Scandinavian Journal of Immunology最新文献

Hepatitis B (HB) infection is a major global health problem. There is limited knowledge about HB vaccination-induced immune memory responses. We compared the frequency of CD8⁺ memory T cell subsets between responders (RSs) and non-responders (NRs) to HB vaccination. Blood samples were collected from RSs and NRs. PBMCs were cultured in the presence of Hepatitis B surface antigens (HBsAg) and PHA for 48 h to restimulate CD8⁺ memory T cells and T cell memory subsets were detected by flow cytometry using memory cell markers. The frequency of T_EM, T_CM, and T_CM ^hi was significantly higher in responders compared to non-responders (p = 0.024, 0.022, and 0.047, respectively). Additionally, we report a positive correlation between the frequency of T_EM cells in RSs with age and anti-HBsAb level (p = 0.03 and r_s = 0.5; p = 0.01 and r_s = 0.06). Responders display a higher level of CD8⁺ T cell-mediated immunity. Therefore, we suggest a possible defect in the formation of immunological CD8⁺ memory T cells in NRs and it may reduce antibody production compared to the RSs, although more experiments are needed.

This report describes two brothers from India and a Chinese patient with somatic reversion of an inherited deleterious mutation in the WAS gene. Both the Indian siblings had inherited a single nucleotide deletion causing a frameshift mutation (c.1190del, p.Pro397Argfs*48) (variant 1: marked in blue) from the mother. Another variant (variant 2: marked in red), a 12-nucleotide deletion at position 1188-1199 (c.1188_1199del, p.P401_P404del) was also found, which resulted in restoration of the frame and subsequent rescue of the protein sequence. DNA sequencing from buccal mucosal cells revealed only the inherited variant (variant 1), while no reversion mutation was identified in the mucosal cells. Similarly, the Chinese patient was found to have a novel germline 14-base duplication (ACGAAAATGCTTGG) c.120_132 + 1dup (variant 1). This resulted in abolishment of the original splice junction coupled with the creation of a new junction 14 bases 3' and a frameshift mutation with predicted protein truncation p. Thr45Aspfs*. DNA from the patient's PBMC showed co-existence of wild-type and mutated sequences, but only the mutant was present in the buccal cells. Genomic and mRNA analysis of the isolated CD3+ T lymphocytes, CD3- mononuclear cells, and EBV-transformed B lymphocytes indicated that the reverant variant (germline variant was restored to wild-type sequence) were selectively found in CD3+ T lymphocytes.

Antigen presenting cells sometimes require T cell "help" to kill and decompose microbes they capture, especially when those microbes resist effector molecules including nitric oxide and reactive oxygen species. Pathogens are more likely to resist those effectors, shared by the innate and adaptive immune systems, than are commensals. Does such resistance alert the immune system to the danger posed by those pathogens? Several lines of evidence suggest this occurs. Mouse studies showed a surprising exacerbation, not alleviation of experimental autoimmune encephalomyelitis, by suppression of nitric oxide production, but only when the suppression was applied to animals undergoing vaccination with myelin. In contrast, animals receiving T cells activated by vaccination without suppression of nitric oxide benefitted from reduced autoimmune cytotoxicity when nitric oxide production was suppressed after adoptive transfer. Vaccinia and adenovirus suppress nitric oxide production and have been successful vaccine platforms, also consistent with the above phagolysosomal resistance hypothesis. The hypothesis solves a long-standing quandary-how can nitric oxide protect against both infection and autoimmunity, especially autoimmune diseases for which it seems a major effector? The importance of physical linkage between epitopes, first proposed in Bretscher's Two-Step, Two-Signal theory dependent on B cells, is extended to include phagolysosomal resistance in general, plus a corollary proposition that the immune system detects resistance to dissociation of high-affinity pathogenic ligands from host binding sites to make neutralizing antibodies.

Lung cancer is the leading cause of cancer-related deaths, in part due to its late diagnosis. Increased epidermal growth factor receptor (EGFR) expression in cancer cells is associated with a poor prognosis, and EGFR tyrosine kinase inhibitors are widely used in cancer treatment. This study aimed to clarify the relationship between EGFR expression on T cells and cancer prognosis in patients with non-small cell lung cancer (NSCLC). Forty patients with NSCLC and 40 healthy volunteers were included in this study. Peripheral CD4⁺T helper (Th1, Th2, Th9, Th17, Th1Th17, follicular and peripheral Th) and cytotoxic T lymphocyte (CD8⁺follicular and peripheral T) subsets were identified with flow cytometry according to their chemokine receptors. EGFR expression on T lymphocytes in relation to overall survival (OS) was investigated in patients with NSCLC. The patients [mean age (min-max) = 64.03 (45-83); 20 stage I-III and 20 stage IV] had increased EGFR expression on CD3⁺T, CD4⁺Th, Th1, Th2, and Th17 cells compared to the controls (p < 0.05). High EGFR expression on CD3⁺T, CD4⁺Th, Th1, and Th2 cells was associated with poor OS. Also, PD-1 expression on lymphocytes, CD3⁺T, and Th cells was increased in patients with NSCLC compared to controls. The high expression of EGFR and PD-1 on Th cells and the reduced percentage of lymphocytes and Th cells, especially in stage IV patients with NSCLC, revealed that increased EGFR activity may trigger apoptosis of Th cells and promote the development of metastases, while high EGFR expression on CD3⁺T, CD4⁺Th, Th1, and Th2 cells may be an independent poor prognostic marker in NSCLC.

Oral mucositis (OM) is a severe side effect of anti-cancer therapy, with limited available treatments. Mesenchymal stem cells (MSCs) and their secreted extracellular vesicles (EVs) have demonstrated effective protection against OM. However, the underlying mechanism remains elusive. In the current study, we purified EVs secreted by human umbilical cord MSCs (hUC-MSC-EVs) and investigated their role in lipopolysaccharide (LPS)-induced human oral keratinocytes (HOKs). We observed that treatment with hUC-MSC-EVs significantly reduced the inflammatory response of HOKs to LPS induction. Through small RNA-seq using miRNAs extracted from hUC-MSC-EVs, we identified hsa-let-7e-5p as one of the most highly expressed miRNAs. Bioinformatic analysis data indicated that hsa-let-7e-5p may inhibit the NF-κB signalling pathway by targeting TAB2. Overexpression of the hsa-let-7e-5p inhibitor significantly attenuated the anti-inflammatory effect of hUC-MSC-EVs in LPS-induced HOKs, which could be reversed by the knockdown of TAB2. In addition, we administered hUC-MSC-EVs in a hamster model for OM and observed that these EVs alleviated OM phenotypes. Taken together, our observations suggest that hsa-let-7e-5p in hUC-MSC-EVs could protect the oral mucosa from OM by repressing TAB2 expression.

Graft-infiltrating lymphocytes (GILs) play an important role in promoting rejection after organ transplantation. We recently reported that GILs that accumulated up to 3 days post-transplantation did not promote rejection, whereas GILs present 3-5 days post-transplantation promoted rejection in a mouse heart transplantation model. However, the immunological behaviour of GILs in murine skin transplantation remains unclear. GILs were isolated on days 3, 5 or 7 post-transplantation from C57BL/6 (B6) allogeneic skin grafts transplanted onto BALB/c mice. BALB/c Rag2^-/- γc^-/- mice (BRGs) underwent B6 skin graft transplantation 10 weeks after adoptive transfer of day 3, 5, or 7 GILs. BRGs reconstituted with day 5 or 7 GILs completely rejected B6 grafts. However, when B6 grafts harvested from recipient BALB/c mice on day 5 or 7 were re-transplanted into BRGs, half of the re-transplanted day 5 grafts established long-term survival, although all re-transplanted day 7 grafts were rejected. BRGs reconstituted with day 3 GILs did not reject B6 grafts. Consistently, re-transplantation using day 3 skin grafts resulted in no rejection. Administration of anti-CD25 antibodies did not prevent the phenomenon observed for the day 3 skin grafts. Furthermore, BRGs reconstituted with splenocytes from naïve BALB/c mice immediately rejected the naïve B6 skin grafts and the re-transplanted day 3 B6 grafts, suggesting that day 3 GILs were unable to induce allograft rejection during the rejection process. In conclusion, the immunological role of GILs depends on the time since transplantation. Day 3 GILs had neither protective nor alloreactive effects in the skin transplant model.

Mucosal-associated invariant T (MAIT) cells are innate-like T cells that can be activated by microbial antigens and cytokines and are abundant in mucosal tissues including the colon. MAIT cells have cytotoxic and pro-inflammatory functions and have potentials for use as adoptive cell therapy. However, studies into their anti-cancer activity, including their role in colon cancer, are limited. Using an animal model of colon cancer, we showed that peritumoral injection of in vivo-expanded MAIT cells into RAG1^-/- mice with MC38-derived tumours inhibits tumour growth compared to control. Multiplex cytokine analyses showed that tumours from the MAIT cell-treated group have higher expression of markers for eosinophil-activating cytokines, suggesting a potential association between eosinophil recruitment and tumour inhibition. In a human peripheral leukocyte co-culture model, we showed that leukocytes stimulated with MAIT ligand showed an increase in eotaxin-1 production and activation of eosinophils, associated with increased cancer cell killing. In conclusion, we showed that MAIT cells have a protective role in a murine colon cancer model, associated with modulation of the immune response to cancer, potentially involving eosinophil-associated mechanisms. Our results highlight the potential of MAIT cells for non-donor restricted colon cancer immunotherapy.