Induction of tumor-specific acquired immunity against already established tumors by selective stimulation of innate DEC-205+ dendritic cells

Two major distinct subsets of dendritic cells (DCs) are arranged to regulate our immune responses in vivo; 33D1+ and DEC-205+ DCs. Using anti-33D1-specific monoclonal antibody, 33D1+ DCs were successfully depleted from C57BL/6 mice. When 33D1+ DC-depleted mice were stimulated with LPS, serum IL-12, but not IL-10 secretion that may be mediated by the remaining DEC-205+ DCs was markedly enhanced, which may induce Th1 dominancy upon TLR signaling. The 33D1+ DC-depleted mice, implanted with syngeneic Hepa1-6 hepatoma or B16-F10 melanoma cells into the dermis, showed apparent inhibition of already established tumor growth in vivo when they were subcutaneously (sc) injected once or twice with LPS after tumor implantation. Moreover, the development of lung metastasis of B16-F10 melanoma cells injected intravenously was also suppressed when 33D1+ DC-deleted mice were stimulated twice with LPS in a similar manner, in which the actual cell number of NK1.1+CD3− NK cells in lung tissues was markedly increased. Furthermore, intraperitoneal (ip) administration of a very small amount of melphalan (l-phenylalanine mustard; l-PAM) (0.25 mg/kg) in LPS-stimulated 33D1+ DC-deleted mice helped to induce H-2Kb-restricted epitope-specific CD8+ cytotoxic T lymphocytes (CTLs) among tumor-infiltrating lymphocytes against already established syngeneic E.G7-OVA lymphoma. These findings indicate the importance and effectiveness of selective targeting of a specific subset of DCs, such as DEC-205+ DCs alone or with a very small amount of anticancer drugs to activate both CD8+ CTLs and NK effectors without externally added tumor antigen stimulation in vivo and provide a new direction for tumor immunotherapy

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Development of the immune system in severe combined immunodeficiency mice reconstituted with transfered fetal liver cells

Severe combined immunodeficiency (SCID) mice were immunologically reconstituted by the transfer of fetal liver cells (FLC) from BALB/c (SCID-isoFLC mice) or C57BL/6 mice (SCID-alloFLC mice). The developmental process of the immune system in the peripheral blood (PB) was almost comparable between SCID-isoFLC and SCID-isoFLC mice. Analysis of the lymphoid organs and the PB from SCID-alloFLC mice indicated that slg+ B cells appeared and were distributed to the periphery within 2 weeks after the transfer of FLC. It was also suggested that precursor T cells entered the thymus before 4 weeks after the transfer, and were differentiated into mature CD4+ or CD8+ T cells which then migrated to the periphery by 6 weeks. All of mature lymphocytes in the periphery of the SCID-alloFLC mice were shown to express donortype H-2 antigens. Additionally, in the SCID-isoFLC mice, cell-mediated immunity such as rejection against alloantigens was functioning from 6 weeks, and humoral immune function was suggested by the detection of cells generating antigen-specific antibodies. We discuss that development of the immune system in SCID mice receiving transferred FLC was comparable to that normally seen in the fetal and neonatal stages

Do SnI4 molecules deform on heating and pressurization in the low-pressure crystalline phase ?

Extended X-ray absorption fine structure (EXAFS) measurements on the crystalline SnI4 were carried out to investigate the change in the environment around a Sn atom at high pressures and temperatures. We could not find clear evidence on the symmetry change of molecules even close to the melting points, where the melting curve becomes abnormally flat against pressure

Emergency medical treatment of patients undergoing otolaryngology in the southeastern part of Okayama Prefecture

To clarify the scenario regarding the emergency medical treatment of patients undergoing otolaryngology in southeastern Okayama Prefecture in Japan, we evaluated the conditions in three hospitals that mainly provide emergency medical treatment to patients undergoing otorhinolaryngology at night or on holidays. The data (age, sex, type of disease, and address) of patients who visited Japanese Red Cross Okayama Hospital, Kawasaki Medical School General Medical Center, and Okayama Medical Center in 2018 were collected and compared. All three hospitals reported many cases of tonsillar abscess and nasal bleeding. In the study population, the number of patients aged ≤10 and 10-20 years were the lowest and highest, respectively. Patients residing in southern Okayama City and Tamano City tended to visit Japanese Red Cross Okayama Hospital or Kawasaki Medical School General Medical Center. Patients residing in northeastern Okayama Prefecture and northern Okayama City tended to visit Okayama Medical Center. A ceiling for the senior physicians’ capacity will be introduced in April 2020, and thus the number of otolaryngology-related treatments performed in Okayama Prefecture is expected to decrease. The otolaryngologyrelated emergency medical treatment in southeastern Okayama Prefecture may collapse. Emergency medical care systems must therefore be considered in the future