Characterization of circulating T cells specific for tumor-associated antigens in melanoma patients

We identified circulating CD8+ T-cell populations specific for the tumor-associated antigens (TAAs) MART-1 (27-35) or tyrosinase (368-376) in six of eleven patients with metastatic melanoma using peptide/HLA-A*0201 tetramers. These TAA-specific populations were of two phenotypically distinct types: one, typical for memory/effector T cells; the other, a previously undescribed phenotype expressing both naive and effector cell markers. This latter type represented more than 2% of the total CD8+ T cells in one patient, permitting detailed phenotypic and functional analysis. Although these cells have many of the hallmarks of effector T cells, they were functionally unresponsive, unable to directly lyse melanoma target cells or produce cytokines in response to mitogens. In contrast, CD8+ T cells from the same patient were able to lyse EBV-pulsed target cells and showed robust allogeneic responses. Thus, the clonally expanded TAA-specific population seems to have been selectively rendered anergic in vivo. Peptide stimulation of the TAA-specific T-cell populations in other patients failed to induce substantial upregulation of CD69 expression, indicating that these cells may also have functional defects, leading to blunted activation responses. These data demonstrate that systemic TAA-specific T-cell responses can develop de novo in cancer patients, but that antigen-specific unresponsiveness may explain why such cells are unable to control tumor growth.

Dendritic cells in cancer immunotherapy

The potential to harness the potency and specificity of the immune system underlies the growing interest in cancer immunotherapy. One such approach uses bone marrow-derived dendritic cells, phenotypically distinct and extremely potent antigen-presenting cells, to present tumor-associated antigens and thereby generate tumor-specific immunity. Support for this strategy comes from animal studies that have demonstrated that dendritic cells, when loaded ex vivo with tumor antigens and administered to tumor-bearing hosts, can elicit T cell-mediated tumor destruction. These observations have led to clinical trials designed to investigate the immunologic and clinical effects of antigen-loaded dendritic cells administered as a therapeutic vaccine to patients with cancer. In the design and conduct of such trials, important considerations include antigen selection, methods for introducing the antigen into MHC class I and II processing pathways, methods for isolating and activating dendritic cells, and route of administration. Although current dendritic cell-based vaccination methods are cumbersome, promising results from clinical trials in patients with malignant lymphoma, melanoma, and prostate cancer suggest that immunotherapeutic strategies that take advantage of the antigen presenting properties of dendritic cells may ultimately prove both efficacious and widely applicable to human tumors.

Interactions among members of the Bcl-2 protein family analyzed with a yeast two-hybrid system

Interactions of the Bcl-2 protein with itself and other members of the Bcl-2 family, including Bcl-X-L, Bcl-X-S, Mcl-1, and Bax, were explored with a yeast two-hybrid system. Fusion proteins were created by linking Bcl-2 family proteins to a LexA DNA-binding domain or a B42 trans-activation domain. Protein-protein interactions were examined by expression of these fusion proteins in Saccharomyces cerevisiae having a lacZ (beta-galactosidase) gene under control of a LexA-dependent operator. This approach gave evidence for Bcl-2 protein homodimerization. Bcl-2 also interacted with Bcl-X-L and Mcl-1 and with the dominant inhibitors Bax and Bcl-X-S. Bcl-X-L displayed the same pattern of combinatorial interactions with Bcl-2 family proteins as Bcl-2. Use of deletion mutants of Bcl-2 suggested that Bcl-2 homodimerization involves interactions between two distinct regions within the Bcl-2 protein, since a LexA protein containing Bcl-2 amino acids 83-218 mediated functional interactions with a B42 fusion protein containing Bcl-2 amino acids 1-81 but did not complement a B42 fusion protein containing Bcl-2 amino acids 83-218. In contrast to LexA/Bcl-2 fusion proteins, expression of a LexA/Bax protein was lethal to yeast. This cytotoxicity could be abrogated by B42 fusion proteins containing Bcl-2, Bcl-X-L, or Mcl-1 but not those containing Bcl-X-S (an alternatively spliced form of Bcl-X that lacks a well-conserved 63-amino acid region). The findings suggest a model whereby Bax and Bcl-X-S differentially regulate Bcl-2 function, and indicate that requirements for Bcl-2/Bax heterodimerization may be different from those for Bcl-2/Bcl-2 homodimerization.

Altered peptide ligand vaccination with Flt3 ligand expanded dendritic cells for tumor immunotherapy

Most tumor-associated antigens represent self-proteins and as a result are poorly immunogenic due to immune tolerance. Here we show that tolerance to carcinoembryonic antigen (CEA), which is overexpressed by the majority of lethal malignancies, can be reversed by immunization with a CEA-derived peptide. This peptide was altered to make it a more potent T cell antigen and loaded onto dendritic cells (DCs) for delivery as a cellular vaccine. Although DCs are rare in the blood, we found that treatment of advanced cancer patients with Flt3 ligand, a hematopoietic growth factor, expanded DCs 20-fold in vivo. Immunization with these antigen-loaded DCs induced CD8 cytotoxic T lymphocytes that recognized tumor cells expressing endogenous CEA. Staining with peptide-MHC tetramers demonstrated the expansion of CD8 T cells that recognize both the native and altered epitopes and possess an effector cytotoxic T lymphocyte phenotype (CD45RA(+)CD27(-)CCR7(-)). After vaccination, two of 12 patients experienced dramatic tumor regression, one patient had a mixed response, and two had stable disease. Clinical response correlated with the expansion of CD8 tetramer(+) T cells, confirming the role of CD8 T cells in this treatment strategy.

Randomized phase III KEYNOTE-045 trial of pembrolizumab versus paclitaxel, docetaxel, or vinflunine in recurrent advanced urothelial cancer: results of >2 years of follow-up

Background

Novel second-line treatments are needed for patients with advanced urothelial cancer (UC). Interim analysis of the phase III KEYNOTE-045 study showed a superior overall survival (OS) benefit of pembrolizumab, a programmed death 1 inhibitor, versus chemotherapy in patients with advanced UC that progressed on platinum-based chemotherapy. Here we report the long-term safety and efficacy outcomes of KEYNOTE-045.

Patients and methods

Adult patients with histologically/cytologically confirmed UC whose disease progressed after first-line, platinum-containing chemotherapy were enrolled. Patients were randomly assigned 1 : 1 to receive pembrolizumab [200 mg every 3 weeks (Q3W)] or investigator’s choice of paclitaxel (175 mg/m² Q3W), docetaxel (75 mg/m² Q3W), or vinflunine (320 mg/m² Q3W). Primary end points were OS and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1) by blinded independent central radiology review (BICR). A key secondary end point was objective response rate per RECIST v1.1 by BICR.

Results

A total of 542 patients were enrolled (pembrolizumab, n = 270; chemotherapy, n = 272). Median follow-up as of 26 October 2017 was 27.7 months. Median 1- and 2-year OS rates were higher with pembrolizumab (44.2% and 26.9%, respectively) than chemotherapy (29.8% and 14.3%, respectively). PFS rates did not differ between treatment arms; however, 1- and 2-year PFS rates were higher with pembrolizumab. The objective response rate was also higher with pembrolizumab (21.1% versus 11.0%). Median duration of response to pembrolizumab was not reached (range 1.6+ to 30.0+ months) versus chemotherapy (4.4 months; range 1.4+ to 29.9+ months). Pembrolizumab had lower rates of any grade (62.0% versus 90.6%) and grade ≥3 (16.5% versus 50.2%) treatment-related adverse events than chemotherapy.

Conclusions

Long-term results (>2 years’ follow-up) were consistent with those of previously reported analyses, demonstrating continued clinical benefit of pembrolizumab over chemotherapy for efficacy and safety for treatment of locally advanced/metastatic, platinum-refractory UC.

Trial registration

ClinicalTrials.gov: NCT02256436.

Dendritic cells injected via different routes induce immunity in cancer patients

Dendritic cells (DC) represent potent APCs that are capable of generating tumor-specific immunity. We performed a pilot clinical trial using Ag-pulsed DC as a tumor vaccine. Twenty-one patients with metastatic prostate cancer received two monthly injections of DC enriched and activated from their PBMC. DC were cocultured ex vivo with recombinant mouse prostatic acid phosphatase as the target neoantigen. Following enrichment, DC developed an activated phenotype with up-regulation of CD80, CD86, and CD83 expression. During culture, the DC maintained their levels of various adhesion molecules, including CD44, LFA-1, cutaneous lymphocyte-associated Ag, and CD49d, up-regulated CCR7, but lost CD62 ligand and CCR5. In the absence of CD62 ligand, such cells would not be expected to prime T cells efficiently if administered i.v. due to their inability to access lymphoid tissue via high endothelial venules. To assess this possibility, three patient cohorts were immunized with Ag-pulsed DC by i.v., intradermal (i.d.), or intralymphatic (i.l.) injection. All patients developed Ag-specific T cell immune responses following immunization, regardless of route. Induction of IFN-gamma production, however, was seen only with i.d. and i.l. routes of administration, and no IL-4 responses were seen regardless of route, consistent with the induction of Th1-type immunity. Five of nine patients who were immunized by the i.v. route developed Ag-specific Abs compared with one of six for i.d. and two of six for i.l. routes. These results suggest that while activated DC can prime T cell immunity regardless of route, the quality of this response and induction of Ag-specific Abs may be affected by the route of administration.

Dendritic cell-based xenoantigen vaccination for prostate cancer immunotherapy

Many tumor-associated Ags represent tissue differentiation Ags that are poorly immunogenic. Their weak immunogenicity may be due to immune tolerance to self-Ags. Prostatic acid phosphatase (PAP) is just such an Ag that is expressed by both normal and malignant prostate tissue. We have previously demonstrated that PAP can be immunogenic in a rodent model. However, generation of prostate-specific autoimmunity was seen only when a xenogeneic homolog of PAP was used as the immunogen. To explore the potential role of xenoantigen immunization in cancer patients, we performed a phase I clinical trial using dendritic cells pulsed with recombinant mouse PAP as a tumor vaccine. Twenty-one patients with metastatic prostate cancer received two monthly vaccinations of xenoantigen-loaded dendritic cells with minimal treatment-associated side effects. All patients developed T cell immunity to mouse PAP following immunization. Eleven of the 21 patients also developed T cell proliferative responses to the homologous self-Ag. These responses were associated with Ag-specific IFN-gamma and/or TNF-alpha secretion, but not IL-4, consistent with induction of Th1 immunity. Finally, 6 of 21 patients had clinical stabilization of their previously progressing prostate cancer. All six of these patients developed T cell immunity to human PAP following vaccination. These results demonstrate that xenoantigen immunization can break tolerance to a self-Ag in humans, resulting in a clinically significant antitumor effect.

Predictors of responses to immune checkpoint blockade in advanced melanoma

Immune checkpoint blockers (ICB) have become pivotal therapies in the clinical armamentarium against metastatic melanoma (MMel). Given the frequency of immune related adverse events and increasing use of ICB, predictors of response to CTLA-4 and/or PD-1 blockade represent unmet clinical needs. Using a systems biology-based approach to an assessment of 779 paired blood and tumor markers in 37 stage III MMel patients, we analyzed association between blood immune parameters and the functional immune reactivity of tumor-infiltrating cells after ex vivo exposure to ICB. Based on this assay, we retrospectively observed, in eight cohorts enrolling 190 MMel patients treated with ipilimumab, that PD-L1 expression on peripheral T cells was prognostic on overall and progression-free survival. Moreover, detectable CD137 on circulating CD8⁺ T cells was associated with the disease-free status of resected stage III MMel patients after adjuvant ipilimumab + nivolumab (but not nivolumab alone). These biomarkers should be validated in prospective trials in MMel.The clinical management of metastatic melanoma requires predictors of the response to checkpoint blockade. Here, the authors use immunological assays to identify potential prognostic/predictive biomarkers in circulating blood cells and in tumor-infiltrating lymphocytes from patients with resected stage III melanoma.

Induction of immunity to antigens expressed by recombinant adeno-associated virus depends on the route of administration

Recombinant adeno-associated virus (rAAV) is a replication-defective parvovirus which is being explored as a vector for gene therapy because of its broad host range, excellent safety profile, and durable transgene expression in infected hosts. rAAV has also been reported by several groups to induce little or no immune response to its encoded transgene products. In this study we examined the immunogenicity of rAAV by studying the immune response of C57BL/6 mice to a single dose of rAAV-encoding ovalbumin (AAV-Ova) administered by a variety of routes. Mice injected with AAV-Ova intraperitoneally (ip), intravenously, or subcutaneously developed potent ovalbumin-specific cytotoxic T lymphocytes (CTL) as well as anti-ovalbumin antibodies and antibodies to AAV. In contrast, mice injected with AAV-Ova intramuscularly developed a humoral response to the virus and the transgene but minimal ovalbumin-specific CTLs. The induced CTL response after ip administration of AAV-Ova protected mice against a subsequent tumor challenge with an ovalbumin-transfected B16 melanoma cell line. Studies of the mechanism by which AAV-Ova induces CTL confirmed that the virus delivers the transgene product into the classical MHC class I pathway of antigen processing. Mice that previously had been exposed to rAAV vectors failed to develop ovalbumin-specific CTL following administration of AAV-Ova. Analysis of these mice revealed the presence of circulating anti-AAV antibodies that blocked rAAV transduction in vitro and inhibited CTL induction in vivo. These results suggest a possible role for rAAV in the immunotherapy of malignancies and viral infections, although induced antibody responses to AAV may limit its ability to be administered for repeated vaccinations.

Intratumoral delivery of tavokinogene telseplasmid yields systemic immune responses in metastatic melanoma patients

BACKGROUND

Interleukin 12 (IL-12) is a pivotal regulator of innate and adaptive immunity. We conducted a prospective open-label, phase II clinical trial of electroporated plasmid IL-12 in advanced melanoma patients (NCT01502293).

PATIENTS AND METHODS

Patients with stage III/IV melanoma were treated intratumorally with plasmid encoding IL-12 (tavokinogene telseplasmid; tavo), 0.5 mg/ml followed by electroporation (six pulses, 1500 V/cm) on days 1, 5, and 8 every 90 days in the main study and additional patients were treated in two alternative schedule exploration cohorts. Correlative analyses for programmed death-ligand 1 (PD-L1), flow cytometry to assess changes in immune cell subsets, and analysis of immune-related gene expression were carried out on pre- and post-treatment samples from study patients, as well as from additional patients treated during exploration of additional dosing schedules beyond the pre-specified protocol dosing schedule. Response was measured by study-specific criteria to maximize detection of latent and potentially transient immune responses in patients with multiple skin lesions and toxicities were graded by the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4.0).

RESULTS

The objective overall response rate was 35.7% in the main study (29.8% in all cohorts), with a complete response rate of 17.9% (10.6% in all cohorts). The median progression-free survival in the main study was 3.7 months while the median overall survival was not reached at a median follow up of 29.7 months. A total of 46% of patients in all cohorts with uninjected lesions experienced regression of at least one of these lesions and 25% had a net regression of all untreated lesions. Transcriptomic and immunohistochemistry analysis showed that immune activation and co-stimulatory transcripts were up-regulated but there was also increased adaptive immune resistance.

CONCLUSIONS

Intratumoral Tavo was well tolerated and led to systemic immune responses in advanced melanoma patients. While tumor regression and increased immune infiltration were observed in treated as well as untreated/distal lesions, adaptive immune resistance limited the response.

Ibrutinib in combination with nab-paclitaxel and gemcitabine for first-line treatment of patients with metastatic pancreatic adenocarcinoma: phase III RESOLVE study

BACKGROUND

First-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC) includes nab-paclitaxel/gemcitabine. Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumor activity through tumor microenvironment modulation. The safety and efficacy of first-line ibrutinib plus nab-paclitaxel/gemcitabine treatment in patients with PDAC were evaluated.

PATIENTS AND METHODS

RESOLVE (NCT02436668) was a phase III, randomized, double-blind, placebo-controlled study. Patients (histologically-confirmed PDAC; stage IV diagnosis ≥6 weeks of randomization; Karnofsky performance score ≥70) were randomized to once-daily oral ibrutinib (560 mg) or placebo plus nab-paclitaxel (125 mg/m²) and gemcitabine (1000 mg/m²). Primary endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS); overall response rate and safety were assessed.

RESULTS

In total, 424 patients were randomized (ibrutinib arm, n = 211; placebo arm, n = 213). Baseline characteristics were balanced across arms. After a median follow-up of 25 months, there was no significant difference in OS between ibrutinib plus nab-paclitaxel/gemcitabine versus placebo plus nab-paclitaxel/gemcitabine (median of 9.7 versus 10.8 months; P = 0.3225). PFS was shorter for ibrutinib plus nab-paclitaxel/gemcitabine compared with placebo plus nab-paclitaxel/gemcitabine (median 5.3 versus 6.0 months; P < 0.0001). Overall response rates were 29% and 42%, respectively (P = 0.0058). Patients in the ibrutinib arm had less time on treatment and received lower cumulative doses for all agents compared with the placebo arm. The most common grade ≥3 adverse events for ibrutinib versus placebo arms included neutropenia (24% versus 35%), peripheral sensory neuropathy (17% versus 8%), and anemia (16% versus 17%). Primary reasons for any treatment discontinuation were disease progression and adverse events.

CONCLUSIONS

Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with PDAC. Safety was consistent with known profiles for these agents.

Efficacy and safety of pembrolizumab in metastatic urothelial carcinoma: results from KEYNOTE-045 and KEYNOTE-052 after up to 5 years of follow-up

BACKGROUND

Immune checkpoint inhibitors are a standard therapy in metastatic urothelial carcinoma (UC). Long-term follow-up is necessary to confirm durability of response and identify further safety concerns.

PATIENTS AND METHODS

In KEYNOTE-045, patients with metastatic UC that progressed on platinum-containing chemotherapy were randomly assigned 1:1 to receive pembrolizumab or investigator's choice of paclitaxel, docetaxel, or vinflunine. Primary endpoints were progression-free survival per RECIST version 1.1 by blinded independent central review (BICR) and overall survival. In KEYNOTE-052, cisplatin-ineligible patients with metastatic UC received first-line pembrolizumab. The primary endpoint was objective response rate per RECIST version 1.1 by BICR.

RESULTS

A total of 542 patients (pembrolizumab, n = 270; chemotherapy, n = 272) were randomly assigned in KEYNOTE-045. The median follow-up was 62.9 months (range 58.6-70.9 months; data cut-off 1 October 2020). At 48 months, overall survival rates were 16.7% for pembrolizumab and 10.1% for chemotherapy; progression-free survival rates were 9.5% and 2.7%, respectively. The median duration of response (DOR) was 29.7 months (range 1.6+ to 60.5+ months) for pembrolizumab and 4.4 months (range 1.4+ to 63.1+ months) for chemotherapy; 36-month DOR rates were 44.4% and 28.3%, respectively. A total of 370 patients were enrolled in KEYNOTE-052. The median follow-up was 56.3 months (range 51.2-65.3 months; data cut-off 26 September 2020). The confirmed objective response rate was 28.9% (95% confidence interval 24.3-33.8), and the median DOR was 33.4 months (range 1.4+ to 60.7+ months); the 36-month DOR rate was 44.8%. Most treatment-related adverse events for pembrolizumab in either study were grade 1 or 2 and manageable, which is consistent with prior reports.

CONCLUSION

With ∼5 years of follow-up, pembrolizumab monotherapy continued to demonstrate durable efficacy with no new safety signals in patients with platinum-resistant metastatic UC and as first-line therapy in cisplatin-ineligible patients.

CLINICAL TRIAL REGISTRY AND ID

With ClinicalTrials.gov NCT02256436 (KEYNOTE-045); https://clinicaltrials.gov/ct2/show/NCT02256436 and NCT02335424 (KEYNOTE-052); https://clinicaltrials.gov/ct2/show/NCT02335424.

I. Depressed immunological function in zinc-deprived rats as measured by mitogen response of spleen, thymus, and peripheral blood

The in vitro responses of splenic, thymic, and peripheral blood lymphocytes to two T-cell mitogens (phytohemagglutinin and concanavalin A) and one B-cell mitogen (pokeweed mitogen) were investigated in zinc-deprived and pair-fed control rats. The responses to phytohemagglutinin of splenic, thymic, and peripheral blood lymphocytes from zinc-deprived animals were depressed by at least 50% in comparison with those of controls, and the difference between the two groups was significant for each tissue (P = 0.05). The responses to concanavalin A of splenic and peripheral blood lymphocytes were suppressed in zinc-deprived animals, and splenic and thymic responses to pokeweed mitogen were depressed by about 50% in comparison with those of controls; these results were significant at the P = 0.05 level. This study is the first to evaluate the effects of diet-induced zinc deprivation on lymphocyte transformation and immune function in rats.

A phase 1 trial of imatinib, bevacizumab, and metronomic cyclophosphamide in advanced colorectal cancer

Background:

This phase 1 clinical trial was conducted to determine the safety, maximum-tolerated dose (MTD), and pharmacokinetics of imatinib, bevacizumab, and metronomic cyclophosphamide in patients with advanced colorectal cancer (CRC).

Methods:

Patients with refractory stage IV CRC were treated with bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks (fixed dose) plus oral cyclophosphamide q.d. and imatinib q.d. or b.i.d. in 28-day cycles with 3+3 dose escalation. Response was assessed every two cycles. Pharmacokinetics of imatinib and cyclophosphamide and circulating tumour, endothelial, and immune cell subsets were measured.

Results:

Thirty-five patients were enrolled. Maximum-tolerated doses were cyclophosphamide 50 mg q.d., imatinib 400 mg q.d., and bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks. Dose-limiting toxicities (DLTs) included nausea/vomiting, neutropaenia, hyponatraemia, fistula, and haematuria. The DLT window required expansion to 42 days (1.5 cycles) to capture delayed toxicities. Imatinib exposure increased insignificantly after adding cyclophosphamide. Seven patients (20%) experienced stable disease for >6 months. Circulating tumour, endothelial, or immune cells were not associated with progression-free survival.

Conclusion:

The combination of metronomic cyclophosphamide, imatinib, and bevacizumab is safe and tolerable without significant drug interactions. A subset of patients experienced prolonged stable disease independent of dose level.

Experience of radiotherapy in lethal midline granuloma with special emphasis on centrofacial T-cell lymphoma: a retrospective analysis covering a 34-year period

Lethal midline granuloma (LMG) is characterized by progressive ulceration and destruction of the midfacial tissue. It occurs more frequently in Oriental than in Western populations. Because of the progress in clinical pathology and immunohistochemistry, most cases have been proven to be malignant lymphomas, especially of T-cell lineage. We describe 92 cases of lethal midline granuloma or centrofacial malignant lymphoma in the period 1959-1993. All received complete courses of radiotherapy. Twenty of them also received combination chemotherapy. Thirty-six cases had specimens available for immunohistochemical study; 25 (69%) of these had a T-cell phenotype, and 6 (17%) were of B-cell lineage. The dose to the nasal region was in the range of 3000-7500 cGy in 11-58 days, and to the neck 3000-6400 cGy in 11-48 days. The overall survival rate for the LMGs was 59.5% at 5 years and 56.2% at 10 years (Kaplan-Meier). Combined chemotherapy seemed not to improve the overall survival in this study (p = 0.63), but the patient number was too small to make a firm conclusion. Based on the results of this study, we recommend a dose of 4500-5000 cGy to the midfacial region, since a higher dosage did not improve the treatment results (p = 0.88). Irradiation has a definite role in good locoregional control of this disease. The recent clarification of the disease nature and the recognition of the background clinicopathological features should provide valuable information for future patient management and prospective studies.

Donor blood monocytes but not T or B cells facilitate long-term allograft survival after total lymphoid irradiation

BACKGROUND

Previous studies showed that a combination of posttransplant total lymphoid irradiation (TLI), rabbit antithymocyte globulin (ATG), and a single donor blood transfusion induced tolerance to ACI heart allografts in Lewis rats. All three modalities were required to achieve tolerance. The objective of the current study was to determine the subset(s) of cells in the donor blood that facilitated long-term allograft survival.

METHODS

Lewis hosts received TLI, ATG, and donor cell infusion after heart transplantation. Graft survival, mixed leukocyte reaction (MLR), and intragraft cytokine mRNA were studied.

RESULTS

The intravenous injection of 25 x 10(6) ACI peripheral blood mononuclear cells (PBMC) significantly prolonged graft survival as compared with that of Lewis hosts given TLI and ATG alone. Injection of highly enriched blood T cells or splenic B cells adjusted for the number contained in 25 x 10(6) PBMC failed to induce significant graft prolongation. Unexpectedly, depletion of monocytes (CD11b+ cells) from PBMC resulted in the loss of graft prolongation activity. Enriched populations of monocytes obtained by plastic adherence were more efficient in prolonging graft survival than PBMC on a per cell basis. Hosts with long-term grafts (>100-day survival) showed evidence of immune deviation, because the MLR to ACI stimulator cells was vigorous, but secretion of interferon-gamma in the MLR was markedly reduced. In situ hybridization studies of long-term grafts showed markedly reduced levels of interferon-gamma mRNA as compared with rejecting grafts.

CONCLUSION

Infusion of donor monocytes facilitated graft prolongation via immune deviation.

Gastric and oesophageal carcinogenesis: models for the identification of risk and protective factors

Male weanling rats of the Charles River Sprague-Dawley strain were exposed to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the water for 3 months at the concentration of 75 ml/litre. Other real or potential risk factors were administered, alone or in combination with MNNG. When MNNG was administered in combination with NaCl, bile acids, aspirin or BHA, forestomach tumours were enhanced. MNNG-induced tumours were inhibited by selenium or by difluoromethylornithine, an ornithine decarboxylase inhibitor. BHA alone caused forestomach tumours. When BHA was administered by dietary means or by gavage, alone or in combination with MNNG, the gavage method resulted in greater tumorigenesis than dietary exposure. This increase was associated with increased [3H]thymidine labelling of forestomach epithelium and increased hyperplasia. Oesophageal carcinogenesis induced by methylbenzylnitrosamine (MBN) was enhanced by zinc deficiency, alcohol and 13-cis-retinoic acid. Zinc deficiency also resulted in oesophageal tumours in rats exposed to the hepatocarcinogen dimethylnitrosamine. Riboflavin deficiency injured oral and oesophageal epithelium and increased sensitivity to MBN-induced oesophageal tumours.

Fetoplacental growth in sheep administered progesterone during the first three days of pregnancy

We have previously shown that administration of progesterone during early pregnancy in sheep enhances fetal weight and crown-rump length. The present study examined the effect of this treatment on individual fetal organ weights and on placental growth and structure. Embryos that had been exposed to either a normal or a high concentration of progesterone on days 1-3 in initial recipient ewes were transferred at random to final recipient ewes that had or had not been treated with progesterone on days 1-3. Embryos in an additional group of ewes were exposed to progesterone on days 1-3 with oviducts of the ewes ligated. An increase in fetal weight was observed in the final recipient group that had been treated with progesterone (P< 0.01) but not in the initial group treated with progesterone. Fetal weight was increased (P< 0.05) in the initial recipients treated with progesterone plus ligation. Placental weight did not differ between any of the treatments in either initial or final recipients, while placental volumes of chorionic membrane and maternal crypts were increased by progesterone, with and without ligation, in initial recipients (P< 0.05). The responses of fetal weight in final recipients were associated with increases in the weight and linear dimensions of specific fetal components (e.g. brain, kidney, heart, spleen, total gut, head width, thorax circumference). Proportionate increases were observed for most parameters with the exception of brain, heart and M tibialis anterior weight; adjusted least squares means indicated disproportionate increases in these of 5 per cent, 32 per cent and 26 per cent respectively. Enhanced fetal weight in the progesterone plus ligation group was associated with increased (P< 0.05) heart weight; a disproportionate increase of 39 per cent was recorded. Increased fetal weight and fetal heart, skeletal muscle and brain weight were correlated with increased volumes and surface area of the fetal trophectoderm and maternal fetomaternal syncytium in the final recipients treated with progesterone. It is concluded that alteration of the embryo's environment during the first few days of development enhances fetal growth disproportionately, in close association with increased abundance of the exchange epithelia in the placenta.

Twenty-month effectiveness of a non-aversive, long-term, low-cost programme for persons with persisting neurobehavioural disability

PRIMARY OBJECTIVE

To examine the effectiveness of a programme developed for persons with persisting neurobehavioural/ neuropsychiatric disorders.

RESEARCH DESIGN

Descriptive study of a programme that has a philosophy of normalization, respect, non-confrontation, positive engagement, support and functional and behavioural skill development.

METHODS AND PROCEDURES

Participants were the 40 clients admitted during the initial 20 months of operation. Prior to admission clients had recurrent placement failures secondary to behavioural disregulation and typically were housed at County or State Hospitals. An expanded version of the Overt Aggression Scale Modified for Neurorehabilitation was used to provide detailed descriptions of assaults.

MAIN OUTCOMES AND RESULTS

Over the 20-month period, 49 incidents of client-to-client aggression occurred representing a rate of 0.11 incidents per client month. Thirty-five of 40 clients remained at the end of 20 months, with only three discharges due to behaviour.

CONCLUSIONS

A long-term, stable living environment has been provided for individuals who had been intractable management problems elsewhere.

Elevated 1,25-dihydroxyvitamin D levels in patients with chronic obstructive pulmonary disease treated with prednisone

Glucocorticoid administration is a well established cause of osteopenia. Mechanisms underlying the deleterious effect of glucocorticoids on bone may include direct inhibition of bone formation as well as indirect effects through changes in intestinal calcium absorption, renal calcium excretion, and/or levels of the calciotropic hormones. To further examine the potential role of the calciotropic hormones we measured serum levels of PTH and 1,25 dihydroxyvitamin D [1,25(OH)2D], as well as serum and urine levels of calcium and vertebral bone density in patients with chronic obstructive pulmonary disease being managed with or without prednisone. Patients treated with prednisone had lower spinal bone density (53 vs. 106 mg/cm3) and higher serum calcium (2.40 vs. 2.33 mmol/l), urine calcium (6.9 vs. 2.7 mmol/24h), and 1,25(OH)2D levels (147 vs. 95 pmol/L). Compared to the patients not treated with glucocorticoids. PTH levels also tended to be higher (33 vs. 26 microliters-eq/ml), but the difference was not significant. Serum and urine calcium levels correlated positively with 1,25(OH)2D levels, but none of these measurements correlated with PTH levels. Our results suggest that prednisone treatment alters the regulation of 1,25(OH)2D production, and this may contribute to the loss of bone mineral induced by prednisone.

Protective effects of Labisia pumila against neuropathy in a diabetic rat model

Purpose

Diabetes accelerates peripheral, distal symmetric polyneuropathy, small fiber predominant neuropathy, radiculoplexopathy, and autonomic neuropathy. This study investigated the neuroprotective effects of gallic acid and myricetin-rich Labisia pumila extract in a diabetic neuropathy rat model and evaluated the neuropathy correlationship with serum inflammatory biomarkers.

Methods

Thirty male rats were divided into 5 groups (n = 6), namely: healthy control; non-treated diabetic control; and diabetic-rats treated with 200 mg/kg metformin; Labisia pumila ethanol extract (LP) at 150 mg/kg or 300 mg/kg doses. Diabetes was induced by 60 mg streptozotocin /kg intraperitoneal injection. Rats were orally treated daily for ten weeks. Their fasting blood glucose (FBG), neurological functions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), biomarkers for inflammation and oxidative stress, the neuro-histopathological changes, and brain somatic index were measured.

Results

The extract significantly prevented abnormal increases in FBG and decreases in body weight gain. It attenuated behavioral dysfunctions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), systemic inflammation (serum TNF-α, prostaglandin-E2) oxidative tension (malondialdehyde), histological brain and sciatic nerve injuries in the diabetic-rats, better than Metformin.

Conclusion

LP mitigated neural dysfunction better than metformin partly by amending diabetic systemic inflammation, oxidative tension, and diabetic abnormalities. The nerve injuries were strongly correlated to serum prostaglandin-E2, TNF-α levels, and walking functions. The motor function was correlated to sensory neuronal functions, inflammation, and oxidation. The sensory neuronal functions were more affected by TNF-α than prostaglandin-E2 or oxidation. Diabetic brain and sciatic nerve deteriorations were influenced by serum TNF-α, PGE2, and MDA levels.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00905-0.

II. In vitro restoration by levamisole of mitogen responsiveness in zinc-deprived rats

The effect of levamisole on the in vitro responses of splenic and peripheral blood lymphocytes to phytohemagglutinin were investigated in zinc-deprived and pair-fed control rats. The in vitro response of lymphocytes from zinc-deprived rats was markedly impaired in comparison with that of controls. The addition of levamisole to cultures of zinc-deprived splenic lymphocytes significantly improved their response to phytohemagglutinin by 54%. The addition of levamisole to cultures of zinc-deprived peripheral blood lymphocytes significantly improved their response by 116.2%. The addition of levamisole to control lymphocyte culture had no effect. This study may be the first to evaluate the beneficial effect of an immunomodulating agent on immune function in a nutritionally deprived host.

Gemifloxacin inhibits cytokine secretion by lipopolysaccharide stimulated human monocytes at the post-transcriptional level

The fluroquinolone gemifloxacin was examined for its capacity to modulate secretion of cytokines by human monocytes stimulated with lipopolysaccharide (LPS). Monocytes from six male and two female healthy volunteers were stimulated with LPS, exposed to gemifloxacin and the amounts of secreted IL-1 alpha, IL-1 beta, IL-6, IL-10 and TNF-alpha measured at 3, 6 and 24 h. The results revealed that LPS alone increased secretion of each cytokine significantly. Treatment of the LPS-stimulated monocytes with gemifloxacin resulted in a significant inhibition (p < 0.01) of secretion of each of the cytokines from monocytes of the eight volunteers. Nuclear extracts of the human monocyte cell line, THP-1, were used in the electrophoretic mobility shift assay to determine whether gemifloxacin affects nuclear factor-kappa B (NF-kappa B) activation. In addition, RNA from THP-1 cells was used in Northern blots to determine whether inhibition of secretion of IL-1 beta and TNF-alpha by gemifloxacin occurred at the transcription or translation level. Whereas LPS induced a rapid increase in NF-kappa B activation, gemifloxacin alone did not. Gemifloxacin did not affect the kinetics or decrease the extent of activation. Northern blots indicated that the inhibitory activity of gemifloxacin occurred post-transcription. Thus, gemifloxacin may modulate the immune response by altering secretion of cytokines by human monocytes. Although the concentrations of gemifloxacin used were higher than those observed in the serum of human volunteers treated with the dose under clinical development, it should be taken into consideration that concentrations at tissue and intracellular levels may be considerably higher than serum concentrations.

Prevalence of Toxoplasma gondii Antibodies in Stray Dogs from Various Locations in West and East Malaysia

Toxoplasmosis is caused by an obligate intracellular protozoan parasite; Toxoplasma gondii, which is one of the most important zoonotic parasite worldwide. In dogs, the sexual reproductive cycle of T. gondii is lacking, and the animals are not widely consumed as food, but they are vital in the mechanical transmission of the parasite. However, there is no present data on the exposure of stray dogs to T. gondii in Malaysia. The objective of this serological survey was to determine the prevalence of T. gondii antibodies (IgG) and associated factors in stray dogs in East and West Malaysia. Antibodies to T. gondii were determined in serum samples from 222 stray dogs from 6 different states in East and West Malaysia (Peninsular Malaysia) using an Indirect ELISA. The seroprevalence for T. gondii was 23.4% (Confidence interval: CI 17.8-29.2%). Stray dogs from Selangor and Kuala Lumpur had the highest seroprevalence (32.4%; CI 13.2-45.5%) and lowest in those from Penang and Kedah (12.5%; CI 1.3-23.5%). Gender and breed were not associated with T. gondii seropositivity. However, adult dogs were more likely to be seropositive for T. gondii (OR=2.89; CI 1.1-7.7) compared with younger dogs. These results revealed that T. gondii is prevalent in stray dogs in the studied areas in Malaysia, and indicative of the level of environmental contamination of this parasite especially in urban areas.