Immunoglobulin synthesis by cultured lymphocytes from spleen and mesenteric lymph nodes after thermal injury.

A 30% burn injury has been previously reported to impair mitogenic response of splenocytes to a B-lymphocyte mitogen and to affect serum levels of serum class-specific immunoglobulin. To further investigate the effect of burn injury on the function of B lymphocytes in gut-associated and systemic immune tissues, we studied class-specific immunoglobulin synthesis by cultured lymphocytes from spleen and mesenteric lymph nodes after burn injury in rats. Male Lewis rats received 30% full-thickness burn injuries, and 4 days later, the animals were killed to remove spleen and mesenteric lymph nodes. The cells from spleen and mesenteric lymph nodes were cultured for 5 days with 25 micrograms/ml of lipopolysaccharide. Concentrations of immunoglobulin G (IgG), IgM, and IgA in the supernatant of each well were then measured with enzyme-linked immunosorbent assay for class-specific immunoglobulin. Synthesis of IgG by lymphocytes from spleen was statistically significantly impaired by burn injury (p less than 0.05), but synthesis of IgG by lymphocytes from mesenteric lymph nodes was not affected. There were no significant differences in IgM and IgA synthesis by lymphocytes from spleen between burned animals and controls. The immunoglobulin synthesis in mesenteric lymph nodes did not differ significantly in burned animals compared with controls. The impaired IgG synthesis by lymphocytes from spleen may contribute to increased risk of infection after burn injury.     

THE PRODUCTION OF THYROIDITIS AND ANTIBODY FOLLOWING INJECTION OF UNALTERED THYROGLOBULIN WITHOUT ADJUVANT INTO RABBITS PREVIOUSLY STIMULATED WITH ALTERED THYROGLOBULIN

Injection of rabbits with arsanil-sulfanil-thyroglobulin without adjuvant resulted in the production of hemagglutinating and precipitating antibody to native thyroglobulin and thyroiditis. Following a latent period of 1 month, these same rabbits responded to an injection of native thyroglobulin with an increase in both circulating antibody to native thyroglobulin and severity and frequency of thyroid lesions. Some rabbits initially immunized with arsanil-sulfanil-thyroglobulin also responded to a second and third monthly injection of native thyroglobulin, but the response to the third injection was usually not as good as the response to the first injection. A few of the rabbits showed a transient production of 19S antibody after the injection of native thyroglobulin was initiated. Neither circulating antibody nor thyroiditis were ever observed in rabbits injected with only native thyroglobulin without adjuvant. The correlation of the thyroiditis with the presence or absence of circulating antibody was discussed. Following a latent period after injections of aqueous arsanil-sulfanil-thyroglobulin some rabbits made a response to their own thyroglobulin released from an autotransplant of thyroid tissue.     

THE ROLE OF MYCOBACTERIA AND THE EFFECT OF PROTEOLYTIC DEGRADATION OF THYROGLOBULIN ON THE PRODUCTION OF AUTOIMMUNE THYROIDITIS

Data are presented which suggest that the initial event involved in experimental autoimmune thyroiditis following injection of rabbits with homologous thyroglobulin in complete Freund's adjuvant is alteration of the thyroglobulin. Alteration of the thyroglobulin does not occur during incorporation into the adjuvant or in vitro storage in the adjuvant, and the mycobacteria in the adjuvant have no direct effect on the thyroglobulin. Most likely, the alteration results from an increase in hydrogen ion concentration within cells or local areas in the granuloma and the subsequent action of proteolytic enzymes. These conditions are probably established in the granuloma as the result of neutrophilic response to the mycobacteria in the adjuvant. Rabbits injected with aqueous preparations of homologous thyroglobulin partially degraded in vitro with pepsin at acid pH produced antibody to native thyroglobulin and developed thyroiditis. Most of these rabbits responded to a subsequent injection of native thyroglobulin given 1 month later.     

Effect of HLA-DR positive thyrocytes on in vitro thyroid autoantibody production

The function of HLA-DR positive thyrocytes on thyroid autoantibody production has been examined to test the hypothesis that such HLA-DR positive thyrocytes may initiate or aggravate autoimmune thyroid disease. Thyrocytes were cultured (precultured) with leucoagglutinin (which stimulated thyrocyte expression of HLA-DR, beta 2-microglobulin (beta 2-m) and thyroid microsomal antigens) and then cocultured with peripheral blood mononuclear cells. Thyroid antibody production by the latter was then measured. There was no evidence of induction or enhancement of thyroid-microsomal and thyroglobulin autoantibody production in supernatants from the cocultures of autologous peripheral blood mononuclear cells and HLA-DR positive thyrocytes from normal controls and patients with Graves' disease. Furthermore, stimulation of B lymphocytes from patients with autoimmune thyroid disease with a combination of Staphylococcus aureus Cowan I plus supernatants from autologous cocultures of peripheral blood mononuclear cells and HLA-DR positive thyrocytes from normal controls and Graves' disease, produced significantly less microsomal antibody and thyroglobulin antibody than similar cocultures with HLA-DR negative thyrocytes, although total immunoglobulin G (IgG) was similar in both groups. The effect of supernatants from allogeneic cocultures on microsomal antibody thyroglobulin antibody and total IgG production was no different between HLA-DR positive and HLA-DR negative thyrocytes. These data suggest that HLA-DR positive thyrocytes may have a protective role against thyroid autoimmunity rather than a pathogenic role for it.     

经阴道超声在盆腔肿瘤髂内淋巴转移诊断中的价值

目的探讨经阴道超声在盆腔肿瘤髂内淋巴结转移诊断中的应用价值。方法选择将接受广泛性子宫切除和盆腔淋巴清扫术治疗的盆腔肿瘤患者42例,术前采用经阴道超声检查髂内淋巴结情况,记录所发现淋巴结数量和大小,术中对切除髂内区组织内的淋巴结进行分离并测量记录送病理检查,与术前超声结果进行对照分析。结果 42例患者中,39例患者髂内淋巴超声检查结果与手术病理相符,准确率为92.8%(39/42),漏诊2例,误诊1例,其中11例患者存在髂内淋巴结转移,超声准确诊断9例;无转移患者31例,超声准确诊断30例。结论经阴道超声可有效诊断盆腔肿瘤髂内淋巴结转移,对肿瘤临床分期和治疗方案的选择有一定应用价值。     

RESISTANCE OF LONG-LIVED LYMPHOCYTES AND PLASMA CELLS IN RAT LYMPH NODES TO TREATMENT WITH PREDNISONE, CYCLOPHOSPHAMIDE, 6-MERCAPTOPURINE, AND ACTINOMYCIN D

The cells of the popliteal lymph nodes of rats were labeled for 4 days after a secondary immunological stimulus. 31 days after the last dose of tritiated thymidine, groups of rats were started on courses of daily, intraperitoneal injections of prednisone, cyclophosphamide, 6-mercaptopurine, or actinomycin D. The initially low doses of these agents were doubled in successive weeks until either lymphoid hypoplasia or death occurred. Rats from each group were killed weekly, and the percentages of persisting, labeled small lymphocytes in the popliteal nodes were determined. Sections of these nodes were examined for persisting, labeled plasma cells. The per cent of lymphocytes labeled increased while the total number of lymphocytes decreased during treatment with prednisone and cyclophosphamide. Prednisone decreased the numbers of long-lived plasma cells, but these cells were preferentially resistant to cyclophosphamide. Neither 6-mercaptopurine nor actinomycin D had an appreciable effect on lymphoid tissues histologically nor on the proportions of labeled, long-lived lymphocytes and plasma cells before causing the deaths of the rats receiving them. These results indicate that long-lived lymphocytes and plasma cells survive treatment with the immunolytic drugs studied, and that long-lived lymphocytes are specifically resistant to prednisone and cyclophosphamide. We believe these results have an application to the attempts to find drugs useful in the treatment of immunologic rejections of organ transplants, and for therapy of autoimmune diseases.     

宫颈癌转移性淋巴结MRI影像学特征

目的探讨MRI检出宫颈癌转移淋巴结大小及盆腔内分布特点。方法54例宫颈癌患者,采用PACS记录MRI检出淋巴结的影像特点,分析MRI检出宫颈癌淋巴结转移的敏感性、特异性。结果MRI检出宫颈癌淋巴结中闭孔区淋巴结检出率最高,左侧为88％,右侧为90％;髂内区淋巴结检出率次之,左侧为85％,右侧为88％;腹股沟深区淋巴结检出率左侧为79％,右侧为77％;髂外区淋巴结检出率左侧为45％,右侧为43％;髂总区淋巴结检出率左侧为31％,右侧为17％;转移组中5～10mm淋巴结占检出总数的51．2％;ROC曲线示以淋巴结直径判断检出淋巴结是否转移,取8mm时敏感性为49．5％,特异性为69．6％,AUC为0．669。结论MRI检出宫颈癌淋巴结主要分布在闭孔区及髂内区,腹股沟深区及髂外区次之;淋巴结直径不能判断转移与否。     

Analysis of T-cell receptor V beta gene repertoires after immune stimulation and in malignancy by use of padlock probes and microarrays

BACKGROUND: Detection of expanded T-cell clones, identified by their receptor (TCR) repertoires, can assist diagnosis and guide therapy in infectious, inflammatory, and autoimmune conditions as well as in tumor immunotherapy. Analysis of tumor-infiltrating lymphocytes often reveals preferential use of one or a few TCR V beta genes, compared with peripheral blood, indicative of a clonal response against tumor antigens. METHODS: To simultaneously measure the relative expression of all V beta gene families, we combined highly specific and sensitive oligonucleotide reagents, called padlock probes, with a microarray read-out format. T-Cell cDNA was combined with a pool of V beta subfamily-specific padlock probes. Reacted probes were selectively amplified and the products hybridized to a microarray, from which the V beta subfamily distribution in each sample could be determined relative to a control sample. RESULTS: In lymphocytes stimulated with the superantigen staphylococcal enterotoxin B, we detected expansions at the mRNA level of TCR subfamilies previously shown to respond to staphylococcal enterotoxin B. Expansions of the same V beta families could also be detected by flow cytometry. In samples from two bladder cancer patients, we detected predominant representations of specific V beta subfamilies in both tumor-infiltrating lymphocytes and in the draining lymph nodes, but not in non-tumor-draining lymph nodes or peripheral blood. Several expression profiles from draining lymph nodes in patients with malignant melanoma were divergent from profiles seen in non-tumor-draining lymph nodes. CONCLUSION: Padlock probe-based parallel analysis of TCR V beta gene distributions provides an efficient method for screening multiple samples for T-cell clonal expansions with reduced labor and time of analysis compared with traditional methods.     

Studies on the immunological response to foreign tumor transplants in the mouse. II. The relation between hemagglutinating antibody and graft resistance in the normal mouse and mice pretreated with tissue preparations

The relation between serum antibody and resistance to tumor homografts in the mouse has been investigated. Production of serum antibody in response to homografts of a transplantable sarcoma (Sarcoma 1) was demonstrated, by cytotoxic action on the cells of the tumor, and also by a hemagglutinin test. The simpler and more repeatable hemagglutinin test was further investigated. Peak hemagglutinin titres were reached after the immunizing homografts underwent breakdown. Following transfer of lymph node cells from immunized mice into hosts of the same strain, hemagglutinin could be detected in the host serum. The course of its production showed that this secondary antibody was not elicited by transferred antigen, nor could it be due to transfer of preformed antibody. The cells developed the capacity to transfer hemagglutinin production later than the power to transfer heightened graft resistance. Spleen cells also transferred hemagglutinin production, at a later stage after immunization and to a lesser extent than cells from the regional lymph nodes. Implantation of the sarcoma in mice pretreated with certain preparations of lyophilized or frozen tissue stimulated hemagglutinin production, although the tumor grew progressively. The regional lymph nodes participated in the response: they could transfer hemagglutinin production into secondary hosts, but not graft resistance, and indeed appeared to diminish resistance. Lymph node cells from immunized donors conferred protection against the tumor on pretreated mice. Lymph nodes from normal donors also appeared in some experiments to confer protection although the effect was obscured by the rapidity with which the growing tumor became immunologically invulnerable. The fate of lymph node cells stained with acriflavine was followed after transfer. No effect of the staining on the power of the cells to confer immunity could be detected. Cells transferred to the peritoneal cavity passed into various host tissues, but were not found in test homografts. The conclusion is drawn that the hemagglutinating antibody is distinct from the antibody effective in combating homografts. The similarity in this respect between the homograft reaction and sensitization is emphasized in discussion.     

CELLS INVOLVED IN THE IMMUNE RESPONSE : IV. THE RESPONSE OF NORMAL AND IMMUNE RABBIT BONE MARROW AND LYMPHOID TISSUE LYMPHOCYTES TO ANTIGENS IN VITRO

Cell suspensions of immune rabbit lymph nodes and spleen were capable of undergoing blastogenesis and mitosis and of incorporating tritiated thymidine when maintained in culture with the specific antigen in vitro. They did not respond to other, non-cross-reacting antigens. The blastogenic response obtained with immune lymph node cells could be correlated with the antibody synthesizing capacity of fragment cultures prepared from the same lymph nodes. Cell suspensions of immune bone marrow responded to non-cross-reacting antigens only whereas cell suspensions of immune thymus, sacculus rotundus, and appendix did not respond when exposed to any of the antigens tested. On the other hand, neither fragments nor cell suspensions prepared from lymph nodes, spleen, and thymus of normal, unimmunized rabbits responded with antibody formation and blastogenesis when exposed to any of the antigens. However, normal bone marrow cells responded with marked blastogenesis and tritiated thymidine uptake. The specificity of this in vitro bone marrow response was demonstrated by the fact that the injection of a protein antigen in vivo resulted in the loss of reactivity by the marrow cell to that particular antigen but not to the other, non-cross-reacting antigens. Furthermore, bone marrow cells of tolerant rabbits failed to respond to the specific antigen in vitro. It was also demonstrated that normal bone marrow cells incubated with antigen are capable of forming antibody which could be detected by the fluorescent antibody technique. This response of the bone marrow cells has been localized to the lymphocyte-rich fraction of the bone marrow. It is concluded that the bone marrow lymphocyte, by virtue of its capacity to react with blastogenesis and mitosis and with antibody formation upon initial exposure to the antigen, a capacity not possessed by lymphocytes of the other lymphoid organs, has a preeminent role in the sequence of cellular events culminating in antibody formation.     

THE EFFECT OF NEURAMINIDASE ON THE FATE OF TRANSFUSED LYMPHOCYTES

Evidence has been obtained that incubation of rat lymphocytes with neuraminidase, prior to intravenous transfusion into allogeneic or syngeneic recipients, alters the distribution of the cells. Many enzyme-treated lymphocytes initially become trapped in the liver, and there is a decrease in the selective accumulation of these cells in the lymph nodes and spleen. Subsequently, many enzyme-altered cells emigrate from the liver, concentrate in lymph nodes, and recirculate to the lymph. The results suggest that sialic acid constituents of the lymphocyte surface play a critical role in ensuring the normal distribution of these cells in the body. The findings also imply that reactions involving surface sialic acid can markedly alter the fate of lymphocytes without "killing" the cells.     

THE PROLIFERATIVE AND ANAMNESTIC ANTIBODY RESPONSE OF RABBIT LYMPHOID CELLS IN VITRO : I. IMMUNOLOGICAL MEMORY IN THE LYMPH NODES DRAINING AND CONTRALATERAL TO THE SITE OF A PRIMARY ANTIGEN INJECTION

Popliteal lymph nodes were obtained from rabbits 4 days to 9 months after a primary injection of diphtheria toxoid or bovine γ-globulin into the footpad. The ability of cells from these nodes to proliferate upon reexposure to antigen in vitro was compared to the height of the secondary response produced by tissue fragments. In addition, a comparison was made between the responsiveness of draining and contralateral lymph nodes. While the secondary antibody response in vitro increased markedly with the time after immunization at which the lymph nodes were taken from the animals, the degree of proliferation induced by antigen was highest with cells from lymph nodes taken early after priming (peak day 7) and was very much lower with lymph node cells taken longer than 3 wk after priming. This striking difference between these two responses has been discussed. Contralateral lymph nodes were much inferior to draining nodes in their ability to give a secondary antibody response in vitro, and never gave a detectable proliferative response. This difference became less marked with time after priming, but could still be demonstrated after 4 months. These results suggest a concentration of primed cells in the lymphoid tissue draining the site of injection, and a slow release of these cells into the circulation, to be distributed to the remaining lymphoid tissue.     

CELLULAR EVENTS DURING THE INDUCTION OF EXPERIMENTAL THYROIDITIS IN THE RABBIT

With a modification of the Jerne plaque technique to enumerate plaque-forming cells (PFC) to bovine and rabbit thyroglobulin, the cellular kinetics of the antibody response were followed during two 5-day series of injections of an aqueous preparation of bovine thyroglobulin. The results support the suggestion that thyroiditis in the rabbit is mediated by antibody. The peak PFC appear in the spleen at the end of the second series of injections and are considerably greater for bovine than for rabbit thyroglobulin. PFC also appear in the thyroid gland; however, the numbers of PFC for bovine and rabbit thyroglobulin were similar, and they did not reach a peak until 7 days after the peak PFC in the spleen. There was an excellent correlation between the appearance of PFC in the thyroid gland and the appearance of thyroid lesions. The disappearance of antibody to rabbit thyroglobulin from the serum also correlated with the appearance of lesions. Migration inhibition factor (MIF) activity was not produced at any time throughout the study when rabbit thyroglobulin was added to peritoneal exudates of immunized rabbits containing circulating antibody to rabbit thyroglobulin. MIF activity was observed when bovine thyroglobulin was added to similar cells in the later stages of the study after lesions were present.     

STUDIES ON ANTIBODY PRODUCTION : IX. THE CELLULAR LOCALIZATION OF ANTIGEN MOLECULES (FERRITIN) IN THE SECONDARY RESPONSE

The physical presence of the antigen used to stimulate a secondary antibody response was demonstrated in the cells of popliteal lymph nodes. Rabbits previously injected with apoferritin (containing no iron), which was prepared from recrystallized horse ferritin, were given an injection of ferritin 5 weeks later. The antigen was traced by means of the Prussian blue reaction, by specific fluorescent antibody, and by electron microscopy. Antiferritin antibody was localized by immunofluorescence, though it was not possible to test cells simultaneously for antigen and antibody. Horse ferritin induces a rather weak primary antibody response, but a brisk secondary response characterized by the appearance in the medullary cords of numerous plasma cells containing antiferritin. Many intact ferritin molecules were found in the nucleus and cytoplasm of numerous reticular and other phagocytic cells in the sinuses. In decreasing amount, ferritin molecules were also clearly demonstrated in hemacytoblasts (plasmoblasts), and immature and mature plasmocytes.     

THE FORMATION OF ANTIBODIES IN THE POPLITEAL LYMPH NODE IN RABBITS

Typhoid vaccine and sheep erythrocytes were injected subcutaneously into the feet of rabbits, and the subsequent formation of agglutinins and hemolysins in the popliteal lymph node was compared with the output of lymphocytes through the efferent lymph and with changes in the lymph node. Antibodies began to appear in the efferent lymph 2 to 4 days after the injection of the antigen and reached their highest titer after 6 days. This was preceded by a sharp rise in the output of lymphocytes through the efferent lymph, while in the lymph node there was lymphatic hyperplasia after preliminary infiltration of granulocytes and monocytes. This hyperplasia was first of a diffuse type, but was later superseded by large so called germinal centers, the latter lagging somewhat behind the rise in antibody titer. The fact that the tissue response accompanying the formation of antibodies was chiefly a lymphocytic one points to the lymphocyte as a factor in the formation of antibodies.     

Laparoscopic pelvic lymph node dissection for malignant foot melanoma

A 39 year‐old woman with malignant foot melanoma underwent wide excision of the primary tumor with a safety margin and sentinel lymph node biopsy (SLNB) for the right inguinal lymph node. SLNB was positive and a computed tomography (CT) scan revealed right iliac lymph node swelling. Positron emission tomography computed tomography (PET–CT) scan of the lymph nodes revealed abnormal uptake of fluorodeoxyglucose (FDG). We performed a laparoscopic pelvic lymph node obturator, iliac lymph node) dissection. During the operation, several black lymph nodes were observed in the iliac lymph node. Pathologically, the iliac lymph node consisted of metastasized atypical melanocytes. This surgical method for pelvic lymph node dissection is not a standard procedure among institutions. There have been no reported cases of malignant melanoma with pelvic lymph node metastasis treated by laparoscopic surgery. However, due to the minimally invasive technique, this method is worth considering to be used for pelvic lymph node dissection in malignant melanoma as well as other cancers in the field of urology or gynecology.     

Natural antibody status in patients with Hashimoto's thyroiditis.

Raised levels of circulating natural antibodies (NABS) have been found in association with systemic lupus erythematosus (SLE) and chronic active hepatitis (CAH), indicative of polyclonal B-cell activation associated with these relatively non-organ specific autoimmune diseases. This study examined the natural antibody response in the organ-specific autoimmune disease Hashimoto's thyroiditis. Serum samples obtained from 69 women with newly diagnosed Hashimoto's thyroiditis together with 64 controls were analysed for IgG and IgM NABS directed at DNA, actin, myoglobin, myosin, trinitrophenyl hapten (TNP) and tubulin as the NAB antigen panel using an established ELISA. The same technique was also used to estimate thyroglobulin and thyroid microsomal autoantibody activities. Compared to a reference panel of normal serum samples, 31 of the Hashimoto's samples showed a greater than 2SD elevation of IgG and/or IgM NABS against one or more of the panel antigens together with elevated IgG thyroglobulin and thyroid microsomal antibody levels. The cases positive for one or more of the NAB panel also showed a greater incidence of active Hashimoto's thyroiditis as indicated by the presence of antibodies directed against the thyroid specific antigens. The above findings suggest that raised levels of NABS are also a feature of this organ-specific autoimmune disease. The wide ranging NAB specificities involved are consistent with an underlying or epiphenomenal state of polyclonal B-cell activation.     

THE ANTIBODY RESPONSE OF RATS DEPLETED OF LYMPHOCYTES BY CHRONIC DRAINAGE FROM THE THORACIC DUCT

The chronic drainage of lymph and cells from a thoracic duct fistula in rats results in a reduction in the weight of all the lymph nodes and of their content of small lymphocytes. The primary immune response to tetanus toxoid or sheep erythrocytes is severely depressed or abolished in such animals. This unresponsive state is related to the loss of lymphocytes from the thoracic duct fistula and, not to stress factors ensuing from the trauma of operation and restraint; it can be reversed by injecting inocula which contain almost exclusively small lymphocytes. In contrast to the severe impairment of the primary immune response in lymphocyte-depleted rats, such animals show a normal response to a second injection of tetanus toxoid. The mechanism by which small lymphocytes mediate the primary immune response is discussed.     

STUDIES ON ANTIBODY PRODUCTION : X. MODE OF FORMATION OF PLASMOCYTES IN CELL TRANSFER EXPERIMENTS

Cells from lymph nodes of rabbits injected repeatedly with bovine serum albumin were transferred subcutaneously to previously irradiated rabbits, and the recipients were immediately injected with bovine serum albumin. A good antibody response resulted. In a series of such animals killed on successive days, skin samples at sites of cell deposition were removed and examined by immunofluorescence and by light microscopy. In these tissues abundant plasmocytes were found to have multiplied and differentiated in a regular progression from immature, to medium, to mature plasmocytes. During the 6 days of the experiment the small plasmocytes accumulated until they reached 85 per cent of the total plasmocytic population. The mitotic index of the large and medium plasmocytes averaged 11 per cent, implying a generation time of 6.3 hours on the basis of a 1 hour mitotic time. This rate of growth is sufficiently rapid to account for all the plasmocytes on the 6th day as deriving from less than 1 per cent of the population initially transferred. This rate and the orderly progression in the evolution of the plasmocytic population, make it highly improbable that plasmocytes arise from transformation of lymphocytes, but rather indicate that they spring from specific precursors already present among the transferred cells.     

THE R?LE OF THE LYMPHOCYTE IN ANTIBODY FORMATION

Following the injection of typhoid antigen or sheep erythrocytes into the pad of the rabbit''s hind foot, lymph from the efferent lymphatic of the popliteal lymph node was collected and analyzed for antibody content. On separating the lymphocytes from the lymph plasma, it was found that the antibody titer of the cell extract was substantially and consistently higher than that of the surrounding fluid. This difference was greatest at the time of greatest rate of increase of antibody titer in the whole lymph, rather than when the antibody titer of the lymph plasma was highest. These results can only be interpreted to mean that the lymphocytes either produce antibodies or take them up from the lymph plasma. Incubation in vitro of lymphocytes containing one species of antibody with lymph plasma containing another showed that antibodies pass from the cells to the supernatant lymph fluid to reach approximate equilibrium; acquisition of antibody from supernatant lymph fluid was not observed. Similar results were obtained when normal lymphocytes were allowed to incubate in vivo in their own lymph fluid to which antibodies had been added. It was again found that antibodies were not absorbed or adsorbed by lymphocytes. These results seem to indicate that lymphocytes are instrumental in the formation of antibodies.