Thymocyte maturation is governed by antigen–T cell receptor (TCR) affinity and the extent of TCR aggregation. Signals provided by coactivating molecules such as CD4 and CD28 also influence the fate of immature thymocytes. The mechanism by which differences in antigen–TCR avidity encode unique maturational responses of lymphocytes and the influence of coactivating molecules on these signaling pr...

While activated T cells are known to have enhanced biological responses to antigen stimulation, the biophysical basis of this increased sensitivity remains unknown. Here, we show that, on activated T cells, the TCR avidity for peptide-MHC complexes is 20- to 50-fold higher than the TCR avidity of naive T cells. This increased avidity for peptide-MHC depends on TCR reorganization and is sensitiv...

The effect of acute heat stress on certain immunological parameters were studied in male albino rats. The test rats were exposed to an ambient temperature of 40 degrees celsius for 30 minutes and sacrificed immediately. Total WBC count, Differential count, Phagocytic index, NBT reduction, organ weight body weight ratio of spleen, thymus, and popliteal lymph nodes, and soluble immune complex lev...

AIM To determine the value of tests for specific IgA, IgE, and IgG avidity in diagnosing Toxoplasma gondii infection during pregnancy. METHODS In a retrospective study, current serological tests (dye test and three IgM assays with different sensitivities) were compared with immunosorbent agglutination assays (ISAGA) for specific IgA and IgE and an IgG avidity enzyme linked immunosorbent assay...

objective: a descriptive study was carried out to determine the significance of igg-affinity in the serological diagnosis of rubella infections in pregnancy. materials and methods: a total of 92 pregnant women who had never received antirubella vaccines were recruited by simple random selection and did not exceed 24 weeks of gestation were recruited from the antenatal clinics of the university ...

Abstract Introduction/Objective Since the start of COVID-19 pandemic, much research has focused on kinetics and magnitude humoral immune response. With advantages monitoring real-time immunoreactions, label-free immunoassay (LFIA) is becoming a powerful tool in serology studies. We have developed LFIAs to measure SARS- CoV-2 antibody avidity neutralization activity cohort patients determine if ...

INTRODUCTION Cross-sectional methods can be used to estimate HIV incidence for surveillance and prevention studies. We evaluated assays and multi-assay algorithms (MAAs) for incidence estimation in subtype C settings. METHODS We analysed samples from individuals with subtype C infection with known duration of infection (2442 samples from 278 adults; 0.1 to 9.9 years after seroconversion). MAA...

Many pneumococcal capsular polysaccharides (PSs) are similar in structure, and a pneumococcal antibody often binds to all of the PSs with a similar structure. Yet, these cross-reactive antibodies may bind to the structurally related pneumococcal capsular PSs with an avidity too low to be effective. If memory B cells producing such weakly cross-reactive antibodies are elicited with pneumococcal ...