Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

PURPOSE: An oral cholera vaccine (OCV), Euvichol, with thimerosal (TM) as preservative, was prequalified by the World Health Organization (WHO) in 2015. In recent years, public health services and regulatory bodies recommended to eliminate TM in vaccines due to theoretical safety concerns. In this study, we examined whether TM-free Euvichol induces comparable immunogenicity to its TM-containing formulation in animal model. MATERIALS AND METHODS: To evaluate and compare the immunogenicity of the two variations of OCV, mice were immunized with TM-free or TM-containing Euvichol twice at 2-week interval by intranasal or oral route. One week after the last immunization, mice were challenged with Vibrio cholerae O1 and daily monitored to examine the protective immunity against cholera infection. In addition, serum samples were obtained from mice to measure vibriocidal activity and vaccine-specific IgG, IgM, and IgA antibodies using vibriocidal assay and enzyme-linked immunosorbent assay, respectively. RESULTS: No significant difference in immunogenicity, including vibriocidal activity and vaccine-specific IgG, IgM, and IgA in serum, was observed between mice groups administered with TM-free and -containing Euvichol, regardless of immunization route. However, intranasally immunized mice elicited higher levels of serum antibodies than those immunized via oral route. Moreover, intranasal immunization completely protected mice against V. cholerae challenge but not oral immunization. There was no significant difference in protection between two Euvichol variations. CONCLUSION: These results suggested that TM-free Euvichol could provide comparable immunogenicity to the WHO prequalified Euvichol containing TM as it was later confirmed in a clinical study. The pulmonary mouse cholera model can be considered useful to examine in vivo the potency of OCVs.
Animals* ; Antibodies ; Cholera Vaccines ; Cholera* ; Clinical Study ; Enzyme-Linked Immunosorbent Assay ; Immunization ; Immunoglobulin A ; Immunoglobulin G ; Immunoglobulin M ; Mice ; Models, Animal* ; Public Health ; Thimerosal ; Vaccines ; Vibrio cholerae O1 ; World Health Organization

Exosomes are Nano-sized lipid vesicles secreted from mammalian cells containing diverse cellular materials such as proteins, lipids, and nucleotides. Multiple lines of evidence indicate that in saliva, exosomes and their contents such as microRNAs (miRNAs) mediate numerous cellular responses upon delivery to recipient cells. The objective of this study was to characterize the different expression profile of exosomal miRNAs in saliva samples, periodically isolated from a single periodontitis patient. Unstimulated saliva was collected from a single patient over time periods for managing periodontitis. MicroRNAs extracted from each phase were investigated for the expression of exosomal miRNAs. Salivary exosomal miRNAs were analyzed using Affymetrix miRNA arrays and prediction of target genes and pathways for its different expression performed using DIANA-mirPath, a web-based, computational tool. Following the delivery of miRNA mimics (hsa-miR-4487, -4532, and -7108-5p) into human gingival fibroblasts, the expression of pro-inflammatory cytokines and activation of the MAPK pathway were evaluated through RT-PCR and western blotting. In each phase, 13 and 43 miRNAs were found to be differently expressed (|FC| ≥ 2). Among these, hsa-miR-4487 (|FC|=9.292005) and hasmiR-4532 (|FC|=18.322697) were highly up-regulated in the clinically severe phase, whereas hsa-miR-7108-5p (|FC|= 12.20601) was strongly up-regulated in the clinically mild phase. In addition, the overexpression of miRNA mimics in human gingival fibroblasts resulted in a significant induction of IL-6 mRNA expression and p38 phosphorylation. The findings of this study established alterations in salivary exosomal miRNAs which are dependent on the severity of periodontitis and may act as potential candidates for the treatment of oral inflammatory diseases.
Blotting, Western ; Cytokines ; Exosomes ; Fibroblasts ; Humans ; Interleukin-6 ; MicroRNAs ; Nucleotides ; Periodontitis ; Phosphorylation ; Pilot Projects ; RNA, Messenger ; Saliva

Typhoid fever, a serious systemic infection caused by Salmonella enterica serovar Typhi, breaks out in developing countries. However, existing vaccines only induce relatively low protective effects with humoral responses and do not stimulate secondary immune response, especially to young people. The objective of this study is to evaluate the immunogenicity of the vaccine containing virulence capsular polysaccharide (Vi) conjugated with the optimal ratios of non-toxic variant of diphtheria toxin (CRM(197)) in mice. Six-week-old BALB/c female mice were injected intraperitoneally three times at intervals of 14 days and sera were collected on days 0, 14, 28, 42 and 56 post-injection. The efficacy of the vaccine was evaluated by comparing between negative control group injected with PBS and vaccine groups injected with Vi or Vi-CRM(197) conjugate of different ratio. Vi and CRM(197)-specific antibody responses were evaluated using enzyme-linked immunosorbent assay. The result showed that Vi-CRM(197)-1 group revealed the highest and significant Vi-specific IgG immune responses among the other groups and Vi group (p < 0.01). In conclusion, Vi-CRM(197)-1 conjugate vaccine induced the highest humoral immune response in mice and may be used as an effective vaccine to replace the existing typhoid vaccine for infants under 2 years old.
Animals ; Antibody Formation ; Child, Preschool ; Developing Countries ; Diphtheria Toxin ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunity, Humoral ; Immunoglobulin G ; Infant ; Mice* ; Salmonella enterica* ; Salmonella typhi* ; Salmonella* ; Typhoid Fever ; Typhoid-Paratyphoid Vaccines ; Vaccines ; Virulence

We found errors in our published article.

We found errors in our published article.

The safety, tolerability and immunogenicity of an oral cholera vaccine (OCV) was assessed in adult Korean male through an open-label, non-comparative clinical study. Two doses of vaccine with an interval of 2 weeks were given to 20 healthy subjects. A total of 7 adverse events occurred in 6 subjects. However, no clinically significant change was observed in electrocardiograms, vital signs, physical examinations, and clinical laboratory tests. The immunogenicity of OCV was evaluated by serum vibriocidal assay where anti-Vibrio cholerae O1 and O139 antibodies were measured at day 0, 14, and 28 of vaccine administration. The antibody titers ranged from < 2.5-5,120 for V. cholerae O1 Inaba, < 2.5-10,240 for V. cholerae O1 Ogawa and < 2.5-480 for V. cholerae O139. In addition, the fold increase in antibody titers ranged from 1-4,096 for O1 Inaba, 1-8,192 for O1 Ogawa, and 1-384 for O139. The seroconversion rate was 95% and 45% for O1 and O139 antibodies, respectively. Our study clearly shows that administration of two doses of OCV at a 2 week-interval increases an appropriate level of antibody titer in the serum of healthy Korean adult males (Clinical Trial Number, NCT01707537).
Administration, Oral ; Adult ; Antibodies, Bacterial/*blood/immunology ; Antibody Formation ; Cholera/*prevention & control ; Cholera Vaccines/adverse effects/*immunology ; Creatine Kinase/blood ; Humans ; Male ; Republic of Korea ; Toothache/etiology ; Vibrio cholerae O1/immunology

The present study was carried out to examine the toxicity and target organs of oral cholera vaccine (OCV) after repeated oral administration in Sprague-Dawley rats for 6 weeks (3 administrations, once every 2 weeks). OCV is an inactivated oral cholera vaccine that contains Vibrio cholerae and confers protection against cholera caused by V. cholera serogroups O1 (Inaba and Ogawa serotypes) and O139 (strain 4260B). The animals were orally administered either OCV placebo (negative control) or OCV at a dose equivalent to 240 times the anticipated human dose. Throughout the administration period, no significant change was detected in clinical signs, body weight, food or water consumption, urinalysis results, hematological and clinical biochemistry test results, organ weights, necropsy, or histopathological examination results. Minor changes were found in hematological and clinical biochemistry tests; however, these changes were within normal ranges. The above results suggest that oral administration of OCV in rats did not induce any toxicologically meaningful changes, and the target organs could not be determined. This study was conducted in accordance with the guidelines established by Good Laboratory Practice (2009-183, KFDA, December 22, 2009) and the OECD Principles of Good Laboratory Practice (1997).
Administration, Oral ; Animals ; Biochemistry ; Body Weight ; Cholera ; Drinking ; Humans ; Organ Size ; Rats ; Rats, Sprague-Dawley ; Reference Values ; Urinalysis ; Vibrio cholerae

The use of antibiotics, including therapeutically in human and veterinary medicine, or as prophylaxis of growth promotion in animal husbandry, ultimately exerts selective pressure favorable for the propagation of antibiotic resistant bacteria. In this study we have determined the resistance for antibiotics of E. coli from pig farm environment, and investigate genetic relatedness by random amplification of polymorphic DNA (RAPD). Six farms were randomly selected in Gyeongsanman-do and Busan provinces for collecting samples from feces, manure and underground water. A total of 88 isolates from feces, 74 isolates from manure and 1 isolate from underground water were analyzed by antibiotic resistance and RAPD. Antibiotic resistance testing was performed by disk diffusion method using 16 antibiotics. The highest percentage of antibiotic resistance of isolates from feces and manure was found to the following antibiotics; tetracycline (100% and 100%), sulfamethoxazole/trimethoprim (60.2% and 62.2%), streptomycin (50.0% and 68.9%), chloramphenicol (56.8% and 56.8%), ampicillin (50.0% and 81.1%) and cephalothin (50.0% and 51.4%). Of isolates from feces and manure, 22.7% and 20.3% showed multiple resistance to 4 and 5 antibiotics, respectively. The isolates from GE pig farm showed six RAPD patterns. A single pattern, RAPD-C, was predominat in feces isolates (50.0%) and manual isolates (46.7%), and the rest of feces isolates showed RADP-A, B and E pattern and manure isolates showed D and E pattern. One isolate from underground water showed F pattern. The appearance of multiresistant in E. coli isolates from pig farms environment is a problem of major concern of public health and RAPD may offer an useful tool of discrimination for the epidemiological investigation.
Ampicillin ; Animal Husbandry ; Anti-Bacterial Agents ; Bacteria ; Busan ; Cephalothin ; Chloramphenicol ; Diffusion ; Discrimination (Psychology) ; DNA ; Drug Resistance, Microbial* ; Escherichia coli* ; Escherichia* ; Feces ; Groundwater ; Humans ; Manure ; Public Health ; Streptomycin ; Tetracycline ; Veterinary Medicine

BACKGROUND AND OBJECTIVES: In this study we investigated the association between the polymorphism of apolipoprotein E and the development of myocardial infarction, and assessed whether this polymorphism produces any changes of plasma lipid level. SUBJECTS AND METHODS: A total of 182 patients participated in this study and were divided into two groups; 91 patients with myocardial infarction (MI group) and 91 patients with no known heart disease (control group). For both groups we analyzed the clinical parameters, the changes of plasma lipid level and the degree of polymorphism of apolipoprotein E. RESULTS: Total cholesterol, triglyceride and LDL cholesterol levels were significantly higher in the MI group, while the HDL cholesterol level was significantly lower. Compared with the control group, the frequency of epsilon2 allele was significantly lower while that of epsilon3 allele was significantly higher in the MI group. As for the control group, the triglyceride level was significantly higher in the patients with epsilon 2 allele than in those without epsilon 2 allele, and the total cholesterol level was significantly higher in the patients with epsilon 4 allele than in those without epsilon 4 allele. In the MI group, the plasma lipid levels were not significantly different from those in the control group. CONCLUSION: We suggested that apolipoprotein E polymorphism could affect the lipid metabolism as well as the development of myocardial infarction. However further study is needed in patients with myocardial infarction.
Alleles ; Apolipoproteins E ; Apolipoproteins* ; Cholesterol ; Cholesterol, HDL ; Cholesterol, LDL ; Heart Diseases ; Humans ; Lipid Metabolism ; Lipoproteins ; Myocardial Infarction* ; Plasma ; Triglycerides