Almost 20 years ago, a unique class of antibodies devoid of L chains was discovered in Camelidae blood serum. Only one variable domain is responsible for antigen recognition in these unusual antibodies. A recombinant protein, which is analogue to such antigen-recognizing variable domain was called the single domain antibody (sdAb), “nanobody” or “nanoantibody”. The single-domain antibodies and their derivatives have been widely used in the field of biology, toxicology and medicine offering new opportunities for diagnosis and treatment of cancer, autoimmune diseases, infectious diseases, and for toxin neutralization. This review focuses on latest researches in the field and concerns some prospectives for creation of nanoantibody-based diagnostic and therapeutic drugs.

An important role in the formation of immunological tolerance during pregnancy play T lymphocytes. In the present review discusses the characteristics of T lymphocytes, decidua and placenta, especially their migration and functional activity during pregnancy. The review discusses the role of the subpopulations of Th1, Th17, Th2 and Treg lymphocytes in the formation of the placenta and the immune regulation of pregnancy, as well as their interaction with the cells of the decidua and trophoblast.

Alpha-1-antitrypsin (A1AT) exerts a wide spectrum of protective effects, being focused on reduction of secondary injury in inflammation. Moreover, A1AT inhibits some serine proteases, and down-regulates production of proinflammatory cytokines. A number of known A1AT phenotypes is accompanied by affection of cytokine profile in inflammatory processes, thus increasing the risk of disorders associated with A1AT deficiency.

The aim of our study was to evaluate cytokine profiles in the patients with different A1AT phenotypes. Were collected eighty-six blood sera from the persons with suspected A1AT deficiency. The A1AT phenotypes

and concentrations were determined in these samples. The patients were divided into four groups, depending on their A1AT variants, i.e., PiMM, PiZZ, PiMZ and rare A1AT phenotypes. The serum levels of IFNγ, TNFα, IL-6, IL-8, and IL-17 were measured in these groups by means of ELISA technique.

The mean levels of IL-6 comprised 73.52±4.363 pg/ml in the patients with PiZZ phenotype, being higher than in cases of PiMM phenotype (45.61±8.01 pg/ml, p < 0.05). The IL-17 levels were also found to be increased in the groups with PiZZ and PiMZ phenotypes, as compared with PiMM phenotype (p < 0.001). The mean IL-17 values in the samples with PiZZ, PiMZ, and PiMM phenotypes were 80.13±13.56 pg/ml, 106.7±26.28 pg/ml and 42.73±18.52 pg/ml, respectively. Meanwhile, there were no significant differences in IL-8, IFNγ and TNFα levels among different A1AT phenotypes.

The results of this study let us conclude that the cytokine imbalance may be crucial to onset of diseases associated with A1AT deficiency.

Vaccine protection against photogenic gram-positive bacteria including different species of streptococci is an important problem of contemporary molecular biology. Streptococcal infections are most common bacterial infections surpassing by the economic losses all the infections excluding influenza. The gates of streptococcal infection, oral cavity or vagina, are covered with immune and non-immune mucosal cells that are the first line of defenses. Subcutaneous immunization not always stimulate the local immunity on mucosal surfaces. On the other hand, mucosal vaccination can provide an appropriate local immune response together with systemic protection. However, mucosal immunization often requires usage of special and effective adjuvants especially in case of vaccines based on recombinant proteins.

For protection against Streptococcus pneumoniae infection, two chimeric recombinant proteins (PSPF and PSP) have been tested as vaccines. Recombinant proteins PSPF and PSP carry immunogenic epitopes from the respiratory pathogen including PspA, Spr1875 and PsaA. PSPF structure also carries a fraction of flagellin-FliC molecule in comparison with PSP, which does not have this fragment. This portion of PSPF was included as internal adjuvant intended for the stimulation of Toll-like receptor 5.

In this work, the adjuvant capacity of two probiotic strains, Lactobacillus rhamnosus CRL1505 and

L. rhamnosus L32 was evaluated. It was demonstrated that both lactic acid bacteria strains were able to provide adjuvant effects by enhancing the mucosal and systemic immune responses after their co-administration with the recombinant chimeric protein PSPF. The adjuvant effect of both Lactobacillus strains was significantly decreased after their thermal inactivation. However, the cell walls of bacteria showed a marked adjuvant activity. An improved protection against several S. pneumoniae serotypes after mucosal immunization of infant mice with PSPF vaccine with probiotic strains or their cell walls was also demonstrated here.

The recombinant chimeric protein PSPF administered with immunomodulatory probiotic strains or their bacterial components would be a promising vaccine for immunization of humans against S. pneumoniae, particularly in children.

Arginine deiminase is a bacterial enzyme that hydrolyses arginine with citrulline and ammonia formation. In recent years, increasing evidence is reported about in vitro and in vivo anti-angiogenic action of arginine deiminase from Mycoplasma spp. Our studies have shown that arginine deiminase from Streptococcus pyogenes M22 exerts similar effects, i.e., inhibits proliferation and other endothelial cell functions related to angiogenesis. To confirm a leading role of arginine deiminase, as a factor responsible for the anti-proliferative effect, we have constructed an isogenic S. pyogenes M49-16 mutant unable to express arginine deiminase. A comparative analysis of anti-proliferative activity of original S. pyogenes M49-16 strain and its isogenic mutant with arginine deiminase gene deletion (M49-16delAD) was performed, using an endothelial EA.hy926 cell line. The bacterial supernatantes obtained by sonication of S. pyogenes M49-16 and M49-16delAD were tested. The ability of S. pyogenes M49-16 and M49-16delAD supernatantes to hydrolyze arginine was assessed. Moreover, we compared effects of the Streptococcus supernatantes upon proliferative activity of endothelial cells and their distribution through the cell cycle phases.

Supernatantes from original S. pyogenes 49-16 strain were shown to inhibit endothelial cell proliferation to a significant degree (down to 50% of controls). This effect was due to its arginine hydrolyzing activity, i. e. addition of exogenous arginine to the medium resulted into recovery of the cell proliferation levels. The supernatante from S. pyogenes M49-16delAD showed a lower ability to hydrolyze arginine as compared to the supernatante of original strain. Culturing of endothelial cells supplied with S. pyogenes M49-16delAD supernatantes resulted into reduction of their proliferative activity by 10% of control values. Analysis of the cell cycle distribution was concordant with these results. S. pyogenes M49-16 supernatante caused a decrease in S-phase cell fraction by 20% against controls. With a supernatants from S. pyogenes M49-16delAD, such drop in DNA-synthesizing cell ratio was significantly weaker (by only 5% of the control). These results reveal new pathogenetic mechanisms of endothelial dysfunction during streptococcal infection and suggest anti-angiogenic potential of streptococcal arginine deiminase.

The article provides a comparative study of immunological parameters and microbiocenosis nasal mucosa in patients with the asthmatic triad (AT) and polypous rhinosinusitis (PRS). Performance evaluation of immunity carried out by flow cytometry and enzyme immunoassay. The study of the microflora of the nasal mucosa was performed by microbiological methods. Analysis of the immune status in the PRS showed an increase of B-lymphocytes, which may indicate the activation of humoral immunity, while reducing the total number of lymphocytes and T-helpers. Also in the group of PRS revealed increased concentration of IgE and decreased sIgA signals the oppression of mucosal immunity. In the group of the PRS found an increase of the total number of white blood cells and cytotoxic cells, and wherein the concentration of circulating immune complexes (CIC) reduced levels of natural killer cells and B-cells. Thus, the asthmatic triad increased levels of T-lymphocytes due to the high content of cytotoxic cells against decrease in NK-cells. In the AT group have low levels of B-lymphocytes, and as a consequence - reducing the concentration of immunoglobulin IgG4 and sIgA. Thus, the immune status with polypous rhinosinusitis is characterized by the activation of B-lymphocytes with a decrease in T-cell immunity, thus to form a deployed asthmatic triad immunogenesis change occurs with the activation of T-lymphocytes, and reduction in humoral immunity. The study of cytokine profile in PRS and AT showed mixed imbalance of cytokine concentration: increasing the concentration of pro-inflammatory (IFNγ, TNFα), anti-inflammatory (IL-4) and a decrease in the concentration of pro-inflammatory (IL-6) cytokines in asthmatic triad compared with a group of polypous rhinosinusitis. Activation, proliferation and differentiation of B-lymphocytes is under the control of IL-2, IL-6 and IL-4, while IL-10 and IFNγ opposite suppress immunoglobulin synthesis. In the study of the microbial landscape of the nasal mucosa showed an increase of the total number of microorganisms and bacteria of the genus Staphylococcus, Streptococcus and Enterobacteriaceae in the both group. In the group of the PRS was found to increase the total amount of bacteria and microorganisms of the genus Staphylococcus, Streptococcus relative to control. Thus, the group revealed AT and PRS increase the total number of conditionally pathogenic microbial flora in the background to reduce the systemic and local immunity.

Interleukin-6 (IL-6) exerts important functions on immune regulation. In case of high expression, IL-6 may promote autoimmune disorders, e.g., arthritis. Systemic IL-6 blockers based on monoclonal antibodies against IL-6, or its specific receptor subunit, are already used in clinical settings, adding to a range of known biological drugs, such as, TNF blockers. Rheumatic disorders and their experimental therapy are reproducible in mice. This study revealed systemically increased levels of IL-6 in developing arthritis caused by transfer of pathogenic antibodies, as well as the effects of IL-6 neutralization by monoclonal antibodies against murine IL-6. Our results suggest a pathogenic role of the two cytokines, TNF and IL-6, in experimental arthritis induced by passive transfer of anti-collagen antibodies.

Search for new compounds providing delivery of drugs into infected or neoplastic cells, is an important direction of biomedical research. Cell-penetrating peptides are among those compounds, due to their ability to translocate through membranes of eukaryotic cells, serving as potential carriers of various therapeutic agents to the target cells. The aim of present work was to investigate the ability of acipensin 1, an antimicrobial peptide of innate immune system, for in vitro penetration into human tumor cells. Acipensin 1 is a cationic peptide that we have previously isolated from leukocytes of the Russian sturgeon, Acipenser gueldenstaedtii. Capability of acipensin 1 to enter the human erytroleukemia K-562 cells has been investigated for the first time. A biotechnological procedure for producing a recombinant acipensin 1 peptide has been developed. The obtained peptide was conjugated with a fluorescent probe BODIPY FL. By means of confocal microscopy, we have shown that the tagged acipensin 1 rapidly enters into K-562 cells and can be detected in the intracellular space within 5 min after its addition to the cell culture. Using flow cytometry technique, penetration kinetics of the labeled peptide into K-562 cells (at nontoxic micromolar concentrations) has been studied. We have observed a rapid internalization of the peptide to the target cells, thus confirming the results of microscopic analysis, i.e, the labeled acipensin was detectable in K-562 cells as soon as wihin 2-3 seconds after its addition to the incubation medium. The maximum of fluorescence was reached within a period of approx. 45 seconds, with further “plateau” at the terms of >100 seconds following cell stimulation with the test compound. These data support the concept, that the antimicrobial peptides of innate immunity system possess the features of cell-penetrating peptides, and allow us to consider the studied sturgeon peptide a promising template for development of new drugs with increased ability to enter the cells implicated into pathological processes, and, therefore, higher therapeutic efficiency.

In order to justify a need for mass screening of primary immunodeficiencies (PID) in a regional program for the newborns, we performed a retrospective study of blood spots (archived screening cards) from the babies who deceased at the first year of life (n = 43). To this purpose, the copy numbers of T-cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) have been measured. Notably decreased levels of TREC and (or) KREC were revealed in 16 cases (37.0%). Typical clinical pattern and presence of 22q11.2 deletion confirmed a PID diagnosis (DiGeorge syndrome) in one case. In five additional cases, the RAG1 gene defects have been detected, i.e., His249Arg (two heterozygous patients in our study), and Lys820Arg variants (one heterozygous case, and one compound heterozygote) have been observed in our group. Morover, one novel mutation was revealed in heterozygous state, i.e., c.1315C>G (Leu439Val). A synopsis of clinical patterns, hematological data, immunological testing and molecular biology could establish the PID diagnosis in these cases. Hence, we have confirmed a need for introduction of TREC and KREC determination in neonatal PID screening programs, aiming for their timely diagnostics and treatment.

Study Objectives – the study of indicators and luminol- lucigenin-dependent chemiluminescence of peripheral blood neutrophils in patients with renal cell carcinoma and bladder cancer prior to the surgery and 10 days after surgery. 

Held for observation of renal cell carcinoma and bladder cancer patients prior to the (n = 60) and 10 days after surgery (n = 46), aged 45-55 years. The control group consisted of 56 healthy blood donors. Luminol- and lucigenin-dependent chemiluminescence of blood neutrophils estimated De Sole et al. (1983).

In patients with renal cell carcinoma and bladder cancer in blood neutrophils showed a change of the system of production of reactive oxygen species in the course of the disease. The observed changes depend on the localization of the tumor process. In patients with renal cell carcinoma changes mainly affect the primary production of reactive oxygen species in patients with bladder cancer early stages of oxidative metabolism and secondary reactive oxygen species. Restoring compensatory metabolic capacity of blood neutrophils in the postoperative period will occur in patients with bladder cancer.

The findings clarify the features of the chemiluminescence response of peripheral blood neutrophils from oncourological patients that should probably be used in the development of immune rehabilitation programs in this category of patients in the postoperative period.