Divergent local and systemic antitumor response in primary uveal melanomas

Uveal melanoma (UM) is the most common cancer of the eye. The loss of chromosome 3 (M3) is associated with a high risk of metastases. M3 tumors are more infiltrated by T-lymphocytes than low-risk disomic-3 (D3) tumors, contrasting with other tumor types in which T cell infiltration correlates with better prognosis. Whether these T cells represent an antitumor response and how these T cells would be primed in the eye are both unknown. Herein, we characterized the T cells infiltrating primary UMs. CD8+ and Treg cells were more abundant in M3 than in D3 tumors. CD39+PD-1+CD8+ T cells were enriched in M3 tumors, suggesting specific responses to tumor antigen (Ag) as confirmed using HLA-A2:Melan-A tetramers. scRNAseq-VDJ analysis of T cells evidenced high numbers of proliferating CD39+PD1+CD8+ clonal expansions, suggesting in situ antitumor Ag responses. TCRseq and tumor-Ag tetramer staining characterized the recirculation pattern of the antitumor responses in M3 and D3 tumors. Thus, tumor-Ag responses occur in localized UMs, raising the question of the priming mechanisms in the absence of known lymphatic drainage.

A conserved transcriptional program for MAIT cells across mammalian evolution

Mucosal-associated invariant T (MAIT) cells harbor evolutionarily conserved TCRs, suggesting important functions. As human and mouse MAIT functional programs appear distinct, the evolutionarily conserved MAIT functional features remain unidentified. Using species-specific tetramers coupled to single-cell RNA sequencing, we characterized MAIT cell development in six species spanning 110 million years of evolution. Cross-species analyses revealed conserved transcriptional events underlying MAIT cell maturation, marked by ZBTB16 induction in all species. MAIT cells in human, sheep, cattle, and opossum acquired a shared type-1/17 transcriptional program, reflecting ancestral features. This program was also acquired by human iNKT cells, indicating common differentiation for innate-like T cells. Distinct type-1 and type-17 MAIT subsets developed in rodents, including pet mice and genetically diverse mouse strains. However, MAIT cells further matured in mouse intestines to acquire a remarkably conserved program characterized by concomitant expression of type-1, type-17, cytotoxicity, and tissue-repair genes. Altogether, the study provides a unifying view of the transcriptional features of innate-like T cells across evolution.

Multimodal profiling reveals site-specific adaptation and tissue residency hallmarks of γδ T cells across organs in mice

γδ T cells perform heterogeneous functions in homeostasis and disease across tissues. However, it is unclear whether these roles correspond to distinct γδ subsets or to a homogeneous population of cells exerting context-dependent functions. Here, by cross-organ multimodal single-cell profiling, we reveal that various mouse tissues harbor unique site-adapted γδ subsets. Epidermal and intestinal intraepithelial γδ T cells are transcriptionally homogeneous and exhibit epigenetic hallmarks of functional diversity. Through parabiosis experiments, we uncovered cellular states associated with cytotoxicity, innate-like rapid interferon-γ production and tissue repair functions displaying tissue residency hallmarks. Notably, our observations add nuance to the link between interleukin-17-producing γδ T cells and tissue residency. Moreover, transcriptional programs associated with tissue-resident γδ T cells are analogous to those of CD8+ tissue-resident memory T cells. Altogether, this study provides a multimodal landscape of tissue-adapted γδ T cells, revealing heterogeneity, lineage relationships and their tissue residency program.

Human MAIT cells inhibit alloreactive T cell responses and protect against acute graft-versus-host disease

Adoptive transfer of immunoregulatory cells can prevent or ameliorate graft-versus-host disease (GVHD), which remains the main cause of nonrelapse mortality after allogeneic hematopoietic stem cell transplantation. Mucosal-associated invariant T (MAIT) cells were recently associated with tissue repair capacities and with lower rates of GVHD in humans. Here, we analyzed the immunosuppressive effect of MAIT cells in an in vitro model of alloreactivity and explored their adoptive transfer in a preclinical xenogeneic GVHD model. We found that MAIT cells, whether freshly purified or short-term expanded, dose-dependently inhibited proliferation and activation of alloreactive T cells. In immunodeficient mice injected with human PBMCs, MAIT cells greatly delayed GVHD onset and decreased severity when transferred early after PBMC injection but could also control ongoing GVHD when transferred at delayed time points. This effect was associated with decreased proliferation and effector function of human T cells infiltrating tissues of diseased mice and was correlated with lower circulating IFN-γ and TNF-α levels and increased IL-10 levels. MAIT cells acted partly in a contact-dependent manner, which likely required direct interaction of their T cell receptor with MHC class I-related molecule (MR1) induced on host-reactive T cells. These results support the setup of clinical trials using MAIT cells as universal therapeutic tools to control severe GVHD or mucosal inflammatory disorders.

Protocol to expand and CRISPR-Cas9 genomic edit murine MAIT cells for subsequent in vivo studies

Generating knockout mice for target molecules in specific T cell populations, without subset-specific promoters, is time-consuming and costly. Here, we describe steps for enriching mucosal-associated invariant T cells from the thymus, expanding them in vitro and performing a CRISPR-Cas9 knockout. We then detail procedure for injecting the knockout cells into wounded Cd3ε-/- mice and characterizing them in the skin. For complete details on the use and execution of this protocol, please refer to du Halgouet et al. (2023).1.

Role of MR1-driven signals and amphiregulin on the recruitment and repair function of MAIT cells during skin wound healing

Tissue repair processes maintain proper organ function following mechanical or infection-related damage. In addition to antibacterial properties, mucosal associated invariant T (MAIT) cells express a tissue repair transcriptomic program and promote skin wound healing when expanded. Herein, we use a human-like mouse model of full-thickness skin excision to assess the underlying mechanisms of MAIT cell tissue repair function. Single-cell RNA sequencing analysis suggested that skin MAIT cells already express a repair program at steady state. Following skin excision, MAIT cells promoted keratinocyte proliferation, thereby accelerating healing. Using skin grafts, parabiosis, and adoptive transfer experiments, we show that MAIT cells migrated into the wound in a T cell receptor (TCR)-independent but CXCR6 chemokine receptor-dependent manner. Amphiregulin secreted by MAIT cells following excision promoted wound healing. Expression of the repair function was probably independent of sustained TCR stimulation. Overall, our study provides mechanistic insights into MAIT cell wound healing function in the skin.

MAIT Cell Development and Functions: the Microbial Connection

Mucosal-associated invariant T (MAIT) cells are an evolutionarily conserved T cell subset, which reacts to most bacteria through T cell receptor (TCR)-mediated recognition of metabolites derived from the vitamin B2 biosynthetic pathway. Microbiota-derived signals affect all stages of MAIT cell biology including intra-thymic development, peripheral expansion, and functions in specific organs. In tissues, MAIT cells can integrate multiple signals and display effector functions involved in the defense against infectious pathogens. In addition to anti-bacterial activity, MAIT cells improve wound healing in the skin, suggesting a role in epithelium homeostasis through bi-directional interactions with the local microbiota. In humans, blood MAIT cell frequency is modified during several auto-immune diseases, which are often associated with microbiota dysbiosis, further emphasizing the potential interplay of MAIT cells with the microbiota. Here, we will review how microbes interact with MAIT cells, from initial intra-thymic development to tissue colonization and functions.

MAIT cell development in mice and humans

MAIT cells arise in the thymus following rearrangement of a T cell receptor (TCR) reactive against microbial vitamin B2-derived metabolites presented by the MHC-Ib molecule, MR1. Mechanisms that are conserved in mammals ensure the frequent production of MR1-restricted TCRs and the intra-thymic differentiation of MR1-restricted thymocytes into effector cells. Upon thymic egress and migration into non-lymphoid tissues, additional signals modulate MAIT cell functions according to each local tissue environment. Here, we review the recent progress made towards a better understanding of the establishment of this major immune cell subset.

Microbial metabolites control the thymic development of mucosal-associated invariant T cells

How the microbiota modulate immune functions remains poorly understood. Mucosal-associated invariant T (MAIT) cells are implicated in mucosal homeostasis and absent in germ-free mice. Here, we show that commensal bacteria govern murine MAIT intrathymic development, as MAIT cells did not recirculate to the thymus. MAIT development required RibD expression in bacteria, indicating that production of the MAIT antigen 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU) was necessary. 5-OP-RU rapidly traveled from mucosal surfaces to the thymus, where it was captured by the major histocompatibility complex class Ib molecule MR1. This led to increased numbers of the earliest MAIT precursors and the expansion of more mature receptor-related, orphan receptor γt-positive MAIT cells. Thus, a microbiota-derived metabolite controls the development of mucosally targeted T cells in a process blurring the distinction between exogenous antigens and self-antigens.

Prevalence of human papillomavirus, human immunodeficiency virus and other sexually transmitted infections among female sex workers in Togo: a national cross-sectional survey

OBJECTIVES

Sub-Saharan Africa is a region with high incidence of both human immunodeficiency virus (HIV) and cervical cancer. We conducted the first national study in Togo to assess prevalence of human papillomavirus (HPV), HIV and other sexually transmitted infections (STIs) among female sex workers (FSW).

METHODS

A multicentric cross-sectional study was conducted among FSW recruited in hot spots (clubs, streets) in four Togolese cities. HPV and STIs were tested from cervical and anal swabs. HIV and syphilis were screened with rapid tests.

RESULTS

In all, 310 FSW were recruited; HIV and cervical high-risk HPV (hrHPV) prevalence were 10.6% (33/310) and 32.9% (102/310), respectively. The most frequent hrHPV types were HPV58 (13.6%, 19/140), HPV35 (12.9%, 18/140), HPV31 (12.1%, 17/140) and HPV16 (10.7%, 15/140). Prevalence of hrHPV and multiple hrHPV infections showed higher rates in HIV-positive than in HIV-negative FSW (48.5% versus 31.0%, p 0.04 and 21.2% versus 9.0%, p 0.03; respectively). Prevalence of hrHPV was higher in cervical than anal swabs (34.1% versus 20.7%, p 0.0004). High-risk HPV anal infections were more frequent among HIV-positive than HIV-negative FSW (51.9% versus 17.3%, p 2 × 10^-5). Concomitant anal and cervical hrHPV infections were present in 43.2% (41/95) of hrHPV-positive FSW. Overall prevalence in the cervix of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium and Trichomonas vaginalis were 4.2%, 6.1%, 5.5% and 6.5%, respectively.

CONCLUSIONS

This first African study on paired cervical and anal samples showed a high prevalence of genital HPV infections with a rather high rate of concomitant HPV infections but low type concordance. We report an unusual distribution of hrHPV types. These findings highlight the critical need for implementation of a national HPV vaccination strategy.

A common transcriptomic program acquired in the thymus defines tissue residency of MAIT and NKT subsets

Salou et al. wondered what could differentiate MAIT and NKT cells, if not for TCR specificity. Once split according to RORγt and T-bet–expressing subsets, MAIT and NKT share almost identical transcriptional programs acquired in the thymus, which result in specific tissue residency patterns.

Mucosal-associated invariant T (MAIT) cells are abundant T cells with unique specificity for microbial metabolites. MAIT conservation along evolution indicates important functions, but their low frequency in mice has hampered their detailed characterization. Here, we performed the first transcriptomic analysis of murine MAIT cells. MAIT1 (RORγt^neg) and MAIT17 (RORγt⁺) subsets were markedly distinct from mainstream T cells, but quasi-identical to NKT1 and NKT17 subsets. The expression of similar programs was further supported by strong correlations of MAIT and NKT frequencies in various organs. In both mice and humans, MAIT subsets expressed gene signatures associated with tissue residency. Accordingly, parabiosis experiments demonstrated that MAIT and NKT cells are resident in the spleen, liver, and lungs, with LFA1/ICAM1 interactions controlling MAIT1 and NKT1 retention in spleen and liver. The transcriptional program associated with tissue residency was already expressed in thymus, as confirmed by adoptive transfer experiments. Altogether, shared thymic differentiation processes generate “preset” NKT and MAIT subsets with defined effector functions, associated with specific positioning into tissues.

Ontogeny of human mucosal-associated invariant T cells and related T cell subsets

There are very few human MAIT cells in cord blood. Ben Youssef et al. show that they slowly expand during childhood and point to a critical role of the TCRαβ repertoire in determining their unique ability to recognize MR1-restricted microbial antigens.

Mucosal-associated invariant T (MAIT) cells are semi-invariant Vα7.2⁺ CD161^highCD4⁻ T cells that recognize microbial riboflavin precursor derivatives such as 5-OP-RU presented by MR1. Human MAIT cells are abundant in adult blood, but there are very few in cord blood. We longitudinally studied Vα7.2⁺ CD161^high T cell and related subset levels in infancy and after cord blood transplantation. We show that Vα7.2⁺ and Vα7.2⁻ CD161^high T cells are generated early during gestation and likely share a common prenatal developmental program. Among cord blood Vα7.2⁺ CD161^high T cells, the minority recognizing MR1:5-OP-RU display a TRAV/TRBV repertoire very similar to adult MAIT cells. Within a few weeks of life, only the MR1:5-OP-RU reactive Vα7.2⁺ CD161^high T cells acquire a memory phenotype. Only these cells expand to form the adult MAIT pool, diluting out other Vα7.2⁺ CD161^high and Vα7.2⁻ CD161^high populations, in a process requiring at least 6 years to reach adult levels. Thus, the high clonal size of adult MAIT cells is antigen-driven and likely due to the fine specificity of the TCRαβ chains recognizing MR1-restricted microbial antigens.

An intermediate level of CD161 expression defines a novel activated, inflammatory, and pathogenic subset of CD8+ T cells involved in multiple sclerosis

Several lines of evidence support a key role for CD8⁺ T cells in central nervous system tissue damage of patients with multiple sclerosis. However, the precise phenotype of the circulating CD8⁺ T cells that may be recruited from the peripheral blood to invade the CNS remains largely undefined to date. It has been suggested that IL-17 secreting CD8 (Tc17) T cells may be involved, and in humans these cells are characterized by the expression of CD161. We focused our study on a unique and recently described subset of CD8 T cells characterized by an intermediate expression of CD161 as its role in neuroinflammation has not been investigated to date. The frequency, phenotype, and function of CD8⁺ T cells with an intermediate CD161 expression level were characterized ex-vivo, in vitro, and in situ using RNAseq, RT-PCR, flow cytometry, TCR sequencing, and immunohistofluorescence of cells derived from healthy volunteers (n = 61), MS subjects (n = 90), as well as inflammatory (n = 15) and non-inflammatory controls (n = 6). We report here that CD8⁺CD161^int T cells present characteristics of effector cells, up-regulate cell-adhesion molecules and have an increased ability to cross the blood-brain barrier and to secrete IL-17, IFNγ, GM-CSF, and IL-22. We further demonstrate that these cells are recruited and enriched in the CNS of MS subjects where they produce IL-17. In the peripheral blood, RNAseq, RT-PCR, high-throughput TCR repertoire analyses, and flow cytometry confirmed an increased effector and transmigration pattern of these cells in MS patients, with the presence of supernumerary clones compared to healthy controls. Our data demonstrate that intermediate levels of CD161 expression identifies activated and effector CD8⁺ T cells with pathogenic properties that are recruited to MS lesions. This suggests that CD161 may represent a biomarker and a valid target for the treatment of neuroinflammation.

Unconventional or Preset αβ T Cells: Evolutionarily Conserved Tissue-Resident T Cells Recognizing Nonpeptidic Ligands

A majority of T cells bearing the αβ T cell receptor (TCR) are specific for peptides bound to polymorphic classical major histocompatibility complex (MHC) molecules. Smaller subsets of T cells are reactive toward various nonpeptidic ligands associated with nonpolymorphic MHC class-Ib (MHC-Ib) molecules. These cells have been termed unconventional for decades, even though only the composite antigen is different from the one seen by classical T cells. Herein, we discuss the identity of these particular T cells in light of the coevolution of their TCR and MHC-Ib restricting elements. We examine their original thymic development: selection on hematopoietic cells leading to the acquisition of an original differentiation program. Most of these cells acquire memory cell features during thymic maturation and exhibit unique patterns of migration into peripheral nonlymphoid tissues to become tissue resident. Thus, these cells are termed preset T cells, as they also display a variety of effector functions. They may act as microbial or danger sentinels, fight microbes, or regulate tissue homeostasis.

MHC class I-related molecule, MR1, and mucosal-associated invariant T cells

The MHC-related 1, MR1, molecule presents a new class of microbial antigens (derivatives of the riboflavin [Vitamin B2] biosynthesis pathway) to mucosal-associated invariant T (MAIT) cells. This raises many questions regarding antigens loading and intracellular trafficking of the MR1/ligand complexes. The MR1/MAIT field is also important because MAIT cells are very abundant in humans and their frequency is modified in many infectious and non-infectious diseases. Both MR1 and the invariant TCRα chain expressed by MAIT cells are strikingly conserved among species, indicating important functions. Riboflavin is synthesized by plants and most bacteria and yeasts but not animals, and its precursor derivatives activating MAIT cells are short-lived unless bound to MR1. The recognition of MR1 loaded with these compounds is therefore an exquisite manner to detect invasive bacteria. Herein, we provide an historical perspective of the field before describing the main characteristics of MR1, its ligands, and the few available data regarding its cellular biology. We then summarize the current knowledge of MAIT cell differentiation and discuss the definition of MAIT cells in comparison to related subsets. Finally, we describe the phenotype and effector activities of MAIT cells.

Neuropathologic, phenotypic and functional analyses of Mucosal Associated Invariant T cells in Multiple Sclerosis

BACKGROUND

The involvement of Mucosal Associated Invariant T (MAIT) cells, which are anti-microbial semi-invariant T cells, remains elusive in Multiple Sclerosis (MS).

OBJECTIVE

Deciphering the potential involvement of MAIT cells in the MS inflammatory process.

METHODS

By flow cytometry, blood MAIT cells from similar cohorts of MS patients and healthy volunteers (HV) were compared for frequency, phenotype, activation potential after in vitro TCR engagement by bacterial ligands and transmigration abilities through an in vitro model of blood-brain barrier. MS CNS samples were also studied by immunofluorescent staining and quantitative PCR.

RESULTS AND CONCLUSION

Blood MAIT cells from relapsing-remitting MS patients and HV presented similar frequency, ex vivo effector phenotype and activation abilities. MAIT cells represented 0.5% of the total infiltrating T cells on 39 MS CNS lesions. This is low as compared to blood frequency (p<0.001), but consistent with their low transmigration rate. Finally, transcriptional over-expression of MR1 - which presents cognate antigens to MAIT cells - and of the activating cytokines IL-18 and IL-23 was evidenced in MS lesions, suggesting that the CNS microenvironment is suited to activate the few infiltrating MAIT cells. Taken together, these data place MAIT cells from MS patients as minor components of the inflammatory pathological process.

Involvement of CD8(+) T Cells in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by focal demyelination patches associated with inflammatory infiltrates containing T lymphocytes. For decades, CD4(+) T cells have been recognized as playing a major role in the disease, especially in animal models, which has led to the development of several therapies. However, interest has recently developed in the involvement of CD8(+) T cells in MS following the analysis of infiltrating T cells in human brain lesions. A broad range of evidence now suggests that the pathological role of this T cell subset in MS may have been underestimated. In this review, we summarize the literature implicating CD8(+) T cells in the pathophysiology of MS. We present data from studies in the fields of genetics, anatomopathology and immunology, mainly in humans but also in animal models of MS. Altogether, this strongly suggests that CD8(+) T cells may be major effectors in the disease process, and that the development of treatments specifically targeting this subset would be germane.

Transcript analysis of laser capture microdissected white matter astrocytes and higher phenol sulfotransferase 1A1 expression during autoimmune neuroinflammation

Background

Astrocytes, the most abundant cell population in mammal central nervous system (CNS), contribute to a variety of functions including homeostasis, metabolism, synapse formation, and myelin maintenance. White matter (WM) reactive astrocytes are important players in amplifying autoimmune demyelination and may exhibit different changes in transcriptome profiles and cell function in a disease-context dependent manner. However, their transcriptomic profile has not yet been defined because they are difficult to purify, compared to gray matter astrocytes. Here, we isolated WM astrocytes by laser capture microdissection (LCM) in a murine model of multiple sclerosis to better define their molecular profile focusing on selected genes related to inflammation. Based on previous data indicating anti-inflammatory effects of estrogen only at high nanomolar doses, we also examined mRNA expression for enzymes involved in steroid inactivation.

Methods

Experimental autoimmune encephalomyelitis (EAE) was induced in female C57BL6 mice with MOG_35–55 immunization. Fluorescence activated cell sorting (FACS) analysis of a portion of individual spinal cords at peak disease was used to assess the composition of immune cell infiltrates. Using custom Taqman low-density-array (TLDA), we analyzed mRNA expression of 40 selected genes from immuno-labeled laser-microdissected WM astrocytes from lumbar spinal cord sections of EAE and control mice. Immunohistochemistry and double immunofluorescence on control and EAE mouse spinal cord sections were used to confirm protein expression in astrocytes.

Results

The spinal cords of EAE mice were infiltrated mostly by effector/memory T CD4+ cells and macrophages. TLDA-based profiling of LCM-astrocytes identified EAE-induced gene expression of cytokines and chemokines as well as inflammatory mediators recently described in gray matter reactive astrocytes in other murine CNS disease models. Strikingly, SULT1A1, but not other members of the sulfotransferase family, was expressed in WM spinal cord astrocytes. Moreover, its expression was further increased in EAE. Immunohistochemistry on spinal cord tissues confirmed preferential expression of this enzyme in WM astrocytic processes but not in gray matter astrocytes.

Conclusions

We described here for the first time the mRNA expression of several genes in WM astrocytes in a mouse model of multiple sclerosis. Besides expected pro-inflammatory chemokines and specific inflammatory mediators increased during EAE, we evidenced relative high astrocytic expression of the cytoplasmic enzyme SULT1A1. As the sulfonation activity of SULT1A1 inactivates estradiol among other phenolic substrates, its high astrocytic expression may account for the relative resistance of this cell population to the anti-neuroinflammatory effects of estradiol. Blocking the activity of this enzyme during neuroinflammation may thus help the injured CNS to maintain the anti-inflammatory activity of endogenous estrogens or limit the dose of estrogen co-regimens for therapeutical purposes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-015-0348-y) contains supplementary material, which is available to authorized users.

Expanded CD8 T-cell sharing between periphery and CNS in multiple sclerosis

Objective

In multiple sclerosis (MS), central nervous system (CNS), cerebrospinal fluid (CSF), and blood display TCR clonal expansions of CD8⁺ T cells. These clones have been assumed – but never demonstrated – to be similar in the three compartments. Addressing this key question is essential to infer the implication of peripheral clonally expanded CD8⁺ T cells in the disease.

Methods

For the first time, TCR Vβ repertoire from paired blood (purified CD8⁺ and CD4⁺ T cells), CSF and CNS (22 lesions, various inflammatory and demyelination statuses) samples from three MS patients was studied using complementary determining region 3 (CDR3) spectratyping and high-throughput sequencing. In parallel, blood and CNS clonally expanded CD8⁺ T cells were characterized by fluorescent staining.

Results

TCR Vβ repertoire analysis revealed strong sharing of predominant T-cell clones between CNS lesions, CSF, and blood CD8⁺ T cells. In parallel, we showed that blood oligoclonal CD8⁺ T cells exhibit characteristics of pathogenic cells, as they displayed a bias toward a memory phenotype in MS patients, with increased expression of CCR5, CD11a and Granzyme B (GZM-B) compared to non oligoclonal counterparts. CNS-infiltrating T cells were mainly CD8 expressing CD11a and GZM-B.

Interpretation

This study highlights the predominant implication of CD8⁺ T cells in MS pathophysiology and demonstrates that potentially aggressive CD8⁺ T cells can be easily identified and characterized from blood and CSF samples.

The autoimmune concept of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS). With growing evidence for environmental and genetic factors, MS is now accepted as an autoimmune disease. This complex disease seems to implicate various cell types in both innate and adaptive compartments. Here, we discuss recent advances in the immunological field of MS research.

Chitinase 3-like proteins as diagnostic and prognostic biomarkers of multiple sclerosis

Background:

Despite sensitivity of MRI to diagnose multiple sclerosis (MS), prognostic biomarkers are still needed for optimized treatment.

Objective:

The objective of this paper is to identify cerebrospinal fluid (CSF) diagnostic biomarkers of MS using quantitative proteomics and to analyze their expression at different disease stages.

Methods:

We conducted differential analysis of the CSF proteome from control and relapsing–remitting MS (RRMS) patients followed by verification by ELISA of candidate biomarkers in CSF and serum in control, clinically isolated syndrome (CIS), RRMS and progressive MS (PMS) patients.

Results:

Twenty-two of the 527 quantified proteins exhibited different abundances in control and RRMS CSF. These include chitinase 3-like protein 1 (CHI3L1) and 2 (CHI3L2), which showed a strong expression in brain of MS patients, especially in astrocytes and microglial cells from white matter plaques. CSF and serum CHI3L1 levels increased with the disease stage and CIS patients with high CSF (>189 ng/ml) and serum (>33 ng/ml) CHI3L1 converted more rapidly to RRMS (log rank test, p < 0.05 and p < 0.001, respectively). In contrast, CSF CHI3L2 levels were lower in PMS than in RRMS patients. Accordingly, CSF CHI3L1/CHI3L2 ratio accurately discriminated PMS from RRMS.

Conclusions:

CSF CHI3L1 and CHI3L2 and serum CHI3L1 might help to define MS disease stage and have a prognostic value in CIS.

Evaluation of 9 rapid diagnostic tests for screening HIV infection, in Lomé, Togo

PURPOSE

HIV rapid diagnostic tests (RDT) could be greatly contributive for a universal access to HIV diagnosis. However, according to the WHO, these tests need to be assessed before they can be used in routine.

METHOD AND RESULTS

We assessed 9 RDT in routine clinical use between 2009 and 2013. The sensitivity and specificity observed for 7 tests were≥99% and≥98%, respectively: FIRST RESPONSE HIV1-2-O PMC Medical, India, GENIE Fast HIV 1-2 and GENIE™ III HIV(1/2) Bio-Rad, France, HIV TRI-DOT+Ag;J. Mitra, INDIA; SD BIOLINE HIV(1/2) 3.0 and SD BIOLINE HIV/SYPHILIS DUO Standard Diagnostic, Korea; and VIKIA HIV(1/2); BioMérieux, France. Two tests had performances inferior to WHO recommendations: INSTI HIV1/2 Biolytical Canada; sensitivity=97.8% and HEXAGON HIV HUMAN GmbH Germany; specificity=94.8%.

CONCLUSION

Seven of 9 RDT had excellent performances. Nevertheless, they can be used only after training staff, and taking into account national algorithm for their safe use.

[Accessibility of early infant diagnosis of HIV infection in Lome (Togo)]

BACKGROUND

Early infant diagnosis of HIV is the key step for the early initiation of HAART among HIV-exposed children. The aim of this study was to estimate the proportion of children born to mothers infected with HIV who completed the early infant HIV diagnosis process and the factors associated with this complete process.

METHODS

We conducted a retrospective cohort study at Tokoin University Hospital in the pediatrics ward. This study included all HIV-exposed children born between July 2009 and June 2011. The association between the mother's, spouse's, and child's characteristics as well as access to early HIV diagnosis by PCR (blood collection and reporting of results before the 6months of age) was studied using logistic regression analysis.

RESULTS

A total of 455 HIV-exposed children were included: for 52.7%, the first test was PCR, 99 of them received their results, 59 of whom received their results before the 6th month of life (undergoing the complete process). In multivariate analysis, the only factor associated with the complete process of early HIV diagnosis was the maternal age≥28years (adjusted odds ratio, 1.75, 95% CI [1.18-2.76]).

CONCLUSION

The availability of early infant PCR diagnosis remains a challenge and innovative strategies must be implemented.

[HIV seroprevalence and associated factors among men who have sex with men in Togo]

BACKGROUND

Limited data are available on HIV infection among vulnerable populations in sub-saharan African countries, especially among men who have sex with men (MSM). The aim of this study was to estimate HIV prevalence and the factors associated with HIV infection among MSM in Togo in 2011.

METHOD

A cross-sectional survey was carried out among MSM aged at least 18years old, living in Togo for at least 3months. They were recruited through the snowball method in six cities of Togo from November 2011 to January 2012. A survey form was used and an HIV screening test was proposed to the participants. The HIV prevalence was estimated with a 95% confidence interval. Univariate and multivariate analyses were performed to identify factors associated with HIV infection.

RESULTS

A total of 758 MSM were enrolled in this study, including 498 (67.5%) from Lomé, the capital of Togo. The median age was 24years with an interquartile range of [21-27years] and 271 MSM (35.7%) were students. The vast majority of MSM were Togolese (90.3%) and 14.6% were married or committed to a woman. HIV testing was accepted by 488 MSM (64.3%) but only 408 (53.8%) finally accepted a blood sample collection. The prevalence of HIV infection was 19.6% [95% confidence interval, 15.9-23.8]. In multivariate analysis, three factors were associated with HIV infection: living in Lomé, with an HIV prevalence of 29.8% against 4.3% in the other cities of Togo [adjusted odds ratio (aOR)=9.68; P<0.001]; having a good knowledge of HIV transmission modes (aOR=0.59; P=0.049); and not having a regular sex partner (aOR=1.69; P=0.049).

CONCLUSION

One MSM out of five was HIV-infected. Intervention programs targeting this vulnerable population are urgently needed, to reduce HIV incidence in Togo.

[What remains today of neonatal conjunctivitis in prefecture of Kozah in Togo?]

AIM

The purpose of this study is to screen the neonatal conjunctivitis in order to evaluate its incidence and especially to seek for the causative germs.

PATIENTS AND METHODS

We have realized cross-sectional study in three health centers of the prefecture of Kozah from March 24 to May 12, 2009. All the newborns followed in these centers are examined in the search of signs of conjunctivitis. A biological diagnosis of conjunctival secretions was carried out at the suspect newborns.

RESULTS

During the study period, 348 newborns were examined including 185 boys and 163 girls corresponding to a sex-ratio (M/F) of 1.1. The middle age was 3.7 days. Twenty-eight newborns presented conjunctivitis, that is to say a rate of incidence of 8%. The cases of conjunctivitis were observed the first four days of life in 39.3% of cases. Eighteen of the newborns presenting conjunctivitis were vaginal deliveries (64.3%) against ten (35.7%) by caesarian. All the mothers of the ill newborns had a syndrome of sexually transmissible infection (STI) during the third quarters of pregnancy. After biological diagnosis, Staphylococcus aureus was found in 25% of the cases.

CONCLUSION

Despite the common herd of neonatal conjunctivitis prophylaxis by Crede's method, its remains in the prefecture of Kozah. In hope for neonatal conjunctivitis eradication, treatment of STI on pregnant women associated to education and communication on the prevention of the infection in neonatal health care centers and at home by hygiene rule application are necessary.

[Trachoma rapid assessment in the infantile population of Togo]

AIM

The aim of this study was to determine the prevalence and types of trachoma in children of central Togo.

MATERIALS AND METHODS

This descriptive cross-sectional investigation was conducted in central Togo in November 2009. At every peripheral health unit (PHU) in 2 villages of the sanitary district, 15 schoolchildren between 6 and 9 years old and 35 children from the community between 1 and 5 years old were examined to detect signs of trachoma using a lamp wipes coupled with binocular magnifying loupes (2.5X). Data were analysed with Excel 2007.

RESULTS

A total of 8200 children were examined at 82 PHU in 164 villages in the sanitary districts. In the 1-5 year age group including 5,740 children, follicular trachomatous inflammation (TF) was observed in 326 cases and intense trachomatous inflammation (TI) in 9 for a prevalence rate of 5.83%. In the 6-9 year age group including 2,460 schoolchildren, TF was observed in 144 and TI in 8 for a prevalence rate of 6.18%. The overall prevalence rate of active trachoma was 5.94 % (n = 487).

CONCLUSION

This study confirms the persistence of active trachoma in children in central Togo. Trachoma may be public health problem in 2 districts: Blitta and Sotouboua. A population-based survey will be carried our to evaluate trachoma prevalence prior to implementation of the SAFE strategy in this region.

[Sputum smear conversion during intensive TB treatment phase according to HIV status, in hospitalised patients in Togo]

METHOD

We prospectively studied patients with pulmonary TB, with or without HIV-1 co-infection, from December 1, 2007 to December 1, 2008. Two groups of patients naive for TB and antiretroviral treatment (group A: 96 co-infected TB/HIV and group B: 171 TB infected but HIV negative) were selected randomly. The CD4 count was assessed according to HIV status, and all patients received RHEZ TB treatment for 2 months. Pulmonary smear was assessed at two weeks, four weeks, six weeks, and eight weeks.

RESULT

Two hundred and sixty seven patients were treated (26.6% of admissions). The mean age was 34.62 ± 11 years and the sex ratio was 1.3. A proportion of 35.75% patients were HIV co-infected with a median CD4 count at 157 cells per millimeter cube. The sputum smear conversion was obtained for more than 87.5% of patients in group A and 24.56% in group B at two weeks; 94% of patients in group A and 61.83% in group B at four weeks; 100% of patients in group A and 87.33% in group B at six weeks, and 100% of patients in group A and 96.77% in group B at eight weeks. P<0.05 at six weeks.

CONCLUSION

HIV infected TB patients were more susceptible to treatment than TB/HIV infected patients in the first six weeks.

[Immunophenotyping of acute leukemias: diagnostic and pronostic utility in Abidjan, Côte d'Ivoire]

Flow cytometry is nowadays the first-line method for immunophenotypic identification of blast cells but is not so usual in limited-resources countries. We have investigated on the usefulness of this tool in Abidjan, Côte d'Ivoire. Bone marrow sample from 13 patients with acute leukemia identified by cytology and cytochemical analysis was immunophenotyped by using monoclonal antibodies directed to: T lymphoid cells (CD3, CD5, CD7); B lymphoid cells (CD10, CD19, CD20, CD22, HLA-DR) and myeloid cells (CD13, CD33). Immunophenotyping allowed us to confirm the diagnosis of 6 de novo acute leukemias (2 acute myeloid leukaemias, 4 acute lymphoid leukemias) and 7 acute leukaemias resulting from chronic myeloid leukaemias. Immunophenotyping also characterizes the atypical/aberrant lineage essential for the prognosis: 2 biphenotypic acute leukemias (myeloid/lymphoid T) were identified. Our results suggest that flow cytometry may be a useful additional tool to identify the specific leukemic cell, to make a better classification as well as a prognosis evaluation of patients with acute leukemias.