bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional conditioning of CD8 T cells by thymoproteasome-dependent positive selection (P1408)
Authors: Takada Kensuke , Takahama Yousuke 
Published: January 2023

Abstract
Proteasomes play an important role in the production of peptides presented by MHC class I. The thymoproteasome, which contains β5t catalytic subunit, is expressed specifically in cortical thymic epithelial cells mediating the positive selection of DP thymocytes. In β5t-deficient mice, the cellularity of CD8SP thymocytes and peripheral CD8 T cells is significantly decreased and their TCR repertoire is altered as characterized by defective responses to alloantigens and viral infections. In the present study, we functionally characterized CD8 T cells generated in β5t-deficient mice. We found that CD8 T cells in the secondary lymphoid organs of β5t-deficient mice were enriched with CD44hiCD122hi memory-phenotype cells. This phenotypic alteration was marginal in the thymus but became apparent in the periphery of mice older than 1 week after birth, suggesting that CD8 T cells generated in the thymus of β5t-deficient mice are aberrantly maintained in the periphery. Surprisingly, the enrichment of memory-phenotype CD8 T cells was also seen in monoclonal β5t-/-Rag-/-OT-I mice. In addition, CD44loCD122lo cells obtained from β5t-/-Rag-/-OT-I mice showed enhanced proliferative responses to antigen stimulations. These results suggest that the thymoproteasome-dependent positive selection not only determines TCR recognition specificity but also preconditions T cell function.
Involvement of microglial CD40 in murine retrovirus-induced peripheral neuropathy (P6173)
Authors: Cao Ling , Butler Michael 
Published: January 2023

Abstract
The underlying mechanism of HIV-associated peripheral neuropathy is unclear. C57BL/6 (B6) mice infected with LP-BM5 develop severe immunodeficiency (termed as MAIDS) and peripheral neuropathy. It is known that CD154-CD40 interactions between CD4+ T and B cells are required for the manifestation of MAIDS post-LP-BM5 infection (p.i.) and that HIV encephalitis is associated with increased expression of CD40 on microglia. We aimed to determine whether spinal cord microglial CD40 signaling is involved in LP-BM5-induced peripheral neuropathy. B6-CD40 KO mice were adoptively transferred with either total leukocytes or B cells and examined for mechanical sensitivity, tissue viral loads, and cytokine responses along with the development of MAIDS p.i.. CD40 KO mice transferred either cell population developed MAIDS, the severity of which was correlated with peripheral cytokine responses. CD40 KO mice displayed transient and slightly increased mechanical sensitivity p.i. regardless of cell transfer. In all peripheral tissues examined, increased viral RNA was detected in all infected mice without significant group differences. However, in the lumbar spinal cord, infected wild type B6 mice had the highest viral load and cytokine responses among all groups. Neither type of cell transfer enhanced the LP-BM5-induced increase in viral load and cytokine responses in CD40 KO mice. Together, these data support the involvement of microglial CD40 in LP-BM5-induced peripheral neuropathy.
Adapted HIV-1 epitopes can elicit functional CD8+ T cell responses (P6177)
Authors: Du Victor , Bansal Anju , Sabbaj Steffanie , Heath Sonya , Goepfert Paul 
Published: January 2023

Abstract
HIV readily mutates and many of these mutations can be predicted based on the human leukocyte antigen class I (HLA-I) allele of the infected individual. Majority of these HLA-associated HIV polymorphisms may represent escape mutations whereby the epitope adapts to HLA-restricted pressure in every individual. Though these adapted epitopes have escaped recognition by some CD8 T cells, others may readily recognize them. However, to truly answer the question as to whether adapted epitopes induce CD8 T cell responses (primary response), acutely infected patient samples must be tested where we can accurately predict the infecting viral strain. We therefore tested whether CD8 T cells are induced when presented with either adapted or non-adapted epitopes encoded by the infecting viral strain in 8 HIV+ acute patients. Primary responses were more likely induced to non-adapted epitopes compared to the adapted (p=0.041). Furthermore, the few adapted epitopes that were able to elicit responses (primary or not) were predicted to exhibit a significantly higher HLA binding affinity compared to ones that did not elicit a response. CD8 T cells responding to adapted epitopes also shared similar magnitude, functional avidity, and polyfunctionality compared to those elicited to the non-adapted. Our results suggest at least some epitopes with HLA-associated mutations are still potentially immunogenic and may have important implications for T cell-based vaccine development.
Analysis of myelomonocytic populations during HIV infection (P6185)
Authors: Barblu Lucie , Porichis Filippos , Hart Meghan , Kaufmann Daniel 
Published: January 2023

Abstract
We hypothesized that alterations in the monocytic and myeloid-derived suppressor cells (MDSCs) subsets contributed to impaired T cell function in HIV infection. CD14++CD16- classical, CD14+CD16+ intermediate, CD14lowCD16+ non classical monocytes and HLA-DR-CD14+CD33+CD11b+ MDSCs surface markers (PDL-1, CD40, HLA-ABC, HLA-DR, CD86, CCR2) and intracellular molecules (IL-12, TNF-α) were analyzed by FACS. Studies were performed on freshly isolated PBMC of healthy controls (HD) and compared to HIV-infected subjects: ART Treated (ARTC), untreated progressors (CP) and elite controllers (EC). CP subjects had significantly higher MDSCs frequency than HD, ARTC and EC. CP also express higher level of all monocyte subsets than HD and ARTC. Classical monocytes of HIV+ individuals express less HLA Class I and II molecules than HD, with a trend observed for CD86. A marked decrease in IL-12 secretion in CP upon stimulation with recombinant IFN-γ and/or LPS was also present. Also, CCR2 looks like a good marker to evaluate the importance of non classical monocytes and MDSC populations as well. Our data show that compared to HD, myelomonocytic subsets in HIV+ individuals present phenotypic and functional differences that are not fully corrected by spontaneous or therapy-induced control of viral replication. Perturbations of these subsets can contribute to ongoing immune dysfunction in treated and untreated HIV-infected subjects and may represent a target for therapeutic interventions.
Evaluating early differences in regulatory T cell levels in the MAIDS model of AIDS. (P6187)
Authors: Ayala Ramirez Maria , Akalu Yemsratch , Kwaa Abena , Stranford Sharon 
Published: January 2023

Abstract
Murine acquired immunodeficiency syndrome (MAIDS), caused by the murine leukemia virus (MuLV), serves as an animal model to study human AIDS. Infection with the LP-BM5 isolate of MuLV leads to progressive immunodeficiency in MAIDS-susceptible C57BL/6 mice, while resistant BALB/c mice are able to mount a direct and controlled immune response to eradicate the virus. Experiments measuring the protein expression of two natural immunosuppressive molecules, indoleamine 2, 3-dioxygenease (IDO) and interleukin-10 (IL-10), showed significant strain specific differences during the first two weeks after infection, as measured by ELISA. Since IDO and IL-10 expression can be either directly or indirectly upregulated by regulatory T (Tregs) cells, we then compared levels of Treg populations between the two strains in both lymph node and spleen using FACS. Our preliminary findings suggest that BALB/c mice may have a higher percentage of regulatory T cells in both lymph node and spleen as compared to their MAIDS-susceptible counterparts.
The role of Regenerating Islet-derived 1 (Reg1) protein in the MAIDS model (P6199)
Authors: Olokode Ifeoluwa , Stranford Sharon 
Published: January 2023

Abstract
Murine acquired immune deficiency syndrome (MAIDS) caused by the LP-BM5 isolate of Murine Leukemia Virus (MuLV), is an animal model used to study HIV-induced AIDS. After infection with the virus, the MAIDS susceptible C57BL/6 strain becomes immunocompromised and develops symptoms similar to that of humans infected with HIV-1. Conversely, MAIDS resistant BALB/c animals overcome their MuLV infection and gain adaptive immunity against subsequent challenge. Although it has been established that T cells and the genes found in the major histocompatibility complex (MHC) play a vital role in the outcome of MuLV infection, recent studies have identified genes outside the MHC that also play a role in MAIDS susceptibility. One resistance-associated gene, regenerating islet-derived 1 (Reg1), was found to be highly expressed in the lymph node and spleen of recently infected BALB/c mice, with much lower expression seen in the susceptible BL/6 strain. The aim of this study was to design an enzyme-linked immunosorbent (ELISA) assay that could be used to identify the murine Reg1 protein and quantify its concentration in mouse tissue samples. Preliminary results with this assay show up to two-fold more Reg1 protein in the spleens of BALB/c versus BL/6 animals at three days post MuLV infection. Evaluation of lymph node samples and the possible role of this protein in susceptibility to MAIDS are currently under investigation.
Early HIV-1 infection differentially alters responses of KIR-expressing Natural Killer cells in individuals carrying cognate HLA-C haplotypes (P6203)
Authors: Korner Christian , Granoff Mitchell , Amero Molly , Jost Stephanie , Altfeld Marcus 
Published: January 2023

Abstract
“NK cell licensing” describes the acquisition of functional competence of KIR-expressing NK cells in the presence of cognate HLA ligands. However, whether licensed NK cells contribute to the control of viral infections is not clear. Therefore, we investigated the response of KIR+ NK cells in association with cognate HLA-C haplotypes in HIV-1 infected individuals. 18 HLA-Bw4(-), KIR2DL1/2/3(+) patients with early HIV-1 infection have been enrolled. NK cell responses and KIR expression were measured by flow cytometry. NK cell responses were defined by levels of degranulation and cytokine production after co-incubation with 721.221 target cells. While the frequency of KIR2DL1+ NK cells was increased in the presence of the cognate C2C2 haplotype, the proportion of KIR2DL2/3+ NK cells was reduced as compared to individuals carrying the C1C1 or C1C2 haplotype (p&lt;.05 for each). Of note, levels of degranulation and cytokine production of bulk NK cells did not differ among the three groups. However, within KIR2DL1+ NK cell subsets the C2C2 haplotype was associated with increased NK cell activity (p&lt;.05), while the C1C1 haplotype had no effect on the respective KIR2DL2/3+ NK cell subset. Our results indicate a C2C2 haplotype-dependent expansion and increased responsiveness of KIR2DL1+ NK cells during early HIV-1 infection. A potentially more efficient licensing of KIR2DL1+ NK cells in C2C2 carriers might explain the observed increased responses in the setting of early HIV-1 infection.
Impact of NK cells on control of HIV infection in humanized BLT mice (P6207)
Authors: Jost Stephanie , Chang Judy , Rands Keith , Tomezsko Phillip , Doyle Erin , Daillere Romain , Dudek Timothy , Vrbanac Vladimir , Allen Todd , Tager Andrew , Altfeld Marcus 
Published: January 2023

Abstract
Evidence suggests natural killer (NK) cells can mediate antiviral activity in HIV-infected humans. Here, we sought to investigate whether the level of NK cell activation in primary HIV infection not only influences the NK cell mediated elimination of HIV infected cells, but also affects the longevity and effectiveness of HIV-specific T cell responses. To address this hypothesis, we monitored HIV viral loads and HIV-specific adaptive immune responses in a humanized BLT mouse model of HIV infection, comparing NK cell-depleted and control mice. Depletion was achieved through the use of an anti-NKp46 antibody prior to HIV infection. Proportions of immune cell subsets and viremia were assessed at baseline and then once a week for at least 5 weeks post-infection using flow cytometry and qRT-PCR. We observed that the impact of NK cells on plasma viral loads varied between batches of mice reconstituted with different tissues. One set of NK cell depleted mice displayed a 4-fold increase in viremia as well as decreased levels of T cell immune activation at 3 weeks post-infection. In a second group of mice reconstituted with independent human tissue, NK cell depletion had no significant effect on viral loads. These results suggest that further investigation is warranted to identify factors accounting for an increased control of HIV replication associated with NK cells in some individuals and not others, such as expression of a protective combination of KIR and HLA alleles.
CD8+ DC trans-presentation of IL-15 to naïve CD8+ T cells produces antigen inexperienced T cells in the periphery with memory phenotype and function (P1315)
Authors: Kedl Ross , Sosinowski Tomasz , White Jason , Cross Eric , Marrack Pippa , Gapin Laurent 
Published: January 2023

Abstract
Various populations of memory phenotype CD8+ T cells have been described over the last 15-20 years, all of which possess elevated effector functions relative to naïve phenotype cells. Using a technique for isolating antigen specific cells from unprimed hosts, we recently identified a new subset of cells, specific for nominal antigen, but phenotypically and functionally similar to memory cells arising as a result of homeostatic proliferation (HP). We show here that these “Virtual Memory” cells are independent of previously identified “innate memory” cells, arising as a result of their response to IL-15 trans-presentation by lymphoid tissue-resident CD8α+ DCs in the periphery. The absence of IL-15, CD8+ T cell expression of either CD122 or Eomes, or of CD8a+ DCs all lead to the loss of Virtual Memory cells in the host. Our results show that CD8+ T cell homeostatic expansion is an active process within the non-lymphopenic environment, is mediated by IL-15, and produces antigen inexperienced memory cells which retain the capacity to respond to nominal antigen with memory-like function. Preferential engagement of these “Virtual Memory” T cells into a vaccine response could dramatically enhance the rate by which immune protection develops.
Effects of senescence on immune parameters in baboons shows differential susceptibilities (P1321)
Authors: Bonnel Caroline , Arteaga-Cortes Lourdes , Rice Karen , Leland M. , Dube Peter , Kraig Ellen 
Published: January 2023

Abstract
Vaccine efficacy declines significantly with age, yet old baboons immunized with Yersinia pestis LcrV antigen generated vigorous humoral responses [JI 181:109 (2008)] while aged rhesus macaques did not. To assess whether these non-human primate (NHP) species are differentially impacted by immunosenescence, animals were immunized with Y. pestis F1, a plasmid-encoded protein which is known to elicit naïve B and T cell responses. Interestingly, age-associated decreases in antibody titers to F1 were observed in both species. However, defects in T cell proliferative responses were seen only in the macaques; T cell reactivity to both mitogen and antigenic stimulation was similar in the old and young baboons. We therefore asked whether other aspects of immune regulation are affected by age. The loss of naive, relative to memory, T cells was seen, as expected. Moreover, there was a decrease, albeit relatively small, in the production of naive T cells (TRECs). However, several parameters known to change with aging were not affected. For example, AID induction was maintained in most, but not all, old baboons. Moreover, the T cell fine specificity was similar in old and young animals. Lastly, TCR-Vβ spectratype analysis revealed that the age-associated repertoire skewing reported in old rhesus and humans is not seen in baboons, even in the CD8+ T cell subset. Thus, baboons do appear to be less affected by aging and this NHP species may provide novel insights into healthy immune aging.
Bioartificial collagen matrix limits IL-7 and IL-15-induced T-cell homeostatic proliferation without affecting T-cell receptor signaling (P1327)
Authors: Mailloux Adam , Epling-Burnette Pearlie 
Published: January 2023

Abstract
Intermittent homeostatic growth governed by STAT3/5-associated common γ chain (γc) cytokines IL-7 and IL-15 is the principal source of new T-cells after thymic involution. Lymphoproliferation, as seen in large granular lymphocyte leukemia and autoimmune lymphoproliferative syndrome (ALPS), results from failed anti-apoptotic and hyper IL-15 response. Contextual constraints in the microenvironment may also regulate homeostasis. Using primary human naïve and memory CD4+ and CD8+ T-cells, we found that bioartifical collagen matrix limits proliferation by IL-7 and IL-15, but not by anti-CD3/CD28. Flow cytometry was used to analyze collagen receptor expression on dividing T-cells. The expression of known activating collagen receptors, discoidin domain receptor (DDR)1, DDR2, and gpVI was not observed. However, the inhibitory collagen receptor, leukocyte associated IgG-like receptor-1 (LAIR-1), was increased with each cellular division, reaching 2-3 fold over non-dividing cells in response to IL-7 and IL-15. Such changes were not observed with anti-CD3/CD28 stimulation. Western blot analysis revealed no difference in cyclins, cyclin-dependant kinase (CDK)4, p21, p27, or STAT3/5 phosphorylation in collagen matrix, but did reveal reduced expression of the cell cycle regulator CDK6. These data provides rational for the future study of LAIR-1 in T-cell homeostasis and indicates that collagen adhesion may provide spatial repression from the microenvironment during homeostatic expansion.
NLRP12 protein function in the regulation of MHC-I expression in monocytes of patients transplanted with HPCs and their relationship to the reconstitution of CD8 T lymphocytes. (P1333)
Authors: Hernandez Marcela , Ortiz-Navarrete Vianney 
Published: January 2023

Abstract
The reconstitution of the T CD8 lymphocyte population in patients subject to hematopoietic cell transplantation (HCT) depends largely of homeostatic peripheral expansion (HPE) of the T CD8 lymphocytes that were not eliminated during the pre-transplant conditioning regimen or the ones that are contained in the transplanted cells. In order to have an efficient HPE, MHC-I molecules, IL-7 and IL-15 are required. Evidences obtained in our lab indicate that the low and/or heterogeneous MHC-I levels of expression correlate with a inefficient reconstitution of T CD8 lymphocytes in patients that received allogeneic HCT. The deficiency in MHC-I expression could be due to a decrease in the expression of the NLRP12 protein, which has been proposed as a positive regulator of classical and non-classical MHC-I molecules expression. Therefore the objective of the following project is to determine the involvement of NALP12 in the MHC-I expression in monocytes from patients subject to HCT. We studied a cohort of 11 patients, 6 of which received autologous transplant and 5 with allogeneic transplant. Most of the patients present normal levels of T CD8 lymphocytes and a homogeneous expression of MHC-I. The patients that received autologous transplantation show a correlation of r=0.56. Our results suggest that NALP12 could act as an enhancer for the expression of the MHC-I molecules and that this expression could be affected in patients subject to allogeneic HPC transplantation.
Distinct apoptotic machinery and selective gene regulation by glucocorticoids in Th17 cells (P1294)
Authors: Banuelos Jesus , Lu Nick 
Published: January 2023

Abstract
Glucocorticoids (GCs) are extensively used in the treatment of inflammatory disorders and surprisingly, are ineffective in suppressing Th17 responses. We sought to determine the mechanisms underlying the insensitivity of Th17 cells to GCs. We found that in vitro polarized murine Th1 and Th2 cells, but not Th17 cells, were sensitive to GC-induced apoptosis as determined by various apoptotic markers such as annexin-V staining. At the mRNA level, GCs suppressed IL-4 and IFN-γ, and unexpectedly IL-22 but not IL-17 (A and F). Despite the distinct GC responses, Th1, Th2, and Th17 cells showed similar levels of GC receptor (GR) isoforms. Using PCR array to survey 84 genes involved in apoptosis, we found significant differences in the apoptotic machinery between Th1 and Th17 cells. Th17 cells showed increased expression of anti-apoptotic survivin and Bfl-1 whereas Th1 cells showed increased expression of pro-apoptotic Bim, Fas ligand, caspase 1, and death receptor 5. GCs induced Bim in both Th1 and Th17 cells while the same treatment decreased the expression of Nod1 and Bcl-xL in Th1 but not Th17 cells. Altered apoptotic machinery and differences in genes regulated after GC treatment may underlie the inability of GCs to induce apoptosis in Th17 cells. These studies on the mechanisms underlying the selective insensitivity of Th17 cells to GCs may provide a basis for improved treatment regimens for severe asthma and other Th17-mediated disorders.
A synthetic compound, PPY-345, ameliorates ovalbumin-induced asthma (P6021)
Authors: Chung Hwan-Suck , Jeong Jin-Hyun , Shin Minkyu , Hong Moochang , Park Soojin , Kim Hankyum , Yoon Moonsik , Kim Hyunseong , Bae Hyunsu 
Published: January 2023

Abstract
Eosinophilia is one of the characteristic signs of allergic inflammation. Previously, we discovered a new compound, PPY, derived from the fruit of Vitex rotundifolia L. and evaluated its anti-inflammatory and anti-asthmatic properties. In this study, we synthesized a new modified compound, PPY-345, which was based on the PPY skeleton, and we evaluated its anti-asthmatic effects. To evaluate the anti-asthmatic effect of PPY-345 in vitro, A549 lung epithelial cells were stimulated with TNF-alpha, IL-4 and IL-1-beta to induce the expression of CCL11, a chemokine involved in eosinophil chemotaxis. PPY-345 treatments significantly reduced CCL11 secretion. PPY-345 treatment did not inhibit the translocation of NF-κB into the nucleus but suppressed the phosphorylation of signal transducers and activators of transcription 6. To characterize the anti-asthmatic properties of PPY-345 in vivo, we examined the influence of PPY-345 in an ovalbumin (OVA)-induced asthma model. PPY-345 treatment significantly reduced airway hyperreactivity as measured by whole-body plethysmography. PPY-345 further reduced total cells, including eosinophil, macrophage and lymphocytes, in the BAL fluid, goblet cell hyperplasia and myosin light chain 2 positive smooth muscle cell area in the lung tissue. Additionally, PPY-345 significantly suppressed the levels of OVA-IgE present in the serum. These results suggested that PPY-345 could improve asthma symptoms in OVA-sensitized mice.