Occurrence of restricted suppressor T-cell activity in man.

Blood leukocytes from an immunologically hyporesponsive patient with urinary bladder carcinoma were found to be deficient in their ability to stimulate 3 of 27 responder leukocyte preparations from normal individuals in one-way mixed leukocyte culture (MLC). The patient's T-depleted leukocytes, however, functioned adequately as stimulator cells. T-enriched lymphocytes from this patient suppressed the MLC responsiveness of those three normals but not the responsiveness of other normals. The patient's cells suppressed the MLC responsiveness of only one of each of the parents of two of the normals who could be suppressed by the patient's leukocytes suggesting a possible genetic restriction to this suppressor cell activity.

Ly phenotype of cytotoxic T cells for syngeneic tumor.

Our present and previous findings may be summarized as follows: The phenotype of C57BL/6 (B6) cytotoxic cells for allogeneic target cells is Thy-1+, Ly-1- Ly-2/3+, MSLA+, and Ig-. the phenotype of B6 cytotoxic cells for syngeneic tumor cells is Thy-1+, Ly-1+, Ly-2/3+, MSLA+, and Ig-. The phenotype of B6 cytotoxic cells for syngeneic tumor cells is Thy-1+, Ly-1+, Ly-2/3+, MSLA+, AND Ig-. Thus, differences in Ly phenotype appear to be exhibited not only by cytotoxic T cells as opposed to helper T cells, but also within subcategories of cytotoxic T cells.

Expression of T-cell differentiation antigens on effector cells in cell-mediated cytotoxicity in vitro. Evidence for functional heterogeneity related to the surface phenotype of T cells.

The cell-mediated cytotoxicity (CMC) of nonadherent cells from the peritoneal cavity (NAPC) of alloimmunized mice can be measured by the [3H]proline microassay. The exhibition of thymus-derived (T) cell antigens on these killer cells was studied by incubating them with the relevant T-cell antisera and complement (C), under optimal conditions for lysis, before performance of the CMC assay. Under these conditions, the following T-cell antigens were demonstrable on the killer population in terms of percent reduction in CMC by the respective antisera: (a) Thy-1.1 (83%) and Thy-1.2 (100%), (b) MSLA (86%), (c) NTA-RA (a T-cell antigen recognized by naturally occurring autoantibody of NZB mice) (62%), (d) Ly1.1 )58%, (e) Ly-2.1 (11%; considered a marginal result) and Ly-2.2 (63%), and (f) Ly-3.2 (77%). The following were not demonstrable: (g) TL, and (h) Ly-1.2. (i) The antigen Ly-3.1 was not studied. Omission of C deprived all T-cell antisera tested of their capacity to suppress CMC, indicating that the cell components recognized by such antisera may perform no direct function in CMC. On the assumption that all Ly+ cells are Thy-1+, it is clear that the T-cell members of the immune NAPC population must be heterogenous. This follows from the fact that the proportions of T cells lysed by different Ly antisera did not correspond with ensuing degree of loss of CMC capacity. The extremes were represented by anti-Ly-1.2 (74% Thy-1+ cells lysed, but no reduction in CMC) and Ly-3.2 (54% Thy-1+ cells lysed, with 77% reduction in CMC). From this initial survey it appears that the C57BL/6 mice killer T-cell population active in CMC in vitro is relatively rich in surface antigens of the Ly-2/Ly-3 category and relatively poor in representation of the Ly-1 surface antigens. It remains to be seen whether this killer cell phenotype, poor in Ly-1 and rich in Ly-2/Ly-3, is characteristic of the mouse generally. From these results it appears that subsets of T cells with different immunological functions may exhibit qualitative or quantitative differences in surface antigens specified by different Ly loci; this will be easier to assess in the future when the results of experiments with the same Ly antisera but dealing with T-cell functions other than CMC become available.

Evidence for increased somatic cell mutations at the glycophorin A locus in atomic bomb survivors.

A recently developed assay for somatic cell mutations was used to study survivors of the atomic bomb at Hiroshima. This assay measures the frequency of variant erythrocytes produced by erythroid precursor cells with mutations that result in a loss of gene expression at the polymorphic glycophorin A (GPA) locus. Significant linear relations between variant frequency (VF) and radiation exposure were observed for three different variant cell phenotypes. The spontaneous and induced VFs agree with previous measurements of radiation-induced mutagenesis in other systems; this evidence supports a mutational origin for variant cells characterized by a loss of GPA expression and suggests that the GPA assay system may provide a cumulative dosimeter of past radiation exposures. VFs for some survivors differ dramatically from the calculated dose response, and these deviations appear to result primarily from statistical fluctuations in the number of mutations in the stem-cell pool. These fluctuations allow one to estimate the number of long-lived hemopoietic stem cells in humans.

Cytotoxic reactions of murine lymphoid cells studied with a tritiated proline microcytotoxicity test.

A lymphocyte cytotoxicity (CTX) test with 3-H-proline-prelabeled target cells was used to detect the immune response of murine lymphoid cells to H-2 and tumor antigens. The specificity of the reaction was determined by simultaneous tests on unrelated target cells and, for reactions directed against H-2 antigens, by blocking experiments with alloantiserum directed against the H-2 antigens of the target cells. After a single intraperitoneal (ip) injection of allogeneic spleen cells, CTX of unfractionated peritoneal cellswas strong, with a sharp peak on day 5. Repeated ip immunization markedly increased the CTX of unfractionated peritoneal cells. The reaction was strongest when the test was done at 37 degrees C. Sometimes CTX should be detected after as little as 6 hours' incubation. CTX depended primarily on the absolute number of effector or target cells per area rather than on the ratio of effector to target cells. Both nonadherent and adherent peritoneal cells destroyed target cells specifically. The CTX of nonadherent peritoneal cells was increased by 2-mercaptoethanol. The CTX reaction depended on effector cells bearing Tyl-1. Destruction of "innocent bystander" target cells was seen with one of four combinations of unfractionated and nonadherent peritoneal cells from hyperimmune animals.

Some immunological considerations relevant to the study of human bladder cancer.

The likelihood that immunosurveillance, concomitant immunity, and immunodepression play a role in the development and spread of neoplasms of the urinary bladder is discussed. The circumstantial evidence for the existence of concomitant immunity to bladder cancer-associated antigens is briefly reviewed, and the implications of the hypothesis of Zinkernagel and Dougherty of a genetic restriction to the cytotoxicity of T-cells for virally determined target cell antigens and of the concept of immunoregulatory cells for our understanding of the immunology of bladder carcinoma are discussed.

Decreased ability of blood leukocytes from patients with tumors of the urinary bladder to act as stimulator cells in mixed leukocyte culture.

Blood leukocytes from patients with active neoplasms of the urinary bladder were found to have a decreased ability to stimulate in one-way mixed leukocyte culture (MLC). The ability of the patients' leukocytes to act as stimulator cells in one-way MLC was assessed by simultaneous comparison to the ability of leukocytes from normal individuals to stimulate. In addition, the ability of the patients' leukocytes to act as responder cells in the one-way MLC was evaluated. Cells from 31 (56%) of 55 patients with active disease exhibited subnormal stimulatory activity in the MLC while 26 of these 31 patients (84%) had normal responsiveness. Cells from 9 of the 55 failed to respond normally. Poor stimulation occurred with both early and advanced disease, and the stimulatory activity increased after tumor removal in 12 of 15 patients who had previously shown subnormal stimulation. Six patients without active disease at the time of testing, in addition to the 55, exhibited normal levels of stimulation and responsiveness. This defective stimulatory activity is suggestive of an acquired, disease-related phenomenon and is not necessarily associated with decreased blood leukocyte responsiveness.

Detection of somatic mutations at the glycophorin A locus in erythrocytes of atomic bomb survivors using a single beam flow sorter.

A modified method was developed for measuring the frequency of variant erythrocytes at the glycophorin A locus using a single beam cell sorter (SBS). Fluorescein- or phycoerythrin-labeled monoclonal antibodies specific for the M or N glycophorin A alleles were used for the SBS assay. To prevent contamination of nucleated cells in the sorting windows, the nucleated cells in the fixed erythrocyte sample were stained with propidium iodide before flow sorting. Blood samples were obtained from atomic bomb survivors who were heterozygous for the MN blood type, and the frequencies of the hemizygous and homozygous variant of the M or N glycophorin A allele were measured by the SBS. For the three types of variants, hemizygotes for M and N allele (Nø and Mø) and homozygotes for M allele (MM), the variant frequency measured by the SBS correlated well with that previously determined by a dual beam cell sorter. Variant frequencies of the Nø, Mø, and MM cell types in atomic bomb survivors determined by SBS measurements were found to increase with radiation dose (DS86, kerma) as well as with the frequency of chromosome aberrations in lymphocytes.

Suppressed antidonor MLC responses in renal transplant candidates conditioned with donor-specific transfusions that carry the recipient's noninherited maternal HLA haplotype.

Forty-seven patients with end-stage renal disease were entered into a donor-specific transfusion protocol consisting of three infusions of whole blood every two weeks prior to transplantation. Fourteen of the patients became sensitized following transfusion and were not transplanted. Thirty-one patients received a transplant from the DST donor and have an estimated two-year graft survival of 97%, three-year survival of 88%, and four-year survival of 69%. Cells of eleven of the 36 recipients tested in one-way MLC before and two weeks after completion of DST exhibited a significantly decreased antidonor MLC response. Deletion of CD8+ positive lymphocytes from suppressed MLCs resulted in restoration of antidonor MLC reactivity in four of six patients. An analysis of the family HLA profile in patients exhibiting a decreased donor-directed MLC response revealed a significant (P less than 0.02) association between decreased MLC reactivity following DST and the expression of noninherited maternal HLA antigens by cells of the transfusion donor. These alterations in cellular immune responses noted in some patients following DST are consistent with the appearance of specific antidonor T suppressor cells as a result of donor-specific transfusion.

In vitro recall of proliferative and cytolytic responses to minor histocompatibility antigens by dendritic cell enriched canine peripheral blood mononuclear cells.

It is difficult in vitro to demonstrate existent in vivo sensitization of dogs and humans to minor histocompatibility antigens. Using conventional one-way mixed leukocyte culture, when sensitized blood cells are stimulated with MHC antigen-matched sibling PBMC bearing the minor histocompatibility antigens, there is usually no proliferative or cytotoxic response detected. We reported previously that 0 of 17 dogs sensitized by transfusion of dog leukocyte antigen-identical littermate blood had proliferative responses in mixed leukocyte culture when unfractionated sibling PBMC were used as stimulator cells. We reasoned that this result might be due to the inability of unfractionated PBMC to efficiently present minor histocompatibility antigens to the in vivo-primed T cells, a function thought best performed by dendritic cells. When we used a low buoyant density Percoll fraction of canine PBMC, shown previously to be enriched in dendritic cells, as stimulator cells, we were able to generate cytotoxic and/or proliferative responses in mixed leukocyte culture in all 5 dogs that had been sensitized to minor histocompatibility antigens by transfusions of dog leukocyte antigen-identical sibling littermate blood. By contrast, using unfractionated PBMC as stimulator cells, we found evidence of sensitization in only 1 of the 5 dogs. These data support the concept that the presentation of minor histocompatibility antigens, in contrast to major histocompatibility antigens, to the immune system may be restricted to a subpopulation of professional APC.

Prevention of transfusion-induced sensitization to minor histocompatibility antigens on DLA-identical canine marrow grafts by gamma irradiation of marrow donor blood.

Dogs given total-body irradiation and marrow transplants from DLA-identical littermates exhibit prompt and sustained hematopoietic engraftment. However, animals given three preceding blood transfusions from the marrow donor before transplant become sensitized and reject the marrow graft. Rejection is due to exposure to polymorphic minor non-DLA histocompatibility antigens expressed on blood mononuclear cells. We sought to determine whether heat treatment would prevent blood from sensitizing recipients in this model since heating blood to 45 degrees C for 45 min abrogates the ability of blood mononuclear cells to stimulate in mixed lymphocyte culture. Three of 4 evaluable dogs given heat-treated blood before transplant rejected their marrow grafts. To prevent possible reexpression/reacquisition of mononuclear cell functional activity in vivo after transfusion, subsequent dogs were given heated blood that was additionally exposed to 2000 cGy gamma irradiation. Eight of 10 evaluable dogs given blood treated in this fashion engrafted. Unexpectedly, 9 out of 10 evaluable dogs transfused with blood treated only with gamma irradiation also engrafted. These results demonstrate that treatment of blood with gamma irradiation alone or in combination with heat prevents transfusion-induced sensitization to minor histocompatibility antigens. Results from this canine model suggest that blood products be gamma irradiated before transfusion in patients who are transplant candidates in order to prevent sensitization to minor histocompatibility antigens and reduce the risk of marrow graft rejection.

Gamma-irradiation of pretransplant blood transfusions from unrelated donors prevents sensitization to minor histocompatibility antigens on dog leukocyte antigen-identical canine marrow grafts.

Pretransplant blood transfusions from a dog leukocyte antigen (DLA)-identical canine littermate marrow donor will sensitize the recipient to non-DLA-linked polymorphic minor histocompatibility antigens, which uniformly results in graft rejection. We observed previously that 2000 cGy gamma-irradiation of marrow donor blood transfusions prevented this sensitization and subsequent marrow graft rejection. The purpose of the present study was to determine whether treatment of unrelated blood transfusions with gamma-irradiation would also prevent sensitization. Conceivably, sensitization to minor histocompatibility antigens might be more efficient or potent and thus more difficult to prevent when those antigens are seen in the context of disparity for DLA antigens. Furthermore, this model, in which sensitization to DLA-identical littermate marrow is caused by unrelated blood transfusions, is directly relevant to the clinical circumstances of human marrow transplantation. We assessed sensitization caused by unrelated blood transfusions by monitoring graft outcome in recipients transplanted with DLA-identical littermate marrow after conditioning with 920 cGy total body irradiation. Two thousand cGy gamma-irradiation of unrelated blood transfusions significantly reduced the incidence of transfusion-induced sensitization of recipients. There was successful marrow engraftment in 15 of 16 (94%, P < 0.003) of these animals in contrast to the previous study in which only 7 of 16 (44%) animals engrafted after they were transfused with unmodified blood on the same schedule. These results suggest that blood transfusions for use in humans, especially for patients with aplastic anemia, should be gamma-irradiated in order to reduce the incidence of marrow graft rejection caused by sensitization to minor histocompatibility antigens.

Tubuloreticular structures and cylindrical confronting cisternae: a review.

Tubuloreticular structures (TRS) and cylindrical confronting cisternae (CCC) are unique subcellular structures that arise from the membranes of the rough endoplasmic reticulum of a variety of cell types. In vivo, they occur most frequently in endothelial cells and lymphocytes from patients with autoimmune diseases and viral infections; they are seen in these cells in almost all acquired immunodeficiency syndrome (AIDS) patients. The inducer(s) of TRS and CCC in vivo is (are) not firmly established. However, clinical and experimental studies indicate that the occurrence of these structures in these diseases is directly related to the endogenous elevation of alpha- and beta-interferon but not to gamma-interferon. Although CCC have been seen and reported to occur in human and primate cells since the late 1970s, their presence did not arouse much clinical and scientific interest until 1983 when they were observed in lymph node tissues of AIDS patients. The nature and pathogenesis of TRS and CCC are obscure. Through the years, many hypotheses have been proposed. They range from suggestions of these structures being incomplete viral particles to being nothing more than accumulated proteins; and from reference to these structures as specific markers for diseases to a generalized cell reaction to certain biological stimuli. In vitro investigations with lymphoblastoid cell lines have contributed a great deal in illuminating the potential clinical significance and the in vivo inducer(s) of TRS and CCC. Both the TRS and CCC are now known to be induced in vitro by alpha- and beta-interferon in some lymphoblastoid cell lines. However, only TRS and not CCC are induced in healthy donor lymphocytes and endothelial cells. Isolation of TRS and CCC using the lymphoblastoid cell system will help clarify the nature, the pathogenesis, and the importance of TRS and CCC in human diseases.

T-cell responses to mitogens in atomic bomb survivors: a decreased capacity to produce interleukin 2 characterizes the T cells of heavily irradiated individuals.

Significant decreases in the fraction of lymphocytes that are CD4(+) and increases in serum levels of some classes of immunoglobulin have been reported to occur in atomic bomb (A-bomb) survivors and in victims of the Chernobyl nuclear plant accident. To investigate the long-term effects of nuclear radiation on cellular immunity in more detail, we used limiting dilution assays with peripheral blood mononuclear cell preparations to analyze the T-cell responses of 251 A-bomb survivors exposed to less than 0.005 Gy and 159 survivors exposed to more than 1.5 Gy. The percentages of CD2-positive cells that were capable of proliferating in response to phytohemagglutinin (PHA) in the presence of exogenous interleukin 2 (IL2) did not differ substantially between distally exposed and more heavily exposed survivors. The heavily exposed survivors appeared to possess fewer T cells that were capable of proliferating in response to concanavalin A (Con A) or of producing interleukin 2. Assuming that CD4 T cells were the ones primarily responsible for producing IL2 in response to Con A, we were able to estimate how many cells in any given CD4 T-cell population were actually producing IL2. The results indicated that peripheral blood samples from heavily exposed survivors contained significantly fewer IL2-producing CD4 T cells than did similar samples from distally exposed survivors, indicating that significant exposure to A-bomb radiation may have a long-lasting negative effect on the capacity of CD4 T-cell populations to produce IL2.