Intratracheal trimerized nanobody cocktail administration suppresses weight loss and prolongs survival of SARS-CoV-2 infected mice

新型コロナウイルスを中和するアルパカ抗体 --マウス実験で有効性を確認--. 京都大学プレスリリース. 2023-02-17.BACKGROUND: SARS-CoV-2 Omicron variants are highly resistant to vaccine-induced immunity and human monoclonal antibodies. METHODS: We previously reported that two nanobodies, P17 and P86, potently neutralize SARS-CoV-2 VOCs. In this study, we modified these nanobodies into trimers, called TP17 and TP86 and tested their neutralization activities against Omicron BA.1 and subvariant BA.2 using pseudovirus assays. Next, we used TP17 and TP86 nanobody cocktail to treat ACE2 transgenic mice infected with lethal dose of SARS-CoV-2 strains, original, Delta and Omicron BA.1. RESULTS: Here, we demonstrate that a novel nanobody TP86 potently neutralizes both BA.1 and BA.2 Omicron variants, and that the TP17 and TP86 nanobody cocktail broadly neutralizes in vitro all VOCs as well as original strain. Furthermore, intratracheal administration of this nanobody cocktail suppresses weight loss and prolongs survival of human ACE2 transgenic mice infected with SARS-CoV-2 strains, original, Delta and Omicron BA.1. CONCLUSIONS: Intratracheal trimerized nanobody cocktail administration suppresses weight loss and prolongs survival of SARS-CoV-2 infected mice

Transient receptor potential vanilloid 1 and transient receptor potential ankyrin 1 contribute to the progression of colonic inflammation in dextran sulfate sodium-induced colitis in mice: Links to calcitonin gene-related peptide and substance P

Transient receptor potential (TRP) vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1), which are non-selective cation channels, play important roles in the sensation of pain. This study investigated the roles of TRPV1 and TRPA1 in dextran sulfate sodium (DSS)-induced murine colitis. DSS (2%) administered for 7 days caused severe colitis that was significantly less severe in TRPV1-deficient (TRPV1KO) and TRPA1-deficient (TRPA1KO) mice than that in wild-type (WT) mice. Similar colitis attenuations were observed in TRPV1KO and TRPA1KO mice but not in WT mice that had been transplanted with bone marrow cells from WT, TRPA1KO, or TRPV1KO mice. DSS treatment upregulated calcitonin gene-relative peptide (CGRP)- and substance P (SP)-positive nerve fibers in the colonic mucosa of WT mice. TRPV1KO and TRPA1KO mice showed significant reductions in the DSS-induced upregulation of SP, but the DSS-induced upregulation of CGRP was not reduced. Sensory deafferentation evoked by pretreatment with high doses of capsaicin markedly exacerbated DSS-induced colitis with reductions in DSS-induced upregulation of SP- and CGRP-positive nerve fibers. These findings suggest that neuronal TRPV1 and TRPA1 contribute to the progression of colonic inflammation. While these responses may be mediated by the upregulation of SP-mediated deleterious mechanisms, CGRP may be associated with protective mechanisms. Keywords: Colonic inflammation, Transient receptor potential channels, Calcitonin gene-related peptide, Substance P, Capsaici

Saireito (TJ-114), a Japanese traditional herbal medicine, reduces 5-fluorouracil-induced intestinal mucositis in mice by inhibiting cytokine-mediated apoptosis in intestinal crypt cells.

Clinical chemotherapy frequently causes intestinal mucositis as a side effect, which is accompanied by severe diarrhea. We recently showed that the cytokine-mediated apoptotic pathway might be important for the development of intestinal mucositis induced by 5-fluorouracil (5-FU). Saireito, the traditional Japanese herbal (Kampo) medicine, is widely used to treat diarrhea and various inflammatory diseases in Japan. In the present study, we investigated the effect of saireito on 5-FU-induced intestinal mucositis in mice, especially in relation to apoptosis in the intestinal crypt. Male C57BL/6 mice were given 5-FU (50 mg/kg), i.p. once daily for 6 days. Intestinal mucositis was evaluated histochemically. Saireito (100-1000 mg/kg) was administered p.o. twice daily for 6 days. Repeated 5-FU treatment caused severe intestinal mucositis including morphological damage, which was accompanied by body weight loss and diarrhea. Daily administration of saireito reduced the severity of intestinal mucositis in a dose-dependent manner. Body weight loss and diarrhea during 5-FU treatment were also significantly attenuated by saireito administration. The number of apoptotic and caspase-3-activated cells in the intestinal crypt was increased, and was accompanied by up-regulated tumor necrosis factor (TNF)-α and interleukin (IL)-1β mRNA within 24 h of the first 5-FU injection. However, all of these measures were significantly lower after saireito administration. These results suggest that saireito attenuates 5-FU-induced intestinal mucositis. This action may come from the reduction of apoptosis in the intestinal crypt via suppression of the up-regulation of inflammatory cytokines. Therefore, saireito may be clinically useful for the prevention of intestinal mucositis during cancer chemotherapy