Many nonprotein antigens, such as polysaccharides and lipids, stimulate antibody
production in the absence of helper T cells, and these antigens are termed thymusindependent
or T-independent. These antibody responses differ in several respects from
responses to T-dependent protein antigens (Table 9-4). As we have discussed in the previous
sections, antibody responses to protein antigens require the participation of helper T cells,
and helper T cells stimulate isotype switching, affinity maturation, and long-lived memory. In
contrast, the antibodies that are produced in the absence of T cell help are generally of low
affinity and consist mainly of IgM with limited isotype switching to some IgG subtypes. Some
nonprotein antigens do induce Ig isotypes other than IgM, but the mechanism of isotype
switching in the absence of T cell help is not known. In humans, the dominant antibody class
induced by pneumococcal capsular polysaccharide is IgG2. In addition, despite their inability
to specifically activate helper T cells, many polysaccharide vaccines, such as pneumococcal
vaccine , induce long-lived protective immunity. A possible reason for this is that
polysaccharides are not degraded efficiently, persist for long periods in lymphoid tissues, and
continue to stimulate newly arising naive B cells. Although it is not known whether long-lived
quiescent memory B cells are generated in response to these polysaccharide antigens, rapid
and large secondary responses typical of memory (but without much isotype switching or
affinity maturation) do occur on secondary exposure to these antigens.
polysaccharides are inefficient inducers of B cell memory, these ...
vaccines often provide long-lived protective immunity, probably because the polysaccharides
are not degraded easily and they persist in lymphoid tissues, where they continue to
stimulate specific B lymphocytes for long periods.
بنظرم این قضیه پر واضح است که درسته !!
برای تایید هم به یه مدالیست گفتم (بعد از بررسی از Abbas!) این موضوع رو تایید کردند.
ولی باز خود دانید
تا الان منبع از کمپبل، NCBI و Abbas دادم ولی باز هم روی حرف خودتون هستید.
---- دو نوشته به هم متصل شده است ----
در ضمن الان تیتری که لینک داده بودید رو گوگل کردم لینک NCBI رو زدم و این تو Abstract ـه ش بود.
"
Unlike T-dependent immune responses against protein antigens, T-independent responses against polysaccharides confer long-lasting humoral immunity in the absence of recall responses and are not known to generate memory B cells. Here we report that polysaccharide antigens elicit memory B cells that are phenotypically distinct from those elicited by protein antigens"
فک کنم این پاراگراف پایانی بر این بحث خسته کننده باشه !!!
جدای از این بحث بخصوص این مقاله رو حتما مطالعه کنید، خیلی جالبه !! مخصوصا کاربر گرامی Ibo-Dec که مکانیسم TI و TD رو می خواستن بدونن !
T-independent type II immune responses generate memory B cells