Regulatory parameters of the lung immune response during the early phase of experimental trichinellosis

2016 ◽  
Vol 231 ◽  
pp. 47-52 ◽  
Author(s):  
Guido H. Falduto ◽  
Cecilia C. Vila ◽  
María P. Saracino ◽  
María V. Gentilini ◽  
Stella M. Venturiello
Keyword(s):  
Immune Response ◽  
Early Phase

scholarly journals Methods for comparing durability of immune responses between vaccine regimens in early-phase trials

2019 ◽  
Vol 29 (1) ◽  
pp. 78-93
Author(s):  
Ted Westling ◽  
Michal Juraska ◽  
Kelly E. Seaton ◽  
Georgia D. Tomaras ◽  
Peter B. Gilbert ◽  
...  
Keyword(s):  
Immune Response ◽  
Early Phase ◽  
Nonlinear Models ◽  
Hiv Vaccine ◽  
Two Phase ◽  
Hiv Vaccine Trials ◽  
Statistical Inferences ◽  
Vaccine Trials ◽  
Early Phase Trials ◽  
The Mean

The ability to produce a long-lasting, or durable, immune response is a crucial characteristic of many highly effective vaccines. A goal of early-phase vaccine trials is often to compare the immune response durability of multiple tested vaccine regimens. One parameter for measuring immune response durability is the area under the mean post-peak log immune response profile. In this paper, we compare immune response durability across vaccine regimens within and between two phase I trials of DNA-primed HIV vaccine regimens, HVTN 094 and HVTN 096. We compare four estimators of this durability parameter and the resulting statistical inferences for comparing vaccine regimens. Two of these estimators use the trapezoid rule as an empirical approximation of the area under the marginal log response curve, and the other two estimators are based on linear and nonlinear models for the marginal mean log response. We conduct a simulation study to compare the four estimators, provide guidance on estimator selection, and use the nonlinear marginal mean model to analyze immunogenicity data from the two HIV vaccine trials.

scholarly journals Lack of Interleukin-6 Affects IFN-γ and TNF-α Production and Early In Vivo Control of Brucella abortus Infection

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1040
Author(s):  
Erika S. Guimarães ◽  
Jéssica M. Martins ◽  
Marco Túlio R. Gomes ◽  
Daiane M. Cerqueira ◽  
Sergio C. Oliveira
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Brucella Abortus ◽  
Interleukin 6 ◽  
Early Phase ◽  
Protective Role ◽  
Myeloperoxidase Activity ◽  
Tnf Α ◽  
Ifn Γ

Interleukin-6 (IL-6) is a pleiotropic cytokine promptly produced in response to infections, which contributes to host defense through the stimulation of acute phase immune responses. Brucella abortus is an intracellular bacterium that causes chronic disease in humans and domestic animals and triggers a robust immune response, characterized by the production of inflammatory cytokines. However, the mechanisms of IL-6-related immune responses in the context of Brucella infections are not completely understood. In this report, we describe an increased susceptibility of IL-6 knockout (KO) mice in the early phase of Brucella infection. Furthermore, we demonstrate that IL-6 is required for interferon (IFN)-γ and tumor necrosis factor (TNF)-α induction by infected splenocytes, indicating a protective role for IL-6 against B. abortus that parallels with Th1 type of immune response. Additionally, IL-6 KO mice exhibited reduced splenomegaly during the early phase of the infection. Corroborating this result, IL-6 KO mice displayed reduced numbers of macrophages, dendritic cells, and neutrophils in the spleen and reduced myeloperoxidase activity in the liver compared to wild-type infected mice. However, we demonstrate that IL-6 is not involved in B. abortus intracellular restriction in mouse macrophages. Taken together, our findings demonstrate that IL-6 contributes to host resistance during the early phase of B. abortus infection in vivo, and suggest that its protective role maybe partially mediated by proinflammatory immune responses and immune cell recruitment.

scholarly journals T Cell Zones of Lymphoid Organs Constitutively Express Th1 Cytokine mRNA: Specific Changes during the Early Phase of an Immune Response

2006 ◽  
Vol 176 (2) ◽  
pp. 741-749 ◽  
Author(s):  
Kathrin Kalies ◽  
Maike Blessenohl ◽  
Julia Nietsch ◽  
Jürgen Westermann
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Early Phase ◽  
Lymphoid Organs ◽  
Cytokine Mrna ◽  
Th1 Cytokine

scholarly journals Cell-Mediated Immune Response during Primary Chlamydia pneumoniae Infection

2000 ◽  
Vol 68 (12) ◽  
pp. 7156-7158 ◽  
Author(s):  
S. Halme ◽  
J. Latvala ◽  
R. Karttunen ◽  
I. Palatsi ◽  
P. Saikku ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Interferon Gamma ◽  
Early Phase ◽  
Lymphocyte Proliferation ◽  
Chlamydia Pneumoniae ◽  
Cell Mediated Immunity ◽  
Specific Cell ◽  
Cell Mediated Immune Response

ABSTRACT The development of Chlamydia pneumoniae-specific cell-mediated immunity was studied during a primary C. pneumoniae infection. The immune response was detected as positive lymphocyte proliferation and secretion of interferon gamma.C. pneumoniae-induced activation of both CD4+and CD8+ T cells was detected in the early phase of infection, but activation of only CD4+ T cells was detected in the later stage.

scholarly journals CD8lowCD100−T Cells Identify a Novel CD8 T Cell Subset Associated with Viral Control during Human Hantaan Virus Infection

2015 ◽  
Vol 89 (23) ◽  
pp. 11834-11844 ◽  
Author(s):  
Bei Liu ◽  
Ying Ma ◽  
Yusi Zhang ◽  
Chunmei Zhang ◽  
Jing Yi ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Early Phase ◽  
Late Phase ◽  
Cell Subset ◽  
T Cell Subsets ◽  
Hantaan Virus ◽  
Viral Control

ABSTRACTHantaan virus (HTNV) infection can cause a severe lethal hemorrhagic fever with renal syndrome (HFRS) in humans. CD8+T cells play a critical role in combating HTNV infections. However, the contributions of different CD8+T cell subsets to the immune response against viral infection are poorly understood. Here, we identified a novel subset of CD8+T cells characterized by the CD8lowCD100−phenotype in HFRS patients. The CD8lowCD100−subset accounted for a median of 14.3% of the total CD8+T cells in early phase of HFRS, and this percentage subsequently declined in the late phase of infection, whereas this subset was absent in healthy controls. Furthermore, the CD8lowCD100−cells were associated with high activation and expressed high levels of cytolytic effector molecules and exhibited a distinct expression profile of effector CD8+T cells (CCR7+/−CD45RA−CD127highCD27intCD28lowCD62L−). When stimulated with specific HTNV nucleocapsid protein-derived peptide pools, most responding CD8+cells (gamma interferon [IFN-γ] positive and/or tumor necrosis factor alpha [TNF-α] positive) were CD8lowCD100−cells. The frequency of CD8lowCD100−cells among HTNV-specific CD8+T cells was higher in milder cases than in more severe cases. Importantly, the proportion of the CD8lowCD100−subset among CD8+T cells in early phase of HFRS was negatively correlated with the HTNV viral load, suggesting that CD8lowCD100−cells may be associated with viral clearance. The contraction of the CD8lowCD100−subset in late phase of infection may be related to the consistently high expression levels of PD-1. These results may provide new insights into our understanding of CD8+T cell-mediated protective immunity as well as immune homeostasis after HTNV infection in humans.IMPORTANCECD8+T cells play important roles in the antiviral immune response. We found that the proportion of CD8lowCD100−cells among CD8+T cells from HFRS patients was negatively correlated with the HTNV viral load, and the frequency of CD8lowCD100−cells among virus-specific CD8+T cells was higher in milder HFRS cases than in more severe cases. These results imply a beneficial role for the CD8lowCD100−cell subset in viral control during human HTNV infection.

scholarly journals Comparison of Immunoglobulin G Subclass Profiles Induced by Measles Virus in Vaccinated and Naturally Infected Individuals

2002 ◽  
Vol 9 (3) ◽  
pp. 693-697 ◽  
Author(s):  
María Beatríz Isa ◽  
Laura Martínez ◽  
Miguel Giordano ◽  
Carlos Passeggi ◽  
María Cristina de Wolff ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Early Phase ◽  
Measles Virus ◽  
Natural Infection ◽  
Immunoglobulin M ◽  
Early Infection ◽  
Healthy Children ◽  
Phase Group ◽  
Memory Phase

ABSTRACT A total of 258 human sera positive for measles antibodies were divided into four different groups: group 1 contained 54 sera from children after natural measles infection (immunoglobulin M [IgM] positive, early infection phase), group 2 contained 28 sera from children after measles vaccination (IgM positive, early infection phase), group 3 contained 100 sera from healthy adults (natural long-lasting immunity), and group 4 contained 76 sera from healthy children (postvaccinal long-lasting immunity). In the early phase of infection, the percent distributions of measles virus-specific IgG isotypes were similar between natural and postvaccinal immune responses. IgG1 and IgG4 were the dominant isotypes, with mean levels of detection of 100% (natural infection) and 100% (postvaccinal) for IgG1 and 96% (natural infection) and 92% (postvaccinal) for IgG4. In comparison, the IgG4 geometric mean titer (GMT) in the early phase of natural infection was significantly higher than the IgG4 GMT detected in the postvaccinal immune response (80 versus 13; 95% confidence interval). In the memory phase, IgG2 and IgG3 responses decreased significantly in both natural infection and postvaccinal groups, while IgG1 levels were maintained. In contrast, the IgG4 postvaccinal immune response decreased strongly in the memory phase, whereas IgG4 natural long-lasting immunity remained unchanged (9 versus 86%; P < 0.05). The results obtained suggest that IgG4 isotype could be used in the early phase of infection as a quantitative marker and in long-lasting immunity as a qualitative marker to differentiate between natural and postvaccinal immune responses.

scholarly journals The flow of blood to lymph nodes and its relation to lymphocyte traffic and the immune response.

1977 ◽  
Vol 145 (1) ◽  
pp. 31-44 ◽  
Author(s):  
J B Hay ◽  
B B Hobbs
Keyword(s):  
Immune Response ◽  
Blood Flow ◽  
Cardiac Output ◽  
Lymph Node ◽  
Lymph Nodes ◽  
Early Phase ◽  
Keyhole Limpet Hemocyanin ◽  
Primary Immune Response ◽  
Pass Through ◽  
Increased Blood Flow

The blood flow to individual lymph nodes of sheep and rabbits has been determined with 85Sr-labeled microspheres. A popliteal node of the sheep received 0.014% of the cardiac output and a comparable node in the rabbit 0.011%. A sheep lymph node weighing 1 g received an average of 24 ml/h of blood. It was calculated that there was a highly selective removal of lymphocytes by the node and that an equivalent to one in every four lymphocytes that entered a normal lymph node migrated out of the blood, through the substance of the node, and into the efferent lymph. During the immune response to either allogeneic lymphocytes or tuberculin, the blood flow to sheep lymph nodes, even without considering the increase in node weight, increased an average of fourfold. During the primary immune response in the rabbit to keyhole limpet hemocyanin, the blood flow increased threefold. The increase in blood flow preceded the antigen-induced increase in lymphocyte traffic recorded in the efferent lymph. The early phase of increased blood flow was considered to be due to hyperemia, whereas the latter phase had a significant angiogenesis component. It was calculated that an equivalent to 60% of the entire mobilizable pool of lymphocytes could pass through an average lymph node in the blood during an immune response lasting 5 days.

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