Os fagócitos contêm uma nicotinamida adenina dinucleotídeo fosfato (NADPH) oxidase associada à membrana, que gera superóxido e outros reativos intermediários do oxigênio. Defeitos nesta oxidase em seres humanos resultam na doença granulomatosa crônica (DGC). Mutações próximas aos sítios de splicing que interferem com o processamento do RNA mensageiro, acarretando deleção de um ou mais exons, são cada vez mais freqüentes na literatura científica, nesses casos, os mecanismos moleculares que levam a DGC nem sempre são totalmente esclarecidos, assim como o efeito do IFN-g, seja sobre o processamento da mensagem ou estabilidade dos transcritos. Com base nessas informações o objetivo geral deste trabalho é investigar o efeito do IFN-g sobre a regulação do sistema NADPH oxidase fagocítico humano. Através dos resultados obtidos, não se pode constatar melhora na produção de ânions superóxido após o tratamento com IFN-g em pacientes com defeito de splicing, no entanto detectou-se aumento da expressão do gene CYBB através de PCR convencional e através de real-time PCR além de um aumento na marcação de proteínas do spliceossoma através do FAN. / Phagocytes have a nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) associated to plasmatic membrane that generates superoxide and other oxygen reactive intermediates. Defects on this oxidase in humans result in a disorder called Chronic Granulomatous Disease (CGD). Mutations next to splicing sites that interfere with the mRNA processing leading to deletion of one or more exons, are even more frequent on scientific literature, in these cases, the molecular mechanisms causing CGD are not always completetly clear, as well as the effect of IFN-g on the mRNA processing or on the stability of transcripts. Based on this information our aim is to investigate the effect of IFN-g on the regulation of the human NADPH oxidase phagocyte system.. With the obtained results it wasnt possible to see an increase in anion superoxide production after the IFN-g treatment in patients with splicing defects, however it was detected an increase on the expression of CYBB gene by conventional and real-time PCR besides an increase in the marking of spliceossomal proteins by FAN.

Orientador: Lair Zambon / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T10:28:19Z (GMT). No. of bitstreams: 1 PerroudJunior_MauricioWesley_D.pdf: 9913138 bytes, checksum: 5dd1ec64b004b6d50e2392e6383c9c98 (MD5) Previous issue date: 2012 / Resumo: Os resultados terapêuticos globais do carcinoma de pulmão não pequenas células em estádio avançado são bem limitados. A imunoterapia com células dendríticas foi desenvolvida como uma nova estratégia para o tratamento de câncer de pulmão. O objetivo deste estudo foi avaliar a viabilidade, segurança e respostas imunológicas em pacientes com carcinoma de pulmão não pequenas células tratados com vacina autóloga de células dendríticas maduras pulsadas com antígenos. Cinco pacientes HLA-A2 com carcinoma de pulmão não pequenas células inoperável (estádio III ou IV) foram selecionados para receber duas doses de 5 x 107 de células dendríticas administradas por vias subcutânea e intravenosa, duas vezes em intervalos de duas semanas. A segurança, tolerabilidade e respostas imunológica e tumoral à vacina foram avaliadas pela evolução clínica e laboratorial, ensaio de linfoproliferação e critérios de RECIST, respectivamente. A dose utilizada para a imunoterapia demonstrou ser segura e bem tolerada. O ensaio de linfoproliferação mostrou uma melhora na resposta imune específica após a imunização, com uma resposta significativa após a segunda dose (p = 0,001). Esta resposta não foi persistente e houve uma tendência à redução após duas semanas da segunda dose da vacina. Dois pacientes apresentaram uma sobrevida quase duas vezes maior que a média esperada e foram os únicos que expressaram os antígenos tumorais HER-2 e CEA Apesar do pequeno tamanho da amostra, os resultados sobre o tempo de sobrevida, resposta imune, segurança e tolerabilidade, combinado com os resultados de outros estudos, são animadores para a condução de um estudo clínico com doses múltiplas em pacientes com câncer de pulmão que foram submetidos a tratamento cirúrgico, seguindo as diretrizes do Cancer Vaccine Clinical Trial Working Group / Abstract: Overall therapeutic outcomes of advanced non-small-cell lung cancer (NSCLC) are poor. The dendritic cell (DC) immunotherapy has been developed as a new strategy for the treatment of lung cancer. The purpose of this study was to evaluate the feasibility, safety and immunologic responses in use in mature, antigen-pulsed autologous DC vaccine in NSCLC patients. Five HLA-A2 patients with inoperable stage III or IV NSCLC were selected to receive two doses of 5x107 DC cells administered subcutaneous and intravenously two times at two week intervals. The safety, tolerability and immunologic and tumor responses to the vaccine were evaluated by the clinical and laboratorial evolution, lymphoproliferation assay and RECIST's criteria, respectively. The dose of the vaccine has shown to be safe and well tolerated. The lymphoproliferation assay showed an improvement in the specific immune response after the immunization, with a significant response after the second dose (p = 0.001). This response was not long lasting and a tendency to reduction two weeks after the second dose of the vaccine was observed. Two patients had a survival almost twice greater than the expected average and were the only ones that expressed HER-2 and CEA together. Despite the small sample size, the results on the survival time, immune response, and safety and tolerability, combined with the results of other studies, are encouraging to the conduction of a large clinical trial with multiples doses in patients with early lung cancer who underwent surgical treatment, following the guidelines of the Cancer Vaccine Clinical Trial Working Group / Doutorado / Clinica Medica / Doutor em Ciências

M.A. / HIV and AIDS are a growing problem with multiple implications on various fields in our society. It looks as if we are conscious only of the tip of the iceberg. This study commits itself to suggest alternatives other than medical support to ensure longevity in HIV and AIDS persons. From within a psychological framework certain psychological and social factors are identified that could possibly have an influence on immunology in the form of CD4 and CD8 counts. The results suggest that definite links exists between certain psychological factors and physical markers of immunology (CD4 and CD8 counts). A Factor analysis show that Social factors (measured with the FES scale) possibly lead to emotions that resort under psychological factors (Conflict, Course of illness and Independence). These factors unleash the need of self- expression. If this need to selfexpression are not relieved it leads to psychological factors (Anger, Depression and Tension). These factors have a marked short-term effect on CD4 count as well as a long-term effect on CD8 count. The result is a circular response comprising of psychological factors (Anger, Depression and Tension) that lead to feelings of avoidance and fatalism. In turn these factors lead to feelings of hopelessness resulting in a strengthening effect on another set of psychological factors (Conflict, Course of illness and Independence). OptimismNigor repeatedly played a leading role in the Course of illness, influencing the cognitive attitude of respondents. Initially 71 respondents took part in the study but comprehensive data over the sixmonth period could only be obtained for 40 respondents. The results suggest that a specific dynamic are concealed in the process between mind, body and illness and needs to be explored through further research. .

Previously, our lab demonstrated that heterologous immunity could result in either gain or loss of protective immunity and alteration in immune pathology following infection by a second un-related pathogen. One of the prototypical models to study T cell-mediated heterologous immunity involves two distantly related arenaviruses, namely lymphocytic choriomeningitis virus (LCMV) and Pichinde virus (PV). Each virus encodes a cross-reactive CD8 epitope that has six out of eight in amino acid (aa) similarity with respect to its counterpart at the position 205-212 of the nucleoprotein (NP205). Heterologous challenge between LCMV and PV results in 1) expansion of the cross-reactive NP205-specific CD8 T cell responses and alteration of the immunodominance hierarchy and 2) partial protective immunity (heterologous immunity). Our lab showed that cross-reactive NP205-specific CD8 T cell receptor (TCR) repertoires become extremely narrowed following a heterologous challenge between LCMV and PV. Therefore, I questioned if LCMV NP205 epitope escape variants could be isolated during a dominant but narrowed crossVI reactive NP205-specific CTL response. In the first part of my thesis, I describe the isolation of a LCMV NP-V207A CTL escape variant in vivo using PV-immune animals challenged with LCMV clone 13. The LCMV NP-V207A variant contains a point mutation, which results in the switching of valine to alanine at the third non-anchoring residue of the LCMV NP205 CD8 epitope. Immunization of mice with the LCMV NP-V207A variant results in a significantly diminished cross-reactive NP205-specific CD8 T cell response. This suggests that the point mutation is responsible for the loss in the immunogenicity of the LCMV NP205 CD8 epitope. In addition, an in vitrorescued(r) recombinant LCMV variant (r/V207A) that encodes the original mutation also induces a highly diminished cross-reactive NP205-specific CD8 T cell response in mice. In agreement with the result obtained from the intracellular cytokine assays (ICS), MHC-Ig dimers loaded with the LCMV NP205 (V-A) peptide could only detect a minute population of cross-reactive NP205-specific CD8 T cells in mice infected with r/V207A variant virus. All the data indicate that the point mutation results in a significant loss in immunogenicity of the LCMV NP205 CD8 epitope. So far, no direct link between the cross-reactive NP205-specific CD8 T cells and heterologous immunity had been established in this system. Therefore, we immunized mice with either LCMV WT or the LCMV NP-V207A variant virus and showed that a significant loss of heterologous immunity is associated with the group immunized with LCMV NP-V207A variant virus. Again, r/V207Aimmune animals also displayed a significant loss in heterologous immunity following PV challenge. This suggests that the cross-reactive NP205-specific CD8 T cells mediate the majority of heterologous immunity between LCMV and PV in vivo. In comparison to the PV-immune control group, PV clearance kinetics mediated by the cross-reactive NP205-specific CD8 T cells were significantly delayed. Finally, these data also suggest that bystander activation plays very little role in heterologous immunity between LCMV and PV. Many studies in murine systems and humans suggest that cross-reactive T cells are often associated with immune pathology. We showed that in mice that were sequentially immunized with PV and LCMV (PV+LCMV WT double immune mice), there was a development of a high incidence and high level of immune pathology known as acute fatty necrosis (AFN) following a final PV challenge. The data suggest that these cross-reactive NP205-specific CD8 T cells might play an important role in immune pathogenesis. Therefore, we asked if the cross-reactive NP205-specific CD8 T cells play a role in immune pathogenesis by comparing the incidence of AFN between the (PV+LCMV WT) and the (PV+LCMV NP-V207A) double immune mice following a final PV challenge. In agreement with our hypothesis, the result showed the (PV+LCMV NP-V207A) double immune mice developed a significantly lower incidence of AFN compared to the (PV+LCMV WT) double immune mice. However, linear correlation studies comparing the frequency of different antigen-specific CD8 T cell populations within the (PV+LCMV WT) double immune mice before challenge and the severity of AFN following the PV challenge suggest that two opposing antigen-specific CD8 T cell populations are involved in determining the final outcome of the immune pathology. The PV NP38-45-specific CD8 T cell response (PV NP38) appears to be more protective than the cross-reactive NP205-specific CD8 T cell response. In addition, a positive linear correlation between the ratio of cross-reactive NP205 to PV NP38 and the severity of AFN seem to suggest that these cross-reactive populations are important contributors to immune pathogenesis. Peptide titration studies examining the functional avidities to different antigenic specificities suggest that both populations consist of high avidity TCR and peptide MHC (TCR:pMHC) interactions. However, skewing within the cross-reactive NP205 specific CD8 T cell response towards the LCMV NP205 epitope response in one of the (PV+LCMV WT) double immune mice suggests that cross-reactive NP205 specific CD8 T cells could constitute a sub-optimal response to a PV challenge. In summary, I questioned what might be some of the immunological consequences of heterologous immunity in this model. First of all, we have established a direct link between the cross-reactive NP205-specific CD8 T cell response and heterologous immunity in LCMV and PV. Second of all, I demonstrated that a LCMV NP205 epitope escape variant could be selected in vivo under the conditions of heterologous immunity. In addition, I showed that PV clearance kinetic was significantly delayed in cross-reactive NP205-mediated heterologous immunity as compared to homologous challenge. Finally, we demonstrated that cross-reactive NP205-specific CD8 T cells could play an important role in immune pathogenesis in this model. However, correlation data indicate that two opposing antigen-specific CD8 T cell populations could ultimately decide the outcome and magnitude of immune pathology in each individual mouse. All the data presented above strongly suggest that the cross-reactive NP205 CD8 T cells play a crucial role in immune pathology in this model system by 1) interfering with the regular establishment of immunodominance hierarchy orders, or 2) exhibiting a sub-optimal protective immunity due to the nature of the cross-reactive epitope.

One of the hallmarks of an infection with pathogenic HIV-1 is the elevated level of immune activation that leads to rapid progression to AIDS. Surprisingly, nonhuman primates naturally infected with SIV do not exhibit an augmented activation phenotype nor severe immunodeficiency. One of the viral components implicated in determining the state of immune activation is the accessory protein Nef which has been demonstrated to affect T cell signaling pathways from within the intracellular compartment and for Nef from SIV, to downregulate TCR surface expression. Recently, Nef from HIV-1 and SIV have been demonstrated to bind the ζ chain of the TCR which functions as the primary signaling subunit of the receptor. However, the molecular details of the Nef-TCRζ interaction as well as the role of complex formation in modulation of immune activation remain largely unknown. This thesis describes work directed at elucidating the biochemical and structural features of the Nef-TCRζ interaction and the functional consequences of complex formation relevant to T cell activation. Chapter I provides a brief introduction on HIV/SIV classification and pathogenesis with an emphasis on Nef and its pleiotropic function in T cells. Chapter II describes the biochemical characterization of the interaction of the conserved core domain of Nef proteins from HIV-1, HIV-2 and SIV with the cytoplasmic domain of TCRζ. The core domains of HIV-2 ST and SIVmac239 are demonstrated to bind the cytoplasmic domain of TCRζ at two distinct regions and with different affinities. In contrast, the core domain of HIV-1 isolate ELI Nef only binds to one region and with the weakest calculated affinity among the HIV-1, HIV-2 and SIV Nef proteins studied. In addition, both the N-terminal domain and the strong TCRζ-binding core domain of SIVmac239 Nef each are demonstrated to be necessary but not sufficient for downregulation of TCR surface expression. Chapter III describes the crystallization and structure determination methods used to solve the crystal structures of the core domain of SIVmac239 Nef in complex with two overlapping TCRζ polypeptides. Crystals of Nef in complex with the longer TCRζDP1 (L51-D93) polypeptide grew in a tetragonal space group but only diffracted to low resolution. In contrast, crystals of the Nefcore-TCRζA63-R80 complex grew in an orthorhombic space group and diffracted to high resolution but were nearly perfectly pseudo-merohedrally twinned thus complicating structure determination. Following identification of the twin law relating the twin domains, the structure of the Nefcore-TCRζA63-R80 complex was determined using refinement procedures that accounted for crystal twinning to 2.05 Å. The structure of the Nefcore-TCRζDP1 complex was solved to 3.7 Å from a single non-twinned crystal. The altered crystal packing induced by the shorter TCRζA63-R80polypeptide is postulated to have led to a reduction in crystal symmetry and increase in proneness to crystal twinning. Chapter IV provides a detailed analysis of the structure of the Nefcore-TCRζA63-R80 complex and demonstrates its effect on modulation of Src family kinase activity. The TCRζ polypeptide adopts an alpha helical conformation and occupies a hydrophobic crevice on Nef not shared by any of Nef’s reported interaction partners. The interaction of Nefcore with TCRζ is mediated primarily by the burial of hydrophobic residues on TCRζ (L75, L77) in a hydrophobic pocket on Nef and a salt bridge between a glutamic acid (E74) on TCRζ and a basic patch on Nef consisting of two conserved arginines (R105, R106). The TCRζ polypeptide additionally orders the N-terminus of Nefcore into a polyproline type II helix that has been described to bind the SH3 domain of Src family kinases. We demonstrate that in vitro phosphorylation of TCRζcyt by Fyn and Src is specifically augmented by HIV-1 and SIV Nefcoreand suggest that Nef-TCRζ complex formation cooperatively enhances kinase activity. Chapter V contains overall conclusions, future directions and a model illustrating the proposed role of the Nef-TCRζ interaction in immune activation modulation. The Appendices contain sequences of the proteins, gene constructs and primers used in this work.

The immune response to an infection is determined by a number of factors, which also affect the generation of memory T cells afterwards. The immune response can also affect the stability of the pre-existing memory populations. The memory developed after an infection can influence the response to subsequent infections with unrelated pathogens. This heterologous immunity may deviate the course of disease and alter the disease outcome. The generation and stability of memory CD8 T cells and the influence of the history of infections on subsequent heterologous infections are studied in this thesis using different viral infection sequences. Previous studies using mice lacking individual immunoproteasome catalytic subunits showed only modest alterations in the CD8 T cell response to lymphocytic choriomeningitis virus (LCMV). In this study, I found that the CD8 T cell response to LCMV was severely impaired in mice lacking all three catalytic subunits of the immunoproteasome, altering the immunodominance hierarchy of the CD8 T cell response and CD8 T cell memory. Adoptive transfer experiments suggested that both inefficient antigen presentation and altered T cell repertoire contribute to the reduction of the CD8 T cell response in the immunoproteasome knockout mice. Immune responses generated during infections can reduce pre-existing memory T cell populations. Memory CD8 T cells have been shown to be reduced by subsequent heterologous infections. In this study, I re-examined the phenomenon using immune mice infected with LCMV, murine cytomegalovirus (MCMV) and vaccinia virus (VACV) in different infection sequences. I confirmed that memory CD8 T cells were reduced by heterologous infections, and showed that LCMV-specific memory CD4 T cells were also reduced by heterologous infections. Reduction of the memory CD8 T cells is thought to be the result of apoptosis of memory CD8 T cells associated with the peak of type I interferon early during infection. I showed that memory CD4 T cells were similarly driven to apoptosis early during infection; however, Foxp3+ CD4+ regulatory T cells were relatively resistant to virus infection-induced apoptosis, and were stably maintained during LCMV infection. The stability of Treg cells during viral infections may explain the relatively low incidence of autoimmunity associated with infections. The history of infections can deviate the course of disease and affect the disease outcome, but this heterologous immunity is not necessarily reciprocal. Previous studies have shown the effects of heterologous immunity during acute infections. In this thesis, I showed that the history of LCMV infection led to higher viral titers during persistent MCMV infection, caused more severe immunopathology at the beginning of infection, and reduced the number of MCMV-specific inflationary memory CD8 T cells after the period of memory inflation. In a different context of infection, the history of LCMV infection can be beneficial. LCMV-immune mice have been shown to have lower viral titers after VACV infection, but VACV-immune mice are not protected during LCMV infection. I found that memory CD8 T cells generated from LCMV and VACV infections were phenotypically different, but the differences could not explain the nonreciprocity of heterologous immunoprotection. By increasing the number of crossreactive VACV A11R198-205-specific memory CD8 T cells, however, I showed that some VACV-immune mice displayed reduced viral titers upon LCMV challenge, suggesting that the low number of potentially cross-reactive CD8 T cells in VACV-immune mice may be part of the reasons for the non-reciprocity of immunoprotection between LCMV and VACV. Further analysis deduced that both number of potentially cross-reactive memory CD8 T cells and the private specificity of memory CD8 T cell repertoire played a part in determining the outcome of heterologous infections.

As humans, we inhabit an environment shared with many microorganisms, some of which are harmless or beneficial, and others which represent a threat to our health. A complex network of organs, cells and their protein products form our bodies’ immune system, tasked with detecting these potentially harmful agents and eliminating them. This same system also serves to detect changes in the healthy balance of normal functions in the body, and for repairing tissue damage caused by injury. Immune recognition of nucleic acids, DNA and RNA, is one way that the body detects invading pathogens and initiates tissue repair. A number of specialized receptor proteins have evolved to distinguish nucleic acids that represent “threats” from those involved in normal physiology. These proteins include members of the Toll-like receptor family and diverse types of cytosolic proteins, all of which reside within the confines of the cell. Few proteins on the cell surface have been clearly characterized to interact with nucleic acids in the extracellular environment. In this dissertation, I present collaborative work that identifies the receptor for advanced glycation end products (RAGE) as a cell surface receptor for nucleic acids and positions it as an important modulator of immune responses. Molecular dimers of RAGE interact with the sugar-phosphate backbones of nucleic acid ligands, allowing this receptor to recognize a variety of DNA and RNA molecules regardless of their nucleotide sequence. Expression of RAGE on cells promotes uptake of DNA and enhances subsequent responses that are dependent on the nucleic acid sensor Toll-like receptor 9. When mice deficient in RAGE are exposed to DNA in the lung, the predominant site of RAGE expression, they do not mount a typical early inflammatory response, suggesting that RAGE is important in generating immune responses to DNA in mammalian organisms. Further evidence suggests that RAGE interacts preferentially with multimolecular complexes that contain nucleic acids, and that these complexes may induce clustering of receptor dimers into larger multimeric structures. Taken together, the data reported here identify RAGE as an important cell surface receptor protein for nucleic acids, which is capable of modulating the intensity of immune responses to DNA and RNA. Understanding of and intervention in this recognition pathway hold therapeutic promise for diseases characterized by excessive responses to self nucleic acids, such as systemic lupus erythematosus, and for the pathology caused by chronic inflammatory responses to self and foreign nucleic acids.

Recent advances in the field of host immunity against parasitic nematodes have revealed the importance of macrophages in trapping tissue migratory larvae. Protective immune mechanisms against the rodent hookworm Nippostrongylus brasiliensis (Nb) are mediated, at least in part, by IL-4-activated macrophages that bind and trap larvae in the lung. However, it is still not clear how host macrophages recognize the parasite. An in vitro co-culture system of bone marrow-derived macrophages and Nb infective larvae was utilized to screen for the possible ligand-receptor pair involved in macrophage attack of larvae. Competitive binding assays revealed an important role for β-glucan recognition in the process. We further identified a role for CD11b and the non-classical pattern recognition receptor ephrin-A2 (EphA2), but not the highly expressed β-glucan dectin-1 receptor, in this process of recognition. This work raises the possibility that parasitic nematodes synthesize β-glucans and it identifies CD11b and ephrin-A2 as important pattern recognition receptors involved in the host recognition of these evolutionary old pathogens. To our knowledge, this is the first time that EphA2 has been implicated in immune responses to a helminth.

The human immune system is made up of cells and molecules distributed across the body, which provide protection from acute viral infection and can be maintained in diverse tissue sites as memory to protect against repeat viral exposure. Vaccine technology has leveraged our understanding of human immunity to induce immune memory in humans without infection. However, we continue to encounter novel infections, as evidenced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which necessitates the development of new vaccines and formulations, including the mRNA vaccine platform. Vaccine development began with serendipitous discoveries and, even today, often relies on empirical approaches that prioritize clinical outcomes over immunologic ones. For the recently developed coronavirus disease of 2019 (COVID-19) mRNA vaccines, we know that they confer clinical protection that wanes over time but have a more limited understanding of the immune memory they induce. Specifically, we do not know the tissue distribution of vaccine memory, these vaccines’ capacity to induce tissue-resident memory or various functional programs, and the relative role of B and T cells in protection. Through a unique collaboration with the New York City area organ procurement organization, LiveOnNY, we collected blood, bone marrow, spleen, lung, and various lymph nodes (LN) from human organ donors who had received COVID-19 mRNA vaccines. Using these tissues, we employed multimodal, high-dimensional analysis tools to investigate the localization, phenotype, maintenance, and functions of COVID-19 vaccine-induced memory in the context of host factors such as age, time post-vaccination, and prior SARS-CoV-2 infection. In samples from 63 organ donors aged 23-86, we found that COVID-19 vaccine memory was distributed across tissues, especially in LN, and was more durable across time post-vaccination and age in tissues than in circulation. Vaccine-specific B cells were mostly class-switched resident memory, while vaccine-specific T cells were variably tissue-resident depending on infection history. Vaccine-specific T cell effector functions were diverse and site-specific with an enhanced regulatory profile in tissues compared to circulating populations. To investigate the interaction between T and B cells in immune memory generation and their relative roles in protection, we also compared the quantity and quality of circulating COVID-19 vaccine induced memory from patients with multiple sclerosis taking B cell depleting (BCD) therapies to those taking other immunomodulatory therapies (non-BCD). In 281 samples from 216 subjects aged 24-78 we found that COVID-19 vaccine induced humoral immunity was completely diminished in the context of B cell depletion, but that cellular immunity, especially CD8+T cells, were enhanced in this context and maintained over time. Further, BCD subjects experienced equivalent numbers of infections following vaccination as non-BCD subjects. Together, these findings demonstrate that T cell responses can develop independently from, and may even be limited by, B cell responses, and that T cells but not B cells are critical for vaccine-induced protection. Ultimately, these findings provide critical insights for future vaccine development; studies must assess LN responses and aim to generate a robust cellular response that includes both regulatory and effector functional profiles within tissues.

Immunologic monitoring is part of the standard care for patients on antiretroviral treatment. Yet, little is known about the routine implementation of immunologic monitoring in Ethiopia. This study assessed the pattern of immunologic monitoring, immunologic response, level of immunologic treatment failure and factors related to it among patients on antiretroviral therapy in selected hospitals in southern Ethiopia. A retrospective longitudinal analytic study was conducted using documents of patients started on antiretroviral therapy. A total of 1,321 documents of patients reviewed revealed timely immunologic monitoring were inadequate. Despite overall adequate immunologic response, the prevalence of immunologic failure was 11.5% (n=147). Having WHO Stage III/IV of the disease and a higher CD4 (cluster differentiation 4) cell count at baseline were identified as risks for immunologic failure. These findings highlight the magnitude of the problem of immunologic failure. Prioritizing monitoring for high risk patients may help in effective utilisation of meager resources / Health Studies / M.A. (Public Health)