Toxoplasma gondii is a widespread protozoan parasite approximately infecting one-third of the world population and can cause serious public health problems. In this study, we investigated the protective effect of the attenuated vaccine Pru:Δcdpk2 against acute toxoplasmosis and explored the underlying immune mechanisms of the protection in pigs. The systemic T-cell and natural killer (NK) cell responses were analyzed, including kinetics, phenotype, and multifunctionality (interferon [IFN]-γ, tumor necrosis factor [TNF]-α), and the IFN-γ levels were analyzed in PBMCs. Our results showed that T. gondii-specific antibodies were induced by Pru:Δcdpk2. After challenging with RH, the antibodies were able to respond quickly in the immunized group, and the expression level was significantly higher than that in the unimmunized group. The expression level of IFN-γ significantly increased after vaccination, and the CD3+ γδ-, NK, and CD3+ γδ+ cell subsets also significantly increased. At the same time, functional analysis indicated that these cells were polarized toward a Th1 phenotype, showing the ability to secrete IFN-γ and TNF-α. The CD4+CD8α-T cell population exhibited a higher frequency of IFN-γ+ producing cells compared with the CD4-CD8α+ and CD4+CD8α+ cell populations during the early days of vaccination. Our results indicated that the attenuated vaccine could induce the expression of NK, γδ, and CD3αβ cells in pigs, and IFN-γ and TNF-α secreted by these cells are important for resistance to T. gondii infection.

OBJECTIVE: This observational study investigated the regulatory mechanism of Pim-1 in inflammatory signaling pathways.
METHODS: THP-1, RAW 264.7, BV2, and Jurkat human T cell lines were used.
METHODS: None.
METHODS: Lipopolysaccharide (LPS) was used to induce inflammation, followed by PIM1 knockdown. Western blot, immunoprecipitation, immunofluorescence, and RT-PCR assays were used to assess the effect of PIM1 knockdown on LPS-induced inflammation.
RESULTS: PIM1 knockdown in macrophage-like THP-1 cells suppressed LPS-induced upregulation of pro-inflammatory cytokines, inducible nitric oxide synthase, cyclooxygenase-2, phosphorylated Janus kinase, signal transducer and activator of transcription 3, extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and nuclear factor kappa B p65 (NF-κB p65). It also suppressed upregulation of inhibitor of NF-κB kinase α/β and enhanced the nuclear translocation of NF-κB p65. Moreover, it inhibited the upregulation of Nod-like receptor family pyrin domain-containing 3 (NLRP3) and cleavage of caspase-1 induced by co-treatment of LPS with adenosine triphosphate. Additionally, p-transforming growth factor-β-activated kinase 1 (TAK1) interacted with Pim-1. All three members of Pim kinases (Pim-1, Pim-2, and Pim-3) were required for LPS-mediated inflammation in macrophages; however, unlike Pim-1 and Pim-3, Pim-2 functioned as a negative regulator of T cell activity.
CONCLUSIONS: Pim-1 interacts with TAK1 in LPS-induced inflammatory responses and is involved in MAPK/NF-κB/NLRP3 signaling pathways. Additionally, considering the negative regulatory role of Pim-2 in T cells, further in-depth studies on their respective functions are needed.

BACKGROUND: The meticulous selection of appropriate vaccine adjuvants is crucial for optimizing immune responses. Traditionally, pemphigus vulgaris (PV), an autoimmune disorder, has been modelled using complete Freund\'s adjuvant (CFA). In this study, we aimed to discern potential variations in immune responses elicited by Toll-like receptor (TLR) ligands as compared to CFA.
METHODS: A comprehensive investigation was conducted, comparing the effects of these adjuvants in conjunction with ovalbumin or desmoglein-3. Flow cytometry was employed to analyse distinct cell subsets, while enzyme-linked immunosorbent assay quantified antigen-specific antibodies and cytokine levels. Histological examination of harvested skin tissues and transcriptome analysis of skin lesions were performed to identify differentially expressed genes.
RESULTS: TLR ligands demonstrated efficacy in inducing PV-like symptoms in wild-type mice, in contrast to CFA. This underscored the substantial impact of the adjuvant on self-antigen tolerance. Furthermore, we proposed an enhanced method for establishing a PV model through adoptive transfer, substituting CFA with TLR ligands. Our results revealed that in contrast to the perception that CFA being the most potent immunopotentiator reported, CFA promoted regulatory T cells (Treg), follicular regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10. This suggested potential implications for the recruitment and activation of Treg subsets. While B cell and CD8+ T cell responses exhibited similarity, CFA induced less activation in dendritic cell subsets. A novel mouse model of PV and systemic comparison of immunostimulatory effects of adjuvants were provided by this study.
CONCLUSIONS: The systematic comparison of CFA and TLR ligands shed light on the distinctive properties of these adjuvants, presenting innovative mouse models for the investigation of pemphigus. This study significantly contributes to adjuvant research and advances our understanding of PV pathogenesis.
UNASSIGNED: Immunization with desmoglein 3 and Toll-like receptor (TLR) ligands effectively induces pemphigus symptoms in wild-type mice, whereas complete Freund\'s adjuvant (CFA) fails. TLR ligands heightened the autoreactivity of donor cells in the adoptive transfer pemphigus model. CFA promoted regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10, leading to more effective immune responses.

Selecting appropriate adjuvants is crucial for developing an effective vaccine. However, studies on the immune responses triggered by different adjuvants in COVID-19 inactivated vaccines are scarce. Herein, we evaluated the efficacy of Alum, CpG HP021, Alum combined with CpG HP021 (Alum/CpG), or MF-59 adjuvants with COVID-19 inactivated vaccines in K18-hACE2 mice, and compared the different immune responses between K18-hACE2 and BALB/c mice. In K18-hACE2 mice, the Alum/CpG group produced a 6.5-fold increase in anti-receptor-binding domain (RBD) IgG antibody titers compared to the Alum group, and generated a comparable level of antibodies even when the antigen amount was reduced by two-thirds, possibly due to the significant activation of germinal center (GC) structures in the central region of the spleen. Different adjuvants induced a variety of binding antibody isotypes. CpG HP021 and Alum/CpG were biased towards Th1/IgG2c, while Alum and MF-59 were biased toward Th2/IgG1. Cytokines IFN-γ, IL-2, and TNF-α were significantly increased in the culture supernatants of splenocytes specifically stimulated in the Alum/CpG group. The antibody responses in BALB/c mice were similar to those in K18-hACE2 mice, but with lower levels of neutralizing antibodies (NAbs). Notably, the Alum/CpG-adjuvanted inactivated vaccine induced a higher number of T cells secreting IFN-γ and IL-2, increased the percentage of effector memory T (TEM) cells among CD8+ T cells, and effectively protected K18-hACE2 mice from Delta variant challenge. Our results showed that Alum/CpG complex adjuvant significantly enhanced the immune response to inactivated COVID-19 antigens and could induce a long-lasting immune response.

Immune-mediated nephritis is a leading cause of acute kidney injury and chronic kidney disease. While the role of B cells and antibodies has been extensively investigated in the past, the advent of immune-checkpoint inhibitors has led to a reappraisal of the role of T cells in renal immunology. However, it remains elusive how T cells with specificity for renal autoantigens are activated and participate in immune-mediated nephritis. Here, we followed the fate and function of pathogen-activated autoreactive CD8 T cells that are specific for a renal autoantigen. We demonstrate that recently activated splenic CD8 T cells developed a hybrid phenotype in the context of renal autoantigen cross-presentation, combining hallmarks of activation and T cell dysfunction. While circulating memory T cells rapidly disappeared, tissue-resident memory T cells emerged and persisted within the kidney, orchestrating immune-mediated nephritis. Notably, T cells infiltrating kidneys of patients with interstitial nephritis also expressed key markers of tissue residency. This study unveils how a tissue-specific immune response can dissociate from its systemic counterpart driving a compartmentalized immune response in the kidneys of mice and man. Consequently, targeting tissue-resident memory T cells emerges as a promising strategy to control immune-mediated kidney disease.

OBJECTIVE: Novel mRNA-based vaccines have been proven to be powerful tools in combating the global pandemic caused by SARS-CoV-2 protecting individuals, especially the immunocompromised, from COVID-19. Still, it remains largely unknown how solid organ transplant and different immunosuppressive medications affect development of vaccine-induced immunity.
METHODS: In this work, we monitored humoral and cellular memory responses after mRNA SARS-CoV-2 two-doses and booster doses vaccination in cystic fibrosis lung transplanted patients (CFT) and compared them with both cystic fibrosis patients without lung transplant (CF) and with kidney transplant recipients (KT). In particular, we investigated the effects of immunosuppressive regimens on immune memory to SARS-CoV-2 after mRNA SARS-CoV-2 vaccine in transplanted patients.
RESULTS: Our results showed that immunocompromised transplanted patients displayed a weak cellular and humoral memory to SARS-CoV-2 mRNA vaccination. In addition, obtained data clearly demonstrate that immunosuppressive therapy regimen including antimetabolites, further reduces patients\' ability to respond to vaccination at both humoral and cell-mediated level. Notably, patient treated with antimetabolites showed a lower humoral and cellular response also after a booster dose vaccination.
CONCLUSIONS: These results, even if obtained on a small patient\'s cohort, question whether immunocompromised patients need interventions to improve vaccine SARS-CoV-2 mRNA vaccine response such as additional jab or modulation of immunosuppressive therapy.

UNASSIGNED: The HVTN 105 vaccine clinical trial tested four combinations of two immunogens - the DNA vaccine DNA-HIV-PT123, and the protein vaccine AIDSVAX B/E. All combinations induced substantial antibody and CD4+ T cell responses in many participants. We have now re-examined the intracellular cytokine staining flow cytometry data using the high-resolution SWIFT clustering algorithm, which is very effective for enumerating rare populations such as antigen-responsive T cells, and also determined correlations between the antibody and T cell responses.
UNASSIGNED: Flow cytometry samples across all the analysis batches were registered using the swiftReg registration tool, which reduces batch variation without compromising biological variation. Registered data were clustered using the SWIFT algorithm, and cluster template competition was used to identify clusters of antigen-responsive T cells and to separate these from constitutive cytokine producing cell clusters.
UNASSIGNED: Registration strongly reduced batch variation among batches analyzed across several months. This in-depth clustering analysis identified a greater proportion of responders than the original analysis. A subset of antigen-responsive clusters producing IL-21 was identified. The cytokine patterns in each vaccine group were related to the type of vaccine - protein antigens tended to induce more cells producing IL-2 but not IFN-γ, whereas DNA vaccines tended to induce more IL-2+ IFN-γ+ CD4 T cells. Several significant correlations were identified between specific antibody responses and antigen-responsive T cell clusters. The best correlations were not necessarily observed with the strongest antibody or T cell responses.
UNASSIGNED: In the complex HVTN105 dataset, alternative analysis methods increased sensitivity of the detection of antigen-specific T cells; increased the number of identified vaccine responders; identified a small IL-21-producing T cell population; and demonstrated significant correlations between specific T cell populations and serum antibody responses. Multiple analysis strategies may be valuable for extracting the most information from large, complex studies.

UNASSIGNED: Accumulating evidence indicates the importance of T cell immunity in vaccination-induced protection against severe COVID-19 disease, especially against SARS-CoV-2 Variants-of-Concern (VOCs) that more readily escape from recognition by neutralizing antibodies. However, there is limited knowledge on the T cell responses across different age groups and the impact of CMV status after primary and booster vaccination with different vaccine combinations. Moreover, it remains unclear whether age has an effect on the ability of T cells to cross-react against VOCs.
UNASSIGNED: Therefore, we interrogated the Spike-specific T cell responses in healthy adults of the Dutch population across different ages, whom received different vaccine types for the primary series and/or booster vaccination, using IFNɣ ELISpot. Cells were stimulated with overlapping peptide pools of the ancestral Spike protein and different VOCs.
UNASSIGNED: Robust Spike-specific T cell responses were detected in the vast majority of participants upon the primary vaccination series, regardless of the vaccine type (i.e. BNT162b2, mRNA-1273, ChAdOx1 nCoV-19, or Ad26.COV2.S). Clearly, in the 70+ age group, responses were overall lower and showed more variation compared to younger age groups. Only in CMV-seropositive older adults (>70y) there was a significant inverse relation of age with T cell responses. Although T cell responses increased in all age groups after booster vaccination, Spike-specific T cell frequencies remained lower in the 70+ age group. Regardless of age or CMV status, primary mRNA-1273 vaccination followed by BNT162b2 booster vaccination showed limited booster effect compared to the BNT162b2/BNT162b2 or BNT162b2/mRNA-1273 primary-booster regimen. A modest reduction in cross-reactivity to the Alpha, Delta and Omicron BA.1, but not the Beta or Gamma variant, was observed after primary vaccination.
UNASSIGNED: Together, this study shows that age, CMV status, but also the primary-booster vaccination regimen influence the height of the vaccination-induced Spike-specific T cell response, but did not impact the VOC cross-reactivity.

UNASSIGNED: The tumor microenvironment (TME) impacts the therapeutic efficacy of immune checkpoint inhibitors (ICIs). No liquid biomarkers are available to evaluate TME heterogeneity. Here, we investigated the clinical significance of PD-1-binding soluble PD-L1 (bsPD-L1) in gastric cancer (GC) patients and non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 blockade.
UNASSIGNED: We examined bsPD-L1, matrix metalloproteinases (MMPs), and IFN-γ levels in plasma samples from GC patients (n = 117) prior to surgery and NSCLC patients (n = 72) prior to and 2 months after ICI treatment. We also examined extracellular matrix (ECM) integrity, PD-L1 expression, and T cell infiltration in tumor tissues from 25 GC patients by Elastica Masson-Goldner staining and immunohistochemical staining for PD-L1 and CD3, respectively.
UNASSIGNED: bsPD-L1 was detected in 17/117 GC patients and 16/72 NSCLC patients. bsPD-L1 showed strong or moderate correlations with plasma MMP13 or MMP3 levels, respectively, in both GC and NSCLC patients. bsPD-L1 expression in GC was associated with IFN-γ levels and intra-tumoral T cell infiltration, whereas MMP13 levels were associated with loss of ECM integrity, allowing tumor cells to access blood vessels. Plasma MMP3 and MMP13 levels were altered during ICI treatment. Combined bsPD-L1 and MMP status had higher predictive accuracy to identify two patient groups with favorable and poor prognosis than tumor PD-L1 expression: bsPD-L1+MMP13high in GC and bsPD-L1+(MMP3 and MMP13)increased in NSCLC were associated with poor prognosis, whereas bsPD-L1+MMP13low in GC and bsPD-L1+(MMP3 or MMP13)decreased in NSCLC were associated with favorable prognosis.
UNASSIGNED: Plasma bsPD-L1 and MMP13 levels indicate T cell response and loss of ECM integrity, respectively, in the TME. The combination of bsPD-L1 and MMPs may represent a non-invasive tool to predict recurrence in GC and the efficacy of ICIs in NSCLC.

Kidney transplant recipients (KTRs) have been identified as a population at increased risk for severe SARS-CoV-2 infection outcomes. This study focused on understanding the immune response of KTRs post-vaccination, specifically examining both serological and cellular responses to the SARS-CoV-2 vaccine. Thirteen individuals, including seven KTRs and six healthy donors, were evaluated for antibody levels and T cell responses post-vaccination. The study revealed that KTRs had significantly lower serological responses, including reduced anti-receptor binding domain (RBD) binding antibodies and neutralizing antibodies against the Wuhan, Delta, and Omicron BA.2 strains. Additionally, KTRs demonstrated weaker CD8 T cell cytotoxic responses and lower Th1 cytokine secretion, particularly IFN-γ, after stimulation with variant spike peptide pools. These findings highlight the compromised immunity in KTRs post-vaccination and underscore the need for tailored strategies to bolster immune responses in this vulnerable group. Further investigations are warranted into the mechanisms underlying reduced vaccine efficacy in KTRs and potential therapeutic interventions.
OBJECTIVE: Some studies have revealed that KTRs had lower serological response against SARS-CoV-2 than healthy people. Nevertheless, limited studies investigate the cellular response against SARS-CoV-2 in KTRs receiving SARS-CoV-2 vaccines. Here, we found that KTRs have lower serological and cellular responses. Moreover, we found that KTRs had a significantly lower IFN-γ secretion than healthy individuals when their PBMCs were stimulated with SARS-CoV-2 spike peptide pools. Thus, our findings suggested that additional strategies are needed to enhance KTR immunity triggered by the vaccine.