INFLUENCE OF ANTIBODIES AGAINST CTLA-4 AND PD-1 UPON QUANTITIES OF THEIR TARGET RECEPTORS

Inhibitory receptors CTLA-4 and PD-1 (immune checkpoints) play a key role in regulation of immune reactions. They suppress excessive immune response against pathogenic microbes and prevent autoimmune reactions. The immune checkpoints are targets of the modern effective therapy based on human and humanized monoclonal antibodies (ipilimumab and nivolumab, tremelimumab, pembrolizumab, etc). However, despite its high efficiency compared to standard chemotherapy, the therapy based on blocking immune check points is facing several problems, i.e., high therapy cost and severe negative autoimmune-related side effects. Unfortunately, this therapy helps to minority of the patients. Hence, further studies are required to improve its efficiency and safety, as well as to search for selection criteria of the patients who would benefit from the therapy. An appealing approach to reduce negative side effects from immune checkpoint inhibition is application of the blocking antibodies, aiming for ex vivo generation of patients’ activated immune cells for cancer therapy, thus avoiding systemic drug administration. Our aim was to elucidate influence of immune checkpoint blocking antibodies on the expression of CTLA-4 and PD-1 in such an in vitro model. First of all, we have determined quantities of lymphocyte receptors in peripheral blood of healthy volunteers, or cancer patients with disseminated melanoma. Moreover, we defined effect from the addition of antibodies against immune checkpoints on proportions of cells expressing CTLA-4 and PD-1 in the population of phytohemagglutininactivated lymphocytes. Our study demonstrated that, in presence of antibodies to either of the two checkpoints during in vitro cell activation, the blockade of specific target receptor is accompanied by reduced number of cells positive for another checkpoint. Hence, the antibodies directed against PD-1 or CTLA-4 seem to suppress both negative signal cascades at once, if tested under such experimental conditions. Noteworthy, the response to blocking antibodies for different immune checkpoints varied for different donors. Our data may be used for development of effective combinations of lymphocyte activators and immune check-point inhibitors, for in vitro generation of activated lymphocytes applied for adoptive cancer therapy, as well as for prediction of possible responses to antibodies against CTLA-4 or PD-1, aiming to select the best personalized cancer immunotherapy

INTRAPLEURAL IMMUNOTHERAPY FOR METASTATIC PLEURISIES IN PATIENTS WITH BREAST CANCER

Intrapleural immunotherapy for metastatic pleurisies demonstrates a high efficiency in the treatment of patients with breast cancer (BC). This immunotherapy modality is regarded as one of the stages of complex treatment in patients with disseminated BC and allows its capabilities to be extended for their further management

Effect of virulent and vaccine variants of influenza virus on the immunophenotype of dendritic cells generated from murine bone marrow

The aim of this study was to generate dendritic cells from the bone marrow of mice (DC) in vitro and to assess the effect of virulent and attenuated variants of influenza virus on the maturation of DCs. Granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) were used in combination, to induce differentiation of mouse bone marrow (BM) mononucleocytes into DCs. On the 5th day, distinct variants of influenza virus were added to the cell culture, and the cells were additionally incubated for 2 days. The morphological characteristics of DCs, immunophenotype of DCs and expression of some Toll-like receptors were evaluated. On the 5th day of incubation. the DCs acquired typical morphological characteristics. DCs were large in size with an eccentrically located nucleous, often irregular in shape, with numerous processes. On the 7th day of incubation with influenza virus variants, their cytoplasm was somewhat denser. DCs acquired more processes, necessary for intercellular contacts. Expression levels of CD11c, a specific marker of BM-derived DCs, and of co-stimulatory molecules such as CD40, CD80, CD86, and MHC-II were elevated in mature DCs. Virulent versus attenuated strains of the influenza virus induced special variants of DCs differentiation, with respect to expression rates of differentiation markers, as well as expression of Toll-like receptors and costimulatory molecules. Conclusions. The in vitro cultured murine mononucleocytes derived from bone marrow can produce a large number of n-DCs, that can mature in the presence of different variants.During evolution of the DC immunophenotype treated with variant influenza viruses, we have found distinct signs of immunosuppression.The attenuated U-2 and M-26 influenza variants obtained by site-specific mutagenesis upon development of DCs immunophenotype, exhibited a decreased immunosuppressive activity and were not inferior to the cold-adapted (CA) reassortant for the most positions, but exceeded it in some instances. These studies can help to assess the criteria for evaluation the efficiency of in vitro developed influenza vaccines

Противоопухолевый ингибитор протеинтирозинкиназ иматиниб как потенциальный корректор пневмофиброза COVID-19

Imatinib mesilate is a well-known antitumor target inhibitor of protein tyrosine kinase, which is effective in different cancer types expressing Bcr / Abl and, in particular, in hemoblastosis. A higher interest to imatinib during the COVID-19 epidemic is explained by the fact that cancer patients are one of the COVID-19 risk groups. Moreover, imatinib target mechanism of action, which is effective in cancer, can have a high potential against the most severe COVID-19 complication such as the disease associated pulmonary fibrosis. COVID-19 associated interstitial pulmonary fibrosis develops as an autoimmune process caused by systemic inflammation with atypical (idiopathic) pneumonia resulting from acute respiratory distress syndrome with the tyrosine kinase mechanism of signaling pathway activation and cellular response. Experi-mental and clinical results showing antifibrotic and dose-related antithrombotic imatinib effect demonstrate perspective use of this antitumor agent to correct COVID-19 associated pneumonia causing a high death rate of patients with COVID-19.The review presents literature data of 2001–2020 discussing pathologic genetic and clinical characteristics of the fibrosis which exacerbates COVID-19 pneumonia in adults. The sequence of the disease processes demonstrates that disease progression with the decreasing oxygen saturation in the peripheral blood intensifies local thrombosis in the lungs. As a result, hypoxia is developing, which is difficult to control and can cause lethal outcome in severe cases. Yet, the conventional antifibrotic and thrombolytic agents can only partially control the process of pneumofibrosis including that of cancer patients. The approximate antifibrotic dose of imatinib 400 mg / day is therapeutic for oncopatho-logy. The antitumor drug registered in many countries and well described side effects and contraindications needs no long-term registration studies for a new indication, therefore, it may be easily prepared for clinical testing.Иматиниб мезилат – известный противоопухолевый таргетный ингибитор протеиновых тирозинкиназ, эффективный при раз-личной онкологической патологии с экспрессией Bcr / Abl, особенно при гемобластозах. На фоне пандемии коронавируса COVID-19 интерес к иматинибу возрос в связи с тем, что онкологические пациенты относятся к одной из групп риска заболевания COVID-19. Более того, определяющий применение иматиниба при онкологических заболеваниях таргетный механизм дейст-вия может быть перспективен для коррекции наиболее опасного осложнения – COVID-19-ассоциированного пневмофиброза. COVID-19-ассоциированный интерстициальный пневмофиброз возникает аутоиммунно вследствие системного воспаления с развитием атипичной (идиопатической) пневмонии под действием острого респираторного дистресс-синдрома с тирозин-киназным механизмом активации сигнальных путей и клеточного ответа. Экспериментальные и клинические данные, выявив-шие антифибротическое и дозозависимое антитромботическое действие иматиниба, свидетельствуют о целесообразности применения этого противоопухолевого препарата для коррекции COVID-19-ассоциированной пневмонии – причины высокой смертности пациентов с COVID-19.В обзоре приведены данные литературы 2001–2020 гг., посвященные патогенетическим и клиническим особенностям развития пневмофиброза, проанализированы данные об особенностях течения пневмонии COVID-19 у взрослых. Приведенная последователь-ность событий показывает, что прогрессирование процесса со снижением сатурации кислорода в периферической крови усили-вает локальное тромбообразование в легких. В результате возникает плохо управляемая гипоксия, которая в тяжелых случаях является причиной летального исхода. Воздействие на процесс развития пневмофиброза с помощью известных антифибротиче-ских и тромболитических препаратов позволяет лишь частично контролировать процесс, в том числе у онкологических пациен-тов. Ориентировочная антифибротическая доза иматиниба 400 мг / сут считается терапевтической для онкологической пато-логии. Зарегистрированный во многих странах противоопухолевый препарат не требует длительных регистрационных исследований по новому показанию, а известные побочные эффекты и противопоказания к применению позволяют быстро под-готовить его клиническую апробацию

Antitumor proteinkinase inhibitor imatinib may be regarded as a potential correcting agent for COVID-19 associated pulmonary fibrosis

Imatinib mesilate is a well-known antitumor target inhibitor of protein tyrosine kinase, which is effective in different cancer types expressing Bcr / Abl and, in particular, in hemoblastosis. A higher interest to imatinib during the COVID-19 epidemic is explained by the fact that cancer patients are one of the COVID-19 risk groups. Moreover, imatinib target mechanism of action, which is effective in cancer, can have a high potential against the most severe COVID-19 complication such as the disease associated pulmonary fibrosis. COVID-19 associated interstitial pulmonary fibrosis develops as an autoimmune process caused by systemic inflammation with atypical (idiopathic) pneumonia resulting from acute respiratory distress syndrome with the tyrosine kinase mechanism of signaling pathway activation and cellular response. Experi-mental and clinical results showing antifibrotic and dose-related antithrombotic imatinib effect demonstrate perspective use of this antitumor agent to correct COVID-19 associated pneumonia causing a high death rate of patients with COVID-19.The review presents literature data of 2001–2020 discussing pathologic genetic and clinical characteristics of the fibrosis which exacerbates COVID-19 pneumonia in adults. The sequence of the disease processes demonstrates that disease progression with the decreasing oxygen saturation in the peripheral blood intensifies local thrombosis in the lungs. As a result, hypoxia is developing, which is difficult to control and can cause lethal outcome in severe cases. Yet, the conventional antifibrotic and thrombolytic agents can only partially control the process of pneumofibrosis including that of cancer patients. The approximate antifibrotic dose of imatinib 400 mg / day is therapeutic for oncopatho-logy. The antitumor drug registered in many countries and well described side effects and contraindications needs no long-term registration studies for a new indication, therefore, it may be easily prepared for clinical testing

Micrometastases identification in malignant tumors

The article reviewed literature data relating to the methods used for detection of single tumor cells in bone marrow, lymph nodes, and peripheral blood. Sensitivity of modern detection methods is analyzed. Despite advances in the development of molecular biology and cytology, until now there is no universal approach to the micrometastases identification, and existing methods optimization are recommended

Characteristics of lymphocyte subpopulations in the peripheral blood and lymph nodes of patients with ovarian cancer

More and more data suggest that ovarian cancer (OC) is an immunogenic tumor. Clinical trials dealing with immunotherapy based on activated natural killer (NK) cells and dendritic cells (DC) are under way. Mononuclear cells (MNCs) from both peripheral blood and lymph nodes (LN) are proposed to be used as a source of immunity effectors. This paper characterizes peripheral blood and LN effector cells in patients with OC. The peripheral blood displayed T cell subpopulations: T helper cells, cytotoxic T lymphocytes, and NK cells. LN showed virtually no expression of NK cell antigens, but exhibited the expression of markers of DC and T regulatory cells at the same time. The cytotoxic activity of MNCs against autologous tumor cells was higher than that against the K562 cell line. OC tissue samples were observed to contain low tumor-infiltrating lymphocyte counts

Characteristics of lymphocyte subpopulations in the peripheral blood and lymph nodes of patients with ovarian cancer

More and more data suggest that ovarian cancer (OC) is an immunogenic tumor. Clinical trials dealing with immunotherapy based on activated natural killer (NK) cells and dendritic cells (DC) are under way. Mononuclear cells (MNCs) from both peripheral blood and lymph nodes (LN) are proposed to be used as a source of immunity effectors. This paper characterizes peripheral blood and LN effector cells in patients with OC. The peripheral blood displayed T cell subpopulations: T helper cells, cytotoxic T lymphocytes, and NK cells. LN showed virtually no expression of NK cell antigens, but exhibited the expression of markers of DC and T regulatory cells at the same time. The cytotoxic activity of MNCs against autologous tumor cells was higher than that against the K562 cell line. OC tissue samples were observed to contain low tumor-infiltrating lymphocyte counts

Neoadjuvant chemotherapy for advanced ovarian cancer: literature data and in vitro studies

This paper analyzes large amounts of literature data on studies of the efficiency of neoadjuvant chemotherapy (NCT) for advanced ovarian cancer (OC), which is performed prior to standard surgery. Clinical trials have demonstrated that a NCT regimen followed by cytoreductive surgery is less effective than primary cytoreductive one; however, evidence for the benefit of NCT is lacking so far. The authors conducted investigations using the intraoperative material obtained from 17 patients with T3a–cNxM0 OC, who were divided for a comparative examination into 2 groups. Group 1 included OC patents who received NCT; Group 2 comprised OC patients who did not. The tumor cells obtained from the intraoperative material of both groups were able to generate a well-proliferating culture in in vitro experiments. The cultured OC cells were characterized, by analyzing cytological specimens and the functional activity of these cells. It was ascertained that 35 % of the cultured tumor cells from OC retained their resistance to the cytotoxic action of effector cells (autologous lymphocytes) at a target cell/effector cell ratio of 1:5. Thus, both the literature and the experiment provide no unambiguous evidence supporting the fact that NCT before cytoreductive surgery is a better approach than primary surgical treatment. The optimal regimen of NCT, which would be able to enhance its efficiency, remains important