Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0393754 (HSA)
 2,996 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The initiation of T cell responses against antigens requires two distinct signals. The first, the essential signal is the engagement of T cell receptor to antigen peptide in the context of MHC molecules on antigen presenting cells (APC). The presence of the second signal (costimulatory signal) determines whether responding T cells to be fully responsive or to be anergic (antigen specific nonresponsiveness). There are numbers of such costimulatory receptor/ligand pairs including B7/CD28: CTLA4, VCAM-1/VLA4, ICAM-1/LFA-1, HSA/unknown, and LFA-3/CD2. Among those ligand receptor pairs, B7/CD28 pathway is chosen and the molecular mechanism how T cell responses are regulated by B7/CD28 is discussed.
 ...
PMID:[The molecular mechanism of costimulatory signal for T cell activation]. 853 79

Infection of T cells with HIV-1 induces loss of CD4 and HLA class I from the cell surface. In the present article we have investigated whether changes in expression of other cell surface molecules could be related to HIV infection. To detect HIV-infected cells at the single-cell level, peripheral blood lymphocytes were infected in vitro with HIV-HSA, a reporter virus encoding the murine heat-stable antigen. Expression of HSA on activated primary lymphocytes was an efficient indicator of productive infection. Expression of the majority of the cell surface proteins studied was unaffected by HIV infection (HLA class I, II, CD11a, CD18, CD25, CD27, CD28, CD29, CD30, CD31, CD38, CD44, CD45R0, CD49d, CD57, CD94, CD95, and CXCR4). However, phenotypic changes specific to the productively infected cells were detected. Expression of the CD4 molecule was progressively lost and this was closely associated with loss of CD62L expression, a molecule involved in T cell homing into the lymph nodes. By contrast, T cells productively infected with this T-tropic reporter virus were enriched for CD54, and for CCR5, the main coreceptor for M-tropic viruses. Given the roles of CD62L, CD54, and CCR5 in lymphocyte trafficking, these results suggest that cells productively infected with HIV might have altered homing patterns in vivo.
 ...
PMID:Altered expression of CD4, CD54, CD62L, and CCR5 in primary lymphocytes productively infected with the human immunodeficiency virus. 1002 48