Streptococcus pneumoniae (the pneumococcus) causes a major upper respiratory tract infection often leading to severe illness and death in the elderly. Thus, it is important to induce safe and effective mucosal immunity against this pathogen in order to prevent pnuemocaccal infection. However, this is a very difficult task to elicit protective mucosal IgA antibody responses in older individuals. A combind nasal adjuvant consisting of a plasmid encoding the Flt3 ligand cDNA (pFL) and CpG oligonucleotide (CpG ODN) successfully enhanced S. pneumoniae-specific mucosal immunity in aged mice. In particular, a pneumococcal surface protein A-based nasal vaccine given with pFL and CpG ODN induced complete protection from S. pneumoniae infection. These results show that nasal delivery of a combined DNA adjuvant offers an attractive potential for protection against the pneumococcus in the elderly.
Aged* ; Aging ; Animals ; Antibody Formation ; Bacterial Infections ; DNA ; DNA, Complementary ; Humans ; Immunity, Mucosal ; Immunoglobulin A ; Mice ; Mucous Membrane ; Plasmids ; Pneumococcal Infections* ; Pneumonia ; Respiratory Tract Infections ; Streptococcus pneumoniae ; Vaccination

Background: Type 1 diabetes mellitus induced by immune-checkpoint inhibitors (ICI-T1DM) is a rare critical entity. However, the etiology of ICI-T1DM remains unclear. Methods: In order to elucidate risk factors for ICI-T1DM, we evaluated the clinical course and immunological status of patients with ICI-T1DM who had been diagnosed during 2016 to 2021. Results: Seven of 871 (0.8%, six men and one woman) patients developed ICI-T1DM. We revealed that the allele frequencies of human leukocyte antigen (HLA)-DPA1*02:02 and DPB1*05:01 were significantly higher in the patients with ICI-T1DM In comparison to the controls who received ICI (11/14 vs. 10/26, P=0.022; 11/14 vs. 7/26, P=0.0027, respectively). HLA-DRB1*04:05, which has been found to be a T1DM susceptibility allele in Asians, was also observed as a high-risk allele for ICI-T1DM. The significance of the HLA-DPB1*05:01 and DRB1*04:05 alleles was confirmed by an analysis of four additional patients. The absolute/relative neutrophil count, neutrophils-lymphocyte ratio, and neutrophil-eosinophil ratio increased, and the absolute lymphocyte count and absolute/relative eosinophil count decreased at the onset as compared with 6 weeks before. In two patients, alterations in cytokines and chemokines were found at the onset. Conclusion Novel high-risk HLA alleles and haplotypes were identified in ICI-T1DM, and peripheral blood factors may be utilized as biomarkers.