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HIV-Resistant Citizens Found

Discussion in 'JF Doctor' started by IronBroom, Apr 5, 2009.

  1. IronBroom

    IronBroom JF-Expert Member

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    Uganda: HIV-Resistant Citizens Found

    Charles Wendo 3 April 2009

    Kampala — A SMALL fraction of Ugandans have been able to naturally knock off HIV from their body, a development that could lead to an HIV vaccine, scientists have said.

    Dr. Pontiano Kaleebu, an immunologist heading the Basic Sciences Programme of the MRC/UVRI Uganda Research Unit on AIDS at the Uganda Virus Research Institute (UVRI), told Saturday Vision that an ongoing study and a previous one at the institute had unearthed signs that some Ugandans may be resistant to HIV.

    They have special white blood cells that can only be produced when the virus attacks the body. However, even with the most sophisticated tests, HIV could not be found in these individuals, implying that the virus had tried to infect them but the immune system kicked it out.

    "We are seeing some immune responses but it is still too early to see if there is a lot of meaning to these responses," said Kaleebu.

    "Such people are of interest to many researchers worldwide."

    At the AIDS Information Centre in Kampala, the UVRI scientists are studying 70 discordant couples to see if some of them are indeed resistant to HIV. These are couples that have had unprotected sex for more than a year, one partner has had HIV for long while the other has not become infected. "We have set up a clinic in Kampala where doctors and counsellors do a lot of counselling and give them condoms to reduce risky sexual behaviour," Kaleebu said.

    Despite early signs of resistance to HIV, Kaleebu said meaningful results can only be released at the end of the study. The five-year research, expected to be completed in 2010, is sponsored by the US National Institutes of Health through the British Medical Research Council (MRC). It is part of a multi-country study coordinated by the US-based Center for HIV/AIDS Vaccine Immunology (CHAVI) and involving Oxford University of UK.

    Prof. Heiner Grosskurth, the Director of the MRC/UVRI Uganda Research Unit on AIDS, said: "A lack of ability to becoming HIV infected is extremely rare, but there is evidence meanwhile that people who have this characteristic exist worldwide, although in very small numbers."

    Although they are so few, he said, studying them could generate new knowledge that would enable scientists to develop a vaccine. "Such work is going on with a lot of speed and effort in many countries, but there is no breakthrough yet! I think it will still take years until we have good vaccine candidates."

    Earlier in 2002, Prof. Andrew Mc Michael of the University of Oxford and the late Dr. Anthony Kebba of UVRI announced that they had identified some eight Ugandans in Kampala and Entebbe, who were exposed to HIV but remained uninfected. One fifth of the discordant couples they studied showed some signs of resistance to HIV, but this required further confirmation. Mc Michael is involved with Kaleebu in the new study. Similar studies are going on in Kenya and the Gambia.

    Kaleebu cautioned that nearly all people are vulnerable to HIV and Ugandans should not relax simply because a few individuals seem to be resistant to the virus. "It has to be clear that this apparent resistance is not a common thing. If you are HIV negative and your partner is HIV positive we cannot say you are resistant and you cannot become infected. If you continue to have unprotected sex you might become infected in the long run," said Kaleebu.

    Indeed, in the late 1990s some people in Rakai were reported to have become infected with HIV after being discordant for many years. On discovering that they were discordant, scientists had advised them to begin using condoms. Later, some of those who declined to use condoms became infected.

    Source:allAfrica.com: Uganda: HIV-Resistant Citizens Found (Page 1 of 1)
     
  2. TIMING

    TIMING JF-Expert Member

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    Mkuu hata hapa kwetu kiasi cha kutosha na nakumbuka a few weeks ago Mzee wa njia panda alikuwa na couple moja ya discordance. Lakini pia we need to understand percentage ya risk pale watu wanapokutana "live" because it is not possible to document 100% risk
     
  3. M

    Mama JF-Expert Member

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    Watu ambao ni HIV resistant wapo, tena wengi tu.

    Mfano kati ya bibi na bwana (hawakuwa wakitumia kinga kwenye tendo la ndoa) anaweza kuwa HIV positive au kuugua AIDS na hata kufariki, wakati mwenzie HIV negative.
     
  4. Masanilo

    Masanilo JF-Expert Member

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    Hey! Can you substatiate your argument? hadithi za kwenye mabaraza ya kahawa ama kwenye kucheza bao, hazina nafasi.....toa scientific proof kwa uanchokisema vinginevyo kaa kimya..
     
  5. Saikosisi

    Saikosisi JF-Expert Member

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    Wapo lakini sio wengi. Wengine wanakuwa hawana CCR5 ambayo ni receptor muhimu ya HIV kwenye CD4+ cells, na watu wa aina hii wako estimated kwenye kama 2% hivi ya population na wanakuwa hawawezi kuwa infected na HIV.
     
  6. Masanilo

    Masanilo JF-Expert Member

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    Saikosisi

    Sidhani kama ni CCR5 receptor deficience, it is more on the CCR5-Delta32 deletion mutation, theres a scientific controversy over the reason(s) for the origin of the mutation in this receptor. Theres evidence that CCR5 mutation that provides protection against HIV infection as well as smallpox. The frequency of the resistance allele is estimated at approximately 10% in European populations hakuna study ilokwisha fanyika kwa waafrika nadhani hii study ya Uganda itatoa mwanga.
     
  7. Mbu

    Mbu JF-Expert Member

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    ...dah,

    wakuu mna ma-scientific proofs ya kumwaga hapa. Sie waswahili acha tubaki na misemo yetu; "nyota ya mwenzio usiilalie mlango wazi"...jamaa Mkewe kafa, ilhali tunda la nyumba'ke ndogo twalila kwa kuibia...!

    kumbe mwenzetu ana resistance na ndipo tunapoponea eeh?
     
  8. Saikosisi

    Saikosisi JF-Expert Member

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    Asante sana mkulu. Hapo nilipo-highlight ni kuonyesha msisitizo kuwa unajichanganya kidogo, 'HUDHANI lakini UNAJUA' CCR5 defect ina-protect against HIV infection. Na uko sahihi kuhusu frequency kwa wazungu. Kwa Waafrika ndio hiyo 2% ninayoisema, na studies zilishafanyika Afrika mfano wa hii ya Kenya soma "Babies by design: the ethics of genetic choice" by Ronald Michael Green, 2007 page 62.

    Asante.
     
  9. Masanilo

    Masanilo JF-Expert Member

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    Tunaongea kitu kimoja umesema CCR5 deficience (kutokuwa nayo) the actual facts is a CCR5-Delta32 deletion mutation.....thanks for the African %
     
  10. p

    p53 JF-Expert Member

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    iko hivi:
    CD4 ndiyo receptor ya HIV in all CD4+ human cells kama T-cells na langerhans cells zile za kwenye rectal mucosa.
    CCR5 is one of the co-receptors.Bila ya co-receptor HIV hawezi kuingia ndani ya cell na kinachofanyika kwanza ni binding ya gp120(glycoprotein ambayo iko kwenye HIV envelope) to CD4 molecules on the surface of the host cell.Then after the binding kunatokea structural changes on the gp120 proteins creating a suitable structure kwa gp120 now to bind any of the 2 co-receptors in this case let say CCR5.hapo ndipo jamaa sasa ataendelea na mechanisms nyingine za kuingia ndani.
    kwahiyo CCR5 ndiyo jina la co receptor na iki mutate ndipo wanaita CCR5-delta32 hiyo wanayosema wanayo caucasians.kwahiyo tusiseme CCR5 deficience tuseme CCR5 mutation.
    lakini hii bado ni crap tu.huwezi ukasema kwavile una mutant CCR5 gene then huwezi catch HIV.Co-receptors ya HIV siyo CCR5 peke yake.Kuna Nyingine inaitwa CXCR4.sasa hata kama una hiyo CCR5 mutation jamaa wanaweza kutumia hii CXCR4 na kuingia ndani vilevile.
     
  11. M

    MzalendoHalisi JF-Expert Member

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    P 53,

    So technical Mkuu! Je mie lay Economist nitaambulia hapo kitu?
     
  12. Saikosisi

    Saikosisi JF-Expert Member

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    Shule umetoa vizuri, umekuja kuharibu na crap yako, ya nini sasa hiyo?! Wanasayansi wengine bwana!

    Kwa wanajamii; ni kweli kuna co-receptors zingine lakini CCR5 ndio co-receptor "muhimu zaidi". Na recently dawa za HIV zimetengenezwa kulenga kuharibu hizi co-receptors, na wanasema kama zitaingia mtaani zitakuwa dawa nzuri sana hasa kwenye prevention (chemoprophylaxis) kwa mfano mtu ukipata accident ya kuingiwa na damu ya mtu mwenye virusi (labda kazini, kwa wafanyakazi wa afya, ama rape, perhaps watoto wakizaliwa) unapata hizi dawa mapema na zinazuia hiyo binding kwa hiyo virusi vinakuwa haviwezi kuingia ndani ya cell, kwani ili vilete matata yao ni mpaka viingie kwenye cell.
     
    Last edited: Apr 7, 2009
  13. Bishanga

    Bishanga JF-Expert Member

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    kwenye hii thread naona ni mambo ya 'nshomile' tu,jamani hayo ma CCR tufasirieni kwa kiswahili rahisi ili na sie tuliokimbia umande tuelewe!
     
  14. p

    p53 JF-Expert Member

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    pole mkuu!wakuu wameanza kujadili mambo ya receptors za HIV sasa nilikuwa najaribu kuweka mambo sawa ili kupata ukweli wake.
    sasa sijui nianzie wapi mkuu manake ni shule ndefu kidogo nikianza kuelezea hizo chemokine receptors mpaka HIV anakuwa ndani ya cell.
     
  15. p

    p53 JF-Expert Member

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    mkuu unaonekana ni mtu wa kitengo kwahiyo twende taratibu tutaelewana!sasa mkuu huoni kwamba ni crap kusema huwezi pata HIV infection kwavile tu una mutant ccr5 gene?
    sikuelewi unaposema ccr5 ndiyo co-receptor muhimu zaidi,how and why mkuu?
    na ccr2 nayo unaizungumziaje mkuu?
    CD4+T helper cells ndiyo major cell type that is infected by HIV japo cells nyingine kama NK,monocytes/macrophages,dendritic cells,CD8+Tcells na cells za CNS ukiacha neurons which are not infected by HIV;na zenyewe huwa zinapata maambukizi na fact ni kwamba ccr5 zinapatikana kwa wingi kwenye macrophages wakati cxcr4 zinapatikana kwa wingi kwenye T-helper cells.sasa mkuu huoni crap ilipo hapo?
     
    Last edited: Apr 7, 2009
  16. u

    uporoto01 JF-Expert Member

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    Kuna kaka yangu alikufa kwa ukimwi mwanzoni mwa miaka ya 90's mkewe ambaye walikuwa hawatumii kinga ni mzima mpaka sasa,kaolewa tena ana watoto 3 na mume mpya.
     
  17. Saikosisi

    Saikosisi JF-Expert Member

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    Evidence ya how na why CCR5 ni the most physiologically important co receptor for HIV hizi hapa;
    *Deng et al, 1996. Nature 381, 661-666
    *Feng et al, 1996. Science 272, 872-877
    *Choe et al, 1998. J Virol 72, 6113-6118
    *Doranz et al, 1996. Cell 85, 1149-1158

    Tunazidi kufahamishana.

    Yeah, kuna sababu nyingi za mtu kutokuambukizwa na partner wake, mojawapo ni haya mambo ya ccr5 yanayosemwa, hata hivyo, kuna watu wanaambukizwa na wanachukua muda mrefu kupata AIDS, kwa hiyo huo uzima wake pia uuchukulie kwa tahadhari, in case ukataka kujinafasi naye!
     
  18. p

    p53 JF-Expert Member

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    nilishaandika ila nitarudia
    1.CD4+T helper cells ndiyo major cell type that is infected by HIV
    2.ccr5 zinapatikana kwa wingi kwenye macrophages wakati cxcr4 zinapatikana kwa wingi kwenye T helper cells
    sasa sioni logic ya kusema ccr5 molecules are more important than cxcr4.
     
    Last edited: Apr 8, 2009
  19. Kang

    Kang JF-Expert Member

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    Ukifanya mapenzi na mtu mwenye Ukimwi sio lazima upate maambukizo, actually chances ziko low like 1 in 500, na nimeona wengine wanasema ziko even lower. So anaweza akawa amebahati tu, si lazima awe na resistance.
     
  20. Saikosisi

    Saikosisi JF-Expert Member

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    HIV-1 ina strains nyingi; baadhi ya strains ni T-cell tropic (T-tropic) na zinatumia CXCR4 kama co-receptor, wakati strains nyingine ni macrophage-tropic (M-tropic) na zinatumia CCR5 kama co-receptor.

    Kuna strains chache za HIV-1 ambazo zaweza ku-bind hata CCR3 ama chemokine receptors zingine kwenye cells ambazo zinazi-express hizo chemokines lakini bado roles zao (including CCR3) kwenye HIV-1 infection iko unclear.

    Science haiendi kwa logic tu la sivyo mambo yangekuwa marahisi. Ndio maana tafiti zaendelea kila siku hata kwa magonjwa ambayo yamejulikana miaka zaidi ya 100 iliyopita. Usipoelewa logic yawezekana ume-miss point ama kwa present knowledge/technology tuliyonayo bado kuna kitu tunaki-miss, tunatakiwa tukigundue. Hivyo usipende kuwa rigid, go back to your lab ama journals na waweza kujifunza kitu kipya.
     
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