Search results for "Immunologic Memory"
showing 10 items of 88 documents
Phenotypical and functional analysis of memory and effector human CD8 T cells specific for mycobacterial antigens
2006
Abstract Mycobacterium tuberculosis infects one-third of the global population and claims two million lives every year. Because memory CD8 T cells exhibit a high heterogeneity in terms of phenotype and functional characteristic, we investigated the frequency, phenotype, and functional properties of Ag85A epitope-specific HLA-A*0201 CD8 T cells in children affected by tuberculosis (TB) before and 4 mo after chemotherapy and healthy contact children. Using Ag85A peptide/HLA-A*0201 pentamer, we found a low frequency of blood peptide-specific CD8 T cells in tuberculous children before therapy, which consistently increased after therapy to levels detected in healthy contacts. Ex vivo analysis of…
Analysis of memory and effector CD8+ T cell subsets in chronic graft-versus-host disease.
2009
In humans, the selective depletion of CD8+ cells may prevent GVHD after allogeneic transplantation. These cells can infiltrate and damage target tissues. It is of interest to investigate the phenotypical characteristics and cytotoxic properties of the different CD8+ subsets in cGVHD patients. In a preliminary study we found that patients with cGVHD had a markedly elevated percentage of peripheral blood CCR7−/CD45RA+ cells compared to patients without cGVHD; conversely, the CCR7+/CD45RA+ subsets of CD8+ cells was significantly decreased. In this study, we report in depth on the phenotype of effector T cell subsets in cGVHD patients, as well as their proliferative capability, cytotoxic prope…
Antibody persistence and immune memory elicited by combined hepatitis A and B vaccination in older adults.
2007
Response to hepatitis A and B vaccines has been reported to decline with age. This open, prospective, single-site study examined the long-term response to the combined hepatitis A/B vaccine Twinrix in 98 primary responders aged 45-67 years. Levels of antibody against hepatitis A virus (HAV) and hepatitis B surface antigen (HBs) were tested 30 months after initial vaccination. At this stage, all participants remained seropositive for anti-HAV and 70% for anti-HBs. A booster vaccination was offered to those who had responded to the first vaccination but then lost protective levels of anti-HBs. An anamnestic response was observed in all cases.
Kinetics of the reactive cell clones after immunosuppression and induction of tolerance. II. Different recovery of 19 S and 7 S plaque-forming cells …
1975
By the aid of two alkylating agents (cyclophosphamide (CP) and 036.5122, (Asta), applied after a single dose of antigen, tolerance to sheep red blood cells (SRBC), has been induced in NMRI mice. Duration and characteristics of recovery were followed by a second antigenic challenge at various time intervals and by determination of 19 S and 7 S plaque-forming cells (PFC) 4 days later. During recovery from the tolerant state two phases of responsiveness could be differentiated: an early phase with no or markedly reduced numbers of total PFC, all of them being of the IgM type; a later phase with a steady increase in total PFC up to normal values, paralleled by an increase in the proportion of 7…
A study of serum immunoglobulin levels in elderly persons that provides new insights into B cell immunosenescence.
2007
The literature on immunosenescence has focused mainly on T cell impairment. With the aim of gaining insight into B cell immunosenescence, we investigated the serum immunoglobulin levels in a cohort of 166 subjects (20-106 years). Serum IgG (and IgG subclasses) were quantified by the nephelometric technique, IgE by CAP system fluorescence enzyme immunoassay, and IgD by radial immunodiffusion (RID). There was an age-related increase of IgG and IgA; the IgG age-related increase was significant only in men, but IgG1 levels showed an age-related increase both in men and women, whereas IgG3 showed an age-related increase only in men. IgE levels remain unchanged, whereas IgD and IgM serum levels d…
Understanding the delayed onset of action of azathioprine in IBD: are we there yet?
2009
In this issue of Gut , Ben-Horin et al propose an innovative explanation for the well known phenomenon of the delayed onset of action of thiopurines ( see page 396 ). They thereby contribute to an improved insight into the exact mode of action of the classic immunosuppressive drug azathioprine.1 Developing azathioprine as an innovative immunosuppressive drug in 1957, Gertrude Elion and George Hitchings laid the basis for the currently utilised concept of steroid-sparing treatment strategies in inflammatory bowel diseases (IBD).2 With regard to the evidence-based immunosuppressive capacity and clinical efficacy of azathioprine in the context of IBD as well as considering the proven long-term…
Characterization of Human γδ T Lymphocytes Infiltrating Primary Malignant Melanomas
2012
T lymphocytes are often induced naturally in melanoma patients and infiltrate tumors. Given that gamma delta T cells mediate antigen-specific killing of tumor cells, we studied the representation and the in vitro cytokine production and cytotoxic activity of tumor infiltrating gamma delta T cells from 74 patients with primary melanoma. We found that gamma delta T cells represent the major lymphocyte population infiltrating melanoma, and both V delta 1(+) and V delta 2(+) cells are involved. The majority of melanoma-infiltrating gamma delta cells showed effector memory and terminally-differentiated phenotypes and, accordingly, polyclonal gamma delta T cell lines obtained from tumor-infiltrat…
Immunogenicity, reactogenicity, and immune memory after primary vaccination with a novel Haemophilus influenzae-Neisseria meningitidis serogroup C co…
2007
ABSTRACT We evaluated two formulations of a new combined Haemophilus influenzae type b (Hib)-meningococcal serogroup C (MenC)-tetanus toxoid (TT) conjugated vaccine and two formulations of a new MenC-TT vaccine (trials 711202/001 and 711202/008; clinical trial register numbers NCT00135486 and NCT00135564 [ www.ClinicalTrials.gov ]). A total of 520 healthy infants were randomized to receive primary vaccination (at 2, 3, and 4 months) with either MenC-TT plus diphtheria-tetanus-acellular pertussis (DTPa)-hepatitis B virus (HBV)-inactivated poliovirus (IPV)/Hib, Hib-MenC-TT plus DTPa-HBV-IPV, or MenC-CRM 197 plus DTPa-HBV-IPV/Hib (control). At 12 to 15 months, subjects received a polysaccharid…
Induction of immunologic memory following primary vaccination with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate …
2011
Background Induction of immunologic memory was assessed following primary vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV). Methods Infants were randomized (1:1) to receive 3 doses of PHiD-CV or 7vCRM (7-valent CRM197-conjugated pneumococcal conjugate vaccine [PCV]) at 2, 3, and 4 months of age followed by 23-valent pneumococcal polysaccharide vaccine (23vPS) booster dose at 11 to 14 months of age. Pneumococcal geometric mean antibody concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers were measured. Results Postprimary immune responses were consistent with those in previous PHiD-CV and 7vCRM studies…
Two Antigenic Peptides from Genes m123 and m164 of Murine Cytomegalovirus Quantitatively Dominate CD8 T-Cell Memory in the H-2 d Haplotype
2001
ABSTRACT The importance of CD8 T cells for the control of cytomegalovirus (CMV) infection has raised interest in the identification of immunogenic viral proteins as candidates for vaccination and cytoimmunotherapy. The final aim is to determine the viral “immunome” for any major histocompatibility complex class I molecule by antigenicity screening of proteome-derived peptides. For human CMV, there is a limitation to this approach: the T cells used as responder cells for peptide screening are usually memory cells that have undergone in vivo selection. On this basis, pUL83 (pp65) and pUL123 (IE1 or pp68 to -72) were classified as immunodominant proteins. It is an open question whether this li…