scholarly journals Mucosal and Cellular Immune Responses Elicited by Recombinant Lactococcus lactis Strains Expressing Tetanus Toxin Fragment C

2004 ◽  
Vol 72 (5) ◽  
pp. 2753-2761 ◽  
Author(s):  
K. Robinson ◽  
L. M. Chamberlain ◽  
M. C. Lopez ◽  
C. M. Rush ◽  
H. Marcotte ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lactococcus Lactis ◽  
Tetanus Toxin ◽  
Humoral Response ◽  
T Cell Response ◽  
Specific Response ◽  
Mucosal Site ◽  
Response Phenotype ◽  
Recombinant Lactococcus Lactis ◽  
Cellular Immune

ABSTRACT The mucosal and cellular responses of mice were studied, following mucosal-route administration of recombinant Lactococcus lactis expressing tetanus toxin fragment C (TTFC), which is a known immunogen protective against tetanus. A TTFC-specific T-cell response with a mixed profile of T-helper (Th) subset-associated cytokines was elicited in the intestine, with a Th2 bias characteristic of a mucosal response. These results correlated with the humoral response, where equivalent titers of anti-TTFC immunoglobulin G1 (IgG1) and IgG2a in serum were accompanied by an elevated IgA-specific response at more than one mucosal site. The route of vaccination had an important role in determining the immune response phenotype, as evidenced by the fact that an IgG1-biased subclass profile was obtained when lactococci were administered parenterally. Stimulation of splenic or mesenteric lymph node cells with lactococci resulted in their proliferation and the secretion of gamma interferon via antigen-specific and innate immune mechanisms. The data therefore provide further evidence of the potential of recombinant lactococcal vaccines for inducing systemic and mucosal immune responses.

scholarly journals mRNA vaccination in people over 80 years of age induces strong humoral immune responses against SARS-CoV-2 with cross neutralization of P.1 Brazilian variant

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Helen Parry ◽  
Gokhan Tut ◽  
Rachel Bruton ◽  
Sian Faustini ◽  
Christine Stephens ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cellular Response ◽  
Humoral Response ◽  
Antibody Responses ◽  
Vaccine Platform ◽  
Humoral Immune ◽  
Vaccine Responses ◽  
Cellular Immune Responses ◽  
Humoral Immune Responses ◽  
Cellular Immune

Age is the major risk factor for mortality after SARS-CoV-2 infection and older people have received priority consideration for COVID-19 vaccination. However, vaccine responses are often suboptimal in this age group and few people over the age of 80 years were included in vaccine registration trials. We determined the serological and cellular response to spike protein in 100 people aged 80–96 years at 2 weeks after the second vaccination with the Pfizer BNT162b2 mRNA vaccine. Antibody responses were seen in every donor with high titers in 98%. Spike-specific cellular immune responses were detectable in only 63% and correlated with humoral response. Previous SARS-CoV-2 infection substantially increased antibody responses after one vaccine and antibody and cellular responses remained 28-fold and 3-fold higher, respectively, after dual vaccination. Post-vaccine sera mediated strong neutralization of live Victoria infection and although neutralization titers were reduced 14-fold against the P.1 variant first discovered in Brazil they remained largely effective. These data demonstrate that the mRNA vaccine platform delivers strong humoral immunity in people up to 96 years of age and retains broad efficacy against the P.1 variant of concern.

Immunogenicity and protective efficacy of orally administered recombinant Lactococcus lactis expressing surface-bound HIV Env

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 223-228 ◽  
Author(s):  
Ke-Qin Xin ◽  
Yuka Hoshino ◽  
Yoshihiko Toda ◽  
Shizunobu Igimi ◽  
Yoshitsugu Kojima ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lactococcus Lactis ◽  
Potential Role ◽  
Protective Efficacy ◽  
Oral Immunization ◽  
Vaccine Strategy ◽  
Regional Lymph Nodes ◽  
Viral Loads ◽  
Recombinant Lactococcus Lactis ◽  
Further Development

Abstract This study investigates whether genetically modified orally administered Lactococcus lactis (L lactis) could be used as an HIV vaccine. L lactis is immunogenic and extremely safe when delivered orally. We created a recombinant L lactis vector expressing the envelope protein of HIV on its cell surface. Oral immunization with this vector induced high levels of HIV-specific serum IgG and fecal IgA antibodies. Cell-mediated immune responses also were generated in both the regional lymph nodes and the spleen. Dendritic cells are readily infected by L lactis and appear to play a potential role in mediating the development of these immune responses. The protective efficacy of this vaccine strategy was demonstrated by challenging mice intraperitoneally with an HIV Env–expressing vaccinia virus. Their viral loads were 350-fold lower than those of control mice. These findings support the further development of L lactis–based HIV vaccines. (Blood. 2003; 102:223-228)

Correlates of T-cell–mediated viral control and phenotype of CD8+ T cells in HIV-2, a naturally contained human retroviral infection

Blood ◽  
2013 ◽  
Vol 121 (21) ◽  
pp. 4330-4339 ◽  
Author(s):  
Thushan I. de Silva ◽  
Yanchun Peng ◽  
Aleksandra Leligdowicz ◽  
Irfan Zaidi ◽  
Lucy Li ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
T Cell Response ◽  
Viral Control ◽  
Retroviral Infection ◽  
Cellular Immune Responses ◽  
Key Points ◽  
Cellular Immune ◽  
Insight Into

Key PointsHIV-2 viral control is associated with a polyfunctional Gag-specific CD8+ T-cell response but not with perforin upregulation. Our findings provide insight into cellular immune responses associated with a naturally contained human retroviral infection.

scholarly journals ISCOM-like Nanoparticles Formulated with Quillaja brasiliensis Saponins Are Promising Adjuvants for Seasonal Influenza Vaccines

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1350
Author(s):  
Mariana Rivera-Patron ◽  
María Moreno ◽  
Mariana Baz ◽  
Paulo M. Roehe ◽  
Samuel P. Cibulski ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Influenza Vaccine ◽  
Public Health Intervention ◽  
Humoral Response ◽  
Influenza Vaccines ◽  
Respiratory Illnesses ◽  
Cellular Immune Responses ◽  
Saponin Fraction ◽  
Cellular Immune

Vaccination is the most effective public health intervention to prevent influenza infections, which are responsible for an important burden of respiratory illnesses and deaths each year. Currently, licensed influenza vaccines are mostly split inactivated, although in order to achieve higher efficacy rates, some influenza vaccines contain adjuvants. Although split-inactivated vaccines induce mostly humoral responses, tailoring mucosal and cellular immune responses is crucial for preventing influenza infections. Quillaja brasiliensis saponin-based adjuvants, including ISCOM-like nanoparticles formulated with the QB-90 saponin fraction (IQB90), have been studied in preclinical models for more than a decade and have been demonstrated to induce strong humoral and cellular immune responses towards several viral antigens. Herein, we demonstrate that a split-inactivated IQB90 adjuvanted influenza vaccine triggered a protective immune response, stronger than that induced by a commercial unadjuvanted vaccine, when applied either by the subcutaneous or the intranasal route. Moreover, we reveal that this novel adjuvant confers up to a ten-fold dose-sparing effect, which could be crucial for pandemic preparedness. Last but not least, we assessed the role of caspase-1/11 in the generation of the immune response triggered by the IQB90 adjuvanted influenza vaccine in a mouse model and found that the cellular-mediated immune response triggered by the IQB90-Flu relies, at least in part, on a mechanism involving the casp-1/11 pathway but not the humoral response elicited by this formulation.

scholarly journals Impaired Cellular Immune Responses During the First Week of Severe Acute Influenza Infection

2020 ◽  
Vol 222 (7) ◽  
pp. 1235-1244 ◽  
Author(s):  
Jackson S Turner ◽  
Tingting Lei ◽  
Aaron J Schmitz ◽  
Aaron Day ◽  
José Alberto Choreño-Parra ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
T Cell ◽  
Immune Responses ◽  
Influenza Infection ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Cell Responses ◽  
Cellular Immune Responses ◽  
Inflammatory Monocytes ◽  
Cellular Immune

Abstract Background Cellular immune responses are not well characterized during the initial days of acute symptomatic influenza infection. Methods We developed a prospective cohort of human subjects with confirmed influenza illness of varying severity who presented within a week after symptom onset. We characterized lymphocyte and monocyte populations as well as antigen-specific CD8+ T-cell and B-cell responses from peripheral blood mononuclear cells using flow cytometry and enzyme-linked immunospot assays. Results We recruited 68 influenza-infected individuals on average 3.5 days after the onset of symptoms. Three patients required mechanical ventilation. Influenza-specific CD8+ T-cell responses expanded before the appearance of plasmablast B cells. However, the influenza-specific CD8+ T-cell response was lower in infected subjects than responses seen in uninfected control subjects. Circulating populations of inflammatory monocytes were increased in most subjects compared with healthy controls. Inflammatory monocytes were significantly reduced in the 3 subjects requiring mechanical ventilation. Inflammatory monocytes were also reduced in a separate validation cohort of mechanically ventilated patients. Conclusions Antigen-specific CD8+ T cells respond early during acute influenza infection at magnitudes that are lower than responses seen in uninfected individuals. Circulating inflammatory monocytes increase during acute illness and low absolute numbers are associated with very severe disease.

A MATHEMATICAL MODEL TO ASSESS THE IMMUNE RESPONSE AGAINSTTRYPANOSOMA CRUZIINFECTION

2015 ◽  
Vol 23 (01) ◽  
pp. 131-163 ◽  
Author(s):  
HYUN MO YANG
Keyword(s):  
Mathematical Model ◽  
Trypanosoma Cruzi ◽  
Immune Responses ◽  
Cellular Response ◽  
Humoral Response ◽  
Cellular Responses ◽  
Cellular Immune Responses ◽  
Trivial Equilibrium ◽  
Cellular Immune ◽  
Cruzi Infection

A mathematical model is developed to assess humoral and cellular immune responses against Trypanosoma cruzi infection. Analysis of the model shows a unique non-trivial equilibrium, which is locally asymptotically stable, except in the case of a strong cellular response. When the proliferation of the activated CD8 T cells is increased, this equilibrium becomes unstable and a limit cycle appears. However, this behavior can be avoided by increasing the action of the humoral response. Therefore, unbalanced humoral and cellular responses can be responsible for long asymptomatic period, and the control of Trypanosoma cruzi infection is a consequence of well coordinated action of both humoral and cellular responses.

scholarly journals Induction of High Levels of Specific Humoral and Cellular Responses to SARS-CoV-2 After the Administration of Covid-19 mRNA Vaccines Requires Several Days

2021 ◽  
Vol 12 ◽  
Author(s):  
Sergio Gil-Manso ◽  
Diego Carbonell ◽  
Luis López-Fernández ◽  
Iria Miguens ◽  
Roberto Alonso ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Vaccination Schedule ◽  
T Cell Response ◽  
Cell Responses ◽  
Fast Development ◽  
Specific Igg ◽  
Cellular Immune

ObjectivesIn the context of the Covid-19 pandemic, the fast development of vaccines with efficacy of around 95% preventing Covid-19 illness provides a unique opportunity to reduce the mortality associated with the pandemic. However, in the absence of efficacious prophylactic medications and few treatments for this infection, the induction of a fast and robust protective immunity is required for effective disease control, not only to prevent the disease but also the infection and shedding/transmission. The objective of our study was to analyze the level of specific humoral and cellular T-cell responses against the spike protein of SARS-CoV-2 induced by two mRNA-based vaccines (BNT162b2 and mRNA-1273), but also how long it takes after vaccination to induce these protective humoral and cellular immune responses.MethodsWe studied in 40 healthy (not previously infected) volunteers vaccinated with BNT162b2 or mRNA-1273 vaccines the presence of spike-specific IgG antibodies and SARS-CoV-2-specific T cells at 3, 7 and 14 days after receiving the second dose of the vaccine. The specific T-cell response was analyzed stimulating fresh whole blood from vaccinated volunteers with SARS-CoV-2 peptides and measuring the release of cytokines secreted by T cells in response to SARS-CoV-2 stimulation.ResultsOur results indicate that the immunization capacity of both vaccines is comparable. However, although both BNT162b2 and mRNA-1273 vaccines can induce early B-cell and T-cell responses, these vaccine-mediated immune responses do not reach their maximum values until 14 days after completing the vaccination schedule.ConclusionThis refractory period in the induction of specific immunity observed after completing the vaccination could constitute a window of higher infection risk, which could explain some emerging cases of SARS-CoV-2 infection in vaccinated people.

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