Zeitschrift für Immunitaetsforschung, Experimentelle und Klinische Immunologie最新文献

Spontaneous cell-mediated cytotoxicity (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) against ⁵¹Cr labeled allogeneic target cells of a human melanoma cell line (IGR 3) were determined with purified effector lymphocytes and defibrinated whole blood from 14 melanoma patients and 13 healthy control persons. Peripheral blood lymphocytes were isolated by Ficoll gradient centrifugation (fraction F) ; subsequently the phagocytic and adherent cells were removed and the supernating cell population (fraction FFF) was passaged through IgG anti-IgG columns to obtain a B cell free lymphocyte suspension (fraction FFF-C). Cells from the 3 lymphocyte fractions and from defibrinated whole blood were simultaneously tested for cytotoxic activity against unsensitized IGR 3 target cells (SCMC assay) and IGR 3 cells previously sensitized with a rabbit anti-melanoma IgG (ADCC assay). Dose-response curves were established with all lymphocyte fractions and with whole blood.

The following results were obtained:

• 1.

  With all lymphocyte fractions tested, ADCC was approximately 15 times higher than SCMC, whereas with whole blood, the difference tended to be less pronounced.

• 2.

  Elimination of phagocytic and adherent cells had no significant effect on SCMC and ADCC.

• 3.

  Passage over IgG anti-IgG columns drastically reduced cytotoxicity in both assays without, however, completely abolishing it.

• 4.

  The only difference seen between lymphocyte cytotoxicity of melanoma patients and control persons was a slight, but non-significant depression of SCMC and ADCC in melanoma patients

The results confirm and extend our previous report that SCMC against an allogeneic tumor cell-line is due to non-specific «Null» or «K» cell-activity rather than to specific T cell cytotoxicity. In one experiment freshly explanted melanoma cells were labeled with ⁵¹Cr and reacted with autologous blood and purified lymphocyte fractions. It was found that cellular cytotoxicity depending on serum factors (ADCC) was an effective lytic mechanism, whereas T cell-mediated cytotoxicity could not be demonstrated.

In 32 beagles heterotopic renal allotransplantations and bilateral nephrectomies were carried out. Control animals (5 dogs) survived 9.4 ± 1.6 days. 22 recipients were pretreated with donor-specific semisoluble spleen antigen; 5 recipients pretreated with the antigen alone (780 mg/kg body weight) survived 16.6 ± 2.3 days. A pretreatment with antigen combined with 5 mg/kg body weight Prednisolone resulted in no significant prolongation of survival time (5 animals), but 5 dogs survived significantly longer after pretreatment with the antigen and 50 mg/kg body weight Prednisolone (27.4 ± 2,7 days). In 5 recipients after preoperative application of 3 doses Prednisolone alone (50 mg/kg body weight each) no prolongation of survival time could be observed (10.2 ± 0.7 days). We found no correlation between lymphocytotoxic antibody titre and survival time.

The administration of mycobacterial adjuvant produced a stimulation of the reticuloendothelial system (RES) phagocytic function. The degree of such a stimulation was greater in Lewis than in AVN inbred strain of rats. There was no relationship between the degree of RES stimulation and clinical signs of adjuvant-induced arthritis.

Complexes formed of Cobra venom factor (CVF) and activated factor B ({ie105-1}) by interaction of CVF and B with trypsin or factor {ie105-2} are capable of activating the third and fifth complement component. When incubated with sheep or guinea pig red cells and guinea pig serum in the presence of EDTA, these CVF{ie105-3} complexes produce «indirect lysis». Addition of a human serum factor, earlier designated as factor E (6), greatly enhances the efficiency of this lytic system. The component with this activity has been purified to homogeneity (disc and immunoelectrophoresis). In chromatographic fractionations it was inseparable from the fifth complement component, it was inactivated by and reacted with several anti-C5 antisera, and kinetics of inactivation by heat (56°C) and trypsin were the same for factor E and hemolytic C5 activities. It is concluded that factor E is the fifth component of human complement. Guinea pig C5 is not capable of supporting indirect lysis in a comparable manner, for as yet unknown reasons. Some possible explanations are discussed.

By means of ferritin- and gold-labelled protectin from the albumen gland of the edible snail Helix pomatia the blood group antigen A was located on human erythrocytes of groups A₁, A₂ and A₁B. With erythrocytes of groups 0 and B the reaction is negative. The antigen is focally distributed on the outer surface of the cell membrane. Cells from groups A₁ and A₁B have an antigen A concentration about 4 times greater than A₂ cells. The numbers of particles after tagging with ferritin or gold are comparable. The gold particles show an extremely high contrast and are therefore very suitable for the immunoelectron microscopic localization of antigens.

In the white pulp of rat spleens cell numbers were studied in the different compartments following intravenous administration of comparable doses of paratyphoid vaccine (PTV, thymus-independent) and sheep red blood cells (SRBC, thymus-dependent). In the periarteriolar lymphatic sheaths (PALS) both cell concentration and volume were measured. For the follicles and the marginal zone only volume was recorded in the first 5 days following antigen administration. Additionally, histologic observations were made. In the thymusdependent area PTV caused oedema 12–24 hours after administration. Following SRBC administration an increase in lymphocyte numbers occurred until the second day, probably representing an influx of T cells from the recirculating pool. Both antigens gave rise to a plasmacellular reaction in the peripheral PALS (2^nd-4^th day).

In the bone marrow-dependent areas a massive shift of medium-sized lymphocytes from the marginal zone to the follicles took place in the first 24 hours following PTV administration. These cells subsequently transformed into blasts. After SRBC (6 and 12 hours) only a few marginal zone lymphocytes seemed to migrate into the follicles. It is aruged that the endotoxin present in PTV is responsible for the fact that, following administration of the antigen, all marginal zone (B) cells responded. Endotoxin stimulation might provide a model for the fate of marginal zone cells stimulated by other agents, such as antigen (stimulating antigen binding B cells) or antigen-antibody complexes (stimulating Fc-receptor B cells).

The leucocyte migration test from capillary tubes was examined for its usefulness as an assay for cell-mediated immunity in melanoma patients. Formalin fixed melanoma cells either obtained from established cell lines or freshly excised tumors were used as antigen source. From a group of 33 melanoma patients 14 reacted positively (42 %) when fixed cultured cells were used, whereas, no positive reactions were found in a group of 14 control donors. However, a considerable proportion of patients with chronic inflammatory processes of the skin reacted positively (4/17 = 24%). A smaller proportion of positive reactions were found in melanoma patients when fixed melanoma cells from excised tumors were used. (1 /16 = 6%).

The positive results in the group with chronic inflammatory processes may be explained as reactions against melanoma associated, but not melanoma-specific, antigens.

Three possible reasons are discussed for the low frequency of positive reactions with cells from excised tumors:

• 1.

  the cells used in this study display only a few of the antigenic determinants typical for malignant melanoma,

• 2.

  antigen expression is quantitatively lower,

• 3.

  the surface antigens are covered by blocking factors