7S Antibody Formation Research Articles

Suppressive effect of catecholamines on 19-S antibody formation in mouse spleen fragments in vitro.

Spleen fragments of Balb/C mice were immunized with sheep red blood cells in vitro and hemolytic plaque forming cells (PFC) were assayed on the 5th day of immunization. Epinephrine in culture medium diminished the number of PFC dose-dependently over the range from 10(-6) M to 2.7 X 10(-4) M. Incubation with 9 X 10(-5) M epinephrine diminished PFC response only when the epinephrine was present on the first day of the culture. No suppression was found for treatment during any other 24-hr periods. Three beta-adrenergic stimulating catecholamines, epinephrine, isoproterenol, and norepinephrine, suppressed PFC response in similar degree. It is concluded that beta-adrenergic stimulation suppressed 19-S antibody formation mainly by inhibiting induction of immune response.

Stimulatory Effect of 5-Azacytidine on 7S Antibody Production in Rats

Summary5-Azacytidine administered to rats simultaneously with immunization by sheep red blood cells results in the stimulation of 7S antibody formation while its administration 48 hr after immunization causes a marked depression of their synthesis. The response of 7S antibody level to 5-azacytidine depends on the time interval of drug administration while the intensity of the effect is proportional to the dose level of analogue.

RES blockade: effects on immunity and tolerance.

Reticuloendothelial cell blockade has been studied for decades in regards to physiological and immunological effects. "Overloading" of RE cells with inert colloidal particles, such as carbon or other particulate substances, has often been used to analyze the role of phagocytic activities in antibody formation, often with contrasting results. In the present studies the effects of colloidal carbon treatment of mice on immunologic responsiveness to sheep erythrocytes was investigated. Pre-treatment of mice with carbon shortly before either primary or secondary immunization with SRBCs markedly suppressed the expected antibody response, as shown by depressed numbers of hemolytic antibody plaque forming cells. Carbon treatment did not affect antibody forming cells per se as shown by lack of an effect on plaque forming cells when carbon was given after SRBCs, either in vivo or in vitro. Carbon injection before primary immunization prevented development of "immunologic memory," as shown by an altered secondary immune response. Mice given carbon and SRBC several weeks before secondary immunization with RBCs developed a primary type antibody response characterized by appearance of 19S antibody with little or no 7S hemolysins, characteristic of a secondary response. Furthermore, by appropriate treatment of mice with carbon and SRBC, immunologic unresponsiveness to SRBCs could also be induced, as evident by absence of both 19S and 7S antibody formation after subsequent challenge immunization with sheep erythrocytes. The mechanisms involved in RE "blockade" induced aberrations of normal immune responses may be related to effects on macrophages or soluble humoral factors, or both. It is unlikely that carbon treatment affects immunocytes directly. Further studies concerning the nature and mechanism of RE blockade on cellular and humoral components of the immune response mechanisms seem warranted and should provide more insight concerning the role of macrophages in antibody formation.

Class, Amounts and Affinities of Anti-Dinitrophenyl Antibodies in Chickens

Abstract Repeated intravenous injections of maximally coupled dinitrophenylated bovine γ-globulin elicited both 7S and 17S anti-dinitrophenyl antibodies in chickens. Only antibodies of low affinity were produced regardless of the priming dose, the interval between injections, and the number of injections. The 7S and 17S antibodies isolated from individual animals had identical affinities and heterogeneity indices. The concentrations of antibodies formed were uniformly low despite many injections over a prolonged period. These studies indicate that stimulation by antigen alone may not be sufficient for the induction of predominant 7S antibody formation and for the synthesis of high affinity antibody.

Thymus Influence on the Conversion of 19S to 7S Antibody Formation in the Response to TNP-Brucella

Serially transferred LAF spleen cells show a deficient 7S PFC response to TNP-Brucella when Tx as compared to normal irradiated intermediate hosts are used. This defect can be corrected by combining the spleen cells with lymph node cells from the Tx intermediate hosts. It is concluded that T helper cells, residing primarily in lymph node, are needed for efficient 19S leads to 7S conversion in the immune response.

Functional and morphological heterogeneity among rabbit peritoneal macrophages

Peritoneal exudate cells obtained from rabbits injected intraperitoneally with mineral oil were separated into several subpopulations by equilibrium density centrifugation on continuous or discontinuous bovine serum albumin gradients. On discontinuous gradients of 5, 8, 11, 15, 20, and 30% bovine serum albumin and, with appropriate attention to technical details, highly reproducible separation of the cells into 5 subpopulations was attained. Cells in bands B, C, and D, which accumulated at the 8 11% , 11 15% , and 15 20% interfaces, respectively, were mainly macrophages, and these cells were tested for endocytic activity for several antigens or particles (ferritin, T2 phage, E. coli, latex beads), and for the ability to produce immunogenic RNA after in vitro incubation with T2 phage. Band D cells showed high endocytic activity but failed to produce immunogenic RNA, whereas band B (15% of recovered cells) cells displayed low endocytic activity but produced immunogenic RNA that gave rise to both 7S and 19S antibodies when incubated with spleen cell cultures. Phase and electron microscopy studies revealed the presence of two morphological cell types in bands B and C. In addition to the typical macrophage, there was a second cell type with a centrally located round or oval nucleus, disperse chromatin, prominent nucleoli, and light staining cytoplasm containing polysomes, dilated lakes of granulated endoplasmic reticulum, densely staining mitochondria, and lacking a ruffled membrane. This glass-adherent cell, which neither meets the morphological criteria for macrophages or lymphocyte, will be referred to as cell “A”. Partial separation of typical macrophages from “A” cells was achieved by recentrifugation of band B cells on a discontinuous gradient of 8, 9, 11, and 30% bovine serum albumin. Band B I ( 8% 9% ), enriched in “A” cells (40%), yielded immunogenic RNA which gave rise to 19S antibody whereas band B II ( 9% 11% ), consisting of about 10% “A”, was responsible for 7S antibody formation.

Influence of parental lymphoid cells on the production of 19S and 7S antibodies in F1 hybrid mice.

Parental spleen cells injected into F1 hybrid mice stimulated the 7S and, to a lesser degree, 19S primary antibody response to thymus-dependent and -independent antigens. The stimulatory effect on 7S antibody formation as compared to mice, injected with syngeneic spleen cells, was exerted by parental spleen cells injected after, as well as prior to antigenic stimulation. Large amounts of parental spleen cells inhibited the antibody response in comparison to the response obtained after injection of syngeneic cells. Allogeneic cells augmented the 7S and 19S antibody response to very small amounts of antigen. The effect of parental cells on host antibody formation could be abolished by treating the cells with anti-Thy 1 serum and complement which confirms that the stimulatory effect was mediated by T cells. The results indicate that 7S antibody formation is more dependent on non-antigen-specific influences from T cells than is 19S antibody production and are compatible with the hypothesis that activated T cells release substances which stimulate or inhibit antibody formation. These substances do not appear to be responsible for the immunologically specific ‘thymic helper’ effect.

The kinetics of plaque-forming cells in experimental hypersplenism.

By i.p. application of methylcellulose (MC) hypersplenism has been induced in C57B1 mice. Decrease of red blood cells (RBC) and increase of reticulocytes and spleen index resemble the hemolytic anemia in man. No antibody formation against RBC of treated animals could be found. After sensitisation with sheep red blood cells a significantly impaired 19S- and 7S-antibody formation in single spleen cells could be demonstrated. These findings suggest an inhibition of macrophages by the uptake of MC

The effect of antigenic competition on various manifestations of humoral antibody formation and cellular immunity.

The effect of antigenic competition on various parameters of humoral antibody formation and cellular immunity was studied in mice. Several pairs of antigens were employed in the investigation of the competitive aspects of induction of humoral antibody formation. Induction of a primary immune response to hemocyanin in Swiss white female mice moderately suppressed the induction of both 19S and 7S antibody formation to goose or rat erythrocytes. Suppression of 7S antibody formation was maximal when a time interval of 1-3 days separated the sequence of injections, although suppression was noted for intervals of up to 14 days. The induction of a primary immune response to rat RBC, the second of the two antigens in sequence, also suppressed The induction of both 19S and 7S antibody formation to goose RBC when appropriate intervals of 1-3 days were employed between injections. The induction of a secondary immune response to rat RBC totally suppressed the primary induction of both 19S and 7S antibody formation to goose RBC administered in the appropriate time sequence. Subsequently, it was shown that the secondary immune response to the suppressed antigen (goose RBC) elicited 30 days after induction of a primary immune response (5 days after secondary immunization with rat RBC) was characterized by deficient 19S and 7S antibody production. These levels were suppressed even in comparison with a normal primary immune response to this antigen. The results were interpreted in part on the basis of a deficiency of formation of primed cells associated with immunological memory. Alternatively, evidence was obtained for the development of a split type of immunological tolerance in 6 of 10 animals studied, since a total suppression of 7S antibody production was obtained in association with deficient 19S antibody synthesis (titers < 1/10). The induction of a primary immune response to several antigens in A/J female mice suppressed the processes of cellular immunity as manifested by prolonged survival of skin grafts from C57 BL/6J female donors. These results were interpreted as evidence for the existence and utilization of processing cells by the initial immune stimulus yielding a deficiency of cells available for processing the second antigen administered in sequence.

The immune response to sheep erythrocytes in the mouse. I. A study of the immunological events utilizing the plaque technique.

The direct and indirect plaque technique for the detection of antibody-forming cells against sheep erythrocytes was utilized for the investigation of a number of biological parameters of the primary and secondary immune response on a cellular level. The sequential pattern of 19S followed by 7S antibody formation was elicited in the primary response after a latent period of at least 1-2 days and 2-3 days respectively. The secondary response initiated 140 days after primary immunization, in contrast, was characterized by the simultaneous appearance of 19S and 7S antibody-forming cells after an observed latent period of 2-3 days. The cellular dynamics of the recruitment phase of the respective immunoglobulins in the primary and secondary response was interpreted as evidence for the derivation of the two classes of immunoglobulins from separate progenitors. The 19S antibody-forming cells were derived predominantly by a process of transformation and maturation and 7S antibody formers by a process of cellular division with a doubling time of about 12 hr. The draining lymph node exhibited maximal immunological reactivity due to its capacity to retain the particulate antigen. This capacity was considerably enhanced in the sensitized draining lymph node. Minimal cellular activity was also noted in distal lymphoid tissues which included the thymus. Focal cellular activity was observed in the draining lymph node for 60 days after immunization. Subsequently, very low level plaque-forming cellular activity was observed in association with persistence of maximal antibody activity. The appearance at 120 days of a generalized peak of cellular activity in lymphoid tissues throughout the host was considered an explanation for this discrepancy. The change in distribution of cellular antibody-forming activity, from a local to a generalized lymphatic response during the late phase of the immune response, implied a fundamental alteration in homeostatic mechanisms associated with maintenance of immune reactivity. Further manifestations of such an alteration were indicated by the appearance of 2-ME-sensitive 7S antibody nearly 3 months after primary intradermal immunization, which in the ensuing 5 months was associated with, and inversely related to, two major fluctuations in 2-ME-resistant 7S antibody. Evidence for the existence of immunological memory in the 19S system was not established in the present work. 19S anamnesis, for which evidence was derived from measurements of circulating antibody levels, was interpreted from cellular studies as the result of the substantial activity of previously uncommitted 19S lymphoid cells in distal lymphoid tissue associated with previously committed 19S cells contained in the draining lymph node.

Suppression of measles 19S antibody formation as evidence of immunity: Primary response masked by maternal antibody

Suppression of measles 19S antibody formation as evidence of immunity: Primary response masked by maternal antibody

EFFECT OF 6-MERCAPTOPURINE (6-MP) ON DIFFERENT CLASSES OF ANTIBODY.

In the primary response of mice and rabbits immunized with foreign red cells, 6-MP administration prolonged the formation of 19S antibody. 7S antibody formation was delayed and reduced in these animals. Animals treated with 6-MP during primary response exhibited a preferential 19S response when challenged in the anamnestic response. Animals immunized with small doses of antigen and treated with 6-MP only during the secondary response, reversed the usual antibody pattern and responded with preferential 19S antibody formation.

SUPPRESSION OF MEASLES 19S ANTIBODY FORMATION AS EVIDENCE OF IMMUNITY. PRIMARY IMMUNE RESPONSE MASKED BY MATERIAL ANTIBODY.

Secondary immune responses to measles virus are characterized by a rise in 7S measles antibodies with little or no 19S antibody production. Sera collected a month after challenge with live measles vaccine of 9-month-old infants who had received inactivated measles vaccine before they were 7 months of age revealed 19S antibodies in 50% of postchallenge sera tested. Suppression of 19S antibody formation in the other 50% was well correlated with resistance to the clinical effects of measles and provided a more sensitive measure of immunization during the maternal antibody period than seroconversion or incidence of clinical reactions to challenge.

ANTIBODY FORMATION IN VITRO BY SEPARATED SPLEEN CELLS: INHIBITION BY ACTINOMYCIN OR CHLORAMPHENICOL.

The formation of 19S antibody to poliovirus by rabbit spleen cells in vitro was interrupted by adding actinomycin D (1 to 10 micrograms per milliliter) for 30 minutes or longer. Shorter treatment (5 to 15 minutes) caused partial suppression. Antibody formation was slowly renewed upon removal of the drug. These results suggest that 19S antibody formation is contingent upon DNA-dependent RNA synthesis and that the genetic messenger has an average lifetime of one-half day or less. Treatment with chloramphenicol (20 to 50 micrograms per milliliter) for 3 days caused the cessation of 19S antibody formation.

ANTIGENS IN IMMUNITY

SummaryAn investigation of the immunogenicity of three flagellar preparations, namely, intact flagella, polymerized flagellin and the soluble, low molecular weight protein flagellin, was performed in rats. Despite the similarity of in vitro serological behaviour of these three antigens, important differences in their in vivo immunological effectiveness were noted. While flagella and polymerized flagellin caused first 19S antibody formation and later prolonged 7S antibody formation, flagellin appeared to be quite incapable of inducing a 19S primary response. Further, the peak titres achieved with Hagellin were lower than those with the other antigens. Polymerized flagellin was somewhat less immunogenic than were flageila.The study covered a dosage range of 10 logs.10, i.e., from 10–12 g. to 10–2 g. Clear‐cut dose‐response relationships could be observed for the shortlived 19S response caused by flagella or polymerized flagellin, over the dose range 10 ng. (0·01 μg.) to 10 μg. For the 7S response, particularly with flagellin, dose‐response relationships were not established. Remarkably small doses, namely, 100 ng. (0·1 μg.) of flagella, 1 μg. of polymerized flagellin and 10 μg. (0·01 μg.) of flagellin caused peak 7S titres to appear. Doses as small as 100 pg. (0·0001 μg.) occasionally caused antibody production.Doses of antigen too small to cause a detectable 19S response were followed by a lag period of about two weeks during which serum antibody levels remained below the threshold of our test. Then antibody litres rose steadily until six or eight weeks after injection, Peak levels were maintained for over six weeks, and fell slowly. At 34 weeks, when the experiments were stopped, antibody litres were still quite high, The lag period with doses which caused 19S antibody production was much shorter, generally less than four days. In such animals, 19S antibody was gradually replaced by 7S antibody during the second week, and again it took several weeks for peak 7S litres to be leached.These results emphasized the need to use small doses in any meaningful study of antigen distribution, localization, behaviour and fate.

THE FORMATION AND PROPERTIES OF POLIOVIRUS-NEUTRALIZING ANTIBODY. I. 19S AND 7S ANTIBODY FORMATION: DIFFERENCES IN KINETICS AND ANTIGEN DOSE REQUIREMENT FOR INDUCTION.

Rapid formation of poliovirus-neutralizing antibody was observed in the rabbit. 19S type antibody was detectable 8 to 12 hours following a single intravenous virus injection and the induction period was of the order of 4 to 5 hours or less. The production of 7S antibody had a longer lag phase (1(1/2) to 2 days) and it was formed at slower rate. The observed rate of early 19S and 7S antibody formation as well as the peak titers of the two antibodies were antigen dose dependent. Normal rabbit sera showed low neutralizing activity to several viral antigens in a sensitive assay system. Following intravenous inoculation of poliovirus either transitory ( 1 month) or enduring ((3/4) to 1(1/2) year) antibody formation resulted depending upon the dose of antigen employed. In transitory responses, which could be induced by a single small antigen dose, only 19S antibody was demonstrable and there was an abrupt cessation of antibody synthesis on day 4 or 5. In enduring responses, both 19S and 7S antibody were formed and the minimum antigen dose required for initiation of such a response was equal to the dose needed for induction of 7S antibody formation. Thus, enduring antibody formation was an all-or-none phenomenon depending upon whether or not 7S antibody formation was induced. The antigen dose requirement for induction of 7S antibody was much higher (by 50-fold or more) than that for 19S antibody. This allowed a determination of antigen dose regions, within which predictably transitory (19S) or enduring (19S + 7S) antibody formation was obtained. These pronounced differences in antigen dose requirement for induction and kinetics of formation of 19S and 7S antibody suggest that the same cells do not participate in the formation of the two antibodies.

THE FORMATION AND PROPERTIES OF POLIOVIRUS-NEUTRALIZING ANTIBODY. II. 19S AND 7S ANTIBODY FORMATION: DIFFERENCES IN ANTIGEN DOSE REQUIREMENT FOR SUSTAINED SYNTHESIS, ANAMNESIS, AND SENSITIVITY TO X-IRRADIATION.

Transient 19S antibody formation was induced in rabbits by single or repeated stimuli with a small dose of poliovirus. Available evidence indicated that cessation of 19S synthesis was due to lack of continuous antigenic stimulation and not to loss of cells participating in antibody formation. "Immunological memory" in 19S antibody formation was demonstrable only within 2 to 3 days following discontinuation of synthesis but not thereafter. Following stimulation with a high dose of polio-virus both 19S and 7S antibodies were formed. The kinetics of their formation differed in several respects: (a) 19S antibody preceded 7S antibody by 1(1/2) days; (b) 19S antibody rose to peak titers at a rapid exponential rate within 1 week, while 7S antibody increased at a slow decelerating rate for 3 weeks; (c) 19S antibody formation was short-lasting while 7S antibody synthesis endured. A renewed formation of both antibodies occurred following restimulation with a high antigen dose. The secondary 19S and 7S antibody responses were similar to the respective primary responses, and the preexistence of 7S antibody synthesis did not detectably alter the secondary 19S response. Both 19S and 7S antibodies were formed and the kinetics of their formation was similar (a) for infectious and non-infectious (UV-) poliovirus antigen; (b) for the serologically unrelated poliovirus and Coxsackie B-4 virus; (c) when poliovirus was administered by different routes; (d) when 1-day-old or adult rabbits were immunized; (e) in antibody responses to poliovirus in rabbit, guinea pig, and man. Whole body x-irradiation 20 hours prior to antigenic stimulus (high dose) resulted in delayed but markedly prolonged 19S antibody formation and inhibition of 7S antibody synthesis. Thus, the formation of 19S and 7S antibody differed in (a) antigen dose requirements for induction and maintained synthesis; (b) kinetics; (c) retention of memory; and (d) sensitivity to prior x-irradiation. These differences are best explained on the assumption that the two antibodies are produced by different cells.