Requirements for suppressor T cell activation

Third-order (Ts3) suppressor cells are generated after conventional immunization. These cells, however, will not mediate suppressor cell function unless specifically triggered by an activating signal, termed TsF2. This report analyzes the mechanism of this TsF2-mediated triggering event. TsF2-mediated suppression is genetically restricted by genes in the I-J and Igh-V regions. The target of the I-J restrictions is a firmly adherent accessory cell, which appears to express I-J-related determinants. These accessory cells are sensitive to cyclophosphamide treatment and 500 R irradiation. In contrast, the target of the Igh-V restriction of TsF2 appears to be the Ts3 cell, which carries antigen-specific, idiotype-related receptors. The mechanism of suppressor cell activation appears to involve two stages. Presentation of I-J-restricted TsF2 by I-J-compatible presenting cells and a second step involving idiotype-anti-idiotype interactions between TsF2 and the Ts3 cell. I-J compatibility is not required with the accessory cell for Ts3 activation. Finally, we hypothesize that the anti-idiotypic determinants expressed on TsF2 can serve as an internal image of antigen, thereby permitting specific targeting of the factor.

Requirements for suppressor T cell activation

Third-order (Ts3) suppressor cells are generated after conventional immunization. These cells, however, will not mediate suppressor cell function unless specifically triggered by an activating signal, termed TsF2. This report analyzes the mechanism of this TsF2-mediated triggering event. TsF2-mediated suppression is genetically restricted by genes in the I-J and Igh-V regions. The target of the I-J restrictions is a firmly adherent accessory cell, which appears to express I-J-related determinants. These accessory cells are sensitive to cyclophosphamide treatment and 500 R irradiation. In contrast, the target of the Igh-V restriction of TsF2 appears to be the Ts3 cell, which carries antigen-specific, idiotype-related receptors. The mechanism of suppressor cell activation appears to involve two stages. Presentation of I-J-restricted TsF2 by I-J-compatible presenting cells and a second step involving idiotype-anti-idiotype interactions between TsF2 and the Ts3 cell. I-J compatibility is not required with the accessory cell for Ts3 activation. Finally, we hypothesize that the anti-idiotypic determinants expressed on TsF2 can serve as an internal image of antigen, thereby permitting specific targeting of the factor.

[An evaluation of antimicrobial removal device to isolate bacteria from bacteremic patients with hematological disorders]

Antibiotics contained in blood specimens often inhibit bacterial growth in culture media. Recently, the antimicrobial removal device (ARD) containing resins to absorb antibiotics has been made available. To evaluate the effectiveness of the ARD, we investigated how much the antibiotics were removed by the ARD. The ARD method was compared to the conventional culturing method in isolating organisms from blood specimens of patients with hematological disorders receiving antimicrobial agents. The antibiotics, including cefotiam, cefsulodin, cefmenoxime, cefazolin and sulbenicillin, were proved to be almost completely removed by the ARD. Bacteria were detected only by use of the ARD in the blood cultures from 2 of 21 blood specimens (11 patients) entered in the study, while all of the blood cultures were negative by the conventional method. These isolated bacteria were S. aureus and P. aeruginosa, of which septicemias were cured by intensive antibiotic therapy for these bacteria. It is suggested that pretreatment with the ARD makes detection of bacteria easier in blood from the patients receiving antibiotics. Literatures were reviewed concerning improvement and shortened time for isolation of organisms by using the ARD.

A role for macrophages in suppressor cell induction

A mechanism responsible for the induction of NP-specific first order (inducer) suppressor cells (TS1) is described. TS1 cells are induced by i.v. administration of hapten-coupled splenic cells. Their activity is assessed by the adoptive transfer of NP-specific suppression during the afferent phase of the contact sensitivity response. NP-coupled firmly adherent, FcR+, I-A-bearing macrophages induce TS1. The antigen-presenting cells required for TS1 induction lack the Thy-1 and Lyt-1 markers, and are resistant to 500 R irradiation and to cyclophosphamide treatment. NP-coupled dendritic cells fail to induce TS1 activity. The induction of TS1 cells is genetically restricted by genes that map in the I-J region of the H-2 complex. The NP-coupled antigen-presenting cells must share at least one I-J allele with the TS1 donor for effective induction of TS1 activity. To minimize allogeneic effects in these studies, the activity of the TS1 population was assessed by adoptive transfer into syngeneic recipients. The present results are compared with the mechanisms required for the induction of second and third order suppressor cells.

A role for macrophages in suppressor cell induction

A mechanism responsible for the induction of NP-specific first order (inducer) suppressor cells (TS1) is described. TS1 cells are induced by i.v. administration of hapten-coupled splenic cells. Their activity is assessed by the adoptive transfer of NP-specific suppression during the afferent phase of the contact sensitivity response. NP-coupled firmly adherent, FcR+, I-A-bearing macrophages induce TS1. The antigen-presenting cells required for TS1 induction lack the Thy-1 and Lyt-1 markers, and are resistant to 500 R irradiation and to cyclophosphamide treatment. NP-coupled dendritic cells fail to induce TS1 activity. The induction of TS1 cells is genetically restricted by genes that map in the I-J region of the H-2 complex. The NP-coupled antigen-presenting cells must share at least one I-J allele with the TS1 donor for effective induction of TS1 activity. To minimize allogeneic effects in these studies, the activity of the TS1 population was assessed by adoptive transfer into syngeneic recipients. The present results are compared with the mechanisms required for the induction of second and third order suppressor cells.

A genetically restricted suppressor factor that requires interaction with two distinct targets

We have previously described a genetically restricted suppressor factor (TsF3) that suppresses the terminal phases of the contact sensitivity response. The activity of TsF3 is restricted by genes in the H-2 (I-J) and Igh complexes. This report analyzes the mechanisms responsible for these genetic restrictions. One cellular target of TsF3 is an I-J-bearing antigen-presenting cell population that is sensitive to low doses of cyclophosphamide. To elicit suppression I-J homology is required between this antigen-presenting cell population and the TsF3 donor. In contrast, the Igh-linked genetic restriction exists between TsF3 and an unprimed cell population present in the recipient. These findings suggest that under these experimental conditions TsF3 acts by bridging the APC with cells of the host. Finally, we demonstrated that nonspecific bystander or cognate suppression can be mediated by TsF3, provided specific antigen is present in the site of the ongoing T cell response.

A genetically restricted suppressor factor that requires interaction with two distinct targets

We have previously described a genetically restricted suppressor factor (TsF3) that suppresses the terminal phases of the contact sensitivity response. The activity of TsF3 is restricted by genes in the H-2 (I-J) and Igh complexes. This report analyzes the mechanisms responsible for these genetic restrictions. One cellular target of TsF3 is an I-J-bearing antigen-presenting cell population that is sensitive to low doses of cyclophosphamide. To elicit suppression I-J homology is required between this antigen-presenting cell population and the TsF3 donor. In contrast, the Igh-linked genetic restriction exists between TsF3 and an unprimed cell population present in the recipient. These findings suggest that under these experimental conditions TsF3 acts by bridging the APC with cells of the host. Finally, we demonstrated that nonspecific bystander or cognate suppression can be mediated by TsF3, provided specific antigen is present in the site of the ongoing T cell response.

The role of I-J and Igh determinants on F1-derived suppressor factor in controlling restriction specificity

In the 4-hydroxy-3-nitrophenyl acetyl (NP) contact sensitivity system, the activity of third-order suppressor cells and their factors is restricted by H-2(I-J) and Igh linked genes. The present report analyzes the specificity of NP-specific Ts3 cells and factors derived from H-2 and Igh heterozygous (B6 X C3H)F1 mice. Two approaches were used. First, heterogeneous populations of F1 Ts3 cells were activated in vitro and then assayed in Ts3-depleted recipients which carried different combinations of H-2 and Igh alleles. The second approach was to hybridize the Ts3 cells and analyze the specificity of the F1-derived TsF3. The combined data demonstrated four functionally distinct populations of Ts3 cells. The activity of each population was restricted by a particular combination of H-2 and Igh haplotypes. Thus, Ts3 cells derived from F1 donors can demonstrate an apparent scrambling of H-2 and Igh restriction specificities. There was functional allelic exclusion of the H-2(I-J) and Igh determinants expressed on (B6 X C3H)F1 hybridoma-derived TsF3. Thus, TsF3 from each cloned hybridoma line expressed only one set of I-J and Igh determinants. Furthermore, there was a complete correlation between the I-J and Igh linked determinants expressed on TsF3 and the restriction specificity. In view of the recent findings on the molecular biology of the I-J region, an alternative interpretation of the role of I-J determinants on suppressor cells and factors is offered.

[Effects of various antibiotics and natural mycotoxins on the hematopoietic stem cells of the bone marrow in normal and adjuvant-treated rats]

This experiment was carried out, in order to investigate the effect of antibiotics and natural mycotoxin on the hematopoietic stem cells at the normal and inflammatory condition. Adjuvant-treated rats (Aj-rats) are considered as a model of human rheumatoid arthritis. We measured the CFU-C and CFU-E of bone marrow of normal and Aj-rats which were injected with large (1.0 g/kg X 3) and small doses (0.5 g/kg X 3) of ampicillin (ABPC), cefazolin (CEZ), chloramphenicol (CP) and fusarenon-X (F-X). In Aj-rats the number of CFU-C was 1.5 times higher and CFU-E 60% less than normal. Injection of large doses of ABPC enhanced markedly the numbers of CFU-C in Aj-rats and suppressed slightly CFU-E in normal rats. Large doses of CEZ inclined to increase CFU-C and decreased CFU-E in normal and Aj-rats. Injection of small doses of CP tended to increase CFU-C and to decrease CFU-E, and large doses of CP to suppress both CFU-C and CFU-E levels in normal or Aj-rats. F-X, natural mycotoxin suppressed markedly both CFU-C and CFU-E levels of normal rats, and slightly the CFU-E in Aj-rats. These results suggest that one should pay attention to the fact that some doses of antibiotics or natural mycotoxin might be harmful on the bone marrow hematopoietic stem cells.

A mechanism responsible for the induction of H-2 restricted second order suppressor T cells

The mechanism by which I-J restrictions were imposed on second-order suppressor cells (Ts2) was analyzed. The induction of Ts2 cells requires presentation of an inducer suppressor factor by a specialized population of factor-presenting cells. The I-J phenotype of this factor-presenting population controls the H-2 restriction of the Ts2 cells. The splenic cells responsible for presenting inducer factor appear to be of macrophage or dendritic cell lineage. Several homologies exist between the mechanism responsible for the induction of H-2-restricted suppressor and helper T cells. Thus, the I region products on specialized presenting cells determine the specificity and genetic restrictions of the T cell. In an H-2 heterozygous F1 animal, two distinct populations of cells can be induced, one specific for each parental H-2 heplotype. Furthermore, the data suggest that the suppressor cells also bear receptors for self H-2 products. The ramifications of these observations for the suppressor cell cascade are discussed.

Induction of immune responses by schistosome granuloma macrophages

In mice, granuloma formation after Schistosomiasis mansoni infection is known to be a T cell-dependent response to schistosome eggs that peaks at 6 to 8 wk after infection (early) then regresses to a minimum by 20 to 32 wk (late). This decline in host responsiveness, termed modulation, has been attributed to T cell-mediated suppression. We now have investigated the macrophages from either Early or Late schistosome granulomas phenotypically and found no difference in expression of I-A subregion encoded antigens. We also tested granuloma macrophage (Gm) populations in their capacity to induce positive and negative antigen-specific immune responses to the hapten 4-hydroxy-3-nitrophenyl acetyl (NP). As few as 10(3) to 10(4) NP-coupled Early or Late Gm given s.c. were equally capable of inducing MHC-restricted NP-specific delayed-type hypersensitivity (DTH) responses and this DTH-inducing capability was equivalent to that of splenic adherent cell (SAC) controls. Further, both Early and Late Gm were able to generate NP-specific induction-phase suppressor cells (Ts1) when as few as 10(2) NP-coupled Gm were given i.v., the same as NP-SAC controls. Finally, NP-specific effector-phase suppressor cells (Ts3) were equally induced by Early Gm, Late Gm, or SAC controls. Therefore, macrophages derived from Early or Late schistosome granulomas or normal spleens are apparently phenotypically indistinguishable and equally capable, in extremely small quantities, of inducing NP-specific DTH, Ts1, and Ts3 immune responses.

Induction of immune responses by schistosome granuloma macrophages

In mice, granuloma formation after Schistosomiasis mansoni infection is known to be a T cell-dependent response to schistosome eggs that peaks at 6 to 8 wk after infection (early) then regresses to a minimum by 20 to 32 wk (late). This decline in host responsiveness, termed modulation, has been attributed to T cell-mediated suppression. We now have investigated the macrophages from either Early or Late schistosome granulomas phenotypically and found no difference in expression of I-A subregion encoded antigens. We also tested granuloma macrophage (Gm) populations in their capacity to induce positive and negative antigen-specific immune responses to the hapten 4-hydroxy-3-nitrophenyl acetyl (NP). As few as 10(3) to 10(4) NP-coupled Early or Late Gm given s.c. were equally capable of inducing MHC-restricted NP-specific delayed-type hypersensitivity (DTH) responses and this DTH-inducing capability was equivalent to that of splenic adherent cell (SAC) controls. Further, both Early and Late Gm were able to generate NP-specific induction-phase suppressor cells (Ts1) when as few as 10(2) NP-coupled Gm were given i.v., the same as NP-SAC controls. Finally, NP-specific effector-phase suppressor cells (Ts3) were equally induced by Early Gm, Late Gm, or SAC controls. Therefore, macrophages derived from Early or Late schistosome granulomas or normal spleens are apparently phenotypically indistinguishable and equally capable, in extremely small quantities, of inducing NP-specific DTH, Ts1, and Ts3 immune responses.

Adenosquamous carcinoma of the pancreas: a clinicopathologic study and report of three cases

Among 27 surgically resected carcinomas of the pancreas, 3 cases were diagnosed histologically as adenosquamous carcinoma (11.1%). This is the highest rate among the medical literature we reviewed. Since a very small focus of squamous cell carcinoma was detected through close observation in 1 case, it would seem that this sort of pancreatic tumor could be more common than is ordinarily expected. From the histologic studies of these 3 cases, it seems likely that the preexisting adenocarcinoma partially underwent malignant transformation into a malignant squamous component. When the different modes of spread of these two histologic elements are compared, the adenocarcinomatous element seems to be more invasive and more likely to metastasize than does squamous cell carcinoma.

Adenosquamous carcinoma of the pancreas: a clinicopathologic study and report of three cases

Among 27 surgically resected carcinomas of the pancreas, 3 cases were diagnosed histologically as adenosquamous carcinoma (11.1%). This is the highest rate among the medical literature we reviewed. Since a very small focus of squamous cell carcinoma was detected through close observation in 1 case, it would seem that this sort of pancreatic tumor could be more common than is ordinarily expected. From the histologic studies of these 3 cases, it seems likely that the preexisting adenocarcinoma partially underwent malignant transformation into a malignant squamous component. When the different modes of spread of these two histologic elements are compared, the adenocarcinomatous element seems to be more invasive and more likely to metastasize than does squamous cell carcinoma.

Budd-Chiari syndrome associated with protein-losing enteropathy

Budd-Chiari syndrome associated with protein-losing enteropathy is reported. A 26-year-old male suffered from ascites, edema in the lower extremities, and engorgement of ascending veins on the abdominal wall. The diagnosis of Budd-Chiari syndrome was made by inferior vena cavography. The 131I-polyvinylpyrrolidone test showed the association of protein-losing enteropathy. The surgical operation was performed successfully, resulting in a marked improvement of signs and symptoms. To date, no similar case has yet been reported. There are, however, a number of reported cases of hypoproteinemia in Budd-Chiari syndrome, which might have been associated with a protein-losing enteropathy.