COMPARISON OF NEONATAL AND ADULT IMMUNE RESPONSES TO PNEUMOCOCCAL INFECTION AND VACCINATION IN A MOUSE MODEL

Author(s):  
Joanne O'Hara
2021 ◽  
Vol 9 (1) ◽  
pp. e001615
Author(s):  
Rachel A Woolaver ◽  
Xiaoguang Wang ◽  
Alexandra L Krinsky ◽  
Brittany C Waschke ◽  
Samantha M Y Chen ◽  
...  

BackgroundAntitumor immunity is highly heterogeneous between individuals; however, underlying mechanisms remain elusive, despite their potential to improve personalized cancer immunotherapy. Head and neck squamous cell carcinomas (HNSCCs) vary significantly in immune infiltration and therapeutic responses between patients, demanding a mouse model with appropriate heterogeneity to investigate mechanistic differences.MethodsWe developed a unique HNSCC mouse model to investigate underlying mechanisms of heterogeneous antitumor immunity. This model system may provide a better control for tumor-intrinsic and host-genetic variables, thereby uncovering the contribution of the adaptive immunity to tumor eradication. We employed single-cell T-cell receptor (TCR) sequencing coupled with single-cell RNA sequencing to identify the difference in TCR repertoire of CD8 tumor-infiltrating lymphocytes (TILs) and the unique activation states linked with different TCR clonotypes.ResultsWe discovered that genetically identical wild-type recipient mice responded heterogeneously to the same squamous cell carcinoma tumors orthotopically transplanted into the buccal mucosa. While tumors initially grew in 100% of recipients and most developed aggressive tumors, ~25% of recipients reproducibly eradicated tumors without intervention. Heterogeneous antitumor responses were dependent on CD8 T cells. Consistently, CD8 TILs in regressing tumors were significantly increased and more activated. Single-cell TCR-sequencing revealed that CD8 TILs from both growing and regressing tumors displayed evidence of clonal expansion compared with splenic controls. However, top TCR clonotypes and TCR specificity groups appear to be mutually exclusive between regressing and growing TILs. Furthermore, many TCRα/TCRβ sequences only occur in one recipient. By coupling single-cell transcriptomic analysis with unique TCR clonotypes, we found that top TCR clonotypes clustered in distinct activation states in regressing versus growing TILs. Intriguingly, the few TCR clonotypes shared between regressors and progressors differed greatly in their activation states, suggesting a more dominant influence from tumor microenvironment than TCR itself on T cell activation status.ConclusionsWe reveal that intrinsic differences in the TCR repertoire of TILs and their different transcriptional trajectories may underlie the heterogeneous antitumor immune responses in different hosts. We suggest that antitumor immune responses are highly individualized and different hosts employ different TCR specificities against the same tumors, which may have important implications for developing personalized cancer immunotherapy.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi Liu ◽  
Yue Zhang ◽  
Di Zhang ◽  
Yun Bai ◽  
Guomei Liu ◽  
...  

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1120
Author(s):  
Dae Woon Choi ◽  
Sun Young Jung ◽  
Gun-Dong Kim ◽  
So-Young Lee ◽  
Hee Soon Shin

Allergic diseases, including atopic dermatitis (AD), induce type 2 helper T (Th2) cell-dominant immune responses. Miquelianin (quercetin 3-O-glucuronide, MQL) is an active compound in Rosae multiflorae fructus extract with anti-allergic properties. Here, we investigate the anti-allergic effects of MQL in an ovalbumin (OVA)-induced Th2-dominant mouse model and the associated mechanisms. Oral MQL suppressed cytokine and IL-2 production and proliferation of Th2 cells and upregulated heme oxygenase-1 (HO-1) in splenocytes. Ex vivo MQL suppressed Th1- and Th2-related immune responses by inhibiting CD4+ T cell proliferation, and upregulated HO-1 in CD4+ T cells by activating C-Raf–ERK1/2–Nrf2 pathway via induction of reactive oxygen species generation. In a trimellitic anhydride-induced AD-like mouse model, both topical and oral MQL ameliorated AD symptoms by suppressing Th2 immune responses. Our results suggest that MQL is a potential therapeutic agent for CD4+ T cell-mediated diseases, including allergic diseases.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Daiko Wakita ◽  
Yosuke Kurashima ◽  
Yoshihiro Takasato ◽  
Youngho Lee ◽  
Kenichi Shimada ◽  
...  

Background: KD is the leading cause of acquired heart disease in the US. We have demonstrated the critical role of innate immune responses via IL-1R/MyD88 signaling in the Lactobacillus casei cell wall extract (LCWE)-induced KD mouse model. The diversity and composition of microflora (both bacterial and fungal) have been associated with the regulation and alterations of immune responses and various pathologies. However, the role of gut microbiota in immunopathology of KD has not been investigated. Objective: To evaluate the role of gut microflora in development of coronary arteritis, and vascular abnormalities in KD mouse model. Methods and Results: We investigated the role of gut microflora in the LCWE-induced KD mouse model, using Specific-Pathogen Free (SPF) and Germ Free (GF) mice (C57BL/6). GF mice showed a significant decrease of KD lesions, including coronary arteritis compared with SPF mice. The development of LCWE-induced AAA, which we recently discovered in this mouse model, was also markedly diminished in GF mice. In addition to GF mice, we also investigated the specific role of commensal bacteria and/or fungi, and determined whether altered microorganism burden in this KD mouse model contributes to disease severity. To deplete bacteria and/or fungi in the gut microflora, we exposed pregnant SPF mice and their offspring to antibiotics cocktail (Abx) or antifungal drug (fluconazole; Fluc) in their drinking water for 5 wks and induced KD. The mice treated with Abx or Fluc had significantly reduced coronary arteritis and AAA compared to controls. The Abx plus Fluc administration showed marked decrease of KD vasculitis. Conclusions: We demonstrate here that gut microflora play a critical role in the development of KD vasculitis in LCWE-induced mouse model. Our results suggest that both bacteria and fungi in the intestinal microbiota may control the induction and severity of KD vasculitis. These findings provide a new perspective on the potential role of the microbiome in KD pathogenesis and may offer new diagnostic and therapeutic strategies for KD patients.


2005 ◽  
Vol 12 (1) ◽  
pp. 218-223 ◽  
Author(s):  
Daniel J. Sikkema ◽  
Nancy A. Ziembiec ◽  
Thomas R. Jones ◽  
Stephen W. Hildreth ◽  
Dace V. Madore ◽  
...  

ABSTRACT Weight-based assignments for immunoglobulin G1 (IgG1) and IgG2 subclass antibodies to Streptococcus pneumoniae capsular polysaccharides (PnPs) in antipneumococcal standard reference serum lot 89-S (lot 89-S), also known as lot 89-SF, have been determined for serotypes 1, 4, 5, 7F, 9V, and 18C. This extends the usefulness of lot 89-S beyond the IgG1 and IgG2 subclass assignments for serotypes 3, 6B, 14, 19F, and 23F made previously (A. Soininen, H. Kayhty, I. Seppala, and T. Wuorimaa, Clin. Diagn. Lab. Immunol. 5:561-566, 1998) to cover 11 major serotypes associated with the highest percentage of pneumococcal disease worldwide. A method of equivalence of absorbances in enzyme immunosorbent assays was used to determine the IgG1 and IgG2 antibody concentrations for the additional serotypes in lot 89-S, based on the subclass values previously assigned for PnPs serotypes 6B, 14, and 23F. This cross-standardization method assures consistency with previous antibody assignments in that reference serum. The newly assigned subclass values for serotype 9V, and previously assigned values for serotype 14, were used to quantitate PnPs antibodies in sera from adult and pediatric subjects immunized with a pneumococcal conjugate vaccine. There was a predominance of IgG1 anti-PnPs antibodies in pediatric sera and IgG2 anti-PnPs antibodies in the adult sera. The IgG1 and IgG2 subclass assignments for the 11 PnPs serotypes in antipneumococcal standard reference serum lot 89-S are useful for quantitating and characterizing immune responses to pneumococcal infection and vaccination regimens.


2021 ◽  
Author(s):  
Saiaditya Badeti ◽  
Hsiang-chi Tseng ◽  
Peter Romanienko ◽  
Ghassan Yehia ◽  
Dongfang Liu

Abstract An animal model that can mimic the SARS-CoV-2 infection in humans is critical to understanding the newly emerged, rapidly spreading SARS-CoV-2 and development of therapeutic strategies. Studies show that the spike (S) proteins of SARS-CoV (SARS-CoV-S-1-S) and SARS-CoV-2 (SARS-CoV-2-S) bind to human angiotensin-converting enzyme 2 (hACE2, a well-recognized, functional receptor for SARS-CoV and SARS-CoV-2) to mediate viral entry. Several hACE2 transgenic (hACE2Tg) mouse models are being widely used, which is clearly invaluable. However, the hACE2Tg mouse model cannot fully explain: 1) low expression of ACE2 observed in human lung and heart, but lung or heart failure occurs frequently in severe COVID-19 patients); 2) low expression of ACE2 on immune cells, but lymphocytopenia occurs frequently in COVID-19 patients; and 3) hACE2Tg mice do not develop strong clinical disease following SARS-CoV-2 infection in contrast to SARS-CoV-1. Moreover, one of most outstanding features of coronaviruses is the diversity of receptor usage, which includes the newly proposed human CD147 (hCD147) as a receptor for SARS-CoV-2-S. It is still debatable whether CD147 can serve as a functional receptor for SARS-CoV-2 infection or entry. Here we successfully generated a hCD147Tg mouse model in the NOD-scid IL2Rgammanull (NSG) background. In this hCD147Tg-NSG mouse model, the hCD147 genetic sequence was placed following the endogenous mouse promoter for mouse CD147 (mCD147), which creates an in vivo model that may better recapitulate physiological expression of CD147 proteins at the molecular level compared to the existing and well-studied K18-hACE2-B6 model. In addition, the hCD147Tg-NSG mouse model allows further study of SARS-CoV-2 in the immunodeficiency condition which may assist our understanding of this virus in the context of high-risk populations with immunosuppressed conditions. The hCD147Tg-NSG mouse mode can serve as an additional animal model for interrogate whether CD147 serve as an independent functional receptor or accessory receptor for SARS-CoV-2 entry and immune responses.


mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Adeline Barthelemy ◽  
Stoyan Ivanov ◽  
Maya Hassane ◽  
Josette Fontaine ◽  
Béatrice Heurtault ◽  
...  

ABSTRACT Influenza A virus infection can predispose to potentially devastating secondary bacterial infections. Invariant natural killer T (iNKT) cells are unconventional, lipid-reactive T lymphocytes that exert potent immunostimulatory functions. Using a mouse model of postinfluenza invasive secondary pneumococcal infection, we sought to establish whether α-galactosylceramide (α-GalCer [a potent iNKT cell agonist that is currently in clinical development]) could limit bacterial superinfection. Our results highlighted the presence of a critical time window during which α-GalCer treatment can trigger iNKT cell activation and influence resistance to postinfluenza secondary pneumococcal infection. Intranasal treatment with α-GalCer during the acute phase (on day 7) of influenza virus H3N2 and H1N1 infection failed to activate (gamma interferon [IFN-γ] and interleukin-17A [IL-17A]) iNKT cells; this effect was associated with a strongly reduced number of conventional CD103 + dendritic cells in the respiratory tract. In contrast, α-GalCer treatment during the early phase (on day 4) or during the resolution phase (day 14) of influenza was associated with lower pneumococcal outgrowth and dissemination. Less intense viral-bacterial pneumonia and a lower morbidity rate were observed in superinfected mice treated with both α-GalCer (day 14) and the corticosteroid dexamethasone. Our results open the way to alternative (nonantiviral/nonantibiotic) iNKT-cell-based approaches for limiting postinfluenza secondary bacterial infections. IMPORTANCE Despite the application of vaccination programs and antiviral drugs, influenza A virus (IAV) infection is responsible for widespread morbidity and mortality (500,000 deaths/year). Influenza infections can also result in sporadic pandemics that can be devastating: the 1918 pandemic led to the death of 50 million people. Severe bacterial infections are commonly associated with influenza and are significant contributors to the excess morbidity and mortality of influenza. Today’s treatments of secondary bacterial (pneumococcal) infections are still not effective enough, and antibiotic resistance is a major issue. Hence, there is an urgent need for novel therapies. In the present study, we set out to evaluate the efficacy of α-galactosylceramide (α-GalCer)—a potent agonist of invariant NKT cells that is currently in clinical development—in a mouse model of postinfluenza, highly invasive pneumococcal pneumonia. Our data indicate that treatment with α-GalCer reduces susceptibility to superinfections and, when combined with the corticosteroid dexamethasone, reduces viral-bacterial pneumonia.


2018 ◽  
Vol 6 (18) ◽  
pp. e13827 ◽  
Author(s):  
Alejandro R. Castañeda ◽  
Christoph F. A. Vogel ◽  
Keith J. Bein ◽  
Heather K. Hughes ◽  
Suzette Smiley-Jewell ◽  
...  

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