Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 Multi-Parameter Detection.

The COVID-19 pandemic has drastically impacted work, economy, and way of life. Sensitive measurement of SARS-CoV-2 specific antibodies would provide new insight into pre-existing immunity, virus transmission dynamics, and the nuances of SARS-CoV-2 pathogenesis. To date, existing SARS-CoV-2 serology tests have limited utility due to insufficient reliable detection of antibody levels lower than what is typically present after several days of symptoms.

Stimulation of PBMC and Monocyte-Derived Macrophages Toll-Like Receptor Activates Innate Immune Pathways in HIV-Infected Patients on Virally Suppressive Combination Antiretroviral Therapy.

In HIV-infected, combination antiretroviral therapy (cART)-treated patients, immune activation and microbial translocation persist and associate with inadequate CD4 recovery and morbidity/mortality. We analyzed whether alterations in the toll-like receptor (TLR) pathway could be responsible for the immune hyperactivation seen in these patients. PBMC/monocyte-derived macrophages (MDMs) of 28 HIV+ untreated and 35 cART-treated patients with HIV-RNA < 40 cp/mL [20 Full Responders (FRs): CD4 ≥ 350; 15 Immunological Non-Responders (INRs): CD4 < 350], as well as of 16 healthy controls were stimulated with a panel of TLR agonists.

A comprehensive ex vivo functional analysis of human NKT cells reveals production of MIP1-α and MIP1-β, a lack of IL-17, and a Th1-bias in males.

NKT cells contribute to the modulation of immune responses and are believed to be important in the pathogenesis of autoimmune and infectious diseases, as well as cancer. Variations in the composite NKT cytokine response may determine individual disease susceptibility or severity. Due to low frequencies in peripheral blood, knowledge of the breadth of ex vivo human NKT cell functions has been limited.

Functionally distinct subsets of human NK cells and monocyte/DC-like cells identified by coexpression of CD56, CD7, and CD4.

The lack of natural killer (NK) cell-specific markers, as well as the overlap among several common surface antigens and functional properties, has obscured the delineation between NK cells and dendritic cells. Here, novel subsets of peripheral blood CD3/14/19(neg) NK cells and monocyte/dendritic cell (DC)-like cells were identified on the basis of CD7 and CD4 expression. Coexpression of CD7 and CD56 differentiates NK cells from CD56+ monocyte/DC-like cells, which lack CD7.

Lupus IgG VH4.34 antibodies bind to a 220-kDa glycoform of CD45/B220 on the surface of human B lymphocytes.

Anti-lymphocyte autoantibodies are a well-recognized component of the autoimmune repertoire in human systemic lupus erythematosus (SLE) and have been postulated to have pathogenic consequences. Early studies indicated that IgM anti-lymphocyte autoantibodies mainly recognized T cells and identified CD45, a protein tyrosine phosphatase of central significance in the modulation of lymphocyte function, as the main antigenic target on T cells. However, more recent work indicates that lupus autoantibodies can also recognize B cells and that CD45 may also represent their antigenic target.