Autoinflammatory process in the pathogenesis of generalized pustular psoriasis and perspectives of its targeted therapy.

The dysregulated inflammatory process not only plays an important role in the development of chronic plaque psoriasis but also is a major pathogenetic mechanism behind the generalized pustular psoriasis (GPP) and other rare pustular forms of the disease. The key players in this process are the cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF), IL-12/23, IL-17A and especially IL-36. Their excessive activity or production in some GPP patients is due to mutations in genes that encode molecules involved in inhibiting the action of IL-36 (IL-36Ra) or in intracellular inflammatory signaling (CARD14, AP1S3). Knowledge about the pathological role of inflammatory cytokines in the development of pustular forms of psoriasis has also found application in their biological therapy with monoclonal antibodies that neutralize the action of IL-12/23, IL-17A, TNF or IL-1β. Other promising agents are monoclonal antibodies against the interleukin 36 receptor, which have already successfully gone through the first phases of clinical trials and are currently being tested for their long-term efficacy, safety and tolerability.

MAIT cells, their biological and medical significance.

MAIT cells are a separate cell population differentiating in the thymus. They are mostly present in the peripheral blood, liver, intestine, and lungs, less often in other tissues, and infrequently in the lymph nodes. The presentation molecules for MAIT cells are MR1 proteins. They are evolutionarily conserved and non-polymorphic, resemble class I HLA molecules, and are expressed by all cell types. They present bacterial and yeast vitamin metabolites which arise during the synthesis of vitamin B2. The effector functions of MAIT cells are promoted through cytokine synthesis. They also act cytotoxically, directly killing infected or tumour cells. MAIT cells may also play a role in pathological processes. Their involvement in the development of rheumatoid arthritis, systemic lupus erythematosus, autoimmune diabetes mellitus, Crohn's disease, and bronchial asthma has been demonstrated. In practical terms, MAIT cells are very sensitive to therapeutic doses of glucocorticoids. Treatment of patients with BA or chronic obstructive pulmonary disease with glucocorticoids increases their susceptibility to pneumonia, especially when caused by Streptococcus pneumoniae.

Mechanisms of action of regulatory lymphocytes and a possibility to use them in the treatment of autoimmune diseases and GvH reactions.

Basic characteristic of the immune system is its ability to distinguish self-molecules, cells, tissues and organs from not self, to tolerate self and dispose of not self. Immunosuppressive mechanisms, especially those mediated by regulatory lymphocytes, play a paramount role in the tolerance mechanisms. When there is an abnormal quantity and/or quality of regulatory cells, various autoimmune diseases are induced, e.g. SLE, RA, T1D, IBD, MS, and others.In recent years, a great progress was achieved in the field how to profit from immunosuppressive properties of T regulatory cells (Treg) in the treatment of patients suffering from autoimmune disorders or transplantation rejections. Nowadays, there are possibilities to up-regulate the function of patient's Tregs or supplement their low numbers. We can up-regulate the function of Treg cells in an affected organism by treatment by low dosage of IL-2 or to treat patients by in vitro expanded Treg cells themselves. Induced Tregs are, however, polyspecific, therefore they have been preferentially used for the treatment graft versus host reactions and some autoimmune disorders only. For those autoimmune diseases, where specific autoantigens are known, Treg cells equipped by antigen-specific chimeric T cell receptor (CARs) were introduced for their treatment (Tab. 1, Fig. 2, Ref. 47). Keywords: AIRE, autoimmune diseases, CAR, cytokines, iNKT cells, regulatory B and T cells.

New biological agents in the treatment of multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory disease induced by autoimmune processes. Their understanding has resulted in an introduction of biological agents to its treatment. Interferon beta and glatiramer acetate have been in clinical practice for more than 20 years. Nowadays, novel biologics, which target molecules involved in immunopathological processes more specifically have entered the scene. They are represented by monoclonal antibodies binding to molecules VLA4 (natalizumab), CD20 (ocrelizumab), CD52 (alemtuzumab) or alpha subunit of IL-2 receptor (daclizumab) or by small molecules such as those modulating the receptors involved in regulation of lymphocyte migration (fingolimod, ozanimod) or in induction of lymphopenia by apoptosis (dimethyl fumarate, cladribine). In the article, we shortly describe their efficacies, adverse reactions and perspectives of a future development in MS biologics. A treatment of neuromyelitis optica by monoclonal antibodies (rituximab, aquaporumab) is given too (Tab. 1, Fig. 2, Ref. 71).

[Crohns disease and ulcerative colitis - current view on genetic determination, immunopathogenesis and biologic therapy]. / Crohnova choroba a ulcerózna kolitída - súcasný pohlad na genetickú determináciu, imunopatogenézu a biologickú liecbu.

Crohns disease (CD) and ulcerative colitis (UC) are chronic inflammatory disorders of the intestine, also called inflammatory bowel diseases (IBD), which are not caused by pathogenic microorganisms but result from non-specific inflammatory processes in the bowel. IBD are polygenic diseases, as evidenced by the genome-wide association studies (GWAS), which have discovered more than 200 genes or genetic regions to be associated with IBD. Some of them are specific for CD or UC; however, there are 110 overlapping genes. In the pathogenesis of CD, activation of adaptive immunity mediated by TH1, TH17, or TH1/TH17 cells is induced because of disturbances in the mechanisms of innate immunity and autophagocytosis. By comparison, the major events that trigger autoimmune processes in UC are an increased translocation of commensal bacteria into the submucosa because of loose inter-epithelial connections with subsequent activation of ILC2, TH9, TH2, and NKT cells. Knowledge of the pathogenesis of a disease enables an effective therapy, which is especially true for biological therapy. It is noteworthy that monoclonal antibodies directed against the major protagonists underlying both CD and UC have failed. It points to the complexity of immunopathologic processes that run in both diseases. One can suppose that a blockade of one inflammatory pathway is circumvented by an alternative pathway. TNF is the principal pro-inflammatory cytokine that plays a major role in CD and UC as well. It was therefore decided to treat IBD patients with anti-TNF monoclonal antibodies, infliximab or adalimumab. Approximately one half of the CD patients and one third of the UC patients respond to this treatment.

VLA4 Gene Polymorphism and Susceptibility to Multiple Sclerosis in Slovaks.

Multiple sclerosis (MS) is an inflammatory autoimmune disease occurring in genetically sensitive individuals. As migration of immune cells into the CNS is facilitated by the Very Late Antigen 4 (VLA-4) integrin molecule, the VLA4 gene may be considered as a plausible candidate genetic risk factor for susceptibility to MS. Therefore, the objective of our study was to investigate the association between two genetic polymorphisms located in the VLA4 gene and the risk of multiple sclerosis. One hundred seventeen MS patients and 165 control subjects from Slovakia were genotyped for VLA4 gene SNP polymorphisms at positions 269 (C/A) and 3061 (A/G). The same study cohorts were also genotyped for the rs3135388 polymorphism tagging the HLA-DRB1*15:01 allele, which is a known genetic factor associated with susceptibility to develop MS in many populations. Our findings show for the first time that the rs3135388 polymorphism is a strong risk factor for MS in the Slovak population. Investigation of the VLA4 gene polymorphisms revealed a significantly higher frequency of the 3061AG genotype in MS patients compared to the controls (P ≤ 0.05). We suggest that the 3061AG polymorphic variant is an independent genetic risk factor for MS development in our population as it was significantly associated with this disease. The association was also confirmed after applying multivariate logistic-regression analysis adjusted for gender, age and HLA-DRB1*15:01 positivity as possible influencing factors.

[Genetic and molecular background in autoimmune diabetes mellitus]. / Genetický a molekulový podklad vývoja autoimunitného diabetes mellitus.

Type 1 diabetes mellitus (T1 DM) is caused by autoimmune-mediated and idiopathic beta-cell destruction of the pancreatic islets of Langerhans resulting in absolute insulin deficiency. Susceptibility to T1 DM is influenced by both genetic and environmental factors. It is generally believed that in genetically susceptible individuals, the disease is triggered by environmental agents, such as viral infections, dietary factors in early infancy, or climatic influences. Many candidate genes for diabetes have been reported; those within the Major Histocompatibility Complex being among the most important. The most common autoantigens are insulin, glutamic acid decarboxylase 65, insuloma-associated antigen 2, and zinc transporter ZnT8. The destruction of beta-cells is mediated mainly by cellular mechanisms; antibodies only seem to reflect the ongoing autoimmune processes and are not directly involved in the tissue damage. They, however, appear prior to the onset of insulin deficiency which makes them suitable for use in the prevention of the disease.

High susceptibility to pemphigus vulgaris due to HLA-DRB1*14:54 in the Slovak population.

The current work describes an association between pemphigus vulgaris (PV) and class II HLA alleles in the Slovak population, the first such study in Slovakia on the 'high-resolution level'. This work takes into account the new HLA allele nomenclature, officially adopted in 2010. In particular, we have focused on the associations between PV and DRB1*14:54 and DRB1*14:01. This case-control study was performed in a cohort of 43 PV Caucasian patients and 113 Caucasian control subjects from Slovakia. HLA typing was performed using PCR-SSP (polymerase chain reaction with sequence-specific primers). We found significantly positive associations between PV and the HLA alleles DRB1*04:02, DRB1*04:04, DRB1*14:54, DRB1*14:04, DRB1*14:05, DQB1*03:02 and DQB1*05:03. In contrast, HLA-DQB1*06, DRB1*07 and DRB1*13 were negatively associated with PV. Importantly, 93% of PV patients possessed at least one of two HLA haplotypes, DRB1*04-DQB1*03 or HLA-DRB1*14-DQB1*05. We confirmed the previously reported associations between HLA class II alleles and PV and described a new association between PV and DRB1*14:54. This allele was first described in 2005, and there has been only one report of its association with PV to date.

No association between bronchial asthma and HLA-DRB1, -DQB1 alleles in the Slovak population.

109 patients (62 boys/men and 47 girls/women) suffering from bronchial asthma induced by pollen allergens were typed for HLA-DRB1 and -DQBl alleles, respectively, by a low resolution SSP technique. Frequencies of DRB1 alleles varied from 0.5 % to 16.1 %. The most frequent was HLA-DRB1*11 (16.1 %), the least frequent HLA-DRB1*09 (0.4 %). Occurrence rates of HLA-DQB1 alleles ranged from 2.3 % to 37.2 %, HLA-DQB1*03 being the most frequent (37.2 %) and DQB1*04 stood on the opposite pole (2.3 %). By comparing to occurrence rates in the healthy population, no statistically significant differences were disclosed (Tab. 2, Ref. 16).

Characterization of MICA gene polymorphism of HLA complex in the Slovak population.

BACKGROUND: The function of the MHC class I polypeptide-related sequence A (MICA) gene, which belongs to the MHC class I chain-related genes, is to trigger cytolysis of target cells mediated by NKG2D receptor recognition in NK (Natural Killer) cells and CD8 T-lymphocytes. The MICA gene has a high degree of polymorphism, especially observed in exons 2-5. MICA allelic diversity has been reported in association with some autoimmune diseases such Behcet's disease, psoriasis and diabetes, as well as with organ rejections. AIM: The aim of this study was to analyse MICA gene polymorphism in the Slovak population, to establish frequencies of MICA alleles and to compare the results with those found in other Western Eurasian populations. No such study has been performed previously in the Slovak population. SUBJECTS AND METHODS: This study examined DNA samples from 124 unrelated Slovak individuals (51 women and 73 men with an average age of 40.3 years) using direct sequencing of MICA exons 2-5. Allele and genotype frequencies were calculated by direct counting and statistical analysis was carried out using Arlequin software. RESULTS: This study identified 15 out of 71 MICA alleles. The most frequent allele was MICA(*)008 (37.1%) followed by alleles MICA(*)002 (16.5%) and MICA(*)009 (11.3%). The rarest alleles were MICA(*)027, MICA(*)006 (both 0.8%) and MICA(*)057 (0.4%), respectively. The most frequent genotypes were 008/008 and 008/002, both with a frequency of 13.7%. Exon 5 microsatellite polymorphism screening revealed five MICA alleles, namely A4, A5, A5.1, A6 and A9. The most frequent was allele A5.1 (37.1%) and the rarest A5 (8.1%). Finally it was found that haplotype MICA*008 A5.1 was the most frequent (37.1%). CONCLUSION: A comparison of these results with those reported in the literature revealed similarity in MICA polymorphism to that found in other Western Eurasian populations. The data will be useful for further association studies on MICA polymorphism and its function.

TNF-alpha and IL-10 gene polymorphisms show a weak association with pemphigus vulgaris in the Slovak population.

BACKGROUND: Pemphigus vulgaris is a rare chronic autoimmune disease of skin and mucous membranes, with several cytokines participating in its development. The role of their gene polymorphisms in susceptibility to the disease is, however, not fully understood. OBJECTIVE: The aim of our case-control study was to investigate whether some of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine genes (IL-1alpha, IL-1beta, IL-1RI, IL-1Ra, IL-4Ralpha, IL-12, IFN-gamma, TGF-beta1, TNF-alpha, IL-2, IL-4, IL-6 and IL-10) are associated with pemphigus vulgaris in the Slovak population. METHODS: DNA samples were obtained from 34 pemphigus vulgaris patients and 140 healthy controls of Slovak origin. Cytokine gene SNPs were determined using the polymerase chain reaction with sequence-specific primers (PCR-SSP) method. Results We found a weak association between pemphigus vulgaris and polymorphic variants in TNF-alpha and IL-10 genes only, with haplotypes TNF-alpha-308G/-238G and IL-10 -1082A/-819C/-592C being significantly overrepresented in pemphigus vulgaris patients (TNF-alpha GG: 94.12% vs. 82.86%, P = 0.0216; IL-10 ACC: 44.12% vs. 30.00%, P = 0.0309). CONCLUSIONS: Our preliminary results suggest that certain TNF-alpha and IL-10 gene polymorphisms might contribute to genetic susceptibility to pemphigus vulgaris; however, their overall impact on disease development will be rather limited.

[Systemic lupus erythematosus--a contemporary view of its genetic determination, immunopathogenesis and therapy]. / Systémový lupus erythematosus--súcasný pohl'ad na genetickú determináciu, imunopatogenézu a liecbu.

Systemic lupus erythematosus (SLE) is an organ non-specific autoimmune disorder, with multiple immunopathogenic mechanisms being implicated in its development. The most conspicuous feature of the disease is an exaggerated synthesis of various types of autoantibodies, followed by the formation of immune complexes that deposit in tissues and elicit an inflammatory response. Apart from antibodies, dendritic cells, T cells and cytokines are substantially involved in the pathogenesis of SLE and class I interferons seem to play a crucial role. SLE is a genetically determined disease. HLA system and complement system genes, apoptosis regulating genes and IgG Fc-gamma receptor genes are among the multiple genes implicated in SLE. The role of hormones, both estrogen and progesterone, in SLE activity has been reported. Some monoclonal antibodies have recently proved effective in the treatment of SLE.

B cell activating factor, its role in autoimmunity, and targeting in autoimmune diseases.

B cell activation factor (BAFF), a recently identified member of the tumour necrosis factor (TNF) family, is a key survival factor during B cell maturation and is essential for the development of B cell tolerance. Breakdown of the regulation of BAFF expression results in excessive BAFF production that impairs B cell tolerance and leads to autoimmune phenomena. Consistent with this, BAFF levels are elevated in plasma of patients with various autoimmune diseases. BAFF is considered to be one of the principal factors that regulate the size and composition of B cell compartment. BAFF acts as an important driving factor for B cell hyperplasia and autoantibody production in autoimmune processes. Thus BAFF has become a very attractive target for the treatment of autoimmune diseases with an altered B cell function. Results of clinical trials have confirmed a crucial role of BAFF in the pathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). BAFF inhibitors in the treatment of RA, SLE and other autoimmune diseases are under intensive investigation. However, BAFF biology remains poorly understood. Nonetheless, results of the ongoing studies may enable the development of a new generation of BAFF inhibitors with more selective efficacy and increased safety (Fig. 2, Ref. 92). Full Text (Free, PDF) www.bmj.sk.

Immune response and cytokine production following immunization with experimental herpes simplex virus 1 (HSV-1) vaccines.

Balb/c mice were immunized with the recombinant fusion protein gD1/313 (FpgD1/313 representing the ectodomain of HSV-1 gD), with the non-pathogenic ANGpath gE-del virus, with the plasmid pcDNA3.1-gD expressing full-length gD1 and with the recombinant immediate early (IE) HSV-1 protein ICP27. Specific antibodies against these antigens (as detected by ELISA) reached high titers with the exception of the DNA vaccine. High-grade protection against challenge with the virulent strain SC16 was found following immunization with the pcDNA3.1-gD plasmid and with the gE-del virus. Medium grade, but satisfactory protection developed after immunization with the FpgD1/313 and minimum grade protection was seen upon immunization with the IE/ICP27 polypeptide. A considerable response of peripheral blood cells (PBL) and splenocytes in the lymphocyte transformation test (LTT) was found in mice immunized with FpgD1/313, with the pcDNA3.1-gD plasmid and with the live ANGpathgE-del virus. For lymphocyte stimulation in vitro, the FpgD1/313 antigen was less effective than the purified gD1/313 polypeptide (cleaved off from the fusion protein); both proteins elicited higher proliferation at the 5 microg per 0.1 mL dose than at the 1 microg per 0.1 mL dose. The secretion of Th type 1 (TNF, IFN-gamma and IL-2) and Th type 2 (IL-4 and IL-6) cytokines was tested in the medium fluid of purified PBL and splenocyte cultures; their absolute values were expressed in relative indexes. The PBL from FpgD1/313 immunized mice showed increased secretion of both T(H)1 (TNF) as well as T(H)2 (IL-4) cytokines (7-10-fold, respectively). Splenocytes from FpgD1/313 immunized mice showed a significant (23-fold) increase in IL-4 production.

Genetic susceptibility to type 1 diabetes mellitus in humans.

Type 1 diabetes mellitus (DM 1A) is an autoimmune disease belonging to the most frequent chronic diseases of the childhood and young adults. DM 1A results from immune-mediated destruction of the insulin-producing beta cells of the pancreas. It is a genetically determined disease and many genes or genetic regions were found to be associated with its induction. In addition to the insulin-dependent diabetes mellitus 1 (IDDM1) gene, which marks the HLA region, and IDDM2 which marks the insulin gene, significant associations of DM 1A to other IDMM genes or genetic regions we reported. We shortly review recent achievements in the field, and the state of current knowledge.

Association of HLA-DPB1 alleles with type I diabetes mellitus in Slovak population.

BACKGROUND: Genes of HLA complex on chromosome 6p21 principally contribute to the genetic risk of insulin-dependent diabetes mellitus type I (T1 DM). Associations of HLA class II loci allelic variants with T1 DM are well established. Another prime candidate, particularly the polymorphic DPB1 gene, has been reported as probably contributing to the disorder, but its relative contribution to the predisposition to the disease is difficult to assess due to strong linkage disequilibrium of HLA alleles. DPB1*0301 and DPB1*0202 have been reported as positively and DPB1*0402 as negatively associated alleles in different Caucasoid populations (predisposing versus protective alleles, respectively). OBJECTIVES: The aim of this study was to establish the occurrence rates of HLA-DPB1 alleles in patients suffering from T1 DM and to compare them with those in healthy subjects. METHODS: A PCR-SSP method was performed to identify HLA-DPB1 alleles in 61 patients and 160 healthy controls. The exact Fisher's test was used to determine the statistical significance of allele frequency differences between patients and control subjects. RESULTS: The analysis of obtained results has shown a significantly decreased frequency of DPB1*0402 and slightly increased occurrence rates of DPB1*0101 and DPB1*1301, respectively in the investigated group of patients. Neither DPB1*0301 nor DPB1*0202 were observed to be over-represented. CONCLUSIONS: The expected significant decrease in the frequency of DPB1*0402 was confirmed, whereas positive associations with DPB1*0301 and DPB1*0202, did not prove to be true, respectively (Tab. 1, Ref: 19).

HLA class II allele frequencies in type 1A diabetes mellitus Slovak patients.

BACKGROUND: Diabetes mellitus type 1A (DM-1A) is an autoimmune disease in which the immune response is directed to pancreatic islet cells. DM-1A occurs in genetically predisposed individuals. Among type 1A diabetes associated genes, those of the HLA region have the greatest effect. OBJECTIVES: The aim of our study was to obtain a comprehensive survey of the HLA-DRB1 and HLA-DQB1 allele frequencies in Slovak patients suffering from DM-1A. METHODS: HLA class II genotyping was performed on genomic DNA by the PCR-SSP method according to the 12th Workshop protocol. RESULTS: Our report gives the first presentation of the distribution of HLA-DRB1 alleles (including complete DRB1*04 subtypes) and that of HLA-DQB1 alleles in the Slovak diabetic patients diagnosed at 0-18 years of age. Susceptibility is significantly associated with the alleles DQB1*0302 (OR = 7.8), DRB1*04 (OR = 4.9), DRB1*0301 (OR = 4.2) and DQB1*02 (OR = 2.2), whereas the alleles DQB*0602 (OR = 0.05), DRB1*11 (OR = 0.2), DRB1*15 (OR = 0.2) and DQB1*0301 (OR = 0.3) were found to be protective. CONCLUSIONS: Our results, consistent with other studies, show increased frequencies of known positively associated HLA class II alleles in our type 1A diabetes mellitus patients compared to the general (nondiabetic) population. The protective effect of previously reported alleles was confirmed as well. Results of our population-based study serve in clinical practice for the identification of subjects at risk of developing DM-1A among the first-degree relatives (Tab. 2, Ref. 12).

Toll-like receptors. I. Structure, function and their ligands.

The innate immune system senses invading microorganisms by a phylogenetically conserved family of proteins PRRs of which TLRs are ones of the most important. There are at least 10 different TLRs in humans and 11 in mice. They have in the course of evolution specialized for the recognition of conserved structures among microorganisms called PAMPs. Activation of TLRs results in induction of innate immunity mechanisms as well in development of antigen-specific adaptive immune responses, thus bridging innate and adaptive immunity.

Toll-like receptors. II. Distribution and pathways involved in TLR signalling.

The innate immune system senses invading microorganisms by a phylogenetically conserved family of proteins--TLRs. They are expressed in several types of cells that represent a route of entry of pathogens into the host organism and that can contribute to protection against infection. Except for cells of the immune system, TLRs are present in epithelial cells of the skin, respiratory, intestinal, and genitourinary tracts that form the first protective barrier to invading pathogens. Polarized regulation of TLR expression in epithelial cells explains why pathogenic but not commensal bacteria elicit inflammatory responses. TLR-induced intracellular signalling pathways show remarkable complexity: apart from a common signalling pathway, additional signalling pathways specific for each of the TLRs are responsible for a fine tuning of the immune response, thus securing effective pathogen-directed biological responses.

Toll-like receptors. III. Biological significance and impact for human medicine.

The ability of the innate immune system to recognize and respond to microbial components has been largely attributed to the family of TLRs. They are able to discriminate among distinct molecular patterns associated with microbial components. Recognition of microbial products by TLRs results in induction of innate immunity mechanisms as well in development of antigen-specific adaptive immune responses. Some of TLR ligands start to be used to enhance immune defence mechanisms in fighting infections or malignancies. On the contrary, others were shown to be involved in immunopathogenesis of autoimmune disorders such as SLE.