Assessment of the cellular immunity response to the new coronavirus infection COVID-19

In December 2019 humanity faced a new coronavirus infection caused by SARS-CoV-2 virus and the disease referred to as COVID-19 has spread globally.Specially adapted for the detection of SARS-CoV-2 RNA tests based on polymerase chain reaction are used to identify infected patients by processing nasal and oropharyngeal swabs. However, often it may not be sufficient to use polymerase chain reaction only, but in many cases it is very important to assess the humoral and cellular immune reactions to the infection.The present review aims to summarize and analyze the available literature data on the formation of the immune response and diagnostic methods used for characteristics of the immune reactions in patients who recovered from COVID-19 or received an anti-COVID-19 vaccine.Currently, the effectiveness of anti-COVID-19 vaccination and the developing immunity after a previous illness are assessed by detecting specific antibodies. A number of observations show that anti-S and anti-RDB IgG titers significantly decline within 6–8 months after diagnosis. It is important to note that although the antibody levels in the blood of recovered patients decrease, the memory cells can be determined by the appropriate tests.The ELISPOT (Enzyme-linked immunospot) method, which is a variation of the ELISA (Enzyme-linked immunosorbent assay), allows estimation the T- and B-cells that release activation factors such as cytokines and antibodies in response to the presented antigens.The assessment of the generation and effective function of the immune memory to SARS-CoV-2 requires the evaluation of the content and functional activity of its various components, including B-lymphocytes, CD8+, CD4+T-lymphocytes, since they have rather independent mechanisms of action of cellular memory.Therefore, it is crucially important to have tools for evaluating the immunity to SARS-CoV-2 when the level of antibodies is insufficient for determination by the available registered tests, and the introduction of test systems into clinical diagnostic practice, allowing to identify markers of long-term cellular memory, are relevant.

Characteristics of the parameters of the innate and acquired immune response during the period of adaptation to training at a Medical University

Adaptation for new social conditions is an inevitable factor which the first-year students undergo when entering a medical school. Immune system as a part of entire structural and functional homeostatic complex, is involved into the adaptive reactions, thus pointing to its participation in fitting the new lifestyle among first-year students. One should note some peculiarities of immune reactions which depend on the organization pattern of educational process: despite common features of studies, the training environment for beginners at the military training center (VTC) is different from those for students at the medical and preventive faculty (LPF). The purpose of our study was to compare quantitative and functional parameters of immune system in the first-year students at a medical university, depending on distinct features of educational arrangement.The study included 36 first-year students of the Medical University divided into two groups, comparable for age, sex, and physical condition. The first group included 18 first-year VUTS students, whereas the second group consisted of 18 LPF pupils. Studies of immunological parameters in peripheral blood were carried out three months after the training was started. We have assessed counts and functional potential of T cells, their subpopulation profile, B lymphocyte counts, and serum level of IgA, IgM and IgG, total numbers of natural killer cells and proportion of cytolytically active forms, oxygen-producing activity of neutrophils, and the numbers of peripheral monocytes expressing type 2,4 Toll-like receptors (TLR). Comparison of the adaptive immune response parameters did not reveal any gross differences between the groups. At the same time, evaluation of markers reflecting functional potential of innate immunity cells revealed distinct signs of immune reactions, depending on the faculty of the first-year students. It has been shown that the proportion of functionally active NK-cells containing lytic granzyme B granules was lower in the EUTC students. Also, military medical students have a statistically significantly lower relative and absolute number of peripheral blood monocytes expressing surface TLR 4. The detected signs of suppressed functional potential of macrophages and natural killer cells in the first-year OUV students represent the possibly alarming factor of impaired adaptive reserves of immune system. The data obtained are of interest for development of immune rehabilitation programs to prevent clinical manifestations of immune dysfunction.

Pathogenesis of IgA Vasculitis: An Up-To-Date Review

Immunoglobin A (IgA) vasculitis (IgAV), formerly called the Henoch-Schönlein purpura (HSP), is a small vessel vasculitis, characterized by IgA1-dominant immune deposition at diseased vessel walls. IgAV is the most common form of vasculitis in children; typical symptoms include palpable purpura, arthritis or arthralgia, abdominal pain, and hematuria or proteinuria. Galactose-deficient IgA1 is detected in the tissues of the kidney and skin in patients with IgAV; it forms immune complexes leading to subsequent immune reactions and injuries. This report provides the recent advances in the understanding of environmental factors, genetics, abnormal innate and acquired immunity, and the role of galactose-deficient IgA1 immunocomplexes in the pathogenesis of IgAV.

Atypical presentations of superficial dermatophytoses associated with Ruocco’s immunocompromised cutaneous district: A case series

An immunocompromised district is an area of irregular immune control of the skin occurring due to cutaneous damage of any sort conducive to the development of infections, immune reactions, and tumors. Superficial dermatophytoses are one of the most commonly encountered cutaneous infections, which, in some cases, may have various atypical presentations. Herein, we present a series of eleven such cases in which the presentation of a superficial dermatophytosis was altered by the concurrent presence of a different unrelated dermatosis on the same anatomical site.

Exploration of Pattern Recognition Receptor Agonists as Candidate Adjuvants

Adjuvants are used to maximize the potency of vaccines by enhancing immune reactions. Components of adjuvants include pathogen-associated molecular patterns (PAMPs) and damage-associate molecular patterns (DAMPs) that are agonists for innate immune receptors. Innate immune responses are usually activated when pathogen recognition receptors (PRRs) recognize PAMPs derived from invading pathogens or DAMPs released by host cells upon tissue damage. Activation of innate immunity by PRR agonists in adjuvants activates acquired immune responses, which is crucial to enhance immune reactions against the targeted pathogen. For example, agonists for Toll-like receptors have yielded promising results as adjuvants, which target PRR as adjuvant candidates. However, a comprehensive understanding of the type of immunological reaction against agonists for PRRs is essential to ensure the safety and reliability of vaccine adjuvants. This review provides an overview of the current progress in development of PRR agonists as vaccine adjuvants, the molecular mechanisms that underlie activation of immune responses, and the enhancement of vaccine efficacy by these potential adjuvant candidates.

Trained Immunity as an Adaptive Branch of Innate Immunity

The concept of trained immunity has become one of the most interesting and potentially commercially and clinically relevant ideas of current immunology. Trained immunity is realized by the epigenetic reprogramming of non-immunocompetent cells, primarily monocytes/macrophages and natural killer (NK) cells, and is less specific than adaptive immunity; therefore, it may cross-protect against other infectious agents. It remains possible, however, that some of the observed changes are simply caused by increased levels of immune reactions resulting from supplementation with immunomodulators, such as glucan. In addition, the question of whether we can talk about trained immunity in cells with a life span of only few days is still unresolved.

Sertoli cells: immunomodulatory properties, methods of isolation and culture

Due to complications caused by the inevitable use of immunosuppressive drugs in organ and cell transplantation, the use of natural mechanisms of immunological tolerance identified in animal and human organisms arouses interest. It has long been known that there are certain areas in them, including the testis, where immune reactions are virtually impossible. Our review focuses on the role of Sertoli cells that provide testicular immune privilege. Methods of isolation and cultivation of Sertoli cells are described and their potentials in biology and medicine are discussed.

Tonsillectomy and the incidence of various types of cancer

A potential connection between tonsillectomy and the development of various cancer types has repeatedly been reported in the scientific literature, but many studies have contradicted these observations. Thus, we have no clear evidence, neither to firmly support nor to refute the above-mentioned connection. Here, I suggest that the main reason for the lack of clearer evidence is that the investigations have so far mainly used incorrect sample groups. I propose that individual differences in the tonsils’ involvement in immune reactions should be taken into account to solve this long-standing puzzle.

Controllers of cutaneous regulatory T cells: ultraviolet radiation and the skin microbiome

For the maintenance of homeostasis termination of immune reactions is as equally important as their induction. In this scenario regulatory T cells (Treg) play an important role. Accordingly a variety of inflammatory diseases are caused by an impairment of Treg. Hence, it is important to identify triggers by which Treg can be induced and activated, respectively. For quite a long time it is known that ultraviolet radiation can induce Treg which inhibit cutaneous immune reactions including contact hypersensitivity. Since these Treg inhibit in an antigen-specific fashion they may harbor therapeutic potential. However similar Treg can be induced also by other triggers which include vitamin D and antimicrobial peptides. Recently it was discovered that the gut microbiome controls the development of Treg in the intestine. The same may apply for the skin. Short chain fatty acids, microbiota-derived bacterial fermentation products, appear to induce and to activate Treg in the skin. Topical application of short chain fatty acids was shown to inhibit contact hypersensitivity and to reduce inflammation in the murine imiquimod-induced psoriasis-like skin inflammation model. Together, these data indicate that induction and activation of Treg may be a potential therapeutic strategy to treat inflammatory diseases in the future.