Human nonspecific suppressive lymphokines

Role of Immune Response in the Prognosis of Carcinoma of the Uterine Cervix: Can in Vitro Analysis Provide a better Framework for more Effective Management?

Cancer of the uterine cervix is the single largest female malignancy in India and also remains a major problem facing oncologists in other parts of the world. While advances in radiation therapy and surgical techniques have made the treatment of cervical carcinoma impressive, limitations to successful management still remain. In fact, the 5-year survival rate, stage for stage, has not improved in the United States or world wide in the past 40 years. With an estimated half a million women developing this disease annually, this lack of improved survival poses an international unresolved health problem. Immune response has been shown to be a major factor involved In the course of the disease for this cancer. Immunologic monitoring was also shown to be of effective value in assessing the prognosis for cervical carcinoma. We studied the various immunologic abnormalities in cervical cancer, the effects of radiation therapy on immune function, prospects of an immunologic staging system, the relationship between human papillomavirus infection and the Immune response, and the possibility of using in vitro Immunologic assessment to provide a better framework for more effective management of cancer of the uterine cervix.

Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome

Intravenous immunoglobulin improves many antibody-mediated autoimmune disorders, but its mode of action is unknown. We investigated its effects on muscle strength and on the serum titer of the calcium-channel autoantibodies that are likely to be pathogenic in the Lambert-Eaton myasthenic syndrome (LEMS). In a randomized, double-blind, placebo-controlled crossover trial, serial indices of limb, respiratory, and bulbar muscle strength and the serum titer of calcium-channel antibodies in nine patients were compared over an 8-week period, using the area-under-the-curve approach, following infusion on two consecutive days of immunoglobulin at 1 g/kg body weight/day (total dose 2.0 g/kg body weight) or placebo (equivalent volume of 0.3% albumin). Calcium-channel antibodies were measured by radioimmunoassay using 125I-omega-conotoxin MVIIC. Direct anti-idiotypic actions of immunoglobulin were tested in this assay. Immunoglobulin infusion was followed by significant improvements in the three strength measures (p = 0.017 to 0.038) associated with a significant decline in serum calcium-channel antibody titers (p = 0.028). Improvement peaked at 2 to 4 weeks and was declining by 8 weeks. Mean serum titers were unchanged at 1 week, however, and direct anti-idiotypic neutralization by immunoglobulin was not demonstrable in vitro. We conclude that immunoglobulin causes a short-term improvement in muscle strength in LEMS that probably results from the induced reduction in calcium-channel autoantibodies. The reduction is not due to a direct neutralizing action of the immunoglobulin, but a delayed anti-idiotypic action cannot be excluded. Improvement following intravenous immunoglobulin in other autoantibody-mediated disorders may similarly be associated with decline in levels of pathogenic autoantibodies.

Homology of partial primary sequences between alpha-enolase and a suppressive lymphokine from human T cells

A relationship is described between TS--a human suppressive lymphokine produced by hybridoma T cells--and alpha-enolase from the U937 monocyte human cell line. A strong homology (92%) was observed by comparing the internal amino acid sequences of 6 TS peptides, corresponding to 52 residues, with the complete sequence of alpha-enolase. The molecular masses of these two molecules were found to be of about 47 kDa and both were detected with the same monoclonal antibody to TS. In contrast, no immunosuppressive activity was detected with the purified enolase fraction, whereas TS did not show any enolase activity. A suppressive monokine secreted by U937 cells was found to be unrelated with TS. Theses results suggest that the TS immunosuppressive factor despite its absence of enzyme activity, belongs to the enolase family.

The role of the lymphocyte in an immune response

The immune system has evolved in the human being as an elaborate mechanism to distinguish itself from all else that is not self. This process serves in the defence against invaders. The cells of the immune system learn to tolerate all tissues, cells and proteins of the body. Failure to control the state of tolerance results in autoimmunity. The understanding of the role of T-cell receptors (TCR), the Major Histocompatibility Complex (MHC), adhesion molecules and growth factors in antigen recognition has lead to the exploration of various means to modulate the immune response. Safety measures exist to prevent the immune system from attacking its host. The antigen has to be recognized by the T-cell. This involves the TCR and the MHC. In addition it must receive a second signal to become activated. The second signal involves a protein such as B7 binding with CD28. Certain specialized cells, macrophages, dendritic cells and activated B-cells can deliver this second signal for activation; receipt of only one signal can prevent activation. The elucidation of the role of cell-to-cell interactions, the adhesion molecules involved and the accessory growth factors provides modalities for selectively modifying the immune response. This would be of great relevance in autoimmunity and transplantation.

Effect of ranitidine on soluble interleukin 2 receptors and CD8 molecules in surgical patients

The effect of perioperative immunomodulation with the H2-receptor antagonist ranitidine on postoperative changes in soluble interleukin (IL) 2 receptor and soluble CD8 levels was assessed in 24 patients undergoing major elective abdominal surgery. Eleven patients were randomized to receive intravenous ranitidine 100 mg twice daily for 4 days from skin incision, followed by oral ranitidine 150 mg twice daily for a further 5 days; 13 control patients received no ranitidine. Routine blood analysis, clinical data, duration of surgery, anaesthesia, antibiotic prophylaxis and perioperative blood transfusion were similar in the two groups. Serum concentrations of soluble IL-2 receptor and CD8 were measured before operation (day 0) and in the morning of postoperative days 1, 3 and 9 using commercial enzyme-linked immunosorbent assay kits. In patients treated with ranitidine, the serum level of soluble IL-2 receptor increased from day 0 to day 9 (P < 0.01); in control patients it decreased from day 0 to day 1, did not change significantly by day 3 and increased by day 9. The change from day 0 to day 1 was significantly different between the two groups (P < 0.01). Five of the 13 control patients developed postoperative infectious complications. No significant differences were shown in soluble CD8 concentration during the postoperative period. The postoperative change in soluble IL-2 receptor level may reflect lymphocyte activation status; ranitidine appears to promote activation of mainly CD4-positive lymphocytes since serum levels of CD8 were unchanged. Ranitidine may, therefore, improve immune function during major surgery.

Cytokine technology in basic and applied research on the hematopoietic system

Cytokines are polypeptide molecules important for the regulation and maintenance of immunity and hematopoiesis. Their central role in the control of a number of physiological mechanisms makes them an important area of both basic and applied biomedical research. This review presents an overview of basic and applied biology, and introduces the term cytokine technology to denote the use of cytokines as research tools for understanding the cellular and molecular regulation of hematopoiesis. A number of frontier technologies are reviewed, including fusion toxins, fusion proteins, and animal models of cytokine expression and regulation.

Immunodeficiency and the role of suppressor cells after human bone marrow transplantation

Although not totally analogous to a fetus or newborn, the donor-derived immune system attempts to recapitulate immune ontogeny over a 1- to 2-year period. Early after BMT, primitive functions such as cytotoxicity are present in an immunologic environment dominated by suppressive signals. The suppressive signals are so intense that helper cells are inhibited in their ability to function. Teleologically, the suppressive signals may be required for the development of specific tolerance. Full immune reconstitution is accompanied by the development of specific suppressor activity and specific immune functions. Cognitive T cell-T cell and T cell-B cell interactions are dependent upon the finely tuned and orchestrated synthesis of lymphokines, as well as the expression of specific receptors for the lymphokines on target cells. Future studies will elucidate the mechanisms involved in such interactions in lymphocytes from BMT recipients. Understanding the mechanisms involved will permit the development of therapeutic strategies to manipulate immune responses after BMT.

Regulation of human lymphocyte proliferation by a tumour cell-derived DNA fraction

A suppressor activity was isolated and partially purified from culture supernatant of human myeloid leukaemic cell line HL-60 by ion-exchange chromatography, HPLC and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This activity was capable of suppressing proliferation of mitogen-stimulated normal human lymphocytes in a dose-dependent manner. The suppressor activity was identified as DNA by its typical absorbance at 260 nm, and by its susceptibility to DNase digestion. The DNA with suppressive activity was found to be double-stranded with the molecular weight range between 0.6 and 1.5 kb. This DNA material did not have cytotoxic activity and did not alter interleukin-2 receptor expression. Cell cycle analysis has suggested that DNA molecules could interact with lymphocytes to arrest the stimulated lymphocytes in the G1 phase, apparently preventing the cells from entering into the proliferating S phase.