Single-cell sequencing on CD8+ TILs revealed the nature of exhausted T cells recognizing neoantigen and cancer/testis antigen in non-small cell lung cancer

BACKGROUND

CD8+tumor infiltrating lymphocytes (TILs) are often observed in non-small cell lung cancers (NSCLC). However, the characteristics of CD8+ TILs, especially T-cell populations specific for tumor antigens, remain poorly understood.

METHODS

High throughput single-cell RNA sequencing and single-cell T-cell receptor (TCR) sequencing were performed on CD8+ TILs from three surgically-resected lung cancer specimens. Dimensional reduction for clustering was performed using Uniform Manifold Approximation and Projection. CD8+ TIL TCR specific for the cancer/testis antigen KK-LC-1 and for predicted neoantigens were investigated. Differentially-expressed gene analysis, Gene Set Enrichment Analysis (GSEA) and single sample GSEA was performed to characterize antigen-specific T cells.

RESULTS

A total of 6998 CD8+ T cells was analyzed, divided into 10 clusters according to their gene expression profile. An exhausted T-cell (exhausted T (Tex)) cluster characterized by the expression of ENTPD1 (CD39), TOX, PDCD1 (PD1), HAVCR2 (TIM3) and other genes, and by T-cell oligoclonality, was identified. The Tex TCR repertoire (Tex-TCRs) contained nine different TCR clonotypes recognizing five tumor antigens including a KK-LC-1 antigen and four neoantigens. By re-clustering the tumor antigen-specific T cells (n=140), it could be seen that the individual T-cell clonotypes were present on cells at different stages of differentiation and functional states even within the same Tex cluster. Stimulating these T cells with predicted cognate peptide indicated that TCR signal strength and subsequent T-cell proliferation and cytokine production was variable but always higher for neoantigens than KK-LC-1.

CONCLUSIONS

Our approach focusing on T cells with an exhausted phenotype among CD8+ TILs may facilitate the identification of tumor antigens and clarify the nature of the antigen-specific T cells to specify the promising immunotherapeutic targets in patients with NSCLC.

Phase 1 studies of personalized neoantigen vaccine TG4050 in ovarian carcinoma (OC) and head and neck squamous cell carcinoma (HNSCC)

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Background: Mutation-associated neoantigens (MANAs) constitute attractive antigens for the design of cancer vaccines. However, clinical implementation remains challenging because of the patient specific nature of MANAs, hereby requiring that a bespoke vaccine is designed for each subject. We developed a pipeline for the genomic characterization and the design of tailored vaccine using a modified vaccinia Ankara viral vector. Methods: Immunogenicity, safety and early clinical activity of personalized cancer vaccines are being assessed in two phase I trials, respectively in high grade serous OC and HPV-negative HNSCC. Patients (Pts) at high risk of relapse are enrolled in the study being in remission following surgical primary treatment. High risk is defined as stage IIIC or IVA for OC and stage III or IVA for HNSCC. A vaccine is manufactured for each patient. OC pts are treated at asymptomatic relapse based on radiological finding or elevation of CA-125 with the vaccine alone; HNSCC pts in complete remission after surgery and adjuvant therapy are randomized to receive the vaccine either at the end of locoregional treatment or in combination with standard of care at relapse. The vaccine was administered weekly for 6 weeks and a booster dose every three weeks over a year or until progression, whichever occurred first. Results: At the time of the data cut-off, a total of 8 pts were treated: 4 relapsing OC pts, 3 HNSCC pts in complete remission and 1 relapsing HNSCC pt. AE attributable to the vaccine were mainly grade 1 injection site reactions and fatigue. One OC pt displayed an objective response 6 weeks after initiation of vaccine and for 9 months with a normalization of CA-125 until death from an unrelated cause; 1 other OC pt remains on treatment with a stable radiological disease for 11 months. The 2 other OC progressed at the first evaluation on day 43. HNSCC pts treated in complete remission received respectively 20, 15 and 4 doses, and remain on treatment and disease free. One HNSCC patient received 9 doses of vaccine after relapse in conjunction with chemotherapy and anti-PD-1 therapy and remains on treatment with stable disease after 5 months. Immune monitoring demonstrates priming of a polyepitopic T cell response against class I and II antigens. Responses were observed regardless of HLA and without cross-reactivity to the germline protein. Adaptive response was associated with a shift of CD4 and CD8 T cells toward an effector phenotype and innate cellular immunity was activated with a strong maturation and activation of NK cells. Immune changes were stronger in pts with controlled disease versus progressors. Conclusions: Data demonstrate that TG4050 is safe, well tolerated and able to induce T cell responses whatever the HLA haplotype. Early signs of clinical activity were observed in OC pt. These data pave the way for further development and synergistic immunotherapeutic combinations. Clinical trial information: NCT04183166.

Abstract 4566: Performance of neoantigen prediction for the design of TG4050, a patient specific neoantigen cancer vaccine

The development of therapeutic cancer vaccines to immunize against tumor antigens constitutes a promising modality. Mutation associated antigens are considered major targets given their specificity to tumor cells. These mutations are specific to the patients and require a tailor-made vaccine targeting mutations identified in each tumor. Many mutations are identified in the tumoral genome in most patients, but only a small fraction (around 1%) is suitable as vaccine target. Herein, we report data documenting the prediction performance of the algorithm used for the design of TG4050, a clinical stage patient specific viral-based neoantigen vaccine.

We have trained a set of independent machine learning algorithms to score each candidate neoantigen for several steps of the MHC antigen presentation pathway, including MHC binding, intracellular processing, similarity to self, and likelihood to elicit a T-cell response in peptide stimulated ELISPOT. Further, we have developed a novel graph neural network to combine all these scores to predict the likelihood that a neoantigen will elicit a T-cell response while also incorporating patient-specific factors, such as expression level and conservation of the mutation across different clones. To validate the system, we collected samples from 6 patients diagnosed with NSCLC, sequenced healthy and tumor tissue, identified mutations and ranked them using our algorithm; then, to evaluate immunogenicity, we focused our analysis on CD8+ T cell and measured the frequency of IFN γ+ cells against predicted peptides in autologous PBMC. Immunogenicity of peptides was assayed in 5 pools then deconvoluted against individual peptides.

From 3339 to 4782 somatic variants were detected in tumor tissue samples. After applying technical filtering, removing synonymous mutations, and filtering on transcript expression we detected a median of 281 (192-471) expressed tumor mutations resulting in a median of 2767 candidate class I epitopes (1769 - 4573). The model resulted in high accuracy allowing us to identify peptides with pre-existing ex vivo immunogenic responses in 5 out of 6 patients. Immunogenicity of peptide pools was correlated with ranking by the algorithm. Immunogenicity of the 6 top ranking individual epitopes in each patient showed a median of 5 (2-6) immunogenic peptides resulting in a 77% of true positive rate (TP). It should be noted that when no response was detected, it cannot be excluded that a response could be primed by a vaccine. In a similar setting, the netMHC 4.0 algorithm yielded a TP of 30% and only identified 39% of positive calls of our algorithm.

We demonstrate that the prediction algorithm is accurate in identifying immunogenic cancer mutations even among a large set of candidates. Ongoing TG4050 clinical studies (NCT03839524 and NCT04183166) will allow further validation of the antitumor activity of the elicited immune response.

Citation Format: Brandon Malone, Caroline Tosch, Benoit Grellier, Kousuke Onoue, Timo Sztyler, Karola Rittner, Yoshiko Yamashita, Eric Quemeneur, Kaidre Bendjama. Performance of neoantigen prediction for the design of TG4050, a patient specific neoantigen cancer vaccine [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4566.

CT Texture Analysis Potentially Predicts Local Failure in Head and Neck Squamous Cell Carcinoma Treated with Chemoradiotherapy

BACKGROUND AND PURPOSE

The accurate prediction of prognosis and failure is crucial for optimizing treatment strategies for patients with cancer. The purpose of this study was to assess the performance of pretreatment CT texture analysis for the prediction of treatment failure in primary head and neck squamous cell carcinoma treated with chemoradiotherapy.

MATERIALS AND METHODS

This retrospective study included 62 patients diagnosed with primary head and neck squamous cell carcinoma who underwent contrast-enhanced CT examinations for staging, followed by chemoradiotherapy. CT texture features of the whole primary tumor were measured using an in-house developed Matlab-based texture analysis program. Histogram, gray-level co-occurrence matrix, gray-level run-length, gray-level gradient matrix, and Laws features were used for texture feature extraction. Receiver operating characteristic analysis was used to identify the optimal threshold of any significant texture parameter. We used multivariate Cox proportional hazards models to examine the association between the CT texture parameter and local failure, adjusting for age, sex, smoking, primary tumor stage, primary tumor volume, and human papillomavirus status.

RESULTS

Twenty-two patients (35.5%) developed local failure, and the remaining 40 (64.5%) showed local control. Multivariate analysis revealed that 3 histogram features (geometric mean [hazard ratio = 4.68, P = .026], harmonic mean [hazard ratio = 8.61, P = .004], and fourth moment [hazard ratio = 4.56, P = .048]) and 4 gray-level run-length features (short-run emphasis [hazard ratio = 3.75, P = .044], gray-level nonuniformity [hazard ratio = 5.72, P = .004], run-length nonuniformity [hazard ratio = 4.15, P = .043], and short-run low gray-level emphasis [hazard ratio = 5.94, P = .035]) were significant predictors of outcome after adjusting for clinical variables.

CONCLUSIONS

Independent primary tumor CT texture analysis parameters are associated with local failure in patients with head and neck squamous cell carcinoma treated with chemoradiotherapy.

Variation and correlation of content and leachability of hazardous metals in MSW molten slag

To increase the amount of accessible municipal solid waste molten slag (MSWS) for its use in aggregates such as sand, MSWS must be deemed environmentally safe. Municipal solid waste (MSW) is a heterogeneous waste source used in MSWS and varies in chemical composition. Due to its nature, there is great concern about hazardous metal contamination among users of MSWS. In this study, MSWS samples were obtained weekly for 1 year from a typical incineration ash melting facility for municipal solid waste in Japan. Variation in heavy metal contents and the leachability of MSWS were investigated using two content analysis methods and two leaching tests, respectively. There is a weak correlation between metal content and concentration, and the leachability of metals in slag could not be reduced by decreasing its metal content. No measured values of hazardous metal concentration and metal content exceed the regulation levels stipulated in Japanese Industrial Standards A5031 and A5032, respectively, thereby demonstrating that the slag can be safely utilized as road and concrete aggregates. However, metal concentrations varied widely and differed by greater than 1 order of magnitude and Pb concentrations of several MSWS samples approach the regulation level. Therefore, frequent monitoring of lead leachability of MSWS and storing MSWS for several weeks to obtain a high quality that is more homogeneous in chemical composition are demanded. This study provides fundamental information for controlling the quality of MSWS and the contributing factors for achieving a safe slag recycling system.

Frontal association cortex is engaged in stimulus integration during associative learning

The frontal association cortex (FrA) is implicated in higher brain function. Aberrant FrA activity is likely to be involved in dementia pathology. However, the functional circuits both within the FrA and with other regions are unclear. A recent study showed that inactivation of the FrA impairs memory consolidation of an auditory fear conditioning in young mice. In addition, dendritic spine remodeling of FrA neurons is sensitive to paired sensory stimuli that produce associative memory. These findings suggest that the FrA is engaged in neural processes critical to associative learning. Here we characterize stimulus integration in the mouse FrA during associative learning. We experimentally separated contextual fear conditioning into context exposure and shock, and found that memory formation requires protein synthesis associated with both context exposure and shock in the FrA. Both context exposure and shock trigger Arc, an activity-dependent immediate-early gene, expression in the FrA, and a subset of FrA neurons was dually activated by both stimuli. In addition, we found that the FrA receives projections from the perirhinal (PRh) and insular (IC) cortices and basolateral amygdala (BLA), which are implicated in context and shock encoding. PRh and IC neurons projecting to the FrA were activated by context exposure and shock, respectively. Arc expression in the FrA associated with context exposure and shock depended on PRh activity and both IC and BLA activities, respectively. These findings indicate that the FrA is engaged in stimulus integration and contributes to memory formation in associative learning.

Characteristics of element distributions in an MSW ash melting treatment system

Thermal treatment of municipal solid waste (MSW) has become a common practice in waste volume reduction and resource recovery. For the utilization of molten slag for construction materials and metal recovery, it is important to understand the behavior of heavy metals in the melting process. In this study, the correlation between the contents of elements in feed materials and MSW molten slag and their distributions in the ash melting process, including metal residues, are investigated. The hazardous metal contents in the molten slag were significantly related to the contents of metals in the feed materials. Therefore, the separation of products containing these metals in waste materials could be an effective means of producing environmentally safe molten slag with a low hazardous metals content. The distribution ratios of elements in the ash melting process were also determined. The elements Zn and Pb were found to have a distribution ratio of over 60% in fly ash from the melting furnace and the contents of these metals were also high; therefore, Zn and Pb could be potential target metals for recycling from fly ash from the melting furnace. Meanwhile, Cu, Ni, Mo, Sn, and Sb were found to have distribution ratios of over 60% in the metal residue. Therefore, metal residue could be a good resource for these metals, as the contents of Cu, Ni, Mo, Sn, and Sb in metal residue are higher than those in other output materials.

Fear extinction requires Arc/Arg3.1 expression in the basolateral amygdala

Background

Prolonged re-exposure to a fear-eliciting cue in the absence of an aversive event extinguishes the fear response to the cue, and has been clinically used as an exposure therapy. Arc (also known as Arg3.1) is implicated in synaptic and experience-dependent plasticity. Arc is regulated by the transcription factor cAMP response element binding protein, which is upregulated with and necessary for fear extinction. Because Arc expression is also activated with fear extinction, we hypothesized that Arc expression is required for fear extinction.

Findings

Extinction training increased the proportion of Arc-labeled cells in the basolateral amygdala (BLA). Arc was transcribed during latter part of extinction training, which is possibly associated with fear extinction, as well as former part of extinction training. Intra-BLA infusions of Arc antisense oligodeoxynucleotide (ODN) before extinction training impaired long-term but not short-term extinction memory. Intra-BLA infusions of Arc antisense ODN 3 h after extinction training had no effect on fear extinction.

Conclusion

Our findings demonstrate that Arc is required for long-term extinction of conditioned fear and contribute to the understanding of extinction as a therapeutic manner.

Purification and characterization of the serotype-specific polysaccharide antigen of Trichosporon cutaneum serotype II: a disease-related antigen of Japanese summer-type hypersensitivity pneumonitis

Summer-type hypersensitivity pneumonitis (SHP) is a unique type of hypersensitivity pneumonitis and the most prevalent in Japan. Our previous study clarified that the causative agent of the disease is Trichosporon cutaneum, and that the patients with SHP have high titres of antibodies against the serotype-specific antigen of polysaccharide nature which exist in the high molecular weight fraction of the culture supernatant of the yeast. In this study, we purified the serotype-specific antigen of serotype II T. cutaneum by gel filtration and affinity chromatography using a monoclonal antibody, D-8, specific for a high molecular weight antigen of serotype II T. cutaneum, and elucidated the structure of the antigen. This affinity-purified antigen was shown to be an essentially acidic polysaccharide comprising mannose, xylose, and glucuronic acid (6:44:4.7). Chemical analysis showed that this polysaccharide antigen contains a (1-3)-linked mannan backbone attached with short side chains of (1-4)-linked mannose and a small proportion of (1-2)-linked xylose residues by substituting the 2- or 4-positions of the (1-3)-linked mannose residues of the main chain. Approximately one-fifth of the side chains were terminated with glucuronic acid residues. The antigenic epitope of the serotype-specific antigen was shown to involve the terminal glucoronic acid residues as revealed by immunodiffusion test and sandwich enzyme-linked immunosorbent assay using monoclonal antibody D-8.

Experimental hypersensitivity pneumonitis in mice induced by Trichosporon cutaneum: histologic and immunologic features and effect of in vivo depletion of T cell subsets

An animal model of hypersensitivity pneumonitis (HP) was developed in C57Black/6J mice by repeated intratracheal inoculations with particulate Trichosporon cutaneum, a causative agent of Japanese summer-type HP. We observed severe alveolitis and bronchiolitis with infiltration of lymphocytes, macrophages, and neutrophils in the lung lesions. Granuloma formation was occasionally seen. Bronchoalveolar lavage (BAL) of the experimental animals showed an increase in the number of lymphocytes, macrophages, neutrophils, and in the total cell yield. Phenotypic analysis of the BAL lymphocytes by flow cytometry revealed that 43.1 +/- 3.1% of lymphocytes were Thy1.2+ (CD3+) cells and that the L3T4+ (CD4+) cells (36.3 +/- 3.5%) predominated over the Lyt2+ (CD8+) cells (18.5 +/- 1.2%). As for the humoral immune response, the specific IgA antibody activities in the BAL fluids well reflected the specific pulmonary inflammatory responses. Studies of lymphocyte depletion were performed by in vivo administration of anti-CD4 and anti-CD8 monoclonal antibodies. Depletions of CD4+ cells and of both CD4+ and CD8+ cells diminished the pulmonary lesions and specific IgA antibody activities in the BAL fluids. These results indicate that CD4+ cells may play a major role in the inflammatory process of this animal model.

The suppressive effect of gelatin-conjugated superoxide dismutase on disease development and severity of collagen-induced arthritis in mice

We studied the effect of superoxide dismutase (SOD) on murine collagen-induced arthritis (CIA), an animal model of human rheumatoid arthritis (RA). Among SOD derivatives studied, only gelatin-SOD conjugate which has prolonged half life in vivo was effective to suppress the development of CIA, while native SOD or gelatin carrier alone was ineffective. Interestingly, pyran polymer-conjugated SOD which also has a long half life showed no suppressive effect on the disease. No significant effect on immune response against type II collagen (CII) was found in any of the experimental groups. In addition, induction of suppressor cells was not detected in spleen or lymph node cells of the gelatin-SOD-treated group. Therefore, these results suggest that oxygen radicals may have an important role in the effector phase of the immune response to manifest this chronic autoimmune polyarthritis. Thus, the use of appropriate antioxidants for the treatment of human RA may be rationalized.

Analysis of serotype-specific antibodies to Trichosporon cutaneum types I and II in patients with summer-type hypersensitivity pneumonitis with monoclonal antibodies to serotype-related polysaccharide antigens

Summer-type hypersensitivity pneumonitis is the most prevalent type of hypersensitivity pneumonitis in Japan. We constructed a sandwich enzyme-linked immunosorbent assay system for diagnosis of summer-type hypersensitivity pneumonitis in which monoclonal antibodies were used to bind serotype-related polysaccharides to plastic plates, and this system was proven to have sufficient sensitivity and specificity.

Interleukin-2 production by primary adult T cell leukemia tumor cells is macrophage dependent

We have investigated the cellular requirements for IL-2 production by autocrine proliferating tumor cells from four patients with adult T cell leukemia (ATL). Cultures of these ATL cells both produced endogenous IL-2 protein in the absence of added mitogen and proliferated at higher levels when exogenous recombinant IL-2 was added. Depletion of macrophages in the tumor cell cultures resulted in a sharp decline in tumor cell IL-2 production, while re-addition of macrophages reconstituted this response. Macrophage-derived factors including IL-6 and IL-1 also reconstituted IL-2 production in these macrophage depleted cultures. These results raise the possibility that macrophages may play a central role in HTLV-I mediated immortalization of T cells.

A 68-kD GTP-binding protein associated with the T cell receptor complex

The identity of the guanine nucleotide-binding protein (G protein) involved in T cell activation pathways remains unclear. We identified a 68-kD GTP-binding protein associated with the T cell receptor (TCR)/CD3 complex using immunoprecipitation and GTP-affinity labeling techniques. Proteins coimmunoprecipitated with the TCR/CD3 complex in digitonin lysate of a human leukemic T cell line, MOLT 16, were incubated with alpha-[32P]GTP and irradiated with ultraviolet rays to covalently link the labeled GTP to GTP-binding proteins. They were then analyzed by electrophoresis. The 68-kD protein exhibited nucleotide specificity for GTP-binding and was insensitive to cholera and pertussis toxins. The 68-kD GTP-binding protein could be coimmunoprecipitated with the TCR/CD3 complex but not with other surface molecules such as major histocompatibility complex class I and lymphocyte function associated-1, which do not cause rapid Ca2+ mobilization. These suggest that the 68-kD GTP-binding protein is specifically associated with the TCR/CD3 complex.

A device for tracheal tube during CO2 laser irradiation in laryngomicrosurgery

We devised that the segment of commercially available defensor II tube coming in contact with the vocal cord was concaved. We used this new tube during CO(2) laser irradiation in laryngomicrosurgery. We came to the conclusion that it was much more superior to the conventional tube in safety and resistance of the material to Co(2) laser irradiation and in increase of the operation field.

The effect of anti-adhesion molecule antibody on the development of collagen-induced arthritis

In order to study how inflammatory cells including autoimmune lymphocytes interact with each other to develop collagen-induced arthritis (CIA), we injected monoclonal antibodies against mouse LFA-1 and ICAM-1 into DBA/1 mice immunized with type II collagen (CII). Both antibodies suppressed the development of CIA. These antibodies showed no effect on anti-CII antibody response, although they both significantly suppressed DTH response. It was suggested that anti-adhesion molecule antibodies suppress CIA mainly through their effect on cell-mediated immunity, without affecting humoral immunity under the conditions used.

Accessory function of human glioma cells for the induction of CD3-mediated T cell proliferation: a potential role of glial cells in T cell activation in the central nervous system

Accessory function of human glial cells for the induction of anti-CD3 antibody-mediated proliferation of T cells was investigated by using seven glioma cell lines. Three of them were found to function as accessory cells and one of them, U118, was used for further analysis. U118 cells showed the cell-contact-mediated accessory function for T cell proliferation. It was found that protein synthesis was required to reveal this function, suggesting that some surface molecules are synthesized and expressed on U118 cells during interaction with T cells to mediate effective signals in T cells. Intercellular adhesion molecule-1 seemed to be one of such inducible molecules and was shown to contribute to effective accessory cell-T cell interaction, but necessity of other molecule(s) was also suggested.

Development of the cell contact-mediated accessory function for T-cell proliferation in a human promyelocytic leukaemia cell line, HL-60, by 1,25-dihydroxyvitamin D3

A human promyelocytic leukaemia cell line, HL-60 cells, did not show accessory cell (AC) function to potentiate the proliferation of human T cells induced by anti-CD3 antibody coupled to latex beads (alpha T3-L). This was found to be at least due to the inability of HL-60 cells to express certain molecules which are inducible with interferon-gamma (IFN-gamma) on mature monocytes and are necessary for interaction with T cells. HL-60 cells acquired the ability to express such surface molecules by stimulation with IFN-gamma when the cells were pretreated with 1,25-dihydroxyvitamin D3 (Vit D). The effect of Vit D was reversible, that is, the AC function of the HL-60 cells was lost when the cells were cultured in Vit D-free medium for 7 days. It was also found that HL-60 cells treated with IFN-gamma and then with Vit D did not show significant AC function. The flow cytometric analysis showed that the expression of HLA-DR and intercellular adhesion molecule-1 (ICAM-1) was highly increased on HL-60 cells when stimulated with IFN-gamma after treatment with Vit D. The expression of ICAM-1 was also induced with IFN-gamma on untreated cells but in lower amounts. Monoclonal antibodies against ICAM-1 and HLA-DR inhibited the alpha T3-L-induced T-cell proliferation, indicating that these molecules are at least required for contact-mediated AC function. Thus our study revealed that HL-60 cells express cell surface interaction molecules necessary for potentiating the T-cell proliferation through two steps, differentiation with Vit D to mature monocyte-like cells followed by stimulation with IFN-gamma.

Lowered responsiveness of bronchoalveolar lavage T lymphocytes in hypersensitivity pneumonitis

We previously reported that Trichosporon cutaneum was the major causative antigen of summer-type hypersensitivity pneumonitis (HP) in Japan. In summer-type HP patients, we noticed that the proliferative responses of bronchoalveolar lavage (BAL) lymphocytes to phytohemagglutinin (PHA) and concanavalin A were significantly lower than those of the peripheral blood lymphocytes of the same patients. It was shown in this study that the low response of BAL lymphocytes was due to an intrinsic lowering of the responsiveness of the T cells. Results of the mixed culture experiments, in which the responses to mitogens of BAL and peripheral blood T cells mixed with either alveolar macrophages or blood monocytes were compared, indicated that the decreased proliferative response was due neither to the suppressive effect nor to defects in accessory function of the alveolar macrophages. BAL T cells did not act as suppressor cells when they were added to the culture of peripheral T cells. The decreased proliferative response was not due to the dominance of CD8+ T cells frequently seen in BAL cells of HP patients, because both CD4+ and CD8+ T cells separated from BAL cells of HP patients showed lower responsiveness than those of peripheral blood T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural differences among guinea pig Fc gamma 1/gamma 2 receptors on macrophages, polymorphonuclear cells, and lymphocytes

Using the cDNA, D-3, coding for Fc gamma 1/gamma 2 receptor of guinea pig macrophages that binds IgG1 and IgG2 (Fc gamma 1/gamma 2R), we examined the cell distribution of this receptor by RNA blot analysis. The Fc gamma 1/gamma 2R mRNA was expressed in polymorphonuclear cells and B cells as well as in macrophages, but not at the detectable level in T cells. The cDNA amplified from RNA of polymorphonuclear cells in the polymerase chain reaction was the same as D-3. The cDNA of B cells was found to have about 140 bp cDNA segment inserted to the cytoplasmic tail of D-3. We found that the cDNA amplified from T cell RNA differed in signal peptide and extracellular domain sequence from cDNAs of other cell types. This cDNA does not seem to be amplified from the mRNAs of contaminating other cell types.

The structure and expression of the guinea pig Fc receptor for IgG1 and IgG2 (Fc gamma 1/gamma 2R)

A cDNA clone encoding the receptor for guinea pig immunoglobulin G was isolated from a guinea pig peritoneal macrophage cDNA library. The cloned cDNA encoded 271 amino acids containing an N-terminal signal sequence. The deduced amino acid sequence is most homologous to murine Fc gamma RII beta 2. The receptor protein could be expressed in COS-7 and L cells transfected with the cDNA, suggesting that the expression of this receptor does not require the co-expression of a second chain such as gamma chain of Fc epsilon RI or CD3 zeta chain. The transformant L cells showed the binding to both the guinea pig IgG1 and IgG2 antibodies complexed with antigen, indicating that the cDNA we cloned was the one for guinea pig Fc gamma 1/gamma 2R.

Importance of serotype-related antigen in the induction of experimental hypersensitivity pneumonitis by Trichosporon cutaneum in rabbits. Correlation between granulomatous alveolitis and cellular and humoral immune responses to polysaccharide-rich antigen

We evaluated the immunopathogenic properties of Trichosporon cutaneum, a major etiologic agent of Japanese summer-type hypersensitivity pneumonitis (HP). When the culture filtrate antigen of T. cutaneum was chromatographed on DEAE-cellulose, two peaks of polysaccharide, fractions A and B, were obtained. Fraction B was highly reactive to the specific IgG and IgA antibodies in the serum and bronchoalveolar lavage fluid samples obtained from sensitized rabbits, whereas fraction A was mainly reactive to the IgG antibodies. When the rabbits sensitized by intratracheal injection with the particulate antigen of T. cutaneum were challenged intratracheally by these antigenic fractions, fraction B induced granulomatous alveolitis, but fraction A induced alveolitis rather than granuloma. Lymphocytes of the mediastinal lymph nodes responded prominently to fraction B, but less to fraction A, as assessed by proliferative response. Each of the fractions B obtained from two strains of different serotypes (TIMM 1573, serotype I and TIMM 1318, serotype II) was reactive in enzyme-linked immunosorbent assay to the serum samples from the rabbits sensitized with homologous antigen, but far less to that from the rabbits sensitized with heterologous antigen, that is, the antigenic specificity of fraction B was related to the serotype of T. cutaneum. Fractionation by gel filtration on Sepharose CL-4B revealed that the molecular weight of the antigenic components in fraction B was larger than 1,000,000 and that the components consisted mainly of polysaccharide.(ABSTRACT TRUNCATED AT 250 WORDS)

Different types of antigen-presenting cells affect the induction of experimental autoimmune arthritis

We obtained a type II collagen-specific murine T cell line containing at least two T cell clones, one reacting with only native collagen II and the other with both denatured and native molecules. Only the former could induce arthritis. The arthritogenic T cell clone(s) was preferentially stimulated to grow when epidermal cells were used as antigen-presenting cells. Conversely, the non-arthritogenic T cell clone(s) was mainly stimulated when spleen cells were used. Thus, it is speculated that different types of antigen-presenting cells preferentially present different epitopes on the same antigen, affecting the resulting in vivo immune phenomena.

Serotype-related antigen of Trichosporon cutaneum in the induction of summer-type hypersensitivity pneumonitis: correlation between serotype of inhalation challenge-positive antigen and that of the isolates from patients' homes

Inhalation challenge with the culture filtrate-antigens prepared from two strains of different serotype of Trichosporon cutaneum (TIMM 1573, serotype I; TIMM 1318, serotype II) was performed on patients with summer-type hypersensitivity pneumonitis and asymptomatic seropositive family members. Of the 17 patients, 12 were strongly positive, four were mildly so, and one was negative. Interestingly, of the 16 inhalation challenge-positive patients, four reacted to both serotypes I and II, five to serotype I only, and seven to serotype II only. There was a good correlation between the serotype inhalation challenge-positive antigen and that of T. cutaneum isolated from the homes of two patients' homes. A strain of T. cutaneum demonstrating a new serotype was isolated from the homes of two patients, one of whom was negative to both serotypes I and II. Specific antibody activity, lymphocyte proliferative response, and skin reaction to the antigens were also positive, but these findings were not useful to discriminate the inhalation challenge-positive from the inhalation challenge-negative antigen. Neither of the two asymptomatic family members responded. These results indicate that inhalation challenge in patients with summer-type hypersensitivity pneumonitis is provoked by the serotype-related antigen of T. cutaneum, reflecting the sensitization of these patients in their homes.

Stability of IL-2 mRNA in T lymphocytes is controlled by a protein kinase C-regulated mechanism

The rate of the degradation of interleukin 2 (IL-2) mRNA produced in stimulated human tonsillar lymphocytes was found to be significantly decreased in cells continuously stimulated with a calcium ionophore, A23187, and a phorbol ester, phorbol 12, 13-dibutylate (PDB) as compared with that in unstimulated cells. When the lymphocytes were stimulated with A23187 and PDB, IL-2 mRNA reached a maximum level at 8 h and gradually decreased to almost the base line by 27 h. IL-2 mRNA produced was rapidly degraded when the stimulants were washed out at 12 h and the cells further cultured in the presence of actinomycin D, which stops mRNA synthesis. However, the stability of IL-2 mRNA was increased by the addition of PDB or A23187. A maximal effect was observed when both were added. The effect of PDB was dose-dependent and inhibited by the inhibitors of protein kinase C (PKC), staurosporine, and K252a, suggesting the involvement of PKC in the control of IL-2 mRNA stability. The involvement of protein phosphorylation in the regulating mechanism of IL-2 mRNA stability was supported by the fact that the addition of okadaic acid, which inhibits serine/threonine protein phosphatases, resulted in an increase in the stability of IL-2 mRNA. Further study demonstrated that the rate of degradation of 32P-labeled IL-2 mRNA, which was prepared by cell-free transcription of IL-2 cDNA, in the polysomal fraction obtained from PDB-stimulated lymphocytes was decreased compared with that obtained from unstimulated lymphocytes. These results indicate the presence of a mechanism controlling the stability of IL-2 mRNA that is regulated by PKC.

Signal delivery by physical interaction and soluble factors from accessory cells in the induction of receptor-mediated T-cell proliferation. Synergistic effect of BSF-2/IL-6 and IL-1

Our recent study revealed that soluble factors derived from accessory cells (AC; monocytes) and physical interaction with T cells of the accessory cells are both required for the induction of the proliferation of human peripheral blood T cells by anti-CD3 antibody coupled on latex beads. The accessory cell-derived soluble factor could be replaced by IL-1 and IL-6, and the role of live macrophages for physical interaction with T cells was found to be replaceable with paraformaldehyde(PFA)-fixed macrophages, provided the macrophages were pretreated with interferon-gamma (IFN-gamma) before fixation. Quantitative analysis in the present study revealed that IL-1 and IL-6 act synergistically to induce T-cell proliferation in the above system but either one of the factors alone reveals only a marginal or weak activity. Furthermore, it was shown that the potentiating activity of the culture supernatants of monocytes was substantially inhibited by anti-IL-6 antibody. Taken together with our previous results that anti-IL-1 serum strongly inhibited the potentiating activity of the culture supernatant, these results indicate that the main responsible molecules in the culture supernatant are IL-1 and IL-6, although a presence of other effective factors is not excluded. The anti-CD3-induced thymidine uptake by T cells in the presence of IL-1 and IL-6 was significantly inhibited by anti-Tac antibody, suggesting that the proliferation of T cells in this system is mostly mediated by a IL-2-dependent pathway. Our study further showed that accessory cells seem to acquire cell surface properties necessary for the effective interaction with T cells during 6-24 hr of culture with IFN-gamma. Presumably, a certain molecule(s) required for the interaction is induced on the cell surface of the AC by IFN-gamma.

Requirement for delivery of signals by physical interaction and soluble factors from accessory cells in the induction of receptor-mediated T cell proliferation. Effectiveness of IFN-gamma modulation of accessory cells for physical interaction with T cells

We analyzed the mechanism by which accessory cells support the induction of the proliferation of human peripheral blood T cells by a monoclonal anti-CD3 antibody, OKT3. Cross-linking of T cell receptor/CD3 complex by anti-CD3 coupled to latex beads and the addition of IL-1 are not enough to induce the IL-2 production and proliferation of T cells extensively depleted of accessory cells, while the addition of both the culture supernatant of macrophages or a monoblastic cell line, U937 cells, and the paraformaldehyde-fixed macrophages or U937 cells which had been precultured with interferon-gamma before fixation into the culture of the T cells with anti-CD3-latex did induce the T cell proliferation. Lack of the addition of either one of these did not induce the response. These results indicate that the signal(s) delivered by soluble factors released from the accessory cells and that delivered by the physical interaction between accessory cells and T cells are both required for the induction of IL 2 production and proliferation of T cells by anti-CD3-latex. Importantly, the macrophages or U937 cells had to be cultured with Con A-stimulated lymphocyte culture supernatant or IFN-gamma prior to fixation with paraformaldehyde, suggesting that a molecule(s) inducible on accessory cells surface by IFN-gamma or other lymphokine is necessary for the effective accessory cell-T cell interaction to induce the T cell response. It was further revealed that the activity of the culture supernatant of accessory cells may be mediated synergistically by IL 1 and a certain other factor(s) and was actually shown to be replaced by the combined addition of rIL-1 and rIL-6 but not by rIL-1 alone. The experimental system described here will be very useful for dissecting the accessory functions for T cell activation.

Requirement for delivery of signals by physical interaction and soluble factors from accessory cells in the induction of receptor-mediated T cell proliferation. Effectiveness of IFN-gamma modulation of accessory cells for physical interaction with T cells

We analyzed the mechanism by which accessory cells support the induction of the proliferation of human peripheral blood T cells by a monoclonal anti-CD3 antibody, OKT3. Cross-linking of T cell receptor/CD3 complex by anti-CD3 coupled to latex beads and the addition of IL-1 are not enough to induce the IL-2 production and proliferation of T cells extensively depleted of accessory cells, while the addition of both the culture supernatant of macrophages or a monoblastic cell line, U937 cells, and the paraformaldehyde-fixed macrophages or U937 cells which had been precultured with interferon-gamma before fixation into the culture of the T cells with anti-CD3-latex did induce the T cell proliferation. Lack of the addition of either one of these did not induce the response. These results indicate that the signal(s) delivered by soluble factors released from the accessory cells and that delivered by the physical interaction between accessory cells and T cells are both required for the induction of IL 2 production and proliferation of T cells by anti-CD3-latex. Importantly, the macrophages or U937 cells had to be cultured with Con A-stimulated lymphocyte culture supernatant or IFN-gamma prior to fixation with paraformaldehyde, suggesting that a molecule(s) inducible on accessory cells surface by IFN-gamma or other lymphokine is necessary for the effective accessory cell-T cell interaction to induce the T cell response. It was further revealed that the activity of the culture supernatant of accessory cells may be mediated synergistically by IL 1 and a certain other factor(s) and was actually shown to be replaced by the combined addition of rIL-1 and rIL-6 but not by rIL-1 alone. The experimental system described here will be very useful for dissecting the accessory functions for T cell activation.

Arachidonic acid release is closely related to the Fc gamma receptor-mediated superoxide generation in macrophages

Stimulation of macrophages with IgG2 immune complexes induced dose-dependently the O2- generation and the release of arachidonic acid and its metabolites. This Fc gamma R-mediated O2- generation was inhibited by a phospholipase A2 inhibitor, 4-p-bromophenacyl bromide (4-pBPB), in parallel to the dose-dependent inhibition of arachidonic acid release. The main arachidonic acid metabolites released were shown to be prostaglandin E2 and thromboxane B2 and blocking of the production of these metabolites by indomethacin did not inhibit the O2- generation. Inhibition of the Fc gamma R-mediated O2- generation and the arachidonic acid release by the C-kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), was less intense than by 4-pBPB. These results support the previously proposed hypothesis that arachidonic acid acts as an intracellular activator of the Fc gamma R-mediated O2- generation in macrophages. Although the C-kinase activation may also contribute to the activation of the O2--generating system, arachidonic acid release appears to play a major role in Fc gamma R-mediated O2- generation. In contrast, activation of C-kinase seems to be contributing mainly in the induction of both the arachidonic acid release and O2- generation by 12-o-tetradecanoylphorbol 13-acetate (TPA). Furthermore, suboptimal concentrations of TPA and arachidonate were found to act synergistically to stimulate O2- generation and the inhibition study suggested a positive synergism between C-kinase and arachidonic acid release to induce O2- generation. This synergistic action may have general importance in receptor-mediated O2- generation.

Thymic accessory cells required for the increased responsiveness of thymocyte subpopulations to interleukin 1-like monokine in guinea pigs

The proliferative response of guinea-pig thymocytes to co-mitogenic stimulation with phytohaemagglutinin and the guinea-pig interleukin 1 (IL-1)-like lymphocyte-activating monokine was lost by removing the cells that adhere to a Sephadex G-10 (G-10) column or the cells of low density in a Ficoll-Conray gradient. The diminished response in the G-10 non-adherent thymocyte or high-density thymocyte fraction was restored by the addition of a macrophage-depleted G-10 adherent thymocyte fraction or a low-density, Ia-positive thymocyte fraction but not by the addition of peritoneal macrophages. These results suggest that the accessory cells which mediate the increased responsiveness of thymocytes to the IL-1-like monokine existed in G-10 adherent cell fractions and the cells with this accessory function were not macrophages. The accessory cells were shown to be of low density, glass-non-adherent, G-10-adherent, Fc receptor-negative, and Ia-positive. These results also suggest that the G-10-non-adherent and high-density thymocyte subpopulation, which is unresponsive or responds very little to the IL-1-like monokine by itself, acquires responsiveness to the monokine and proliferates by stimulation with the IL-1-like monokine and lectin in the presence of the accessory cells.

Effect of wheat germ agglutinin on T lymphocyte activation

Wheat germ agglutinin (WGA) is low mitogenic or nonmitogenic for human T lymphocytes and inhibits phytohemagglutinin (PHA)-induced mitotic response of the lymphocytes. In this study, the effect of WGA was analyzed in terms of interleukin 2 (IL2) production, expression of IL2 receptor, and IL2 responsiveness of the T lymphocytes. WGA as well as PHA could induce IL2 mRNA and IL2 production and also elevate cytoplasmic free Ca2+ concentration. The IL2 production was reduced by inhibitors of calmodulin and protein kinase C. The IL2 receptor (Tac) expression was induced at about 20% of the lymphocytes by WGA and the expression induced by PHA was not blocked by the addition of WGA. The lymphocytes precultured with WGA for 3 days could proliferate by the addition of IL2 after removal of WGA. The IL2-dependent proliferation of PHA-blasts was blocked by the addition of WGA. These results indicate that WGA inhibits T lymphocyte proliferation by inhibiting the responsiveness of the lymphocytes to IL2 but not by interfering with IL2 production and IL2 receptor expression.

Calmodulin inhibitors, W-7 and TFP, block the calmodulin-independent activation of NADPH-oxidase by arachidonate in a cell-free system

The calmodulin inhibitor, N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7), or trifluoperazine inhibited not only Fc gamma-receptor mediated cytosolic free Ca2+ increase and O2- generation in macrophages, but also an arachidonate-induced activation of NADPH-oxidase in a cell-free system. Although these results suggested the involvement of Ca2+-calmodulin system, the cell-free activation of NADPH-oxidase occurred in the presence of EGTA and addition of calmodulin had no effect. Furthermore W-7 shifted the optimal concentration of arachidonate required for the activation to a higher level, suggesting that W-7 may block the interaction between arachidonate and NADPH-oxidase system rather than inhibiting a Ca2+-calmodulin system.

Arachidonic acid acts as an intracellular activator of NADPH-oxidase in Fc gamma receptor-mediated superoxide generation in macrophages

A protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), inhibited phorbol ester (12-o-tetradecanoylphorbol 13-acetate)-induced and Fc gamma receptor-mediated superoxide anion (O2-) generations in guinea pig macrophages, but the inhibitory effect on Fc gamma receptor-mediated O2- generation was only partial. Both O2- generations were inhibited extensively by a phospholipase A2 inhibitor, 4-p-bromophenacyl bromide (4-pBPB). It was confirmed in control experiments that H-7 and 4-pBPB had no direct inhibitory effect on NADPH-oxidase activity. Dose-dependent stimulation of O2- generation was induced by arachidonate in macrophages, and the arachidonate-induced O2- generation was not inhibited by H-7. Arachidonate could also induce NADPH-oxidase activation in a post-nuclear fraction obtained from unstimulated macrophages and this activation was not inhibited by H-7, indicating that protein kinase C activation was not involved in this cellfree system. These results support the hypothesis that the O2- generation induced by Fc gamma receptor stimulation is mainly mediated by arachidonic acid which is released by the action of phospholipase A2 activated by receptor stimulation. Arachidonic acid seems to be acting rather directly in activating the NADPH-oxidase system of macrophage membrane. Protein kinase C may have a significant role in Fc gamma receptor-mediated O2- generation but it is not obligatory, and protein kinase C seems to activate NADPH-oxidase rather indirectly, probably by inducing the arachidonic acid release.

Arachidonic acid acts as an intracellular activator of NADPH-oxidase in Fc gamma receptor-mediated superoxide generation in macrophages

A protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), inhibited phorbol ester (12-o-tetradecanoylphorbol 13-acetate)-induced and Fc gamma receptor-mediated superoxide anion (O2-) generations in guinea pig macrophages, but the inhibitory effect on Fc gamma receptor-mediated O2- generation was only partial. Both O2- generations were inhibited extensively by a phospholipase A2 inhibitor, 4-p-bromophenacyl bromide (4-pBPB). It was confirmed in control experiments that H-7 and 4-pBPB had no direct inhibitory effect on NADPH-oxidase activity. Dose-dependent stimulation of O2- generation was induced by arachidonate in macrophages, and the arachidonate-induced O2- generation was not inhibited by H-7. Arachidonate could also induce NADPH-oxidase activation in a post-nuclear fraction obtained from unstimulated macrophages and this activation was not inhibited by H-7, indicating that protein kinase C activation was not involved in this cellfree system. These results support the hypothesis that the O2- generation induced by Fc gamma receptor stimulation is mainly mediated by arachidonic acid which is released by the action of phospholipase A2 activated by receptor stimulation. Arachidonic acid seems to be acting rather directly in activating the NADPH-oxidase system of macrophage membrane. Protein kinase C may have a significant role in Fc gamma receptor-mediated O2- generation but it is not obligatory, and protein kinase C seems to activate NADPH-oxidase rather indirectly, probably by inducing the arachidonic acid release.

Heterogeneity in response to interleukin 2 and interleukin 2-producing ability of adult T cell leukemic cells

To examine the possibility of heterogeneous mechanisms in the proliferation of adult T cell leukemia (ATL) cells, leukemic cells from 13 patients, nine acute-type and four chronic-type ATL, were examined for the production of interleukin 2 (IL 2) with or without mitogenic stimulation and their response to recombinant IL 2 when exogeneously added. The leukemic cells were classified into four groups, as follows. Group 1 (two patients): Cells of this group produced IL 2 messenger RNA, secreted IL 2, and proliferated when cultured in mitogen-free medium. The spontaneous proliferation of the cells in mitogen-free medium was inhibited by anti-Tac/IL 2 receptor and anti-IL 2 monoclonal antibodies. Moreover, the thymidine incorporation by the cells was enhanced in response to exogeneously added recombinant IL 2 and IL 2 produced by themselves. These results indicate that the ATL cells of this group proliferate with autostimulation by IL 2. Group 2 (seven patients): Cells of this group did not secrete IL 2 when cultured in mitogen-free medium, but the cells showed response to exogeneously added recombinant IL 2 and proliferated in culture. These results indicate that the ATL cells of this group proliferate by a paracrine mechanism. Group 3 (one patient): Cells of this group secreted IL 2 in mitogen-free medium. However, the spontaneous proliferation of these cells in vitro was very low, and the response to recombinant IL 2 was also very low. Group 4 (three patients): Cells of this group did not secrete IL 2 in mitogen-free medium. Spontaneous proliferation and the response to recombinant IL 2 were also very low. The clinical feature of all patients of Groups 1 and 2 was acute-type, and that of Groups 3 and 4 was chronic-type. Thus, we conclude that heterogeneous mechanisms exist in the proliferation of leukemic cells, and that growth rate in mitogen-free medium and response to IL 2 of the cells may have a significant relationship to the clinical feature, acute- or chronic-type.

Heterogeneity in response to interleukin 2 and interleukin 2-producing ability of adult T cell leukemic cells

To examine the possibility of heterogeneous mechanisms in the proliferation of adult T cell leukemia (ATL) cells, leukemic cells from 13 patients, nine acute-type and four chronic-type ATL, were examined for the production of interleukin 2 (IL 2) with or without mitogenic stimulation and their response to recombinant IL 2 when exogeneously added. The leukemic cells were classified into four groups, as follows. Group 1 (two patients): Cells of this group produced IL 2 messenger RNA, secreted IL 2, and proliferated when cultured in mitogen-free medium. The spontaneous proliferation of the cells in mitogen-free medium was inhibited by anti-Tac/IL 2 receptor and anti-IL 2 monoclonal antibodies. Moreover, the thymidine incorporation by the cells was enhanced in response to exogeneously added recombinant IL 2 and IL 2 produced by themselves. These results indicate that the ATL cells of this group proliferate with autostimulation by IL 2. Group 2 (seven patients): Cells of this group did not secrete IL 2 when cultured in mitogen-free medium, but the cells showed response to exogeneously added recombinant IL 2 and proliferated in culture. These results indicate that the ATL cells of this group proliferate by a paracrine mechanism. Group 3 (one patient): Cells of this group secreted IL 2 in mitogen-free medium. However, the spontaneous proliferation of these cells in vitro was very low, and the response to recombinant IL 2 was also very low. Group 4 (three patients): Cells of this group did not secrete IL 2 in mitogen-free medium. Spontaneous proliferation and the response to recombinant IL 2 were also very low. The clinical feature of all patients of Groups 1 and 2 was acute-type, and that of Groups 3 and 4 was chronic-type. Thus, we conclude that heterogeneous mechanisms exist in the proliferation of leukemic cells, and that growth rate in mitogen-free medium and response to IL 2 of the cells may have a significant relationship to the clinical feature, acute- or chronic-type.

Muramyl dipeptide induced augmentation of the proliferative response of thymocytes to phytohemagglutinin

N-Acetylmuramyl-L-alanyl-D-isoglutamine (MDP) augmented the proliferative response of thymocytes to phytohemagglutinin (PHA). The augmenting effect of MDP disappeared by passage of glass-nonadherent thymocytes through Sephadex G-10 (G-10) column or by removal of low density cells by the Ficoll-Conray gradient centrifugation. The diminished augmenting effects of MDP on the proliferative response of glass-nonadherent-G-10 nonadherent thymocytes was restored by the addition of the G-10 adherent cells. When G-10 adherent cell fraction was extensively depleted of macrophages by glass adherence and EA-rosetting, it was found that neither the macrophage-depleted G-10 adherent cell fraction nor the macrophage fraction supported by itself the proliferative response of G-10 nonadherent thymocytes. However, addition of macrophage fraction together with the macrophage-depleted G-10 adherent cells did support the proliferation of G-10 nonadherent thymocytes. It was further shown that peritoneal exudate macrophages could be substituted for thymic macrophage fraction. These results suggested that both the G-10 adherent-glass nonadherent cells and macrophages were essential for the MDP-induced augmentation of the proliferative response of thymocytes to PHA and these cells exerted different accessory roles in this response.

Urethral metastasis from prostatic carcinoma as diagnosed by immunoperoxidase technique using prostate-specific antigen and prostate-specific acid phosphatase

A rare case of urethral metastasis from prostatic adenocarcinoma is reported. Ordinary histological examination by hematoxylin and eosin staining could not determine whether the primary site was the prostate or the urethra. However, with an immunoperoxidase technique using prostate-specific acid phosphatase and prostate-specific antigen as markers for prostatic cells, we obtained a precise diagnosis of the primary sites. As a result, the patient could be successfully treated with hormonal therapy.

Autocrine growth of interleukin 2-producing leukemic cells in a patient with adult T cell leukemia

Leukemic cells in the peripheral blood of a patient with adult T cell leukemia (ATL), which expressed the Tac antigen/interleukin 2 (IL2) receptor, were investigated in vitro for autocrine growth by IL 2. The cells showed spontaneous proliferation in mitogen-free medium. The spontaneous proliferation of the cells was inhibited by monoclonal anti-IL 2 or anti-Tac antibody. These cells were found to produce messenger RNA for IL 2 and secrete IL 2 during short-term culture in the same medium. Recombinant IL 2 and IL 2 secreted by the cells enhanced the proliferation of the cells in a dose-dependent manner when added to the initial culture. These findings demonstrate that an autocrine mechanism by IL 2 is involved in the proliferation of ATL cells during short-term culture.

Induction and regulation of human interleukin 2 gene expression: significance of protein kinase C activation

Phytohemagglutinin (PHA) and a tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) act synergistically to induce interleukin 2 (IL2) mRNA in human lymphocytes in vitro. The induction was inhibited by a potent inhibitor of protein kinase C (C-kinase), 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7) at less than 10 microM. H-7 inhibited C-kinase activity itself in lymphocytes at the same range of the concentration but did not interfere with the translocation of C-kinase from the cytosol to the membrane fraction of the lymphocytes induced by TPA. H-7 is also known to inhibit cAMP-dependent protein kinase (A-kinase) and cGMP-dependent protein kinase (G-kinase). However, the lymphocytes cultured with dibutyryl cAMP or dibutyryl cGMP could not be activated to produce IL2 mRNA. These results show that activation of C-kinase but not A-kinase and G-kinase is necessary in signal transduction for IL2 gene expression. Prostaglandin E2, which is known to elevate intracellular cAMP level, also inhibited IL2 mRNA induction in the lymphocytes stimulated with PHA and TPA. Addition of alpha-methylornithine and methylglyoxal bis (guanyl hydrazone), which inhibit polyamine synthesis, did not affect the induction of IL2 mRNA in the lymphocytes stimulated with PHA and TPA, indicating that polyamine synthesis is not necessary for IL2 mRNA induction.

Dissection of the role of macrophages in triggering T lymphocytes for interleukin 2 production by monoclonal antibody OKT3

Unfractionated human peripheral blood mononuclear cells produce a small amount of interleukin 2 (IL 2) by stimulation with a monoclonal anti-T3 antibody (OKT3) in vitro. The IL 2 production could be greatly augmented by the addition of a phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). In the presence of TPA, the T cell enriched fraction deprived of macrophages did not produce IL 2, but the T cells pulse-incubated with OKT3 and reconstituted with macrophages efficiently produced IL 2 in subsequent culture in the presence of TPA as did T cells reconstituted with OKT3-pulse-incubated macrophages. The stimulating effect of OKT3 in the presence of macrophages was inhibited dose-dependently by the addition of immunoglobulins, particularly by mouse IgG2a which is the same isotype as that of the OKT3 antibody, showing that it inhibits by blocking the binding of OKT3 to Fc receptors on macrophages. The same extent of IL 2 production was induced in T cells when paraformaldehyde-fixed macrophages were substituted for intact macrophages. Remarkable IL 2 production was also induced by OKT3 when latex beads coated with rabbit anti-mouse IgG2a antibody and TPA were added to the culture. It was confirmed that the production induced by these stimulations was due to an increase of IL 2 mRNA. These results show that effective signals for IL 2 production are generated by efficient crosslinking of T3 molecules which results from multi-interaction of T3 molecules on the T cell membrane and anti-T3 antibody molecules on macrophage membrane or on the surface of the latex particle.

The purification and biological activity of a macrophage-derived factor with interleukin 1-like activities from guinea pigs

A macrophage-derived factor with interleukin 1-like activity was purified from culture supernatant of muramyl dipeptide-stimulated peritoneal exudate macrophages of guinea pigs. Starting with serum-free culture supernatant, the purification was carried out by gel permeation chromatography, affinity chromatography on procion red agarose, removal of carry-over serum proteins by Sepharose-coupled antibodies against bovine serum proteins, anion exchange chromatography and hydrophobic chromatography. The purified sample potentiated the phytohemagglutinin-induced thymidine uptake of thymocytes with a 50% effective concentration of 9.6 X 10(-11) M. The sample showed a single band in polyacrylamide gel electrophoresis, and a 65 kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis by silver staining. A single peak of activity was detected by thymocyte assay at the position corresponding to the stained band in both of the electrophoretic analyses. The purified factor had activities to potentiate the antigenic activation of sensitized T cells for the production of a lymphokine, macrophage migration inhibitory factor, and also the proliferative response of sensitized T cells to antigen. Thus, the 65 kDa factor has activities to modulate various T cell responses in guinea pigs such as interleukin 1 does in other species. The molecular relationship of the 65 kDa macrophage factor to interleukin 1 remains to be determined.

Interleukin 2 mRNA induction in human lymphocytes: analysis of the synergistic effect of a calcium ionophore A23187 and a phorbol ester

Induction of interleukin 2 (IL2) mRNA in human tonsillar lymphocytes under various conditions was examined by cytoplasmic dot hybridization using a 32P-labeled IL2 cDNA probe to study the signal transduction mechanisms which lead to IL2 gene expression. A tumor-promoting phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate (TPA), acted synergistically with a Ca2+ ionophore A23187 or phytohemagglutinin (PHA) to induce a high level of IL2 mRNA in lymphocytes, whereas each of them by itself could not induce the mRNA production. In two-step culture experiments the lymphocytes pulse-incubated with TPA for 1 h (the first culture) could efficiently initiate IL2 mRNA production by subsequent culture with A23187 or PHA (the second culture). Results obtained by removal of extracellular Ca2+ from either the first or second culture revealed that Ca2+ was not necessarily required during the first culture with TPA, but it is essential in the second culture with A23187 or PHA, regardless of the presence or absence of Ca2+ in the first culture. A reagent known to be a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), almost completely inhibited the IL2 mRNA induction in A23187-TPA-stimulated lymphocytes at a concentration of 25 microM, whereas N-(6-aminohexyl)-1-naphthalenesulfonamide that has much lower affinity for calmodulin than W-7 did not inhibit at this concentration. The IL2 mRNA induction was also blocked by the addition of 50 microM of 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate hydrochloride which is known to block the release of Ca2+ from intracellular storage sites. These results show that mobilization of Ca2+ and the calmodulin-dependent regulatory system appear to work synergistically with TPA which probably activates protein kinase C in the pathway to IL2 gene expression.