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Defensins are immune peptides - HDP (Host Defense Peptides) that present high activity against viruses, bacteria and fungi in mammals, including humans. They are an important element of natural resistance in macroorganisms, when microorganisms couldn’t developed this resistance during the evolution. Defensins in vertebrate macroorganisms, have direct and indirect impact on germs, including stimulating the synthesis of immune substances such as cytokines, chemokines and growth factors.

Purpose Germline mutations within melanoma susceptibility genes are present only in minority of melanoma patients and it is expected that additional genes will be discovered with next generation sequence technology and whole-exome sequencing (WES). Materials and Methods Herein we performed WES on a cohort of 96 unrelated Polish patients with melanoma diagnosed under the age of 40 years who all screened negative for the presence of CDKN2A variants. A replication study using a set of 1,200 melanoma patient DNA samples and similarly large series of healthy controls was undertaken. Results We selected 21 potentially deleterious variants in 20 genes (VRK1, MYCT1, DNAH14, CASC3, MS4A12, PRC1, WWOX, CARD6, EXO5, CASC3, CASP8AP2, STK33, SAMD11, CNDP2, CPNE1, EFCAB6, CABLES1, LEKR1, NUDT17, and RRP15), which were identified by WES and confirmed by Sanger sequencing for an association study. Evaluation of the allele distribution among carriers and their relatives in available family trios revealed that these variants were unlikely to account for many familial cases of melanoma. Replication study revealed no statistically significant differences between cases and controls. Conclusion Although most of the changes seemed to be neutral we could not exclude an association between variants in VRK1, CREB3L3, EXO5, and STK33 with melanoma risk.

Cathelicidins are Important immunological peptides – HDPs (Host Defense Peptides) with high biological activity in mammals, including human and vertebrate animals. These evolutionary ancient molecules in these organisms are natural elements of antimicrobial, antiviral, antifungal and antiparasitic immunity against which germs and parasites have not developed immunity, which makes them alternatives to antibiotics. Catelicidins in human and vertebrates affect the germs and parasites directly and indirectly by activating the immune system. 1.What are immune peptides. 2. Cathelicidins. 2.1. Catelicidins in humans. 2.2. Cathelicidins in animals. 3. Summary

Evaluation of the prevalence of POT1, ACD, and TERF2IP mutations among Polish melanoma patients. A cohort of 60 patients from melanoma-prone families, 1500 unselected cases and 1500 controls were genotyped. Methodology included Sanger sequencing, in-silico software predilection, and TaqMan assays. We identified three nonsynonymous variants: POT1 c.903 G>T; TERF2IP c.970 A>G; and ACD c.1544 T>C and a splice site variant ACD c.645 G>A. The c.903 G>T was predicted to be pathogenic according to PolyPhen-2, benign according to Mutation Taster, PROVEAN, AGVGD, and SIFT. The c.645 G>A was defined as disease caused by Mutation Taster and Human Splicing Finder and as variant of unknown significance by ClinVar. The other detected variants were described as benign. The c.903 G>T variant was present in two unselected cases and one control [P = 0.57, odds ratio (OR) = 2.00]; the c.645 G>A variant was not detected among the unselected cases and the controls; the c.970 A>G variant was present in 110 cases and 133 controls (P = 0.14, OR = 0.81); the c.1544 T>C variant was present in 687 cases and 642 controls (P = 0.11, OR = 1.07). We found no loss of heterozygosity of the c.903 G>T, c.970 A>G, and c.645 G>A variants. C.645 G>A variant had no effect on splicing or expression. The changes in POT1 c.903 G>T and ACD c.645 G>A can be classified as rare variants of unknown significance, the other variants appear to be polymorphisms. Germline mutations in POT1, ACD, and TERF2IP are infrequent among Polish melanoma patients.

Red blood cells (RBCs)—erythrocytes—of Osteichthyes are primarily known for their involvement in the process of gas exchange and respiration. Currently, physiological properties of RCBs in fish should also include their ability to participate in defense processes as part of the innate and adaptive immune mechanisms. In response to viruses, bacteria, and fungi or recombinant nanoparticles, they can modulate expression of genes responsible for immune reactions, influence activity of leukocytes, and produce cytokines, antimicrobial peptides, and paracrine intercellular signaling molecules. Via the complement system (CR1 receptor) and owing to their phagocytic properties (erythrophagocytosis), RBCs of Osteichthyes can eliminate pathogens. In addition, they are probably involved in the immune response as antigen-presenting cells via major histocompatibility complex class II antigens.

Shiga toxin-converting bacteriophages (or Stx phages) are responsible for virulence of enterohemorrhagic Escherichia coli strains. Although they belong to the group of lambdoid phages, which have served as models in studies on DNA replication mechanisms, details of regulation of replication of Stx phage genomes are poorly understood. Despite high similarity of their replication regions to that of phage lambda, considerable differences occur between them. Here, we present a comparison of origins of replication and O proteins of lambda and selected Stx phages (phages P27 and 933W). Stx initiator proteins, similarly to the lambda O protein, exist in the form of dimers. Only 4 iteron sequences are strongly bound in vitro by the O proteins, despite the presence of 6 such fragments in the Stx ori, while the function of the other two iterons is still crucial for transformation of E. coli wild-type strain by the P27-derived lambdoid plasmid. As these sequences are found in the gene coding for Stx O proteins, the sequences of these proteins themselves are also extended compared to lambda phage. Therefore, proteins O of Stx phages P27 and 933W have 13 additional amino acids. They can act as a space barrier, thus affecting the lesser packing of the O-some Stx complex compared to the structure found in lambda. Such structure of the DNA replication initiation complex may determine its lesser dependence on the processes occurring in the host cell, including transcriptional activation of the origin. Differences between molecular processes occurring during formation of replication complexes in lambda and Stx phages may indicate the specialization of the latter phages and their adaptation to specific environmental conditions where quick genetic switches are crucial.

Background Although the results of studies in populations with low selenium status indicate an inverse correlation between body selenium levels and the risk of the lung cancer, the effect of this microelement on survival has not been studied. Materials and Methods We performed a prospective study of 302 patients diagnosed with lung cancer in Szczecin, Poland. Selenium concentration in serum was measured at the time of diagnosis and before treatment. All patients were followed for a maximum of 80 months or until death. Vital status was obtained from the Polish National Death Registry. Results Using Cox proportional hazard analysis, performed for all individuals with lung cancer, the hazard ratio (HR) for death from all causes was 1.25 (95% CI: 0.86–1.83, P = 0.99) for patients in the lowest tertile compared to those in the highest tertile of serum selenium levels. Among the patients with stage I disease this relationship was significant (HR-2.73; P = 0.01) for selenium level in tertile 1 ( 69 μg/L, reference). The 80 months crude survival after diagnosis was 79.5% (95% CI: 68.5–92.4%) for individuals in the highest tertile and 58.1% (95% CI: 45.1–74.9%) for individuals in the lowest tertile with stage I lung cancer. Conclusion These results suggest that in patients undergoing treatment for stage I lung cancer, serum selenium levels at the time of diagnosis (>69 μg/L) may be associated with improved overall survival.

In the study we have used a standard Thermo Scientific TaqMan protocol which can be found under this link: http://tools.thermofisher.com/content/sfs/brochures/taqman-assay-genetic-variation-research-br.pdf

In the study we have used a standard Thermo Fisher Scientific Sanger sequencing protocol which can be found under this link: http://www.ramaciotti.unsw.edu.au/wp-content/uploads/2016/08/sequencing_handbook_FLR.pdf

The association of BRCA1/2 mutations with melanoma is not completely determined; the interpretation of variants of unknown significance is also problematic. To evaluate these issues we explored the molecular basis of melanoma risk by performing whole-exome sequencing on a cohort of 96 unrelated Polish early-onset melanoma patients and targeted sequencing of BRCA1/2 genes on additional 30 melanoma patients with familial aggregation of breast and other cancers. Sequencing was performed on peripheral blood. We evaluated MutationTaster, Polyphen2, SIFT, PROVEAN algorithms, analyzed segregation with cancer disease (in both families with identified BRCA2 variants) and in one family performed LOH (based on 2 primary tumors). We found neither pathogenic mutations nor variants of unknown significance within BRCA1. We identified two BRCA2 variants of unknown significance: c.9334G>A and c.4534 C>T. Disease allele frequency was evaluated by genotyping of 1230 consecutive melanoma cases, 5000 breast cancer patients, 3500 prostate cancers and 9900 controls. Both variants were found to be absent among unselected cancer patients and healthy controls. The MutationTaster, Polyphen2 and SIFT algorithms indicate that c.9334G>A is a damaging variant. Due to lack of tumour tissue LOH analysis could not be performed for this variant. The variant segregated with the disease. The c.4534 C>T variant did not segregate with disease, there was no LOH of the variant. The c.9334G>A variant, classified as a rare variant of unknown significance, on current evidence may predisposes to cancers of the breast, prostate and melanoma. Functional studies to describe how the DNA change affects the protein function and a large multi-center study to evaluate its penetrance are required.