Effect of chronic developmental lead exposure on cell-mediated immune functions

Studies were performed to investigate the effects of chronic, low level pre- and post-natal lead exposure on cell-mediated immune function in rats. Weanling female rats were exposed to lead (as lead acetate) in their drinking water at 0, 25, and 50 ppm for 7 weeks. At the end of 7 weeks they were mated with untreated males and continued on the same dosage throughout gestation and lactation. The offspring of these females were weaned at 21 days of age and continued on the same lead exposure regimen as their mothers. These offspring were used in immune surveillance procedures between 35 and 45 days of age. Lead exposure at the levels employed had no statistically significant effect on growth and did not result in overt signs of toxicity. Thymic weights were significantly decreased in both males and females of the two lead dosage groups. Furthermore, lead exposure resulted in suppression of responsiveness of lymphocytes to mitogen stimulation and in reduced delayed hypersensitivity responsiveness. Results indicate that chronic low-level lead exposure causes suppression of cell-mediated immune function.

Effects of 2,3,7,8-tetrachlorodibenzofuran (TCDF) on the immune system in guinea pigs

The effects of TCDF exposure on the immune system were investigated in Hartley guinea pigs. TCDF was administered by gavage at doses of 0.05, 0.17, 0.5 or 1.0 microgram/kg body weight once weekly for six weeks. Thymus/body weight ratios were suppressed in the higher dosage groups. Parameters of cell-mediated and humoral immune function were investigated. TCDF modestly suppressed cell-mediated immune function and had slight effects on humoral-mediated functions. TCDF immunosuppression appears similar to that induced following exposure to TCDD.

Effects of polybrominated biphenyls (PBB) on immune response in rodents

Studies were performed to investigate the effects of FireMaster FF-1, a chemical fire retardant consisting of a mixture of polybrominated biphenyls (PBB), on immune functions in mice and rats. Animals received 22 daily treatments of 0.03, 0.3, 3.0, or 30 mg PBB/kg body weight in a period covering 30 days. PBB exposure severely depressed cell mediated immunity in both mice and rats at the higher dosage levels as indicated by depressed responsiveness of splenic lymphocytes to mitogenic stimulation by polyclonal T-cell activators. Additionally, humoral immunity was depressed in mice at the 30.0 ppm dosage level. Assays for humoral immune functions included antibody production, serum immunoglobulin levels, and mitogenic stimulation of splenic lymphocytes to a polyclonal B-cell activator. These studies indicate that PBB exposure can lead to suppression of both humoral and particularly cell-mediated immune responses.

Radioimmunoassay for mono-(2-ethylhexyl) phthalate in unextracted plasma

We report a radioimmunoassay for mono-(2-ethylhexyl) phthalate that has been coupled to a protein carrier as a radioligand. Competitive interference tests with a variety of related compounds indicated the assay to be highly specific. Quantitative comparison of mono-(2-ethylhexyl) phthalate values in plasma and serum samples between the radioimmunoassay and gas chromatographic procedures indicated a high reliability. Because this potentially toxic compound can leach into plasma from polyvinyl plastics, this assay should be particularly useful for those involved in the manufacture or use of medical devices made of them.

Depression of humoral immunity in rats following chronic developmental lead exposure

Chronic pre- and postnatal exposure of CD rats to low levels of lead resulted in a marked depression in the antibody response to SRBC as well as decreased serum IgG levels. Serum IgM and IgA levels were normal. The fact that the antibody response to LPS, a thymus independent antigen, was not altered, suggested that the T-lymphocyte rather than the B-lymphocyte is affected by lead exposure. Additional significance is lent to these results when blood lead levels in treated rats were found to be similar to levels found in many children in urban areas.

Radioimmunoassay for mono-(2-ethylhexyl) phthalate in unextracted plasma

We report a radioimmunoassay for mono-(2-ethylhexyl) phthalate that has been coupled to a protein carrier as a radioligand. Competitive interference tests with a variety of related compounds indicated the assay to be highly specific. Quantitative comparison of mono-(2-ethylhexyl) phthalate values in plasma and serum samples between the radioimmunoassay and gas chromatographic procedures indicated a high reliability. Because this potentially toxic compound can leach into plasma from polyvinyl plastics, this assay should be particularly useful for those involved in the manufacture or use of medical devices made of them.

Immunoglobulin class distribution of measles virus antibodies in serum and spinal fluids of patients with subacute sclerosing panencephalitis

Sera and cerebrospinal fluids (CSF) from patients with subacute sclerosing panencephalitis (SSPE) were tested by indirect immunofluorescence for the presence of measles virus specific antibodies of the various heavy chain classes. IgG and IgA antibodies were detected in the CSF while IgG, IgM, IgA, IgD and IgE measles virus antibodies were found in a significant number of the patient sera. Sera from SSPE patients had slightly elevated levels of IgG, IgM, IgD and IgE while IgA was decreased. The heterogeneous heavy chain class distribution of measles antibodies suggests the possibility that non-complement fixing antibodies serve as blocking antibodies which aid in the persistence of intracellular measles virus infection in patients with SSPE.

Alloantigens defined by cytotoxic isoantisera prepared against peripheral rabbit lymphocytes

Seven lymphocytotoxic antisera were produced in rabbits by means of isoimmunization with purified peripheral lymphocytes. The phenotypic profile of the defined lymphocyte antigens was determined in a panel of 97 rabbits. The results indicated the existence of at least two major antigenic determinants. Further typing and cross-absorptions were performed with several of the lymphocytotoxic antisera in order to demonstrate monospecificity. The anti-3 antiserum was used to determine the distribution of the respective antigens in various rabbit organs. The highest concentration of the alloantigen was contained in the spleen, followed in descending order by the lymph nodes, lung, skin, kidney, heart and liver. Fat and red blood cells (rbc) contained no detectable antigen. A two-stage physical adherence column method was used to separate T-derived from B-derived lymphocytes and each fraction was tested for the alloantigen. Alloantigen was detected on both cell types. The fact that the anti-3 antiserum never killed more than 30% of the cells suggests that it could define a subpopulation of lymphocytes.

Measles virus-specific IgD antibodies in patients with subacute sclerosing panencephalitis

Indirect immunofluorescent analysis revealed that sera from five patients with subacute sclerosing panencephalitis possessed IgD antibodies directed against measles virus components in persistently infected HeLa cells. IgD levels in these sera were within the normal range. Control studies indicated that the reaction was specific for measles virus. The detection of IgD measles antibodies in these patients suggested that IgD may be involved in the pathogenesis of this viral disease.

Erythrocyte antinuclear antibodies in sera of chickens hyperimmunized with group A streptococcal vaccine

Chickens hyperimmunized with group A streptococcal vaccine often synthesize high levels of antibody to group A streptococcal carbohydrate (SACHO). Indirect immunofluorescent analysis revealed that sera of these chickens also contain antinuclear antibodies capable of reacting with chicken erythrocyte nuclei (EANA) at titers up to 2,560. Removal of the anti-SACHO antibodies from hyperimmune serum did not significantly reduce EANA titers, indicating that anti-SACHO antibodies are not responsible for the EANA reactions. The time course for antibody development as well as the immunoglobulin class distribution of EANA and anti-SACHO antibodies were very similar. Localization of EANA activity to Fab fragments indicated that the immunfluorescent reaction represents an antigen-antibody reaction. Findings point out an important consequence of using chicken immunoglobulin Y in immunofluorescent assays. The purified Fc fragment of immunoglobulin Y is cytophilic for the substrate when tested at high concentrations, which suggests that some cytophilic immunoglobulins are involved in the reaction.

Structure and biological functions of human IgD. VII. IgD antinuclear antibodies in sera of patients with autoimmune disorders

Indirect immunofluorescent tests were employed to study antinuclear antibodies (ANA) of the IgD class in sera from patients with autoimmune disease. In sera containing IgG-ANA, IgD-ANA was detected in 48% of patients with systemic lupus erythematosus, 37% with rheumatoid arthritis, 30% with Raynaud's disease, 23% with systemic scleroderma and 20% with discoid lupus erythematosus. Quantitative comparison of serum IgG, IgA, IgM and IgD between IgG-ANA-positive sera with and without IgD-ANA revealed that patients with IgD-ANA also had elevated serum IgA levels. The detection of IgD-ANA in over 36% of the patient population suggests that IgD may play a role in autoimmune disorders.

Structure and biological functions of human IgD. VI. Serum IgD in patients with allergic bronchopulmonary aspergillosis

Serum IgD levels were quantified in a large population of individuals with a variety of atopic and/or pulmonary disorders. As a group, patients with allergic bronchopulmonary aspergillosis (ABPA) have markedly elevated (5.03 mg%) serum IgD when compared with serum IgD levels from either normal individuals (2.17 mg%) or patients with a variety of pulmonary and/or atopic disorders. Evidence is presented suggesting that the increased serum IgD levels in ABPA patients are not necessarily related to a hyper-IgE or panhyperimmunoglobulinemia common to most of all these patients, but is rather associated with an additional quantitative difference in the immunological responsiveness of some of these individuals. An understanding of why these patients produce supranormal levels of IgD may reveal the basis for inducing an IgD antibody response and subsequently help in elucidating the biological function(s) of IgD.