Sally A. Hensen

Impaired in Vitro Cell-Mediated Immunity to Rubella Virus during Pregnancy

Abstract A significant depression in cell-mediated immunity, measured by phytohemagglutinin and mixed-lymphocyte-culture responsiveness was observed in 11 pregnant women. Specific cell-mediated immunity to rubella virus, measured by a 51Cr-release microassay, was also found to be diminished during pregnancy. The mean (± S.D.) specific immune release for 13 seropositive subjects during pregnancy was 4.3 ± 5.9 per cent as compared to a mean of 19.9 ± 0.9 per cent in 14 seropositive nonpregnant women. This impairment in specific cell-mediated immunity to rubella virus was shown to be transient because there was subsequent increase in immunity in each of four subjects studied post partum. Thus, these changes in cell-mediated immunity during pregnancy may contribute to the known increased severity of viral infections in the gravid state. (N Engl J Med 289:604–606, 1973)

Effects of Adenine Arabinoside on Cellular Immune Mechanisms in Humans

In vitro lymphocyte blastogenic responses to the commonly employed mitogens, phytohemagglutinin, pokeweed, and concanavalin A, were evaluated when adenine arabinoside (ara-A) in a concentration of 3 μg/ml was added to the culture materials. Similarly, blastogenic and cytotoxic responses to cell cultures persistently infected with herpes simplex virus 1, herpes simplex virus 2, and varicella-zoster virus were determined in the presence of ara-A. No depression of these cellular immune responses by ara-A was demonstrated. This was in contrast to the effect of cytosine arabinoside, which at a concentration of 3 μg/ml severely inhibited these immune responses. Further studies examined lymphocyte blastogenic responses to the mitogens and blastogenic and cytotoxic responses specific for the herpes group virus infecting patients who were subsequently treated with ara-A; determinations were made before, during, and after treatment. In vitro responses during and after treatment with ara-A were unchanged or often enhanced as compared to pretreatment values. Therefore, the antiviral chemotherapeutic agent, ara-A, does not appear to depress the hosts cellular immune responses, which are vital to successful elimination of invading herpes group viruses.

Inhibitory effects of bilirubin on cellular immune responses in man

A significant depression in cell-mediated immunity as measured by lymphoproliferative responses to phytohemagglutinin and responsiveness to mixed lymphocyte culture was observed when adult lymphocytes or cord blood lymphocytes were incubated with increasing concentrations of bilirubin. The inhibitory effect of bilirubin could only be demonstrated with suboptimal concentrations of PHA (0.01 and 0.005%) and was more marked in premature infants than in term neonates or adults. This effect was partially reversible after short preincubation with bilirubin, but was more protracted with preincubations of 24 hours or more. Inhibition of MLC responsiveness of 80.1 plus or minus 5.1% was also demonstrated at a bilirubin concentration of 20 mg/dl. Specific cytotoxicity to rubella virus-infected cells, measured by a 51Cr-release microassay, was not found to be depressed. Bilirubin thus appears to have an inhibitory effect on immune responsiveness which is greater on the afferent limb than on the effrent limb of immunity.

Specific inhibitory factors of cellular immunity in children with subacute sclerosing panencephalitis.

Employing a 51Cr release cytotoxicity microassay, and using both measles-and SSPE-infected target cells, four patients with documented SSPE were evaluated for specific cellular and humoral immunity. Mononuclear leukocytes from SSPE patients and control subjects exhibited comparable cytotoxicity. Serum and CSF from these SSPE patients inhibited the cellular response to SSPE-infected cells but not to measles-infected cells. Moreover, fresh whole serum alone from control donors produced significant 51Cr release from both cell lines, whereas SSPE whole serum was effective only against measles-infected cells. CSF from an additional ten patients with SSPE was examined for inhibitory activity: seven of these completely blocked and one partially blocked cell-mediated cytotoxicity to SSPE-infected cells. Preliminary characterization of the serum inhibitory factor suggested that it is IgM or antigen-antibody complexes. These data also suggest antigenic differences between the SSPE and measles viruses.

The immunologic role of tonsillar tissues in local cell-mediated immune responses†

THE ROLE OF SECRETORY IMMUNOGLOBULINS in local immunity to infectious agents has been extensively examined, l Although secretory antibodies of the IgA class have been shown to be important in the protection of mucosal surfaces against certain infectious agents, relatively little information is available concerning the role of local cell-mediated immunity in such areas. Recent evidence, derived from animal studies, suggests that respiratory tract CMI is relatively independent of systemic CMI. 25 Recently, Jurgensen and associates, 6 in studies of local cell-mediated immunity in the human being, reported a good correlation between CMI in circulating lymphocytes and in cells obtained by bronchial alveolar lavage. Furthermore, these workers have shown that local CMI was best st imulated

Lymphocyte-mediated cytotoxicity to viruses in patients with multiple sclerosis: Presence of a blocking factor

Abstract Lymphocyte-mediated cytotoxicity to virus-infected target cells was investigated in 14 patients with multiple sclerosis (MS) by using a 51Cr-release lymphocytotoxicity microassay. Lymphocytes from patients and normal controls were incubated with 51Cr-labeled target cells persistently infected with either measles, SSPE (subacute sclerosing panencephalitis) or rubella virus, and the culture supernatant fractions were assayed for released 51Cr in the presence or absence of serum from normal measles-immune individuals or from patients with MS. Specific immune release (SIR) was similar in both groups studied with all three virus strains in the absence of added serum. Serum from patients with MS, however, inhibited the SIR effected by normal or patient lymphocytes from measles or SSPE-infected cells but not from rubella-infected cells; normal immune serum did not inhibit the SIR from any of the target cell lines tested. Partial characterization of this blocking factor by fractionation on a Sephadex G-200 column revelas that it is associated with the 7S fraction. These data suggest a normal lymphocyte “killer” function in patients with MS but present evidence for a serum blocking factor(s) with specificity for measles and SSPE viruses in these patients.

Effect of hydrocortisone on in vitro cellular immunity to viruses in man

Abstract A 51 Cr lymphocytoxicity microassay was used to examine certain aspects of the mechanism by which corticosteroids suppress cellular immunity to viruses. A partial suppression of specific immune release was observed at 10 μg/ml concentration of hydrocortisone, and was completely abolished at 100 μg/ml concentration. This effect was not reversible by vitamin A. The suppressive effect was more pronounced when corticosteroids were introduced at the onset of lymphocyte-target cell interaction, than at 3 or 6 hr later. A parallel set of responses was observed with mitomycin-C, actinomycin-D, and chloramphenicol. We conclude that the immunosuppressive effects of corticosteroids may be related to their known capacity to inhibit metabolic processes, steps essential for the afferent phase of lymphocyte activation.

THE IMMUNOLOGIC ROLE OF TONSILLAR TISSUES IN LOCAL CELL-MEDIATED IMMUNE RESPONSES

The present studies were performed to compare local cell-mediated immune (CMI) responses of tonsillar lymphoid tissues with those of systemic CMI employing lymphoproliferative responses to PHA, T-rosette formation, and specific rubella CMI studies using a 51Cr lymphocytotoxic microassay. Suspensions of peripheral blood lymphocytes (PEL) and tonsillar tissue lymphocytes (TTL), obtained from 12 subjects ranging in age from 5 to 22 years, were purified by hypaque-ficoll sedimentation and adjusted to equal concentrations. The mean ± SD responses to PHA were 56,642 ± 10,329 cpm for PEL and 38,851 ± 6,804 cpm for TTL (p > 0.6); the mean ± SD values for T-rosette formation were 30 ± 1.7% for PBL and 36.4 ± 3.8% for TTL (p > 0.1); the mean ± SD rubella specific immune release was 13.8 ± 3.7% with PBL compared to 12.6 ± 3.3% for TTL (p > 0.9). No correlation was demonstrated between serum rubella HAI antibody titers and local or systemic rubella specific CMI or between local and systemic rubella specific CMI. These results provide further evidence for the role of local CMI to viruses at mucosal surfaces and suggest the participation of tousillar tissues in these responses.

CELLULAR IMMUNE RESPONSES TO HERPES-SIMPLEX 1 |[lpar]|HSV-1|[rpar]| IN RECURRENT HERPES LABIALIS

Cellulair immunity to HSV-1 in 10 children and adults with recurrent herpes labialis was evaluated with two microassays: (1) Blastogenesis: lymphocytes were incubated with tissue culture cells (MA-160) persistently infected with HSV-1. Uninfected MA-160 cells were used as controls with a blastogenic index (BI) calculated from cpm of C14 thymidine uptake for lymphocytes incubated with infected cells divided by uptake following incubation with uninfected cells. (2) Cytotoxicity: utilizing the same persistently infected cell line as target cells, release of 51Cr from these cells or controls was used as the index of lymphocyte reactivity (Steele, R. W. et al. J.Immunol. 110:1502, 1973).Blastogenesis for subjects with recurrent herpes labialis demonstrated a mean BI of 25.9(7.8-49). The mean BI in control donors was 17.6(5.3-40). In the cytotoxicity assay specific immune release attributable to HSV-1 averaged 2.8% (0-5.7%) in patients compared to 14.9%(8.0-31.5%) in controls. These data suggest a dissociation between the afferent and efferent mechanisms of cellular immunity with normal or enhanced lymphocyte blastogenesis but decreased cytotoxicity. Recurrent herpes labialis may therefore be a consequence of subtle cellular immune deficiency involving at least one of the efferent mechanisms.