Secreted heat shock protein gp96-Ig and OX40L-Fc combination vaccine enhances SARS-CoV-2 Spike (S) protein-specific B and T cell immune responses

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gp96-Ig-S-OX40L-Fc vaccine enhances S-specific IgG responses.

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gp96-Ig-S-OX40L-Fc vaccine enhances TFH cell responses.

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gp96-Ig-S-OX40L-Fc vaccine enhances lungs S-specific CD8 + T cell responses.

Encouraging protection results from current mRNA-based SARS-CoV-2 vaccine platforms are primarily due to the induction of SARS- CoV-2- specific B cell antibody and CD4 + T cell. Even though, current mRNA vaccine platforms are adept in inducing SARS-CoV2-specific CD8 + T cell, much less is known about CD8 T cells contribution to the overall vaccine protection. Our allogeneic cellular vaccine, based on a secreted form of the heat-shock protein gp96-Ig, achieves high frequencies of polyclonal CD8 + T cell responses to tumor and infectious antigens through antigen cross-priming in vivo. We and others have shown that gp96-Ig, in addition to antigen-specific CD8 + T cell anti-tumor and anti-pathogen immunity, primes antibody responses as well. Here, we generated a cell-based vaccine that expresses SARS-Cov-2 Spike (S) protein and simultaneously secretes gp96-Ig and OX40L-Fc fusion proteins. We show that co-secretion of gp96-Ig-S peptide complexes and the OX40L-Fc costimulatory fusion protein in allogeneic cell lines results in enhanced activation of S protein-specific IgG antibody responses. These findings were further strengthened by the observation that this vaccine platform induces T follicular helper cells (TFH) and protein-S -specific CD8 + T cells. Thus, a cell-based gp96-Ig vaccine/OX40-L fusion protein regimen provides encouraging translational data that this vaccine platform induces pathogen-specific CD8+, CD4 + T and B cell responses, and may cohesively work as a booster for FDA-approved vaccines. Our vaccine platform can be rapidly engineered and customized based on other current and future pathogen sequences.

Induction of SARS-CoV-2 Protein S-Specific CD8+ T Cells in the Lungs of gp96-Ig-S Vaccinated Mice

Given the aggressive spread of COVID-19-related deaths, there is an urgent public health need to support the development of vaccine candidates to rapidly improve the available control measures against SARS-CoV-2. To meet this need, we are leveraging our existing vaccine platform to target SARS-CoV-2. Here, we generated cellular heat shock chaperone protein, glycoprotein 96 (gp96), to deliver SARS-CoV-2 protein S (spike) to the immune system and to induce cell-mediated immune responses. We showed that our vaccine platform effectively stimulates a robust cellular immune response against protein S. Moreover, we confirmed that gp96-Ig, secreted from allogeneic cells expressing full-length protein S, generates powerful, protein S polyepitope-specific CD4+ and CD8+ T cell responses in both lung interstitium and airways. These findings were further strengthened by the observation that protein-S -specific CD8+ T cells were induced in human leukocyte antigen HLA-A2.1 transgenic mice thus providing encouraging translational data that the vaccine is likely to work in humans, in the context of SARS-CoV-2 antigen presentation.

Tumor microenvironment modulation enhances immunologic benefit of chemoradiotherapy

BACKGROUND

Chemoradiotherapy (CRT) remains one of the most common cancer treatment modalities, and recent data suggest that CRT is maximally effective when there is generation of an anti-tumoral immune response. However, CRT has also been shown to promote immunosuppressive mechanisms which must be blocked or reversed to maximize its immune stimulating effects.

METHODS

Therefore, using a preclinical model of human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC), we developed a clinically relevant therapy combining CRT and two existing immunomodulatory drugs: cyclophosphamide (CTX) and the small molecule inducible nitric oxide synthase (iNOS) inhibitor L-n6-(1-iminoethyl)-lysine (L-NIL). In this model, we treated the syngeneic HPV-HNSCC mEER tumor-bearing mice with fractionated (10 fractions of 3 Gy) tumor-directed radiation and weekly cisplatin administration. We compared the immune responses induced by CRT and those induced by combinatory treatment (CRT + CTX/L-NIL) with flow cytometry, quantitative multiplex immunofluorescence and by profiling immune-related gene expression changes.

RESULTS

We show that combination treatment favorably remodels the tumor myeloid immune microenvironment including an increase in anti-tumor immune cell types (inflammatory monocytes and M1-like macrophages) and a decrease in immunosuppressive granulocytic myeloid-derived suppressor cells (MDSCs). Intratumoral T cell infiltration and tumor antigen specificity of T cells were also improved, including a 31.8-fold increase in the CD8+ T cell/ regulatory T cell ratio and a significant increase in tumor antigen-specific CD8+ T cells compared to CRT alone. CTX/LNIL immunomodulation was also shown to significantly improve CRT efficacy, leading to rejection of 21% established tumors in a CD8-dependent manner.

CONCLUSIONS

Overall, these data show that modulation of the tumor immune microenvironment with CTX/L-NIL enhances susceptibility of treatment-refractory tumors to CRT. The combination of tumor immune microenvironment modulation with CRT constitutes a translationally relevant approach to enhance CRT efficacy through enhanced immune activation.

TGF-β1 programmed myeloid-derived suppressor cells (MDSC) acquire immune-stimulating and tumor killing activity capable of rejecting established tumors in combination with radiotherapy

Cancer-induced myeloid-derived suppressor cells (MDSC) play an important role in tumor immune evasion. MDSC programming or polarization has been proposed as a strategy for leveraging the developmental plasticity of myeloid cells to reverse MDSC immune suppressive functions, or cause them to acquire anti-tumor activity. While MDSC derived ex vivo from murine bone marrow precursor cells with tumor-conditioned medium efficiently suppressed T cell proliferation, MDSC derived from conditioned medium in presence of TGF-β1 (TGFβ-MDSC) acquired a novel immune-stimulatory phenotype, losing the ability to inhibit T cell proliferation and acquiring enhanced antigen-presenting capability. Altered immune function was associated with SMAD-2 dependent upregulation of maturation and costimulatory molecules, and downregulation of inducible nitric oxide synthase (iNOS), an effector mechanism of immunosuppression. TGFβ-MDSC also upregulated FAS-ligand expression, leading to FAS-dependent killing of murine human papillomavirus (HPV)-associated head and neck cancer cells and tumor spheroids in vitro and anti-tumor activity in vivo. Radiation upregulated FAS expression on tumor cells, and the combination of radiotherapy and intratumoral injection of TGFβ-MDSC strongly enhanced class I expression on tumor cells and induction of HPV E7 tetramer-positive CD8 + T cells, leading to clearance of established tumors and long-term survival. TGFβ-MDSC derived from human PBMC with tumor conditioned medium also lost immunosuppressive function and acquired tumor-killing activity. Thus, TGFβ1 mediated programming of nascent MDSC leads to a potent anti-tumor phenotype potentially suitable for adoptive immunotherapy.

Abstract PR005: TGF-beta1 primed myeloid derived suppressor cells decrease tumor growth and lose their ability to inhibit T cell proliferation via iNOS downregulation

Background: Myeloid derived suppressor cells or MDSC are a heterogeneous population of bone marrow-derived cells that consist of myeloid progenitor and immature. Cancer-induced pro-inflammatory signals recruit MDSC from the bone marrow and maintain them in an undifferentiated state. MDSCs inhibit T cell proliferation via up regulation of iNOS and ROS thereby suppressing antitumor immune responses. MDSC have also been shown to promote tumor growth by stimulating angiogenesis and other mechanisms. TGF-b1 is a pleiotropic cytokine abundantly expressed in the tumor microenvironment with diverse effects on myeloid, lymphoid and tumor cells. The aim of this study is to determine the effect of TGF-b1 in the generation and function of MDSC, including its effects on T cell proliferation and tumor growth.

Methods: Ex vivo MDSC generation: Bone marrow progenitor cells were derived from WT C57bl/6 mice and co-cultured with MTEC (mouse tonsil epithelial cells transformed with HPV16 E6+E7 oncogenes and H-Ras ) tumor supernatants in the presence or absence of TGF-β1 for 5 days at 370C. Cells were then harvested, processed into single cell suspensions, and stained for MDSC surface markers, DAF-DA (to determine nitric oxide levels),iNOS and other functional markers analysis was performed by flow cytometry (FACS).

MDSC functional assay: A) T cell proliferation assay MDSCs were generated in the presence or absence of TGF-β1 with supernatants from MTEC cells and co-cultured with CFSE labeled T cells activated with anti CD3 and anti CD28 antibodies. T cell proliferation was measured by using CFSE dilution, which was analyzed by flow cytometry.

B) Effect of MDSC on tumor growth Control and TGF-β1 conditioned MDSC were co-cultured with MTEC tumor (grown as spheroids) for 72 hrs at the end of which histological sections of the spheroids were prepared and analyzed for tumor proliferation by Ki-67 staining. Sorted MDSCs were also co-cultured with T-hep3 cells grown in a monolayer (human oral cancer line) and tumor growth was determined by flow cytometry.

Results: While control MDSC suppressed T cell proliferation in a dose-dependent fashion, we observed that TGF-β1 primed MDSCs lost the ability to inhibit T cell proliferation. Further, TGF-β1 primed MDSC inhibited tumor growth in an ex vivo co-culture system. Histological sections of tumor spheroid / MDSC co-cultures revealed diminshed ki-67 expression in spheroids cultured with TGF-B1 conditioned MDSC compared to control. Upon further examining the cellular mechanism, it was seen that TGF-β1 treated MDSCs down regulate iNOS expression and produced decreased amounts of nitric oxide compared to their control counterparts, without altering the expression of other MDSC functional markers like arginase, PD-1 and PD-L1.

Conclusions: We conclude that TGF-β1 reprograms MDSC via an iNOS/NO dependent mechanism to a) T cell suppressive capacity and b) inhibit tumor cell growth. These observations have a direct translational implication wherein the inherent pro-tumor nature of MDSCs could potentially be reprogrammed with TGF-β1 and directed toward the tumor thereby suppressing tumor growth.

Citation Format: Padmini Jayaraman, Falguni Parikh, Rosemarie Krupar, Robin Parihar, Indu Varier, Andrew Sikora. TGF-beta1 primed myeloid derived suppressor cells decrease tumor growth and lose their ability to inhibit T cell proliferation via iNOS downregulation. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr PR005.

Myeloid cell-derived inducible nitric oxide synthase suppresses M1 macrophage polarization

Here we show that iNOS-deficient mice display enhanced classically activated M1 macrophage polarization without major effects on alternatively activated M2 macrophages. eNOS and nNOS mutant mice show comparable M1 macrophage polarization compared with wild-type control mice. Addition of N6-(1-iminoethyl)-L-lysine dihydrochloride, an iNOS inhibitor, significantly enhances M1 macrophage polarization while S-nitroso-N-acetylpenicillamine, a NO donor, suppresses M1 macrophage polarization. NO derived from iNOS mediates nitration of tyrosine residues in IRF5 protein, leading to the suppression of IRF5-targeted M1 macrophage signature gene activation. Computational analyses corroborate a circuit that fine-tunes the expression of IL-12 by iNOS in macrophages, potentially enabling versatile responses based on changing microenvironments. Finally, studies of an experimental model of endotoxin shock show that iNOS deficiency results in more severe inflammation with an enhanced M1 macrophage activation phenotype. These results suggest that NO derived from iNOS in activated macrophages suppresses M1 macrophage polarization.

In response to microbial ligands, IRF5 promotes pro-inflammatory M1 macrophage activation and production of nitrous oxide. Here the authors show that nitrous oxide modifies IRF5 tyrosine residues as a negative feedback, limiting the inflammatory response and protecting from endotoxin shock.

Requirement for innate immunity and CD90⁺ NK1.1⁻ lymphocytes to treat established melanoma with chemo-immunotherapy

We sought to define cellular immune mechanisms of synergy between tumor-antigen-targeted monoclonal antibodies and chemotherapy. Established B16 melanoma in mice was treated with cytotoxic doses of cyclophosphamide in combination with an antibody targeting tyrosinase-related protein 1 (αTRP1), a native melanoma differentiation antigen. We find that Fcγ receptors are required for efficacy, showing that antitumor activity of combination therapy is immune mediated. Rag1(-/-) mice deficient in adaptive immunity are able to clear tumors, and thus innate immunity is sufficient for efficacy. Furthermore, previously treated wild-type mice are not significantly protected against tumor reinduction, as compared with mice inoculated with irradiated B16 alone, consistent with a primarily innate immune mechanism of action of chemo-immunotherapy. In contrast, mice deficient in both classical natural killer (NK) lymphocytes and nonclassical innate lymphocytes (ILC) due to deletion of the IL2 receptor common gamma chain IL2γc(-/-)) are refractory to chemo-immunotherapy. Classical NK lymphocytes are not critical for treatment, as depletion of NK1.1⁺ cells does not impair antitumor effect. Depletion of CD90⁺NK1.1⁻ lymphocytes, however, both diminishes therapeutic benefit and decreases accumulation of macrophages within the tumor. Tumor clearance during combination chemo-immunotherapy with monoclonal antibodies against native antigen is mediated by the innate immune system. We highlight a novel potential role for CD90⁺NK1.1⁻ ILCs in chemo-immunotherapy.

iNOS expression in CD4+ T cells limits Treg induction by repressing TGFβ1: combined iNOS inhibition and Treg depletion unmask endogenous antitumor immunity

PURPOSE

Expression of inducible nitric oxide synthase (iNOS) in different cellular compartments may have divergent effects on immune function. We used a syngeneic tumor model to functionally characterize the role of iNOS in regulation of CD4(+)FOXP3(+) regulatory T cells (Treg), and optimize the beneficial effects of iNOS inhibition on antitumor immunity.

EXPERIMENTAL DESIGN

Wild-type (WT) or iNOS knockout mice bearing established MT-RET-1 melanoma were treated with the small-molecule iNOS inhibitor L-NIL and/or cyclophosphamide alone or in combination. The effect of iNOS inhibition or knockout on induction of Treg from mouse and human CD4(+) T cells in ex vivo culture was determined in parallel in the presence or absence of TGFβ1-depleting antibodies, and TGFβ1 levels were assessed by ELISA.

RESULTS

Whereas intratumoral myeloid-derived suppressor cells (MDSC) were suppressed by iNOS inhibition or knockout, systemic and intratumoral FOXP3(+) Treg levels increased in tumor-bearing mice. iNOS inhibition or knockout similarly enhanced induction of Treg from activated cultured mouse splenocytes or purified human or mouse CD4(+) T cells in a TGFβ1-dependent manner. Although either iNOS inhibition or Treg depletion with low-dose cyclophosphamide alone had little effect on growth of established MT-RET1 melanoma, combination treatment potently inhibited MDSC and Treg, boosted tumor-infiltrating CD8(+) T-cell levels, and arrested tumor growth in an immune-dependent fashion.

CONCLUSIONS

iNOS expression in CD4(+) T cells suppresses Treg induction by inhibiting TGFβ1 production. Our data suggest that iNOS expression has divergent effects on induction of myeloid and lymphoid-derived regulatory populations, and strongly support development of combinatorial treatment approaches that target these populations simultaneously.

Development of a Translation-Ready Combination Cancer Immunotherapy Regimen Based on Clinically Available Drugs

Objectives:

Immunosuppressive immunocytes induced by cancer-associated inflammation, such as myeloid derived suppressor cells (MDSC) and T-regulatory cells (Treg), mediate immune-escape critical to development of solid tumors, including melanoma and oral squamous cell carcinoma (OSCC). Novel therapeutic approaches, which block tumor-mediated immunosuppression, unmasking endogenous anti-tumor immune responses, are thus a rational treatment approach. The aims of the study were: (1) Demonstrate that inhibition of inducible nitric oxide synthase (iNOS, critical for MDSC development) and Treg depletion in preclinical cancer models leads to potent anti-tumor activity; (2) Design a regimen suitable for testing in clinical trials.

Methods:

Mouse bone marrow cells were co-cultured with MT-RET melanoma supernatants ex vivo to generate MDSC in the presence of doxycycline, an iNOS inhibitor. C57/BL6 wild-type mice were injected with syngeneic MT-RET-1 melanoma. Tumor-bearing mice were treated with injection(s) of cyclophosphamide and/or doxycycline. Tumor growth and survival times were measured, and tumors and spleens harvested for CD8+ T-cell and other immunocyte levels.

Results:

In co-cultures, induction of MDSC was significantly reduced in the presence of doxycycline. Treatment of MT-RET melanoma-bearing C57/B16 mice with doxycycline resulted in tumor-infiltrating CD8+ T cells enhancement and tumor growth suppression. Treatment with cyclophosphamide suppressed intratumoral Treg accumulation. Dual treatment with cyclophosphamide and doxycycline suppressed tumor growth more efficiently than either alone.

Conclusions:

Treatment with the immunomodulators doxycycline and cyclophosphamide is a promising approach to reversing tumor-mediated immunosuppression and suppressing cancer growth in solid tumors, like melanoma and OSCC. Thus, we have designed a window of opportunity clinical trial of doxycycline and cyclophosphamide before surgical resection of OSCC.

Inducible nitric oxide synthase drives mTOR pathway activation and proliferation of human melanoma by reversible nitrosylation of TSC2

Melanoma is one of the cancers of fastest-rising incidence in the world. Inducible nitric oxide synthase (iNOS) is overexpressed in melanoma and other cancers, and previous data suggest that iNOS and nitric oxide (NO) drive survival and proliferation of human melanoma cells. However, specific mechanisms through which this occurs are poorly defined. One candidate is the PI3K-AKT-mTOR pathway, which plays a major role in proliferation, angiogenesis, and metastasis of melanoma and other cancers. We used the chick embryo chorioallantoic membrane (CAM) assay to test the hypothesis that melanoma growth is regulated by iNOS-dependent mTOR pathway activation. Both pharmacologic inhibition and siRNA-mediated gene silencing of iNOS suppressed melanoma proliferation and in vivo growth on the CAM in human melanoma models. This was associated with strong downregulation of mTOR pathway activation by Western blot analysis of p-mTOR, p70 ribosomal S6 kinase (p-P70S6K), p-S6RP, and p-4EBP1. iNOS expression and NO were associated with reversible nitrosylation of tuberous sclerosis complex (TSC) 2, and inhibited dimerization of TSC2 with its inhibitory partner TSC1, enhancing GTPase activity of its target Ras homolog enriched in brain (Rheb), a critical activator of mTOR signaling. Immunohistochemical analysis of tumor specimens from stage III melanoma patients showed a significant correlation between iNOS expression levels and expression of the mTOR pathway members. Exogenously supplied NO was also sufficient to reverse the mTOR pathway inhibition by the B-Raf inhibitor vemurafenib. In summary, covalent modification of TSC2 by iNOS-derived NO is associated with impaired TSC2/TSC1 dimerization, mTOR pathway activation, and proliferation of human melanoma. This model is consistent with the known association of iNOS overexpression and poor prognosis in melanoma and other cancers.

T cell–derived inducible nitric oxide synthase switches off Th17 cell differentiation

Nitric oxide derived from iNOS in activated T cells negatively regulates Th17 cell differentiation.

RORγt is necessary for the generation of T_H17 cells but the molecular mechanisms for the regulation of T_H17 cells are still not fully understood. We show that activation of CD4⁺ T cells results in the expression of inducible nitric oxide synthase (iNOS). iNOS-deficient mice displayed enhanced T_H17 cell differentiation but without major effects on either T_H1 or T_H2 cell lineages, whereas endothelial NOS (eNOS) or neuronal NOS (nNOS) mutant mice showed comparable T_H17 cell differentiation compared with wild-type control mice. The addition of N6-(1-iminoethyl)-l-lysine dihydrochloride (L-NIL), the iNOS inhibitor, significantly enhanced T_H17 cell differentiation, and S-nitroso-N-acetylpenicillamine (SNAP), the NO donor, dose-dependently reduced the percentage of IL-17–producing CD4⁺ T cells. NO mediates nitration of tyrosine residues in RORγt, leading to the suppression of RORγt-induced IL-17 promoter activation, indicating that NO regulates IL-17 expression at the transcriptional level. Finally, studies of an experimental model of colitis showed that iNOS deficiency results in more severe inflammation with an enhanced T_H17 phenotype. These results suggest that NO derived from iNOS in activated T cells plays a negative role in the regulation of T_H17 cell differentiation and highlight the importance of intrinsic programs for the control of T_H17 immune responses.

Tumor-expressed inducible nitric oxide synthase controls induction of functional myeloid-derived suppressor cells through modulation of vascular endothelial growth factor release

Inducible NO synthase (iNOS) is a hallmark of chronic inflammation that is also overexpressed in melanoma and other cancers. Whereas iNOS is a known effector of myeloid-derived suppressor cell (MDSC)-mediated immunosuppression, its pivotal position at the interface of inflammation and cancer also makes it an attractive candidate regulator of MDSC recruitment. We hypothesized that tumor-expressed iNOS controls MDSC accumulation and acquisition of suppressive activity in melanoma. CD11b(+)GR1(+) MDSC derived from mouse bone marrow cells cultured in the presence of MT-RET-1 mouse melanoma cells or conditioned supernatants expressed STAT3 and reactive oxygen species (ROS) and efficiently suppressed T cell proliferation. Inhibition of tumor-expressed iNOS with the small molecule inhibitor L-NIL blocked accumulation of STAT3/ROS-expressing MDSC, and abolished their suppressive function. Experiments with vascular endothelial growth factor (VEGF)-depleting Ab and recombinant VEGF identified a key role for VEGF in the iNOS-dependent induction of MDSC. These findings were further validated in mice bearing transplantable MT-RET-1 melanoma, in which L-NIL normalized elevated serum VEGF levels; downregulated activated STAT3 and ROS production in MDSC; and reversed tumor-mediated immunosuppression. These beneficial effects were not observed in iNOS knockout mice, suggesting L-NIL acts primarily on tumor- rather than host-expressed iNOS to regulate MDSC function. A significant decrease in tumor growth and a trend toward increased tumor-infiltrating CD8(+) T cells were also observed in MT-RET transgenic mice bearing spontaneous tumors. These data suggest a critical role for tumor-expressed iNOS in the recruitment and induction of functional MDSC by modulation of tumor VEGF secretion and upregulation of STAT3 and ROS in MDSC.

Targeted inhibition of inducible nitric oxide synthase inhibits growth of human melanoma in vivo and synergizes with chemotherapy

PURPOSE

Aberrant expression of inflammatory molecules, such as inducible nitric oxide (NO) synthase (iNOS), has been linked to cancer, suggesting that their inhibition is a rational therapeutic approach. Whereas iNOS expression in melanoma and other cancers is associated with poor clinical prognosis, in vitro and in vivo studies suggest that iNOS and NO can have both protumor and antitumor effects. We tested the hypothesis that targeted iNOS inhibition would interfere with human melanoma growth and survival in vivo in a preclinical model.

EXPERIMENTAL DESIGN

We used an immunodeficient non-obese diabetic/severe combined immunodeficient xenograft model to test the susceptibility of two different human melanoma lines to the orally-given iNOS-selective small molecule antagonist N(6)-(1-iminoethyl)-l-lysine-dihydrochloride (L-nil) with and without cytotoxic cisplatin chemotherapy.

RESULTS

L-nil significantly inhibited melanoma growth and extended the survival of tumor-bearing mice. L-nil treatment decreased the density of CD31+ microvessels and increased the number of apoptotic cells in tumor xenografts. Proteomic analysis of melanoma xenografts with reverse-phase protein array identified alterations in the expression of multiple cell signaling and survival genes after L-nil treatment. The canonical antiapoptotic protein Bcl-2 was downregulated in vivo and in vitro after L-nil treatment, which was associated with increased susceptibility to cisplatin-mediated tumor death. Consistent with this observation, combination therapy with L-nil plus cisplatin in vivo was more effective than either drug alone, without increased toxicity.

CONCLUSIONS

These data support the hypothesis that iNOS and iNOS-derived NO support tumor growth in vivo and provide convincing preclinical validation of targeted iNOS inhibition as therapy for solid tumors.

The effect of upper extremity weight bearing on upper extremity function in children with hemiplegic type of cerebral palsy

The main objective of this study was to quantify the effects ofweight bearing on upper limb function in children with hemiplegic cerebralpalsy. This study also sought to monitor the change in spasticity immediatelyfollowing weight bearing exercises. A  quasi-experimental, one group pre-test,post-test design was used. Eleven children with hemiplegic type of cerebral palsyfrom a special school in KwaZulu Natal participated after fully informed consentof the caretaking guardian. The intervention consisted of a standardized programof weight bearing. The Melbourne A ssessment of Upper Extremity function wasused to quantify upper extremity function of reach, grasp and manipulation and the modified A shworth grading of spasticity was used to grade and monitor spasticity. The data was analysed using the Wilcoxon signed rank test.  A  significant decrease in spasticity during elbow extension (p= 0,004), wrist flexion (p=0,026) and extension (p=0,004)was noted. Statistically significant improvement in function, reach (p=0, 00), grasp (p=0, 02) manipulation (p=0, 05)and overall quality of function (p= 0,003) was also found. A n overall significant effect of weight bearing exercises onupper extremity function was noted providing evidence for practice.

The effects of a 12-week program of static upper extremity weight bearing exercises on weight bearing in children with hemiplegic type of cerebral palsy

The  major  objective  of  this  study  was  to  quantify  the  effects  of a  12-week  program  of  weight  bearing  exercises  on  weight  borne  through  the hand and grip pressures in children with hemiplegic cerebral palsy. This study also sought to monitor the change in spasticity immediately following weight-bearing  exercises.  A  quasi-experimental,  one  group  pre-test,  post-test  study  was used. Eleven children with hemiplegic type of cerebral palsy from a special school in KwaZulu Natal participated after fully informed written consent. The intervention consisted of a 12-week program of weight bearing. The Tekscan Grip system was used to quantify weight borne through the hand during extended arm prone and quadruped positions and whilst holding a pencil and a tumbler. The modified Ashworth grading of spasticity was used to monitor spasticity. The data was analysed using the random effects GLS model Wald Chi Square test. Significant increases in contact pressure in extended arms prone (p=0,012) and quadruped (p=0,002) and when holding a pencil (p=0,045) was noted post-test compared to pre-test. Significant increases in contact area of the hand was also noted in prone (p=0,000), quadruped (p=0, 03 at assessment 7) and when holding a pencil (p=0,035).  A significant decrease in spasticity during elbow extension (p=0,004), and wrist flexion (p=0,026) and extension (p=0,004) was noted. An overall significant effect of static weight bearing exercises on weight borne through the hands, grip strength and spasticity justifies the use of static weight-bearing in therapy.

A pilot study on the test re-test and the inter-rater reliability of the Melbourne Assessment of Unilateral Upper Limb Function

Objective: The Melbourne Assessment of Unilateral Upper Limb Function(commonly referred to as the Melbourne A ssessment) was identified as atool to quantify the quality of upper extremity function in children with cerebral palsy aged 5 to 15 years in South Africa. Since the tool was nottested in a South African population before, it became necessary to determine its inter-rater and test-retest reliability.Methods: Five South African Black children with hemiplegic cerebral palsy served as the test sample. The raters were 2 neurodevelopmental trained physiotherapists with more than 2 and 8 years of experience in pediatric physiotherapy but novice to the use of the Melbourne Assessment. Both therapists acquainted themselves with the tool kit and manual prior to the rating. The entire assessment of each child was video taped and reassessed a week later by one of the therapists for test-retestreliability. Results: Ratings of the 2 raters and test-retest scores were correlated using the weighted Kappa due to the small sample size. Kappa scores for individual scores for interrater reliability and test-retest was 0, 75 and that for the totalscores were 0, 72 and 0, 82 respectively. Conclusion: These findings suggest that good inter-tester and test-retest reliability can be achieved for the MelbourneA ssessment when used in a group of South African Black children.

Unrestrained glycogen synthase kinase-3 beta activity leads to activated T cell death and can be inhibited by natural adjuvant

Activated T cell death (ATCD) after peak clonal expansion is required for effective homeostasis of the immune system. Using a mouse model of T cell clonal expansion and contraction, we found that regulation of the proapoptotic kinase glycogen synthase kinase (GSK)-3beta plays a decisive role in determining the extent to which T cells are eliminated after activation. Involvement of GSK-3beta in ATCD was tested by measuring T cell survival after GSK-3beta inhibition, either ex vivo with chemical and pharmacological inhibitors or in vivo by retroviral expression of a dominant-negative form of GSK-3. We also measured amounts of inactivating phosphorylation of GSK-3beta (Ser9) in T cells primed in the presence or absence of LPS. Our results show that GSK-3beta activity is required for ATCD and that its inhibition promoted T cell survival. Adjuvant treatment in vivo maintained GSK-3beta (Ser9) phosphorylation in activated T cells, whereas with adjuvant-free stimulation it peaked and then decayed as the cells became susceptible to ATCD. We conclude that the duration of GSK-3beta inactivation determines activated T cell survival and that natural adjuvant stimulation decreases the severity of clonal contraction in part by keeping a critical proapoptotic regulatory factor, GSK-3beta, inactivated.

Bcl-3 is required for adjuvant mediated T cell survival and sustained inhibition of GSK3ß (87.38)

Increased transcription of bcl3 correlates with adjuvant-mediated survival of activated T cells. To determine whether Bcl3 is required for adjuvant-dependent survival of activated T cells, OT-II.Bcl3 knockout (KO) mice were challenged with ova peptide (Ova) in the presence or absence of LPS and T cell survival was assessed after 20 hr culture. Ova-treated CD4 T cells from the Bcl3 KO mice activated with or without LPS failed to survive whereas wild type (WT) OTII cells survived when activated with LPS. Using low-number adoptive transfer of WT or KO OTIIs, we show that Bcl3 is required for effective adjuvant-dependent increase in clonal expansion in response to antigen. At peak expansion, 10-fold fewer KO OTIIs were recovered after LPS treatment, compared to the WT OTIIs. Similar defects were seen in adjuvant treated OT-I.Bcl3 KO cells. GSK3ß is a target molecule whose activity is affected by adjuvants during T cell expansion. Bcl3 KO T cells do not maintain the inhibitory p(ser9) on GSK3ß as the WT OTII cells although the initial increase after T cell activation is not affected. This indicates increased phosphatase activity in Bcl3 KO T cells. Studies are underway to address unchecked phosphatase activity as a mechanism of death in the KO cells. These data establish the importance of Bcl-3 in adjuvant- mediated survival of in vivo activated T cells.

This work was supported by USPHS grants AI51377 and AI059023 and the Commonwealth of Kentucky Research Challenge Trust Fund.

Prevalence of anaemia and iron deficiency in three trimesters in Rural Vellore district, South India

A multistage sampling technique was used to select 845 pregnant women from two blocks in Vellore district. Haematological measurement of haemoglobin (Hb) was done on all women and serum ferritin (SF) on a subsample of 445. The prevalence of anaemia (Hb <11 g/dl) was 56.6%, 70.2% and 69.5%, respectively among the first, second and third trimester women. The mean Hb of 10.7 g/dl was significantly higher among the first trimester than among the second and third trimester women, which was less than the recommended value of 11 g/dl. Iron deficiency (SF <12 microg/L) was significantly (P< 0.05) more among the third trimester women than among the first. The high prevalence of anaemia in each trimester in pregnancy indicates the need for iron supplementation as early as possible starting from the fourth month of pregnancy.

Changes in moisture content, mycoflora and aflatoxin content of rice bran during storage

The changes in moisture content, storage mycoflora and aflatoxin B1 (AFB1) in bran from untreated or raw rice (Rr) and parboiled rice (Pbr) stored in small lots in polyethylene bags were studied at 15-day intervals up to 60 days, using five lots of each type of bran. Deterioration was more rapid with reference to all the three parameters, in Rr bran compared to Pbr bran, the former becoming completely overgrown and caked with fungi by the end of 60 days. Aspergillus flavus was the dominant fungus in Pbr bran, whereas A. candidus and Trichoderma viride were abundant in Rr bran. The frequency of incidence as well as concentration of AFB1 increased with storage time in both types of bran, but the rate of increase as well as overall concentration were much higher in Rr bran. Thus raw rice bran is unsuitable for prolonged storage.

Natural occurrence of toxigenic fungi and mycotoxins in rice bran

Thirty four samples of rice bran, of which 9 were from raw (untreated) rice (RR) and 25 from parboiled rice (PbR) were collected from commercial rice mills in and around Madras and analysed for storage mycoflora and mycotoxins. Fungi of the Aspergillus flavus group were present in 29 of the 34 samples (8 from RR and 21 from PbR) in quantities ranging from less than 1-432 thousand propagules/g, though not always as the dominant mycoflora. Fungal numbers were usually higher in RR than in PbR samples. Five of the 9 RR samples and 6 of the 25 PbR samples were positive for aflatoxins. Among 29 isolates of A. flavus obtained from the bran samples, 16 isolates -6 from RR bran and 10 from PbR bran - were found to be toxigenic in vitro. Some isolates of A. candidus also seemed to produce aflatoxin and other fluorescent substances.