of KIR2DS4 gene. Simultaneous presence of both KIR2DS4 variants strongly increased the probability of rejection. Interestingly, KIR2DS5 seemed to protect the graft in the presence of KIR2DS4fl but in the absence of KIR2DS4del. CONCLUSIONS/SIGNIFICANCE: Our results suggest a protective role of KIR2DS5 in graft rejection and an association of KIR2DS4 with kidney rejection, particularly in recipients with glomerulonephritis.

HLA-C C1C2 heterozygosity may protect women bearing the killer immunoglobulin-like receptor AA genotype from spontaneous abortion.

Spontaneous abortion is the most common complication of human pregnancy. Natural killer (NK) cells expressing killer immunoglobulin-like receptors (KIRs), which may recognize HLA-C (i.e. its C1 or C2 groups) on trophoblast cells, constitute a large leukocyte population in the endometrium. This study investigated whether genetic polymorphisms in the KIR and HLA-C genes are risk factors for spontaneous abortion. One hundred and twenty-five couples with at least two spontaneous abortions, including eighty-five couples with idiopathic recurrent abortion (RSA; three or more abortions), and 117 control couples (with two or more healthy-born children) were tested. The frequencies of the individual KIR genes in the patients were similar to those in the controls. In the group of KIR AA women with HLA-C C2C2 partners, the HLA-C C1C2 heterozygotes were present in the controls but not in the patients (p=0.015 for all patients and p=0.0048 for RSA, but both comparisons lost significance after Bonferroni correction), whereas both homozygotes, C1C1 and C2C2, were absent in the control women but present among the aborting ones. Therefore, our results suggest that among KIR AA women who have HLA-C C2C2 partners, HLA-C heterozygous females show a trend towards an increased chance of successful pregnancy.

Regulatory immunotherapy in bone marrow transplantation.

Every year individuals receive hematopoietic stem cell transplantation (HSCT) to eradicate malignant and nonmalignant disease. The immunobiology of allotransplantation is an area of ongoing discovery, from the recipient's conditioning treatment prior to the transplant to the donor cell populations responsible for engraftment, graft-versus-host disease, and graft-versus-tumor effect. In this review, we focus on donor-type immunoregulatory T cells, namely, natural killer T cells (NKT) and regulatory T cells (Treg), and their current and potential roles in tolerance induction after allogeneic HSCT.

Does the KIR2DS5 gene protect from some human diseases?

BACKGROUND: KIR2DS5 gene encodes an activating natural killer cell receptor whose ligand is not known. It was recently reported to affect the outcome of hematopoietic stem cell transplantation. METHODOLOGY/PRINCIPAL FINDINGS: In our studies on KIR2DS5 gene associations with human diseases, we compared the frequencies of this gene in patients and relevant controls. Typing for KIR2DS5 gene was performed by either individual or multiplex polymerase chain reactions which, when compared in the same samples, gave concordant results. We noted an apparently protective effect of KIR2DS5 gene presence in several clinical conditions, but not in others. Namely, this effect was observed in ankylosing spondylitis (p=0.003, odds ratio [OR]=0.47, confidence interval [CI]=0.28-0.79), endometriosis (p=0.03, OR=0.25, CI = 0.07-0.82) and acute rejection of kidney graft (p=0.0056, OR=0.44, CI=0.24-0.80), but not in non-small-cell lung carcinoma, rheumatoid arthritis, spontaneous abortion, or leukemia (all p>0.05). In addition, the simultaneous presence of KIR2DS5 gene and HLA-C C1 allotype exhibited an even stronger protective effect on ankylosing spondylitis (p=0.0003, OR=0.35, CI=0.19-0.65), whereas a lack of KIR2DS5 and the presence of the HLA-C C2 allotype was associated with ankylosing spondylitis (p=0.0017, OR=1.92, CI=1.28-2.89), whereas a lack of KIR2DS5 and presence of C1 allotype was associated with rheumatoid arthritis (p=0.005, OR=1.47, CI=1.13-1.92). The presence of both KIR2DS5 and C1 seemed to protect from acute kidney graft rejection (p=0.017, OR=0.47, CI=0.25-0.89), whereas lack of KIR2DS5 and presence of C2 seemed to favor rejection (p=0.0015, OR=2.13, CI=1.34-3.37). CONCLUSIONS/SIGNIFICANCE: Our results suggest that KIR2DS5 may protect from endometriosis, ankylosing spondylitis, and acute rejection of kidney graft.

Combinations of DNA methyltransferase and histone deacetylase inhibitors induce DNA damage in small cell lung cancer cells: correlation of resistance with IFN-stimulated gene expression.

Because epigenetic inhibitors can reduce cancer cell proliferation, we tested the hypothesis that concurrent inhibition of histone acetylation and DNA methylation could synergistically reduce the viability of small cell lung cancer (SCLC) cells. Sub-IC(50) concentrations of the DNA methyltransferase (DNMT) inhibitor decitabine (5-AZA-dC) and the histone deacetylase (HDAC) inhibitors (LBH589 or MGCD0103) synergistically reduced the proliferation of five of nine SCLC cell lines. Loss of viability of sensitive SCLC cells did not correlate with the inhibition of either DNMT1 or HDACs, suggesting nonepigenetic mechanisms for synergy between these two classes of epigenetic modulators. Because combinations of 5-AZA-dC and HDAC inhibitors had marginal effects on the apoptosis index, Comet assay was undertaken to assess DNA damage. MGCD0103 and 5AZA-dC cotreatment augmented DNA damage in SCLC cells, resulting in increased tail length and moment in Comet assays by 24 hours in sensitive cell lines (P < 0.01). Consistent with augmented DNA damage, combination of a DNMT and HDAC inhibitor markedly increased the levels of phospho-H2A.X in sensitive cells but not in resistant ones. Comparison of basal gene expression between resistant and sensitive cells identified markedly higher basal expression of IFN-stimulated genes in the resistant cell lines, suggesting that IFN-stimulated gene expression may determine SCLC cell sensitivity to epigenetic modulators or other DNA damaging agents.

Polymorphism of the TGFB1 gene is not associated with bronchial allergic asthma in a Polish population.

Allergic asthma is a complex genetic disorder that involves interactions between genetic and environmental factors. Some studies have indicated that transforming growth factor beta(1) (TGF-beta(1)), a pleiotropic cytokine regulating inflammatory reactions and airway remodeling, may participate in the pathogenesis of asthma. Several polymorphisms have been described in the TGFB1 gene; some were tested in allergic asthma, with conflicting results. The aim of this study was to investigate the possible associations of four TGFB1 gene polymorphisms (-800G>A, -509C>T, 869T>C, and 915G>C) with allergic asthma in a Polish population. These four single nucleotide polymorphisms were genotyped in 247 asthmatic patients (including 207 atopic individuals) and 287 unrelated healthy volunteers by means of the polymerase chain reaction-restriction fragment length polymorphism method. No significant differences between patients and controls in allele, genotype, and haplotype frequencies were reported. Logistic regression analysis of genotype distribution and allele positivity adjusted for age and sex did not reveal any significant differences between all patients or patients selected for atopy and controls. Thus, no evidence was reported for a contribution of the TGFB1 gene to allergic asthma in a Polish population. The results are discussed in the context of similar studies in other populations.

Association of PTPN22 single nucleotide polymorphism with rheumatoid arthritis but not with allergic asthma.

PTPN22 gene encodes a lymphoid tyrosine phosphatase (LYP), an important negative regulator of T-cell responses. The 1858C>T (Arg620Trp) single nucleotide polymorphism (rs2476601) was found associated with autoimmune diseases, including rheumatoid arthritis (RA). Allergic diseases are similar to autoimmune diseases, by an exaggerated immune response to an antigen (allergen in this case) normally not invoking such response in healthy individuals. We investigated whether polymorphism 1858C>T in PTPN22 gene is associated with susceptibility to allergic asthma and RA in a Polish population. PTPN22 was genotyped in 173 patients with RA, in 198 patients with allergic asthma, and in 543 controls using PCR-RFLP. The patients with RA differed from healthy controls in frequencies of PTPN22 1858C>T alleles (P=0.0004; odds ratio (OR), 1.8; 95% CI, 1.33-2.55) and genotypes (P=0.0009). Strong associations of 1858T allele with RA limited to joints (0.21 vs 0.12, P=0.0002; OR, 2.1; 95% CI, 1.44-3.00), with erosive disease (0.20 vs 0.12, P=0.0003; OR, 1.92; 95% CI, 1.34-2.71), with a lack of rheumatoid factor (RF; 0.23 vs 0.12, P=0.0008; OR, 2.29; 95% CI, 1.44-3.63), and weak association with the presence of RF (0.17 vs 0.12, P=0.02; OR, 1.6; 95% CI, 1.10-2.40) in comparison with healthy controls were observed. Very strong association of 1858T allele (P<0.0001; OR, 2.72; 95% CI, 1.9-3.9) and T phenotype (P<0001; OR, 3.2; 95% CI, 2.1-4.9) with antibodies to cyclic citrullinated peptide (CCP) was found. When patients with allergic asthma were typed for PTPN22 1858C>T polymorphism, no difference with control was found. Subdivision of patients into those with mild, moderate, or severe asthma did not reveal any associations. In conclusion, we confirmed associations between several clinical manifestations of RA and PTPN22 1858T allele. However, no association with 1858C>T polymorphism was found for susceptibility to allergic asthma or for severity of the disease.

Distribution of CTLA-4 polymorphisms in allergic asthma.

BACKGROUND: The CTLA-4 molecule is an important negative regulator of T cell activation. It is encoded on chromosome 2q33 and found to be associated with several allergic phenotypes including asthma. However, the association of CTLA-4 gene polymorphisms with allergic asthma is still controversial and therefore was the subject of this study. METHODS: By PCR-RFLP, the distribution of three single nucleotide polymorphisms (SNPs), -1147 C/T, -318 C/T, and +49 A/G, was examined in 219 Polish Caucasoid patients diagnosed with allergic asthma and in 102 ethnically matched healthy control individuals. (AT)(n) microsatellite polymorphism was also tested in the same individuals. RESULTS: No statistically significant differences in SNPs or microsatellite allele, genotype or haplotype frequencies between patients and controls were found. CONCLUSION: CTLA-4 polymorphisms do not seem to be a risk factor for allergic asthma in Poles.

A role for KIR gene variants other than KIR2DS1 in conferring susceptibility to psoriasis.

Recently we described an association between psoriasis and KIR2DS1, a gene for a stimulatory natural killer cell receptor, in a Polish population. The association was independently reported among Japanese and confirmed in a U.S. population. Prompted by these findings, we reanalyzed data by a multivariate approach in search of possible effects of KIR genes other than KIR2DS1 (non-KIR2DS1). The methodology was based on a stratified analysis and multiple logistic regression. We found that the non-KIR2DS1 genes had joint effects comparable to or stronger than the effects of KIR2DS1 in both the fraction of explained variance (0.174 vs 0.204, respectively, for KIR2DS1 and non-KIR2DS1) and the statistical significance (p = 0.000008 vs p = 0.000001, respectively). When individual genes were considered, a decrease in KIR2DS5 among patients vs controls (OR = 0.2, pcor = 0.0005) and a decrease in KIR2DS3 restricted to KIR2DS1-positive individuals (OR = 0.2, pcor = 0.005) were evident. We also performed a multivariate analysis of the HLA-Cw genotypes but failed to demonstrate any effects in addition to the known association with HLA-Cw*06. We conclude that the effect of the KIR genes on psoriasis susceptibility is complex, extending beyond the association with KIR2DS1 and involving protective effects and interactions.

Are single nucleotide polymorphisms of the immunoglobulin A Fc receptor gene associated with allergic asthma?

BACKGROUND: Eosinophils are important components of allergic inflammation. The immunoglobulin A (IgA) Fc receptor (FcalphaRI), encoded by the FCAR gene, is a possible candidate for eosinophil activation at mucosal surfaces, where IgA is abundant. Both elevated cell surface expression of FcalphaRI and increased avidity for IgA were described on eosinophils from allergic subjects. The aim of our study was to examine the possible association of FCAR gene polymorphisms with allergic asthma. METHODS: We screened three regions of the FCAR gene: (1) the promoter region, (2) exon 3, encoding the first extracellular domain (EC1), and (3) exon 5, coding for the transmembrane and cytoplasmic domain, for new and published polymorphisms using a sensitive temperature gradient gel electrophoresis technique and compared their frequencies in 112 patients diagnosed with allergic asthma and 100 healthy controls. RESULTS: Six polymorphisms, including two novel ones, were detected. No differences between patients and controls were found in the distribution of any of these polymorphisms. CONCLUSION: FcalphaRI polymorphism does not seem to be a risk factor in allergic asthma. Nevertheless, this is the first report on the distribution of 6 single nucleotide polymorphisms of the FCAR gene in a human population and the first study on FCAR polymorphism in allergic asthma.

Gene for the activating natural killer cell receptor, KIR2DS1, is associated with susceptibility to psoriasis vulgaris.

Psoriasis vulgaris, particularly its juvenile form, is strongly associated with the HLA-Cw*06 allele encoding the HLA-Cw6 molecule. This molecule is recognized by the inhibitory receptor KIR2DL1 and the activatory receptor KIR2DS1, which are expressed on natural killer cells and subpopulations of T lymphocytes. Humans differ by the presence or absence of particular KIR genes. We hypothesized that either activatory KIR2DS1 or inhibitory KIR2DL1 gene frequencies might be different in psoriatic patients from a control population. Therefore, we compared the frequencies of KIR2D inhibitory (L) and activatory (S) genes in 116 psoriasis vulgaris patients and in 123 healthy controls. Fourteen novel gene combinations were found. KIR2DS1 was present in 85% of the patients, but only in 51% of the controls (corrected p [pc] < 0.0009). Similarly, HLA-Cw*06 was much more frequent in patients (77%) than in controls (17%; pc < 0.00002). Statistical analysis suggests that, although the contribution of these two factors to psoriasis is partially independent, they interact nevertheless. This result strongly speaks for a role of KIR2DS1 on recognition of HLA-Cw6 in susceptibility to psoriasis.

Distribution of LILRA3 (ILT6/LIR4) deletion in psoriatic patients and healthy controls.

The leukocyte immunoglobulinlike receptor (LILRA3; ILT6) gene is localized on human chromosome 19 in the region 19q13.4, in the leukocyte receptor complex that encodes leukocyte receptors LILR (ILT/LIR), killer cell immunoglobulinlike receptors (KIR), LAIR, Fc IgA receptor, and others. The biologic role of the LILRA3 molecule and the nature of its ligand are not known. Comparison of LILRA3 gene sequence with those of other LILRs suggests LILRA3 is a soluble molecule. If LILRA3 binds human leukocyte antigen (HLA) class I molecules like other LILRs whose ligands are known, then it might block recognition of HLA by these receptors, influencing immune response and susceptibility to HLA class I associated disease. A deletion of LILRA3 gene was found in a minority of British population. We typed 108 healthy individuals from the Low Silesia region and 103 patients diagnosed with psoriasis vulgaris (a disease associated with HLA class I antigen, HLA-Cw6) for LILRA3 to examine whether LILRA3 deletion was distributed differently in patients affected with the disease. No differences in frequencies of the LILRA3 deletion were found between controls and patients or between HLA-Cw6(+) and HLA-Cw6(-) controls or patients, suggesting that LILRA3 has no role in psoriasis.