ABSTRACT
The extension efficiency of PCR-driven DNA amplification was examined by step-controlled limiting dilution method using as internal controls 8E5 lymphocytes carrying a single copy of HIV genome. The results reveal that under standard conditions recommended by the PCR kit manufacturer the exponential growth of DNA template is approximately one third of the theoretical doubling rate.
Subject(s)
DNA/chemical synthesis , Polymerase Chain Reaction/methodsABSTRACT
The early serologic response of infants to infection with human immunodeficiency virus type 1 (HIV-1) is normally obscured by the presence of transplacentally acquired maternal HIV antibody. By measuring HIV antibody produced in vitro by lymphocytes isolated from peripheral blood of infants and children of HIV-1-infected mothers, we have been able to study the natural acquisition of humoral immunity to perinatal HIV-1 infection. One hundred ninety-seven infants of HIV-1-infected women were studied prospectively and longitudinally from birth. In the neonatal period, infected infants produced only small amounts of HIV-specific IgG antibodies to a restricted number of antigens. The amount of immunoglobulin to HIV-1 and the number of HIV-1 antigens recognized increased with age. After 6 months of life 85% of infected infants made detectable antibody to two or more viral proteins. Antibody to gp160 appeared first and was the most frequently found at all ages, followed by antibody to the envelope proteins gp120 and gp41. The amount of HIV antibody produced correlated positively with the percentage of CD4+ T lymphocytes in peripheral blood. This assay provides a method of studying the immunogenicity of vaccines against HIV-1 in HIV-1-infected infants and of assessing the effect of early therapeutic interventions on the humoral response to HIV-1.
Subject(s)
Acquired Immunodeficiency Syndrome/immunology , Aging/immunology , Antibody Formation , HIV Antibodies/blood , HIV-1/immunology , Immunoglobulin G/blood , Pregnancy Complications, Infectious/immunology , Acquired Immunodeficiency Syndrome/blood , Acquired Immunodeficiency Syndrome/transmission , Adult , Aging/blood , CD4 Antigens/analysis , Female , HIV Antigens/immunology , Humans , Infant , Infant, Newborn , Pregnancy , T-Lymphocyte Subsets/immunologyABSTRACT
Infants are reported to be devoid of memory T cells at birth but acquired them with time. A cross-sectional study of peripheral blood mononuclear cells from HIV-infected and uninfected infants and children that bear the CD4R0 antigen was undertaken to describe the development of memory T cells. Linear regression lines derived from the data revealed increasing percentages of memory CD4 and CD8 cells in the uninfected children. Memory CD4 cells in the infected children were detected at a frequency equal to or greater than that seen in uninfected children until 6 months of age but subsequently declined with age. In contrast, memory CD8 cells were found to be significantly increased in HIV-infected children early in life with a rate of increase similar to that seen in the uninfected population. This increase in memory CD8 cells may facilitate the early diagnosis of HIV infection.
