Mangabey Monkeys Research Articles

A Review of Evidence Related to the Zoonotic Characteristics of the Monkeypox Virus.

The 2022 monkeypox virus (MPXV) outbreaks spurred global public health concern. In response, we undertook a living systematic review of its zoonotic characteristics, including potential reservoirs and susceptible species, transmissibility, and clinical presentation in nonhuman species. Electronic database searches yielded 148 eligible records published between 2000 and 2022. Primary reservoirs remain unidentified, with natural isolation identified in 2 species, the sooty mangabey monkey and rope squirrel. Transmission primarily occurs from animals to humans, but evidence of reverse zoonosis has emerged. Data on clinical infection and manifestations are sparse, with evidence of potentially susceptible species drawn primarily from experimental studies. Only 10% of articles were appropriate for quality assessment and most of these were rated as critically low. Overall, while evidence regarding MPXV exists, the quality of data are extremely poor, resulting in significant uncertainty regarding MPXV's zoonotic traits. High-quality empirical research to understand the impact of MPXV on animal and human populations is warranted.

A Review on Monkeypox

Monkeypox is a re-emerging zoonotic disease caused by a DNA virus that belongs to the orthopox virus genus of the Poxviridae family. After the eradication of smallpox in 1980, monkeypox has gradually emerged as the most important orthopox virus from a public health perspective. Monkeypox typically causes fever, chills, rash, and lesions on the face or genitals. MPXV (monkeypox virus) is considered a large virus that measures about 200–250 nm with the appearance “brick-like” or ovoid shape, The virus’s original source is wild animals. It can be found in a variety of mammals including squirrels, mangabey monkeys, and Gambian rats. Viral transmission can occur through direct and indirect contact with live or dead animals, including handling wild game, a bite or scratch, or contact with fluids or lesions from an infected animal. Human-to-human transmission likely occurs through contact with lesions, body fluids, contaminated bedding or clothing, and exposure to respiratory droplets from infected persons. Animal-to-human transmission of MPXV may occur via animal bites or scratches by infected small mammals, including rodents and nonhuman primates, or through the consumption of bush meat. Any patient with a fever and disseminated vesicular or pustular rash should be immediately placed on airborne and contact precautions, as these are the classic symptoms of Orthopox virus infections. smallpox antivirals with poxvirus activity, such as cidofovir, brincidofovir, and tecovirimat, are active against the monkeypox virus. Monkeypox is usually a self-limiting disease; however, new-borns, children, and people with underlying immune deficiencies may be at risk of more serious illness and death.

A REVIEW ON MONKEY POX DISEASE

After the disastrous COVID-19 pandemic, now, monkey pox has spreaded its legs all over the world. Disease originated in Africa but its outbreak occurred in 89 countries since January 2022. As per the World Health Organization report, in between January 1, 2022, and August 10, 2022, 27,814 confirmed cases and 11 deaths occurred across 89 countries. Monkey pox is a viral infection which may occur in humans as well as in animals. Rope squirrel (Funisciurus spp.), Gambian pouched rat (Cricetomys gambianus), and Sooty mangabey monkey (Cercocebus atys) are suspected reservoir host for monkey pox. Its symptoms are similar to but milder than small pox. As orthopox viruses are morphologically identical to each other, Polymerase chain reaction is only test for detection of monkey pox-specific DNA signatures. There is no specific treatment for monkey pox infection but as monkey pox and small pox infections are hereditarily comparative so antiviral medications and antibodies created to safeguard against small pox are generally prescribed to prevent and treat monkey pox. One of the important measures for prevention from monkey pox is small pox vaccination to the individual and also to the healthy people in occupation who are at high risk of exposure except in immunocompromised individuals.

Urogenital Lesions in Nonhuman Primates at 2 National Primate Research Centers.

Given their genetic and anatomic similarities to humans, nonhuman primates (NHPs) may serve as animal models for urogenital diseases of humans. The purpose of this study was to examine the frequency of spontaneous urogenital lesions occurring over a 30-year period at the Yerkes and Southwest National Primate Research Centers and to compare and contrast lesions occurring in Old World versus New World primates. Lesions occurring in the chimpanzee (Pan troglodytes), baboon (Papio spp.), rhesus macaque (Macaca mulatta), cynomolgus macaque (Macaca fascicularis), pig-tailed macaque (Macaca nemestrina), sooty mangabey (Cercocebus atys), common marmoset (Callithrix jacchus), cotton-top tamarin (Sanguinus oedipus), and squirrel monkey (Saimiri sciureus) are discussed. The most common lesions of the kidney were medullary amyloidosis, renal cysts, renal tubular degeneration, glomerulonephritis or glomerulopathy, nephritis, nephrocalcinosis, pyelonephritis, and hydronephrosis. Specific causes of renal tubular disease included pigmentary nephrosis and tubular lipidosis. Renal tumors, including renal adenoma and carcinoma, lymphoma, and nephroblastoma, were infrequent diagnoses in all species. Endometriosis was the most frequently diagnosed lesion of the female genital tract. Of the animals examined in this study, it was most frequent in Old World primates. Leiomyoma was the most common uterine tumor. Granulosa cell tumor was the most frequently observed neoplasm of the ovaries, followed by teratoma. Of animals included in the study, most ovarian tumors occurred in baboons. Neoplasms of the male reproductive tract included interstitial cell tumor, seminoma, penile squamous cell carcinoma, penile papilloma, and histiocytoma. In New World monkeys, renal lesions were reported more frequently than genital lesions.

Prevalence and morphotype diversity of Trichuris species and other soil-transmitted helminths in captive non-human primates in northern Nigeria

A study to determine the prevalence and morphotype diversity of soil-transmitted helminths in captive non-human primates (NHPs) in northern Nigeria was conducted. Simple flotation and sedimentation methods were used to examine fecal samples. A Morphometric analysis was done on Trichuris spp. eggs to determine the diversity of whipworm circulating in NHPs in the study area. High prevalence (60%) of infection was recorded in captive NHPs; Patas Monkey (n=17), Tantalus Monkey (n=9), Mona Monkey (n=7), Vervet Monkey (n=2), Mangabey Monkey (n=1), Baboon (n=14), and Chimpanzee (n=8) from parks and zoological gardens located in four Nigerian states (Borno, Gombe, Kano, and Plateau) and the Federal Capital Territory (FCT), Abuja. Captive NHPs examined were infected with helminths either as single, double or triple infections. Four zoonotic soil transmitted helminth (STH) genera, Trichuris, Strongyloides, Ancylostoma, and Enterobius were detected in the examined animals. Eggs of Trichuris spp. were the most prevalent with four morphotypes suggesting several morphotypes of whipworm were circulating among the NHPs in this region. Further studies are required to elucidate the epidemiologic and public health implications of these findings.

Human immunodeficiency virus type 2 (HIV-2) dynamics and whole genome deep sequence analysis in Mauritian-origin cynomolgus macaques (Macaca fascicularis)

Human immunodeficiency virus type 2 (HIV-2) is a pathogenic human retrovirus with a distinct natural history and lineage derivation from pandemic HIV-1. HIV-2 infections in humans are the result of zoonotic transmission from sooty mangabey monkeys naturally infected with SIVsm. Unlike HIV-1, HIV-2 infects other non-human primate species, including baboons and macaques. We determined the infectivity and infection kinetics of a Gambian-origin HIV-2 isolate HIV-2SBL6669 strain in Mauritian-derived cynomolgus macaques (MCM) in the context of a heterologous superinfection resistance study. The ability of HIV-2 to replicate in unvaccinated MCM with limited host genetic MHC and TRIM5 spectrum was determined where the kinetics of plasma HIV-2 RNA mimic the phenotypic response typically observed in HIV-2-infected humans. HIV-2SBL669 replication is not completely restricted in this species and may establish a persistent infection. This is determined by moderate peak viral loads (105–6 log10 HIV-2 RNA copies/ml) controlling to a low level determined by qRT-PCR and detectable in-situ hybridisation signals in lymphoid tissue 20 weeks after challenge. In MCM vaccinated for 20 weeks with an attenuated SIV, we observed high levels of superinfection resistance as determined by virus-specific PCR analysis of tissues and low total plasma viral RNA levels in vaccinates compared to unvaccinated HIV-2 controls. Recovery of whole viral genome and next generation sequence analysis of challenge controls, including low-level breakthrough variants characterises viral challenge and vaccine-escape viruses. HIV-2 in cynomolgus macaques recapitulates many of the features of HIV-2 infections in humans.

Armadillos and leprosy: from infection to biological model.

ABSTRACT Mycobacterium leprae is the primary causative agent of Hansen’s disease or leprosy. Besides human beings, natural infection has been described in animals such as mangabey monkeys and armadillos. Leprosy is considered a global health problem and its complete pathogenesis is still unknown. As M. leprae does not grow in artificial media, armadillos have become the primary experimental model for leprosy, mimicking human disease including involvement of the peripheral nervous system. Leprosy transmission occurs through continuous and close contact of susceptible people with untreated infected people. However, unknown leprosy contact has been reported in leprosy-affected people, and contact with armadillos is a risk factor for leprosy. In the USA, leprosy is considered a zoonosis and this classification has recently been accepted in Brazil. This review presents information regarding the role of wild armadillos as a source of M. leprae for human infections, as well as the pathogenesis of leprosy.

Diversity of Primate Lentiviruses Rebooted

Highlight: The present report reveals for the first time natural lentiviral infection of wild Indian NHPs, rhesus monkeys (Macaca mulatta) and langurs (Semnopithecus entellus) by SIVs that are phylogenetically diverse from all known SIVs, including “SIVmac”, which infects captive rhesus monkeys. The novel SIVs are intriguingly homologous to HIV-1, based on serology and partial lentiviral genomic sequence analyses. Diverse lenti-viruses infect human and nonhuman primates (NHPs). There are more than 45 different “species-specific” simian immunodeficiency viruses (SIVs) that infect their cognate NHP hosts in natural habitats in Africa. Indian NHPs are not known to be infected by SIVs in the wild. Conventionally SIVs are named after their natural hosts, except for SIVmac, which infects captive rather than wild rhesus macaques. SIVmac is therefore a misnomer. It is a genetic variant of the African SIVsmm, which infects wild African sooty mangabey monkeys. SIVsmm is the progenitor of human immunodeficiency virus (HIV-2), while SIVcpz that infects wild chimpanzees is the progenitor of HIV-1. Although natural infections cannot be easily studied in wild NHP populations, we have previously reported co-infection of wild Indian NHPs by other retroviruses: simian retroviruses (SRVs) and Simian Foamy viruses (SFV). Apart from zoonosis, transmission of pathogens from humans to animals: anthroponosis, has also been reported in literature.

Decision-making under risk of gain in young children and mangabey monkeys.

In contrast to human adults, risk proneness in the gain domain is usually observed in both young children and non-human primates. It is currently unclear what mechanism might be underlying such economic preferences. We investigated decision-making under risk of gain in toddlers and monkeys. The choices of 2.5-year-old children and red-capped mangabeys (Cercocebus torquatus torquatus) were examined in a gambling task for food reward in which participants have to choose between two options, a secure option and a risky option. In contrast to monkeys, toddlers showed a strong preference for the risky option over the safe option. In order to test the hypothesis that risky choices in participants reflect inhibitory control difficulties, toddlers and mangabeys were presented in Experiment 2 with a situation analogous to that used in Experiment 1 except for the fact that the opaque cover under which was placed the secure option was replaced by a transparent cover. In this second experiment, toddlers continued to show a preference for the risky option over the safe option. In contrast, mangabeys showed a preference for the safe option over the risky option in Trial 1 but they shifted their economic preferences in Trial 2. We argue that decision-making strategies under risk of gain in both toddlers and mangabeys (a) do not reflect poor behavioral control and (b) are not reducible to perception-action couplings.

Vegetarian diet in Guenon and Mangabey monkeys of Moukalaba-Doudou National Park, Gabon: similarities and differences

To order to know any differences and similarities between Mangabeys and Guenons study of their vegetarian diet was conducted for 10 months between 2013 and 2014 in Moukalaba-Doudou National Park, Gabon. By using the direct observation method, we identified 84 plant species integral to the vegetarian diet of these two groups of monkeys. Thus, we have recorded similarities and differences. Guenons (69 species) consume the same plant species as the Mangabeys (49 species; V = 1594 p-value = 0.1796). They are considered frugivores at large because they consume an average of 84.77% fruit for guenons and 63.37% for the mangabeys, with a difference in the consummation of seeds 18.93% and 3.31% respectively. These results suggest that Mangabey have a seed-eating regime while the guenons tend to consume even when they are unavailable fruits. Our analyzes also showed that these two groups have preference different family of the species that they consume. This is due to the nature of the fruit produced by each family. Furthermore the mangabey (chi-squared = 5.6989, df = 5, p-value = 0.3366) interested in several of plants while monkeys (chisquared = 15.817, df = 5, p-value = 0.007387) remain more attached to fruit consumption.© 2016 International Formulae Group. All rights reserved.Keywords: Mangabeys, Guenons, diet, Moukalaba-Doudou, difference and similarity

TRIM5α Resistance Escape Mutations in the Capsid Are Transferable between Simian Immunodeficiency Virus Strains

Many strains of SIV from sooty mangabey monkeys are susceptible to resistance by common rhesus macaque TRIM5α alleles and result in reduced virus acquisition and replication in macaques that express these restrictive alleles. We previously observed that spontaneous variations in the capsid gene were associated with improved replication in macaques, and the introduction of two amino acid changes in the capsid transfers this improved replication to the parent clone. In the present study, we introduced these mutations into a related but distinct strain of SIV that is commonly used for challenge studies for vaccine trials. These mutations also improved the replication of this strain in macaques with the restrictive TRIM5α genotype and thus will eliminate the confounding effects of TRIM5α in vaccine studies.

Vif Proteins from Diverse Human Immunodeficiency Virus/Simian Immunodeficiency Virus Lineages Have Distinct Binding Sites in A3C.

The APOBEC3 restriction factors can serve as potential barriers to lentiviral cross-species transmissions. Vif proteins from lentiviruses counteract APOBEC3 by proteasomal degradation. In this study, we found that monkey-derived A3C, rhA3C and smmA3C, were resistant to HIV-1 Vif. This was determined by A3C residues N/H130 and Q133. However, HIV-2, SIVagm, and SIVmac Vif proteins were found to be able to mediate the depletion of all tested primate A3C proteins. In addition, we identified a natural HIV-1 Vif (F-1 Vif) that was inactive in the degradation of hA3C/hA3F. Here, we provide for the first time a model that explains how an internal salt bridge of E171-K167-D101 influences Vif-mediated degradation of hA3C/hA3F. This finding provides a novel way to develop HIV-1 inhibitors by targeting the internal interactions of the Vif protein.

Development of HTLV-1 associated myelopathy/tropical spastic paraparesis in a patient with simian T-lymphotropic virus type 1-like infection.

Virus transmission from various wild and domestic animals contributes to increased risk of emerging infectious diseases in human populations. HTLV-1 is a human retrovirus associated with acute T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which originated from zoonotic transmission from various African and Asian nonhuman primates (NHPs). Similar to HTLV-1, the simian counterpart, STLV-1, causes chronic infection and leukemia and lymphoma in naturally infected monkeys. However, other clinical syndromes typically seen in human such as a chronic progressive myelopathy have not been observed in NHPs. Little is also known about the development of any neurologic and inflammatory diseases in human populations infected with STLV-1-like viruses following NHP exposure. We identified and analyzed the complete genome of a primate T lymphotropic virus type 1 (PTLV-1) isolated from a patient with typical HAM/TSP who resides in the United States but was born in Liberia. Using a novel droplet digital PCR for the detection of the HTLV-1 tax gene, the proviral load in PBMC was 14.01%; however there was a distinct difference in fluorescence amplitude compared to all other H!M/TSP patient's, suggesting viral heterogeneity. A complete PTLV-1 proviral genome was amplified from DNA extracted from the PBMCs of the HAM/TSP patient using PCR to generate nine overlapping subgenomic fragments. Phylogenetic analysis of PTLV-1 env and LTR regions showed the virus was highly related with PTLV-1 from sooty mangabey monkeys and humans exposed from NHPs in West Africa. These results suggest the patient is likely infected with STLV-1, suggesting for the first time that viral transmission from monkey to human may be associated with a chronic progressive neurologic disease.

Lv4 Is a Capsid-Specific Antiviral Activity in Human Blood Cells That Restricts Viruses of the SIVMAC/SIVSM/HIV-2 Lineage Prior to Integration.

HIV-2 and SIVMAC are AIDS-causing, zoonotic lentiviruses that jumped to humans and rhesus macaques, respectively, from SIVSM-bearing sooty mangabey monkeys. Cross-species transmission events such as these sometimes necessitate virus adaptation to species-specific, host restriction factors such as TRIM5. Here, a new human restriction activity is described that blocks viruses of the SIVSM/SIVMAC/HIV-2 lineage. Human T, B, and myeloid cell lines, peripheral blood mononuclear cells and dendritic cells were 4 to >100-fold less transducible by VSV G-pseudotyped SIVMAC, HIV-2, or SIVSM than by HIV-1. In contrast, transduction of six epithelial cell lines was equivalent to that by HIV-1. Substitution of HIV-1 CA with the SIVMAC or HIV-2 CA was sufficient to reduce HIV-1 transduction to the level of the respective vectors. Among such CA chimeras there was a general trend such that CAs from epidemic HIV-2 Group A and B isolates were the most infectious on human T cells, CA from a 1° sooty mangabey isolate was the least infectious, and non-epidemic HIV-2 Group D, E, F, and G CAs were in the middle. The CA-specific decrease in infectivity was observed with either HIV-1, HIV-2, ecotropic MLV, or ALV Env pseudotypes, indicating that it was independent of the virus entry pathway. As2O3, a drug that suppresses TRIM5-mediated restriction, increased human blood cell transduction by SIVMAC but not by HIV-1. Nonetheless, elimination of TRIM5 restriction activity did not rescue SIVMAC transduction. Also, in contrast to TRIM5-mediated restriction, the SIVMAC CA-specific block occurred after completion of reverse transcription and the formation of 2-LTR circles, but before establishment of the provirus. Transduction efficiency in heterokaryons generated by fusing epithelial cells with T cells resembled that in the T cells, indicative of a dominant-acting SIVMAC restriction activity in the latter. These results suggest that the nucleus of human blood cells possesses a restriction factor specific for the CA of HIV-2/SIVMAC/SIVSM and that cross-species transmission of SIVSM to human T cells necessitated adaptation of HIV-2 to this putative restriction factor.

Prevalence of gastro-intestinal parasites in primates and their keepers from two zoological gardens in Ibadan, Nigeria.

A study was conducted to determine the levels of infestation of gastro-intestinal parasites in 36 non-human primates (NHP) and 19 zoo keepers at the University of Ibadan Zoological Garden (UIZG) and Agodi Zoological Garden (AZG) in Ibadan, Nigeria. Freshly passed faecal samples were collected from NHP, zoo keepers, and from apparently healthy individuals (control). The faecal samples were processed using standard parasitological techniques. Twenty-two (61.1%) out of 36 NHP at UIZG and AZG were infested with gastro-intestinal parasites. Infestations at UIZG and AZG were 61.3% and 60%, respectively. All the red patas, mangabey and mandrill monkeys and 90.9% (10/11) of the green monkeys were infested. There were higher infestation rates in young NHP than in adults (P

Prevalence of gastro-intestinal parasites in primates and their keepers from two zoological gardens in Ibadan, Nigeria

A study was conducted to determine the levels of infestation of gastro-intestinal parasites in 36 non-human primates (NHP) and 19 zoo keepers at the University of Ibadan Zoological Garden (UIZG) and Agodi Zoological Garden (AZG) in Ibadan, Nigeria. Freshly passed faecal samples were collected from NHP, zoo keepers, and from apparently healthy individuals (control). The faecal samples were processed using standard parasitological techniques. Twenty-two (61.1%) out of 36 NHP at UIZG and AZG were infested with gastro-intestinal parasites. Infestations at UIZG and AZG were 61.3% and 60%, respectively. All the red patas, mangabey and mandrill monkeys and 90.9% (10/11) of the green monkeys were infested. There were higher infestation rates in young NHP than in adults (P<0.05). The infestation rate in males and females were the same (61.1%). The most prevalent gastro-intestinal parasites were Trichuris trichiura (47.2%), Strongyle spp(13.9%), Entamoeba spp (13.9%) and Stronglyloides spp (5.6%). Six (27.3%) of the infested NHP have mixed infestations. Only one of the 19 zoo keepers screened was infested with Ascaris lumbricoides and two (15.4%) of the 13 members of control group (non-zoological garden workers) were infested with Ancylostoma duodenale. There was no evidence of cross transmission of gastro-intestinal helminths between the NHP and the zoo keepers.Keywords: Gastro-intestinal parasites, Helminths, Infestation, Primates, Prevalence, Zoos

Vif Proteins from Diverse Primate Lentiviral Lineages Use the Same Binding Site in APOBEC3G

APOBEC3G (A3G) is a cytidine deaminase that restricts human immunodeficiency virus type 1 (HIV-1) and other lentiviruses. Most of these viruses encode a Vif protein that directly binds A3G and leads to its proteasomal degradation. Both Vif proteins of HIV-1 and African green monkey simian immunodeficiency virus (SIVagm) bind residue 128 of A3G. However, this position does not control the A3G degradation by Vif variants derived from HIV-2 and SIVmac, which both originated from SIV of sooty mangabey monkeys (SIVsmm), suggesting that the A3G binding site for Vif proteins of the SIVsmm/HIV-2 lineage differs from that of HIV-1. To map the SIVsmm Vif binding site of A3G, we performed immunoprecipitations of individual A3G domains, Vif/A3G degradation assays and a detailed mutational analysis of human A3G. We show that A3G residue 129, but not the adjacent position 128, confers susceptibility to degradation by SIVsmm Vif. An artificial A3G mutant, the P129D mutant, was resistant to degradation by diverse Vifs from HIV-1, HIV-2, SIVagm, and chimpanzee SIV (SIVcpz), suggesting a conserved lentiviral Vif binding site. Gorilla A3G naturally contains a glutamine (Q) at position 129, which makes its A3G resistant to Vifs from diverse lineages. We speculate that gorilla A3G serves as a barrier against SIVcpz strains. In summary, we show that Vif proteins from distinct lineages bind to the same A3G loop, which includes positions 128 and 129. The multiple adaptations within this loop among diverse primates underscore the importance of counteracting A3G in lentiviral evolution.

A lamprey monoclonal VLR antibody recognizes a novel plasma cell antigen (P3020)

Abstract Variable lymphocyte receptor B (VLRB) antibodies of the jawless sea lamprey are composed of leucine-rich repeat (LRR) units instead of the Ig-based units of conventional mammalian antibodies. Structural analyses of three monoclonal VLRB antibodies paired with their cognate antigens indicate that antigens bind to variable residues in the beta-sheets located on the inner concave surface of the solenoid VLRB protein and to a flexible loop structure protruding from the C-terminal LRR. We recently demonstrated that VLRB antibodies can be used in standard laboratory techniques such as flow immunocytometry, western blotting, immunoprecipitation and mass spectrometry-based protein identification. In an effort to identify novel biomarkers on human plasma cells, we screened a VLRB library generated from lamprey larvae immunized with human bone marrow of multiple myeloma patient and isolated a monoclonal VLRB antibody (MM3) that selectively recognized plasma cells from myeloma patients, normal individuals and two non-human primates, Rhesus macaque and Sooty mangabey monkeys. Surprisingly, screening of a diverse panel of human cell lines indicated expression of the MM3 antigen by two of nine B cell lines, but not by plasmacytoma cell lines. Trypsin and periodate sensitivity of the MM3 epitope suggested the glycoprotein nature of the cell membrane antigen. We conclude that the recombinant VLR MM3 antibody recognizes a novel plasma cell marker.

Acute SIV Infection in Sooty Mangabey Monkeys Is Characterized by Rapid Virus Clearance from Lymph Nodes and Absence of Productive Infection in Germinal Centers

Lymphoid tissue immunopathology is a characteristic feature of chronic HIV/SIV infection in AIDS-susceptible species, but is absent in SIV-infected natural hosts. To investigate factors contributing to this difference, we compared germinal center development and SIV RNA distribution in peripheral lymph nodes during primary SIV infection of the natural host sooty mangabey and the non-natural host pig-tailed macaque. Although SIV-infected cells were detected in the lymph node of both species at two weeks post infection, they were confined to the lymph node paracortex in immune-competent mangabeys but were seen in both the paracortex and the germinal center of SIV-infected macaques. By six weeks post infection, SIV-infected cells were no longer detected in the lymph node of sooty mangabeys. The difference in localization and rate of disappearance of SIV-infected cells between the two species was associated with trapping of cell-free virus on follicular dendritic cells and higher numbers of germinal center CD4+ T lymphocytes in macaques post SIV infection. Our data suggests that fundamental differences in the germinal center microenvironment prevent productive SIV infection within the lymph node germinal centers of natural hosts contributing to sustained immune competency.

Die Evolution von HIV, dem humanen Immunschwächevirus

HIV-1 evolved by zoonotic transmission of chimpanzee lentivirus to man around 1920. HIV-1 is now divided in four groups that had been transmitted by at least four independent events. HIV-2 originates from sooty mangabey monkeys in West Africa and was transmitted to man around 1940. For HIV-2 at least eight transmission events, forming the groups A to H, led to the ongoing epidemic. Regarding HIV and the AIDS epidemic it should be prevented that further animal viruses will be introduced to the human population.